Tau Zero: The Steps Ahead

by Marc Millis

Recently I asked you, our readership, what you want from an interstellar organization, given the emergence of Kelvin Long’s Interstellar Institute and the pending symposium of the 100 Year Starship Organization. How to sort out which organization does what? I suspect that the 100YSS will start inviting memberships (fee-based) at their Sept 13-16 symposium. Unfortunately, we will not be able to launch our new Tau Zero website until after that, in October, at which time we will finally be able to take on members (yes, it has been a long arduous process). Then you can see exactly what we have accomplished beyond our continuing Centauri Dreams news forum. I have no idea if Icarus Interstellar or the others will invite memberships around that time too. All of us have been open for donations for some time.

To put the available support into context, I did a little hunting to estimate the total funds that have been contributed to all of our uniquely interstellar organizations (does not include the British Interplanetary Society, Planetary Society, etc.). To date, and if my hunting is reliable, the combined contributions to all our organizations total less than $100k. This, of course, does not include the $500k from DARPA to Mae Jemison’s 100 Year Starship organization. Thus, short of having a substantial increase in funding, there is not much to go around for one organization, let alone a handfull of them.


I compiled and edited your answers about what you want from an interstellar organization, plus some subsequent discussions for your contemplation and feedback. I did include the answers posted from other organizations, where they listed the services they are offering. I did not include ‘motherhood’ statements which are more about subjective consequences (e.g. “bold & inspiring”) than actionable work.

(1) Promotion and Fund Raising. The distinctions between “promotional” and “enabling,” functions, and “a driver for interstellar flight,” were raised, with the further suggestion that different organizations take on different functions. The suggestion included a recommendation that Tau Zero pursue only the “enabling” functions.

(2) Information: A common theme from the majority of answers, was to have easy access to the most relevant and reliable information. This includes:

— Free (or at least low-cost) journal of interstellar issues and progress (peer-reviewed), the one, go–to, source of emerging information. This includes more than just spacecraft ideas. It should also cover societal implications and the effects of ancillary developments (such as extended human life spans, hibernation, artificial intelligence, and trans-humanism, energy prowess, extinction hazard probabilities, etc.).

— Anthologies that compile the best papers of the past (again covering the full span of relevant topics).

— Detailed books on the key technology options, at a level of detail where the assertions from various studies can be checked against reliable information.

(3) Guiding Scenarios: To provide some context for “how do we get from today to the era of star flight?,” create hypothetical scenarios of the events (technical and societal) that would eventually lead to interstellar missions. There is more than one scenario to create:

— Extrapolating the present rate of progress (technical and societal) till the first mission. Note: Three different studies estimate 2-centuries in this scenario.

— Responding to an impending threat to humanity’s survival.

— Possible technological progress if money and societal support were not limits.

— Implications from the discovery of propulsion physics breakthroughs.

(4) Making Progress: When it comes to making progress (given the information, above, is available), the following statements were made:

— Staged progress where approaches at different levels of technical maturity are treated differently. Where technological progress is nearing implementation, conduct detailed system-level analyses that could lead to implementation plans. For items needing laboratory verification, perform experiments. Items whose feasibility is still uncertain should be treated as basic research, but where it is desired to present some sort of estimate of their viability.

— Want to see “concrete achievements,” not just plans.

— Want “well led projects,” not just visionaries (I’m not sure exactly what is meant here, since I can interpret the statement in more than one way).

— Educational opportunities (many variations on this possible).

— Conducting Mission-Vehicle Studies [The prime activity of Icarus Interstellar]

— Funding individual proposals with clear selection criteria.

(5) Institutes: Both Mae Jemison, of the 100 Year Starship organization, and Kelvin Long each want their own interstellar Institutes. How will they determine who to involve, and how will they get those people to relocate to their central institute? How many people would this involve? How much will it cost? Would its higher costs pull resources away from all the other activities to become the only activity? What services will these institutions offer for the rest of us (those who are not in the institute)?

(6) Symposia and Workshops: Although this was not mentioned in the comments, it has been discussed before. What I would like to hear from our readership is: How frequently do you want them? What do you want to get out of such events? Do you want presentations to be pre-filtered to ensure quality, or do you want full openness? Is it worth having symposia if no potential sponsors are in the audience? How much of a registration fee are you willing to pay?

(7) Inclusivity and Participation: The notion of letting a broad audience participate is a recurring theme. The challenge includes finding worthy tasks for the various skill levels of our audience, and then gleaning the progress made.


The following estimates are based on my experiences at NASA and on lessons learned in the course of creating the Tau Zero Foundation. Your mileage might vary. I’m providing these estimates to give you and idea of the relative difficulty of these tasks, and so you will know how much funding any organization will need before being able to offer such services.

(1) Promotion and Fund Raising. For nonprofit organization, a common advice is to allocate 20% of your total funds to fundraising. In other words, if the organization needs $80k to perform its duties, you need $20k just to raise $100k of funding. I have only started to learn about nonprofit fundraising since 2010, and still have a lot to learn. Prior to that, my NASA affiliation made it illegal for me to raise funds actively for Tau Zero.

(2) Information: With our network of practitioners, this is the primary function that Tau Zero has been doing, so our estimates here are fairly accurate:

Centauri Dreams news forum: This is virtually a full-time job for one person [Paul Gilster], plus it relies on several knowledgeable volunteers to scout for meaningful source material. On this I must share that I am impressed with how much information Paul can process and how frequently he can write. I’m not sure what it would take to provide this service if starting over from scratch.

Social Network Presence: Here are some of the social networks that Tau Zero has been able to keep up, due to the continuing volunteer services of Larry Klaes. This does not require a full-time position, but it is definitely a serious commitment. My thanks to Larry for helping spread our news via these other organizations:

Interstellar Travel (Tau Zero Fan Page)

Icarus Interstellar

Project Hyperion (an Icarus Interstellar project)

Passionate Universe

Space-Time Travel

Paul Gilster also maintains a Twitter presence as @centauri_dreams.

Interstellar Journal (free or at least low-cost) (peer-reviewed): Right now, we’ve been relying mostly on the Journal of the British Interplanetary Society since it already exists and has the staff to perform the required functions. If you have access to a university library which carries this journal, you can visit and read articles without having to pay the annual subscription.

To create a new journal would require at least one full-time editor/manager, a staff of part-time help to process submissions through review, revisions, and properly formatted and copyright manuscripts (and maintain the website), and a network of willing & able reviewers who do not have conflicts of interest about what they are reviewing. A rough dollar estimate to provide such a ‘free’ and quality journal would be about $200k annually.

In my personal experience, the hardest part about doing this (even with ample volunteers) is to find qualified reviewers without conflicts of interest. The interstellar community is still relatively small, and although there are many enthusiasts, most of those are not fully qualified. The number of qualified reviewers is small enough that most already know each others’ works and often have conflicts of interest. A double-blind review might solve the conflict of interest problem, but again, since the community is small, it is pretty easy to guess whose paper you are reviewing. Other qualified reviewers could be drawn in from related fields, but we would probably have to offer a small honoraria to get them to review papers that are not within their fields of interest.

Anthologies that compile the best papers of the past (again covering the full span of relevant topics). As much as I like this idea and would like to see it happen, the challenge again is finding the people who are qualified and impartial that will, indeed, pick the “best” papers, not just their favorite papers. Right now, this is happening only when individuals in our community have enough passion, time, and material to work from. I applaud those who have done, or are attempting such work.

Detailed books on the key technology options: To assemble a book at this level is a 2-3 year endeavor requiring at least ½ time lead editor, plus a team of authors who can write the detailed chapters spanning the topic. Since this function can fall within the scope of a researcher’s day job, there is a possibility of getting such books written with only minor funding.

The difficulty we have found is to find enough willing experts to write impartial and instructive material amidst the more common advocacy papers. Also, I am encountering difficulty when discussing books with publishers since many seem to be waiting for the electronic rights issues to be resolved first… or so that is what I’m hearing.

Library of open technical problems that need to be solved: I like this idea so much that we’ve already been working into on our new Tau Zero website. The challenge here is distilling the key issues from all the literature, and then categorizing them so that it is easy for a newcomer to find what they are looking for. Right now, we have a backlog of notes and references that will still take hours of labor to go through, convert, and post into our list. This is something suitable for volunteers at the skill level of undergraduate students.

Library of reference missions: I like this idea too, and know that Icarus Interstellar is creating these. What I do not know yet – and this gets back to the journal and review challenges –is the level of fidelity and impartiality of those mission/vehicle reports. Historically, before Icarus, there was a tendency in our community to devise mission and vehicle studies to promote a preconceived solution, rather than conducting a requirements-driven, system-level study that is not biased by a favorite power or propulsion option. Such biases are just human nature and are quite common in many fields — Freeman Dyson calls this the ‘Problem of Premature Choice.’ A mitigating strategy to this “premature choice” phenomenon, absent of a team of unbiased, qualified reviewers, is to (1) take all of these studies with a healthy dose of skepticism, and (2) focus on the weakest link of their system to identify what problems still need to be solved (It is common in prior studies to skimp on the assessment of realistic heat rejection and realistic magnetic nozzles). In other words, convert their weakest links into key, next-step tasks… and make progress on those tasks.

(3) Guiding Scenarios: I really like this idea. I will find a way, when we can, to work this into Tau Zero’s activities. This was not already a part of our plans. Off the cuff, I would imagine needing some discussions amongst of our sci-fi authors to kick around possibilities, and then volunteers to distill those discussions into hypothetical scenarios. Each scenario will likely require the same level of effort as a journal paper, but with less rigor, since it is only a prediction. Another option is to run a contest to invite scenarios from our readership. The challenge in that case would be to assemble the review team, support staff, and lead. Provided we had a lead, I consider this a feasible low-cost, mostly volunteer effort. Again, considering that these scenarios will be attempts to predict the future, they should be taken as possibilities, rather than definitive plans.

(4) Making Progress: This is the other area where I’ve aimed Tau Zero to support. Right now, absent of funding to support research, all the progress being made is from our community, where those individuals take on the work themselves to make progress in their area of specialty. At Tau Zero we have been able to forge collaborations to avoid redundancy and to fill niches so that these individual works will have more impact overall. Considering the number of non-redundant and relevant publications that have been forthcoming (technical, science-fiction, journalistic, and artistic), I think our community is doing well. I would like to think that Tau Zero has boosted this, but there is no way to measure it. For example, I have no idea if David Brin’s new novel, Existence, (science-fiction that touches on many issues raised by Tau Zero), was influenced by Tau Zero. Brin is in our network or practitioners, but I’ve not discussed this with him.

When it comes to progress, the other tactic Tau Zero promotes (in addition to the cited collaboration, above), is to focus on the next-step detailed questions instead of advocating a particular solution. This is where Tau Zero differs from others in the community. Several others want to promote their solution and get that solution funded at levels sufficient to launch missions. This includes solar sails, beamed energy sails, nuclear rockets, and nuclear fusion rockets. It is my personal and professional opinion that (1) There is not yet enough prospective funding to support this strategy (requires at least 10’s of millions for any real implementation progress), and (2) It is premature to down select to ‘the’ solution until after we have a more accurate definition of the problem, requirements, and promising technical options.

Regarding educational opportunities, we are collaborating with the Ohio Aerospace Institute to set up graduate student projects, where the student, university, and Tau Zero collaborate to purse a grant for that student to work on a challenge within Tau Zero’s interest. More on this as it develops. To really pull this off would require $500k annually, but we are first seeing what we can do on crumbs.

If there were enough funding to sponsor targeted research, here is how Tau Zero would handle it. In prior estimates, we concluded that a reasonable annual budget to sponsor a research solicitations would be $6M:

— Convene a team of sponsors and practitioners to devise and agree on selection criteria.

— Invite proposals for short-duration tasks (1-3yrs duration) and rank them per the selection criteria just devised.

— To the limit of available funding, select a suite of divergent options from the top-scoring set. By “divergent” I mean that different approaches are supported (diversified portfolio) rather than having all the research cover the same approach.

— Host a symposium to review the findings when that research is done, and refine the next solicitation based on the lessons learned from the prior findings and symposium.

— Repeat that process until enough viable technology has accrued to make interstellar missions possible within the constraints of society’s available support.

(5) Institutes: It has been my experience from watching the creation and fate of other institutes that institutes do more to serve their founders than to serve the community. Regardless, this function still faces the challenges of being able to recruit and successfully manage a fitting team. Rough cost estimates for this sort of approach – absent of the actual research – is about $1-2M annually. Typically, the ‘faculty’ of such institutes are then required to seek additional grants from other sources for the actual topic progress.

Furthermore, it is my professional opinion that the skill set to answer the challenges of interstellar flight are still too fledgling to merge into one institute. Star flight is more than just the vehicle and propulsion. It includes the societal factors, and consideration of a number of specialties that are still emerging, such as synthetic biology, transhumanism, and the pending ‘singularity’ of artificial intelligence. It is because of this widespread and fledgling nature that Tau Zero is pursuing the graduate project idea that is open to all universities.

(6) Symposia and Workshops: This is a necessary function to regularly inform the community of progress, provide opportunities for face-to-face interactions, and invite new participants. Given how long it takes to create new content, It is my professional opinion that symposia should be spread 2 to 3 years apart. The actual costs of hosting a symposium can vary dramatically based on sponsorships, registration fees, and attendance. As a minimum, it requires the full time labor of 2 people for at least a year to assemble a meaningful event.

Due to the difficulty of finding that labor and the over-abundance of symposia and conferences at which interstellar work can be discussed, Tau Zero has no plans to conduct workshops. Instead, we will participate in others’ events as able.

(7) Inclusivity and Participation: The challenge includes finding worthy tasks for the various skill levels of our audience. The discussion forum in Centauri dreams gives our readership the opportunity to participate in discussions. These discussions are moderated to filter out inappropriate comments. The next level of participation is volunteer help. I already have more offers for volunteer help than I can manage. It requires a lot of work to create, assign, and then utilize volunteer tasks. If any of you are willing to manage our Tau Zero pool of volunteers ( ? 4-dozen) and are willing to do this as a volunteer for a while, please let me know. This is a job that requires people skills, not engineering or science.


To refresh your memory, my cohorts and I founded Tau Zero to find and forge collaborations amongst genuine pioneers and then share that progress broadly via Centauri Dreams and other publications. Rather than advocating specific vehicles, technologies, or missions, we want to find and encourage progress over the span of options. We also want to make sure we have a realistic set of requirements and constrains (i.e. understanding the problem) before devising ‘the’ solution. Our progress is largely based on the work of our network of practitioners; scientists, engineers, educators, writers, and artists, who work on these topics on their own, but collaborate via Tau Zero to avoid duplication of effort and to find the needed skill mix. In the near future we will debut our new “Discovery Log” – a repository of facts related to interstellar flight, covering these categories:

– Humanity’s Journey

– Destinations

– Getting there.

The services we offer will be articulated in that new website, along with the opportunity to become “members” whose fees grant members access to exclusive information and discounts on Foundation merchandise.

There have been some overtures between some of the organizations to collaborate, to at least avoid redundancy. To help all of these organizations serve you, please add your comments in the discussions. Are these activities what you really want? Which of these do you want first, and most? Which do you think will result in the most progress considering the limited funding? Offer suggestions for where to get the funds and support to your most desired functions.

Ad Astra Incrementis,

Marc Millis


Customer Feedback from the Discussions

Marc Millis August 10, 2012 at 13:43
“Who do ya call?” Dear readers, Are getting confused as to who is doing what and why there is a proliferation of interstellar flight groups?
– British Interplanetary Society
– Tau Zero Foundation w/ Centauri Dreams
– Peregrinus Interstellar
– Icarus Interstellar
– 100 Year Starship Organization, and now..
– Institute for Interstellar Studies.
Rather than advocate our own, I want to take this opportunity to ask YOU, our readership: What do YOU want an interstellar organization to do? And when answering, keep in mind that none of these groups has “serious” money. The bulk of work is till subsidized by volunteered labors of love.

Tell us, all of us, Where are your preferences? What services do you need?

Bob Steinke August 10, 2012 at 15:14
I think one valuable thing that interstellar organizations could do is build up a library of reference mission designs and open technical problems.
Beyond that, if there is any preliminary experimental work that is within their capabilities like the Planetary Society’s work on solar sails.

Interstellar Bill August 10, 2012 at 20:46
We need advanced, graduate-level textbooks on each propulsion option
1. Laser sail
2. Advanced Ion
3. Nuclear Electricity for Space (every non-fusion method from radio isotopes to full scale fission reactors
4. Fusion
We also need anthologies of already-published, specialized interstellar papers. Both IEEE and BIS could alone do great anthologies.
A textbook with one chapter each on these is far too introductory for the dear readers of this blog.

Greg August 10, 2012 at 23:47
“What do YOU want an interstellar organization to do? And when answering, keep in mind that none of these groups has “serious” money. ”
Excellent question Marc, personally I would like to see a staged approach analysis to possible interstellar propulsion solutions. I think if a site could show a stage 1 analysis of possible technologies as well as theoretical physics giving its likelihood between a 1 and 10, 1 being next to impossible 10 being highly likely. It would simply be a group of researchers giving their best guess or analysis of a technology/theory and if it would be feasible or not.
An example is this article on the Giant Casimir effect,
using meta-materials to possibly amplify the Casimir effect. Between 1 and 10 what is the likelihood this is a possibility and if this could be worth pursuing as a means for energy production or propulsion for interstellar travel.
Stage 2 could be a more detailed analysis of technologies. With stage 3 possibly moving to testing in a lab.
It would be nice to cut through the impossible stuff and speaking for myself, see what may get through.

Jean-Pierre Le Rouzic August 11, 2012 at 6:22
To contribute with my own answer to Marc’s question: What I wait from an organization is any concrete achievement, even if small. Like Bob Steinke, I found Planetary society’s solar sail design and launch attempts to have lots of merits. If someone wants to search (as Paul proves daily) there are valuable scientific papers, but for every good paper there are tons of s**t papers, often using arcane physics concepts to propose what is basically perpetual movement machines. There are already many students that are interested by interstellar concepts (f.e. see what F. Loup did). What we need is not visionaries, there are already some very impressive people and it’s good to talk about them, but we now need project leaders with common sense and attention to details and engineers. We need people able to understand that to build interstellar probes, we have to demonstrate concepts validity and how it could be useful by some aspect to humanity in short term.

Marc: What you can do without money is set a call for realistic interstellar proposals with positive impact on today’s life, with a team of volunteers to select a few very interested works with clear selection criterion. You don’t need to propose a price to recruit volunteers and contributors, many organisations only propose fame and it works (IEEE/Arthur B. Guise Medal (fire protection engineers)). Some even do not propose fame (scouts).

Astronist August 11, 2012 at 10:10
Marc Millis wrote: “What do YOU want an interstellar organization to do?”
To my mind, possibly the most urgent task is to develop and publicise a scenario in which we actually get to do interstellar travel, starting from the present day. Why urgent? Imagine that we start discussing interstellar travel with a member of the large majority of people who are not, for whatever reason, excited by the prospect. What will be on their minds? Overpopulation: we must reduce the world’s population. Climate change: we must give up an energy-intensive lifestyle (see Tom Murphy’s “Do the Math” blog for a diet of pessimism on this point, thus directly contradicting any chance of a starfaring future, given the enormous energy demands of interstellar travel). World hunger: we must abandon spaceflight and spend the money on feeding the poor instead. Militarism: we must abandon spaceflight because all it’s doing is spreading evil American militarism and greedy anti-human capitalism into space (the position of the Global Network Against Weapons and Nuclear Power in Space, and of its sociologist supporters who came to talk at the BIS a couple of years ago).

In other words, I detect a general mood of antipathy towards the value system of growth and progress, which would basically shut down space technology and economic growth if it could, and impose a competing value system based on values of being contented with what one already has and renouncing the accumulation of more material possessions, as well as halting progress towards such things as artificial intelligence, genetic engineering and nanotech.

Clearly, the market is on our side: people generally place a higher value on their comfort and on having the latest gadget than on ideology, particularly self-effacing ideology, and the market is great at driving forward economic and technological progress. But I still think we would be well advised to put at the heart of our message to the broader world a reasoned explanation of why growth and progress are still good, why their benefits outweigh their risks, why climate change, peak oil and nanotech are not about to destroy us, and why the interstellar enterprise is not merely a juvenile-minded hobby that we happen to want to indulge in at everyone else’s cost, but the logical result of the growth of civilisation in a way which benefits everybody.
Oxford, UK

Kelvin F. Long August 11, 2012 at 12:54
Marc Millis wrote:
“…Rather than advocate our own, I want to take this opportunity to ask YOU, our readership: What do YOU want an interstellar organization to do? ”

My top five answers:

1. Demonstrate both theoretical and experimental progress towards the long term vision, utilizing rigorous scientific techniques, across the spectrum of options, producing tangible benefits and real technologies.

2. Demonstrate inspired leadership, good mangement and governance in an open, transparent and responsible way.

3. Initiate bold and exciting projects and programs which inspire the world, swell our numbers, and produce more reliable studies.

4. Work together, co-operatively and co-ordinatively, for common purpose, shared ambitions and increased national and international impact, in a way that rises above politics and human behaviours.

5. Break down barriers to participation, knowledge, and belief in the seemingly impossible, by the creation and facilitation of opportunity through education and outreach, using positive-optimistic motivation.

Kelvin F. Long

Jack Crawford August 11, 2012 at 15:51
At this early juncture I think Tau Zero needs to differentiate between being a promoter, an enabler, and a driver of interstellar flight. Of these three things I think acting as an enabler is the easiest to do on a tight budget because it can be done by volunteers as a labor of love while research and public awareness cost money. As an enabler, Tau Zero’s role is to act as a compiler and distributor of knowledge. By acting as a venue for the exchange of information, such as a a free peer reviewed online journal, the Tau Zero Foundation can be a safe haven for scholarly writing, review papers, and general education.

Currently, the literature for interstellar studies is greatly scattered which makes finding and following the literature trail difficult. This impedes research. Review papers can address this and another problem: the academic pay wall to information. Think of the audacity of having to pay $80 for a 10 page paper on the subject you are interested in only to find the paper doesn’t deliver what the abstract says was in the paper. This is our enemy: inaccessible and poor quality information. Help from academia is not coming any time soon so the burden for progressing interstellar studies is on the citizen scientist and engineer, but someone has to give them the tools to succeed. Tau Zero can do this. Important but obscure information can be compiled and rewritten for public consumption. Code for common numerical calculations can be made freely available. Scholarly articles can be held to a higher standard. Proper education articles aimed at the armchair enthusiast can also be written. All you need are volunteers to write and some editors.

~ Jack Crawford

spaceman August 12, 2012 at 3:08
The aforementioned interstellar organizations will– certainly in a more realistic manner than does the film industry– definitely go along way as it pertains to keeping the grand goal of crossing the light years alive. Assuredly, new ideas will originate from these groups and existing ideas will be further refined as technology advances.

As a lover of puzzles, I would like to see the interstellar dream presented as the ultimate puzzle– a puzzle that combines several branches of science both natural and social. So geniuses put down your NYTimes Saturday crossword, which of you has what it takes to crack this one? What could be more challenging and exciting, more important in terms of ensuring human species survival than solving this intricate conundrum of epic proportions?

But it’s like what a friendly fellow at a recent singles party said to me: “When I was your age I used to think that if I waited around it would all fall into place. The right woman would just enter my life…but that’s unlikely. You have to get out there and do the hard work of finding her.”

How true. I can and do imagine her. I think about the pros and cons of getting involved with her, but at the end of the day I know the imagining will only get me so far. He’s right, I have to get out there more and test the waters. Same is the case with interstellar societies…they are a great resource for thinking about, for example, which candidate propulsion systems might work best as well as other aspects of deep spaceflight. Imaginative interstellar groups are crucially important in terms of developing ideas on how it might be possible to effectively span the immense interstellar gulf, but eventually they—like me, will have to get out there and test/implement the ideas in the real world.

Ric August 13, 2012 at 4:10
Seems to me that the Interstellar Institute already exists: Zero Tau. So why not slightly expand the scope of the Zero Tau website and merge the Intersteller Institute topics into it?

Adam Crowl August 13, 2012 at 7:29
An interstellar organisation with the aim of achieving interstellar flight needs to look at the many propulsion suggestions made over time and the broader pre-conditions needed to make the various scenarios happen. For example, what kind of society can make a large multi-stage fusion-propelled probe happen? What economic pathway will make that feasible? And how will it transform life for the rest of humanity?

Or what would lead to huge multi-terawatt lasers able to push sail-craft to half the speed of light? Would powering such devices lead to abundant solar-power systems for human-kind?

Being able to live in space for decades at a time would have implications for recycling and food-processing in a multitude of ways, surely a vital concern on a crowded Earth. By promoting development of minaturised industry, food-production, medical facilities and scientific equipment – all applicable to humans thriving in other star-systems – then we’d be sparking unimaginable leaps forward for everyday life on Earth.

Kick-starting the economic infrastructure needed to develop the solar-system will be another area for the interstellar organisation. For example, Philip Metzger (and his NASA colleagues) have some interesting proposals for boot-strapping space-industry via the Moon’s resources.
Well worth exploring further the whole idea of teleoperated, semi-self-replicating remote facilities on the Moon.

What we need to do is get away from the vision of the one-shot effort. Interstellar involves everyone and could well transform the world.


A Circumbinary Planetary System

Among the more interesting items coming out of the XXVIII General Assembly of the International Astronomical Union (IAU) in Beijing is news of a circumbinary system containing two planets. We’ve seen circumbinary worlds before — Kepler-16b is a planet orbiting not one but two stars, as are Kepler-34b and Kepler-35b. There was a time that the idea of a planet orbiting two stars, as opposed to orbiting one or the other of two stars in a binary system, seemed unlikely. Now we have a multiple-planet system in exactly this configuration.

It’s an interesting one, too. Some 4900 light years from Earth in the constellation Cygnus, the two stars orbit each other roughly every 7.5 days. One of the stars is fairly similar to the Sun, though about 15 percent less bright, while the other is an M-dwarf about a third of Sol’s size and 175 times fainter. Of the two planets, one — Kepler-47b — is three times the diameter of Earth and eight times its mass, orbiting the twin stars every 49 days. The outer planet — Kepler-47c — catches the eye because it orbits the stars every 303 days, placing it within the twin stars’ habitable zone.

To be sure, this looks to be a gas giant a bit larger than Uranus in size, with about 20 times the Earth’s mass. While not itself a candidate for habitability, its placement allows speculation that an exomoon around it could potentially hold life. The diagram below relates the Kepler-47 system to our own, with the two newly discovered worlds shown for comparison:

Credit: NASA/JPL-Caltech/T. Pyle.

Jerome Orosz (San Diego State University), lead author of the study, notes the tricky nature of the observations that revealed the two worlds:

“In contrast to a single planet orbiting a single star, planets whirling around a binary system transit a moving target. The time intervals between the transits and their duration can vary substantially, from days to hours, and therefore the extremely precise and almost continuous observations with Kepler space telescope were fundamental.”

As this IAU news release notes, the loss of light caused by the eclipse is tiny. While Venus, for example, blocked out about 0.1 percent of the Sun’s surface during its most recent transit in June, Kepler-47b and c blocked out 0.08% and 0.2 percent respectively. Ground-based observations at McDonald Observatory (University of Texas at Austin) backed the Kepler data as the researchers studied the properties of this system. Michael Endl and colleagues studied the binary star with the 9.2-meter as well as the 2.7-meter instruments at McDonald.

“It’s Tatooine, right?” said Endl. “But this was not shown in Star Wars.” The astronomer was referring to the highly variable daylight that would fall upon a planet orbiting two stars. In fact, measurements of the stellar orbits told Endl’s team that daylight on the two planets would vary by a large margin over the 7.4 day period that the stars needed to complete their orbits. A closer look at the McDonald Observatory work can be found in this UT-Austin news release.

Meanwhile, planet hunter Greg Laughlin (UC-Santa Cruz) has this to say:

“The presence of a full-fledged circumbinary planetary system orbiting Kepler-47 is an amazing discovery. These planets are very difficult to form using the currently accepted paradigm, and I believe that theorists, myself included, will be going back to the drawing board to try to improve our understanding of how planets are assembled in dusty circumbinary disks.”

Indeed. We now know that close binaries can host not just single planets but complete planetary systems. The paper is Orosz et al., “Kepler-47: A Transiting Circumbinary Multiplanet System,” published online in Science August 28, 2012 (abstract / preprint).


Remembering the Early Robotic Explorers

Reflecting back on the history of robotic space missions, Larry Klaes offers a look at the early missions to Venus and Mars, harbingers of the far more complex probes we would later send into the Solar System. The Pioneers, Veneras and Mariners were, in their day, on the forefront of planetary research, blazing the trail most recently followed by Curiosity on Mars. As a site focused on deep space issues, we often return to Voyager and Pioneer, but let’s not forget how planetary exploration got its start.

By Larry Klaes

Once upon a time, our Solar System was a very lively place.

In past centuries, most if not all of the known planets and their moons, along with the even smaller members of our celestial neighborhood, were imagined to have native life forms as numerous and diverse as those found on Earth. Otherwise, it seemed pointless for whole worlds to exist without any inhabitants.

Then along came the Twentieth Century. Improved knowledge about the Sol system caused the majority of contemporary astronomers and other scientists to realize that most of these distant bodies were just too hot or too cold or too airless to support complex organisms, especially intelligent ones capable of building civilizations.

There were some holdouts, however.

The fourth world from the Sun, the planet Mars, retained enough of its Earth-like characteristics to convince scientists that plant life and perhaps even some lower animal forms dwelled in the harsh environment. It was also considered that while the canal-building beings of the Red Planet were probably figments of the Nineteenth Century imagination of Percival Lowell and his followers, astronomers could not entirely rule out the possibility that an advanced society once did exist in the Martian past, when that alien globe was warmer and wetter. The crumbling ruins of their civilization might be awaiting discovery, buried by ages of unchecked planet-wide dust storms.

Image: A once enigmatic planet, Mars began to yield its secrets to our early probes. This HST image shows the Valles Marineris region (centered on roughly 60 degrees longitude). Credit: NASA/NSSDC.

Moving in the direction of our yellow dwarf star past Earth, the planet Venus was even more of an enigma than Mars. The primary mystery of our other celestial neighbor came from its being sheathed in an unbroken cover of vaguely yellowish clouds.

The rather high limitations on factual information about the second world from the Sun due to its global atmospheric conditions did very little to stem some rather high levels of speculation about what was going on far beneath the Venusian cloud deck.

Some assumed that because Venus was perpetually shrouded with clouds, it must be raining there everywhere all the time. Toss in the fact that Venus is closer to the Sun than every other planet but Mercury and it became easy to conclude that the whole world was a very tropical place bathed in a perpetual twilight. Perhaps Venus was reminiscent of the Carboniferous Period on Earth, with alien swamps full of strange plants and reptilian creatures crawling through the dankness.

Even when astronomers were able to do more than just stare at the nearly blank visage of Venus with their optical telescopes, conflicting data ruled the day. As a result, some scientists theorized that the planet was covered in a global ocean of either boiling oil or seltzer. Others concluded that Venus was a desert world where fast, hot winds whipped across the utterly dry surface and the clouds were made not of water droplets but of constantly elevated dust.

Image: Venus’ hidden surface would not be understood until Soviet and American probes confirmed its extreme temperatures and pressures. Credit: NASA/NSSDC.

Nor could the scientists come to an agreement on the average surface temperature of Venus: Some thought their measurements meant that the face of the planet was very hot, many hundreds of degrees warmer than on Earth; any water present would be turned to vapor and any known forms of native life would be out of the question. The other camp said the high temperatures came not from the planet’s surface but its surrounding ionosphere. Perhaps Venus was just hospitable enough to keep water in a liquid state, thus preserving the Venusian ferns and dinosaurs – at least in theory.

Enter the Space Age

Two major events of the Twentieth Century played important roles in helping science to discover the true nature of the planet Venus: World War Two and the subsequent Cold War. Both international conflicts provided the technology, engineering, and motivation to bring about the Space Age, which officially began in the fall of 1957.

On October 4, the Soviet Union lofted into Earth orbit a silvery sphere named Sputnik 1, its four swept-back whip antennae transmitting to the world far below a deceptively simple signal of its existence, along with the wider implications of what had been and could be achieved in this new era. Then, just one month later, the Soviets sent a dog named Laika into space aboard Sputnik 2, the first living creature to circle the globe.

In response to this geopolitical challenge and potential military threat, the United States ramped up its own space efforts, quickly turning the Space Age into the Space Race. Both superpowers began to use the rest of the Universe as a generally non-destructive means to show the rest of humanity that its capabilities, resources, and especially its ideologies were the best.

Science and the expansion of human knowledge into the Cosmos were often touted as the first and foremost reason for lofting these new machines into space: One of the goals of the International Geophysical Year (IGY) of 1957-1958 was to achieve the orbiting of an artificial satellite. While not a fabrication, it was clear to anyone who looked beyond the rhetoric and propaganda that without the swiftly growing military-industrial complex of both sides, most space science and exploration plans would have remained largely science fiction for many more years if not decades into the future.

The early years of the Space Age/Race were dominated by achieving a series of firsts in the Final Frontier. Once low Earth orbit, or LEO, had been reached (and won in the political sense by the USSR), the next obvious goals were the nearest worlds to Earth: Our celestial home’s singular natural satellite, the Moon, and the two closest planets in the Solar System, Venus and Mars.

By the end of the 1950s, the geopolitical winner in the robotic race to the Moon was again the Soviet Union. After several launch failures by both superpowers in 1958, the next year witnessed the USSR’s aptly named Luna series sending one probe past the Moon (and subsequently becoming the first artificial satellite to orbit the Sun), a second vessel impacting on the lunar surface, and a third robot revealing to humanity with its onboard cameras the face of the mysterious lunar farside.

The next obvious goal in this celestial competition was Venus. With a closest approach to Earth of 26 million miles during its 224.7-day dance around the Sun, an unmanned probe could reach that world in less than four months with the most ideal launch window. This relatively short trip time was a most important factor, for the environment of the inner Sol system held many potentially hazardous unknowns for an exploring spacecraft.

Another key milestone to conquer was the endurance of the prevailing space technology itself. If a vessel survived the initial launch and escape from its Earth parking orbit – for numerous rockets during that pioneering era had an alarming frequency of exploding or otherwise malfunctioning – the probe then had to last long enough to communicate its scientific findings to Earth across many millions of miles of near vacuum.

The farthest any vessel had reached into that celestial region at the time was the American probe named Pioneer 5. Originally intended to be part of an ambitious double mission to flyby and orbit Venus, the goals were scaled back until Pioneer 5’s primary focus became the interplanetary space between Venus and Earth. The probe spent over three months in 1960 returning precious scientific data and was tracked out to a distance of 22.5 million miles from home. Pioneer 5 paved the way for the flotilla of Venus probes that were soon to follow.

As with Mars in 1960, the Soviets were the first nation to attempt sending automated spacecraft to the second world from the Sun. Two probes were launched from their primary space center in a remote region of Kazakhstan just over one week apart in February of 1961.

The first machine never left Earth orbit due to a technical issue with one of its rocket stages. The second probe, later to be known as Venera 1 (the Russian word for Venus), was successfully injected into deep space but ceased communicating with its controllers before the month was out. Attempts were made to detect and resume contact with Venera 1 through its predicted arrival at Venus in May of 1961, but the probe was never heard from again.

Years later, the West learned that the Soviets had intended to place simple instrumented capsules on the surface of Venus with these 1961 missions and not just fly by the planet as originally thought, just as they had tried and failed with Mars one year earlier. As a number of the Soviet scientists had sided with the Venus model that included some kind of liquid ocean covering the planet, the capsules were designed to float.

The Soviets’ confidence in a watery Venus was demonstrated by the fact that the landers were not equipped with any mechanical means to touch down softly on the planet. Instead the capsules would have to rely on the thick Venusian atmosphere along with its presumed alien ocean for cushioning, which the Soviets estimated to be five times denser than on the surface of Earth.

The Mariners of a Vaster Sea

When the next launch window to Venus opened up in the late summer of 1962, the United States was finally ready to join the Soviets in sending robotic representatives to that alien world.

The first American Venus explorer, named Mariner, was based on the Ranger series of lunar probes made by the Jet Propulsion Laboratory (JPL). Designed to image the lunar surface until impact and place on the Moon a seismometer wrapped in a protective sphere of balsa wood to record any quakes, the Ranger craft were not performing as planned. Various technical issues kept the three Rangers launched throughout 1962 from returning any images or data about Earth’s natural satellite. National prestige took some small comfort when Ranger 4 impacted on the lunar farside, becoming the first American probe to touch the Moon.

The Soviets attempted to trump the planned American deep space efforts by sending three rather sophisticated probes toward Venus between August 25 and September 12 of that year. One vessel would conduct a photographic flyby of the planet, while its two siblings would place landers on the surface, analyzing the thick and cloudy atmosphere during their descents.

Unfortunately for Soviet prestige and planetary science, none of the three unnamed Venus explorers were able to get any further than temporary Earth orbits at best due to technical failures with their launch rockets. The Soviet Union officially downplayed the loss of their newest Venus probes. This was standard procedure for many of their space efforts, failed and otherwise depending on the mission, during the Cold War.

An Oil Rig to Venus

At first glance, the design of the first two planetary Mariners bears some resemblance to an old fashioned oil rig, albeit one with two rectangular wing-like solar panels and a parabolic high-gain antenna attached to its hexagonal base where the basic computer, electronics, batteries, and attitude control devices were stored. The lattice-work mast held the majority of the probes’ forty pounds of scientific instruments and was capped off by a cylindrical omni-directional antenna.

Of all the scientific devices on the Mariners, perhaps the most important ones were the microwave and infrared radiometers. They would determine the actual overall temperature of the planet’s surface and the makeup of the obscuring cloud deck, scanning Venus across its day and night hemispheres. The rest of the instruments would search for any magnetic and radiation fields generated from the planet, along with detecting high-energy cosmic radiation, interplanetary dust, and charged particles streaming from the Sun, also known as the solar wind.

Small sensors spread about the Mariners would constantly measure the state and health of the space probes while in flight. They would alert mission controllers to any technical problems during the long and potentially hazardous trek to Venus and provide the space agency with vital data for improving future vessels on interplanetary journeys.

An optical imaging system was not included among the scientific equipment of these pioneering robotic explorers, partly because it was felt there would be little or nothing to witness beyond the bland, yellowish cloud cover. Earth-based astronomers sometimes reported and photographed diffuse darker patches on the clouds of Venus (and a strange luminous glow on the night side called the Ashen Light) and even cloud breaks through the turgid atmosphere straight to the surface, but the last claims were always questionable at best.

One last item placed aboard each Mariner was neither a scientific instrument nor a sensor: A small American flag was sandwiched between some layers of thermal material at the top of the probes. The Soviets also placed commemorative mementos aboard their Venus explorers. Their tributes consisted of small metal Earth globes designed to survive the plunge to the planet’s surface with their Venera landers. Inside the hollow spheres were medallions with the Soviet Coat of Arms engraved on one side. The other face of the metallic disk displayed a diagram of the inner Sol system depicting the space probe’s (planned) journey from Earth to Venus.

Donald Mitchell offers a very nice collection of images of the Soviet space medallions and pendants which now rest on Venus and several other nearby worlds.

First Try

The first of the twin 447-pound robotic probes to be aimed for the second world from the Sun was naturally named Mariner 1. Encased atop an Atlas-Agena B launch vehicle, the vessel was sent on its way from Launch Complex 12 at Cape Canaveral in Florida into the predawn skies of July 22, 1962.

Oran W. Nicks, who was the Director of Lunar and Planetary Programs for NASA and present at the launch of Mariner 1, poignantly described what happened next in his wonderfully written book Far Travelers: The Exploring Machines (NASA SP-480, 1985):

“Our friend died violently at 4:26 A M. on a hot July night. Her finish was spectacular; she was trapped amid the flaming wreckage of an explosion that lit the night sky. Four of us watched helplessly, standing together at a site that gave us a perfect view. We had come there with a common interest in her adventuresome goal, though we came from different backgrounds, and each of us brought a different perspective and commitment to her tragic performance.

“We were soon to learn that she had been blown up intentionally by a man with no firsthand knowledge of her ability and promise. My emotion changed from disappointment to bitterness when I learned that she was destroyed barely seconds before flying beyond his reach [just six seconds, to be exact]. We had witnessed the first launch from Cape Canaveral of a spacecraft that was directed toward another planet. The target was Venus, and the spacecraft blown up by a range safety officer was Mariner 1, fated to ride aboard an Atlas/Agena that wobbled astray, potentially endangering shipping lanes and human lives.”

Guidance equipment for the rocket carrying Mariner 1 had become faulty, sending the entire vehicle off course. The Range Safety Officer (RSO) at Cape Canaveral sent a destruct signal to explosive devices on the booster to keep it from potentially causing harm or worse to people and property in the vicinity. Falling from the sky with the shattered remains of its rocket, Mariner 1 continued to transmit right until it slammed into the Atlantic Ocean. The first American attempt at Earth’s nearest planetary neighbor joined the ranks of the Soviet Venera probes which never left their home world.

Second Time’s the Charm

Since the early days of robotic planetary exploration, NASA’s plans for a typical deep space probe mission often included constructing at least three versions of a space probe: The primary craft that would be sent to the target world, an identical or sometimes improved backup probe, and a full-scale engineering model that stays home. This third version allows the mission team members to directly test the probe and to recreate and (hopefully) resolve any technical issues the flight version may have while enroute to and at the planet.

With the sudden loss of Mariner 1, the wisdom of having built more than one version of the same probe became all too apparent. America would still have a chance to explore Venus thanks to the existing backup vessel, which became known as Mariner 2. However, with the 1962 launch window to Venus closing rapidly, the mission team would need to complete their preparations sooner than normal.

Just over one month after Mariner 1 had found itself at the bottom of the Atlantic rather than on its way to Venus, Mariner 2 found itself rising into the sky above Cape Canaveral on August 27 aboard another Atlas-Agena B launch vehicle. Several times on its way to an Earth parking orbit, the booster behaved erratically, but thankfully the situations corrected themselves before any drastic action had to be taken.

Within two hours after launch, Mariner 2 found itself in open space with its two solar panels fully extended and on its way for a four-month journey to an alien world. The solar cells were found to be generating a bit more power than expected, so on August 29 the mission team activated the craft’s science cruise experiments that would let them know what the probe was finding out there and experiencing on its way to Venus.

The interplanetary voyage for Mariner 2 across millions of miles of space was anything but calm and routine, and not just because it was something rather new for NASA JPL.

The first major technical problem for Mariner 2 arose on September 8 when the probe suddenly lost its attitude control. Three gyroscopes automatically restored stability to the vessel just three minutes later. A possible strike by a stray meteoroid was suspected but never confirmed.

Even before the official Space Age, meteoroids were a particular concern to space engineers, as no one knew to any high degree just how much cosmic debris roamed the Sol system and how much damage they could do to a spacecraft. One of the staples of early science fiction involving spaceflight often had the intrepid crew of a silvery V-2 style rocket ship being threatened by whole storms of meteoroids as they bravely explored the Universe.

Had Mariner 2 been unable to realign itself, the probe could have begun tumbling, eventually resulting in a loss of contact with Earth and a serious loss of power due to the probe being unable to keep its solar panels focused on the Sun.

The next serious threat to the health of Mariner 2 while in deep space took place right on Halloween. One of the probe’s two solar panels began to malfunction by short circuiting. Concerned that Mariner might not have enough onboard energy to examine Venus and transmit back to Earth the priceless data on that planet, the mission team turned off the science cruise instruments to conserve power.

One week later, the errant solar panel appeared to have healed itself, so the Mariner team reactivated the cruise devices. The panel’s revival was short-lived, though: By mid-November, the panel had permanently broken down, leaving Mariner 2 with just one solar panel for collecting energy, along with its short-term batteries.

Thankfully for the mission, the probe was now close enough to the Sun that it could survive on the energy from just one panel all the way to Venus. There was, of course, a down side to being much nearer to our yellow dwarf star: An increase in solar heating.

Anyone seriously putting together a satellite to operate in open space plans for the craft to deal with extremes of heat and cold among other factors in the harsh environment beyond our planet’s relatively comfortable lithosphere. In the essentially airless void of space, the outer skin of a spacecraft facing away from the Sun can be hundreds of degrees below freezing, while the sunlight side is above the boiling point of water.

Not only did Mariner 2 have to contend with these same incredible temperature variations as other spacecraft have done before and since, but the probe was also approaching 26 million miles closer to the Sun than when its journey began back in August. The scientific instruments were starting to encounter temperatures much higher than they were nominally designed for. The Mariner team became increasingly worried that their robot emissary to Venus might succumb to the equivalent of a mechanical fever before it could arrive.

Then, just two days before Mariner 2 would encounter Venus, the onboard computer failed to give what was called a “cyclic calibrate pulse” which normally took place every 16.6 hours. The team worried this error meant that when the probe came upon the planet, the computer would fail to initiate the critical final encounter sequence that would activate the science instruments to examine the planet and return all that precious information to Earth.

Venus Day

On December 14, 1962, just six hours before much of the sky would be filled with the looming presence of the planet Venus from the perspective of the Mariner probe, the mission team discovered that their fears about the vessel’s mechanical “brain” were true: The computer had not told the probe to switch to encounter mode. Mariner 2 was in danger of flying past Venus without conducting a single scientific scan of the planet.

A command was radioed from the Goldstone tracking facility in California to Mariner 2, which was 36 million miles from Earth at that moment, father than any operating spacecraft had ever been before. Traveling at the speed of light, the command was received and replied to by the probe 6.5 minutes later, which took another 6.5 minutes to let the humans conducting the mission know that all their efforts were not in vain.

Approaching the planet’s darkened hemisphere at 39,000 miles per hour, Mariner 2 flew by Venus at a distance of 21,648 miles from its surface. If the probe had possessed electronic eyes, it would have seen that cloudy world appearing 900 times larger than the full phase Moon does in Earth’s skies. For the first time in history, a space vessel had reached another planet intact and functioning well enough to return scientific information about such a world. This was a mere five years after Sputnik 1 had been sent beeping into Earth orbit.

For 35 minutes, Mariner 2’s two radiometers scanned across the planet from its night side into the daylight hemisphere. The resulting data that streamed across interplanetary space back to the eagerly waiting scientists at a mere 8.33 bits each second confirmed that the high temperatures astronomers had previously detected were coming from the very surface of the planet and not its ionosphere.

Not only was Venus a very hot world, averaging 800 degrees Fahrenheit, but that temperature remained constant across the entire globe; not just from its equator to the poles, but also both in the day and night hemispheres. Clearly the planet retained its heat through the “greenhouse effect”, allowing solar energy to penetrate its cloud layers and thick air, but not to escape back into space. No other terrestrial world approached the surface temperatures Mariner 2 found at Venus, not even Mercury.

Gone almost instantly were the humid swamps of strange plants and even stranger animals. Gone too were the seas of oil, seltzer, and especially liquid water, for not even a single drop could survive there except to become a very temporary vapor. On the planet revealed by the American robot probe, even bars made of zinc and lead would melt into puddles, and no human being exposed on the surface would last beyond mere seconds.

Image: This 1961 photo shows Dr. William H. Pickering, (center) JPL Director, presenting a Mariner spacecraft model to President John F. Kennedy. NASA Administrator James Webb is standing directly behind the Mariner model.

As for native life, anything that had ever lived on Venus or could exist there as Mariner 2 slipped by their world would be nothing like organisms from Earth. Those who envisioned the second planet from the Sun as a scorching, desolate desert had been closest to the truth.

Readings from the other science instruments aboard Mariner 2 gave further evidence that about the only aspects Venus had left in common with Earth were its size and mass. Neither a magnetic field nor a radiation belt could be found around the planet, at least to the detection limits of the probe’s magnetometer. Venus appeared to be rotating very slowly and in the direction opposite to that of our planet. If a person standing on Venus could somehow observe the Sun rising at morning, our star would appear to come up from the western horizon, crawl across the sky, and then slowly set in the east several hundred terrestrial days later.

Seven hours after its historic encounter with Venus, the mission team sent another command to the Mariner to switch the probe back into science cruise mode. Along with its invaluable and startling revelations at Venus, Mariner 2 also reported several important discoveries about the interplanetary environment to which the terrestrial worlds of the inner Sol system are immersed.

Scientists were surprised to learn that the charged particles streaming from the Sun, known as the solar plasma or solar wind, were always present and constant in deep space. Mariner 2 also revealed it had received far fewer hits from cosmic dust than expected, though at least one jarring meteoroid impact was suspected during its journey through the interplanetary realm. All of this data would do much for better preparing future deep space missions.

The Last Days of Mariner

Though Venus would soon be well behind Mariner 2 as it plunged even closer to the vicinity of the Sun, its overall mission was hardly at an end. The probe continued to send back a stream of data about existence just beyond its metal skin, none of which had ever been examined directly before.

However, as Mariner 2 made its closest approach to the Sun two days after Christmas of 1962 at 65.5 million miles, the temperatures inside and outside the probe continued to rise.

On January 3, 1963, Mariner 2 had transmitted thirty minutes of real-time telemetry data to the monitoring station in Johannesburg, South Africa. The probe appeared to be functioning as well as it often had during most of the 129 days it had spent in deep space since leaving Florida the previous August. Mariner’s home planet was almost 54 million miles distant, while Venus was reduced to a brilliant white point of light in the perpetual night sky 5.7 million miles away.

Then Mariner 2 was heard from no more.

NASA JPL attempted to find the probe via its radio signal through August of 1963, but without success. In addition to its already vaunted legacy in the history of space exploration, Mariner 2 had transmitted over eleven million measurements while traversing 223.7 million miles of deep space during its known functional lifetime, a record not to be broken until the United States and Soviet Union began sending probes to the planet Mars in the next several years. Mariner 2 now orbits the Sun inside Earth’s solar circuit once every 345.9 days – silent, inoperative, and presumably largely intact.

Image: Mariner 2 celebrated at the Tournament of Roses Parade.

Oran W. Nicks, a man most personally invested in the early Mariner missions, eulogized the space probe in his work, The Far Travelers, thusly:

“Thus ended the saga of Mariner 2 – A robot, designed and directed by men, given a mission to extend the search for knowledge beyond the limited reach of Homo sapiens. Though it accomplished a voyage that was clearly “superhuman”, Mariner was a simple exploring machine, with only a very modest capability to perform on its own. A total of 11 real-time commands and a spare were possible, along with a stored set of 3 onboard commands which could be modified. Other functions, such as updating antenna position and adjusting thermal control louvers, were provided, but in every sense it was a simple robot with the capability for only a small amount of human interaction.

“From the meager information returned by telemetry, we know that Mariner 2 endured significant stress, but how many meteorite impacts it received and why it developed an ultimately fatal fever will forever remain a mystery. Perhaps in its passage from Earth to Venus and its transfer from orbit to orbit, it had other experiences which we will better understand when man repeats the voyage in person, with his own sensors and the additional capabilities that will exist at the time.”

The Legacy of Mariner 2

It is not an exaggeration to state that what Mariner 2 accomplished at Venus on December 14, 1962 changed the course of the American and Soviet space programs. When the intrepid probe reported back to humanity that what lay beneath the clouds of our neighboring world was anything but neighborly to all known forms of terrestrial life, the United States turned its planetary focus towards Earth’s other celestial neighbor, Mars.

Though almost no professional scientist of the early Space Age still looked upon the Red Planet as a haven for an alien civilization, many members of the relevant sciences did seriously think that Mars supported some form of simple plant life or perhaps even more complex creatures, albeit not highly intelligent. In addition, Mars looked much easier to land and maintain machines and astronauts upon compared to Venus. Now while NASA did not intend to stop exploring Venus altogether, being closer to Earth than any other planet in the Sol system was no longer good enough to devote a substantial amount of the space agency’s time, resources, and funds to that shrouded inferno. It was Mars that appeared to offer the best planetary return on their investment in terms of finding extraterrestrial life and founding permanent colonies.

Soviet space scientists had a decidedly different reaction to the findings of Mariner 2. Already invested in the concept of a Venus with a surface covered in some form of liquid, plus the indignity of being scientifically and politically trumped at once by their chief Cold War rival, the Soviet space agency was determined to learn the true nature of Venus for themselves. After all, Mariner 2 actually opened more key questions about the planet than it had answered, among them being: Exactly how dense was the atmosphere of Venus? What were the main constituents of the air? What did the surface of Venus really look like? In addition, the Soviets were far ahead of the United States when it came to developing and launching planetary landers, even if none had yet made it to the second planet from the Sun.

The years 1964 and 1965 saw America fling its next two Mariner probes away from the Sun towards the Red Planet. In the same time period, the Soviets hurled three more flyby probes and three more landing vehicles at Venus. While none of them achieved their intended scientific goals, suffering either from launch failures or overheating in space enroute, the Soviets were at least able to glean another planetary first in the Space Race from these efforts, specifically the first craft to land on another planet with Venera 3. Although the probe had stopped transmitting to Earth by the time it reached Venus in March of 1966, Venera 3 may have been functioning when it impacted on the night side of that world. Despite this technical achievement, the scientific questions about Venus left by Mariner 2 were still wide open.

Mariner 5: The Sequel

By the late 1960s, NASA was prepared to solve some of those critical questions about the second world from the Sun left open by the second Mariner. Taking leftover parts from the two 1964 Mariners they built for exploring Mars, JPL put together a single deep space probe they named Mariner 5.

Modified to survive in the much warmer vicinity of Venus, the fifth member of the Mariner probe series was lofted upwards on the night of June 14, 1967 from the same launch complex with the same kind of rocket configuration that its trailblazing predecessor had used almost five years earlier.

Meanwhile, just two days earlier on the other side of the globe, the Soviet Union had launched their latest effort to reach not just Venus but the very surface of the planet itself.

Named Venera 4 – once the probe had successfully escaped its Earth parking orbit – the nearly spherical landing capsule it carried strongly reflected the Soviet view of a liquid-covered planet: Not only could the one yard-wide capsule float, the probe’s makers also included with it a protective lock composed of sugar. Upon being dunked in the alien sea, the sugar lock would dissolve and release the probe’s transmitter antennae, which would send home the incredible news that Earth was no longer the only known world able to keep water in a liquid state on its surface. That was the expectation, at least.

As Venera 4 descended towards whatever fate awaited it on that distant realm dangling beneath a large parachute, the vessel’s scientific instruments would perform the first direct readings of Venus’ dense atmosphere. While some of the elements and molecules making up the planet’s air were already know to astronomers, exactly how much of each constituent was present and if any other kinds were waiting to be discovered remained a mystery as Venera 4 plunged through interplanetary space to Venus, with the American Mariner 5 probe following close behind.

Having been launched first, Venera 4 arrived at Venus one day ahead of its American counterpart on October 18, 1967. The entire probe sailed right into the planet’s night side. The main bus carrying the lander capsule conducted several scientific measurements of its own before its demise as an undoubtedly brilliant meteor far above the cloud deck.

In agreement with Mariner 2, the Soviet probe bus could find no evidence for either a magnetic field or radiation belts around Venus. What Venera 4 did discover was a weak corona of hydrogen particles sixteen thousand miles above the planet.

The automated capsule, operating on batteries with a 100-minute lifetime and drifting slowly downwards beneath a successive series of braking parachutes, began letting the scientists back on Earth know exactly what the Venusian air is made of: To their surprise, at least 93 percent of the planet’s atmosphere was composed of carbon dioxide, with nitrogen following at around seven percent and just traces of oxygen and water vapor. Many assumed nitrogen would have been the dominating element of that alien air as it is with Earth, but the reverse was true.

Venera 4 ceased transmitting 93 minutes into its mission. The last atmospheric pressure reading the probe reported was about 18.5 times what is experienced at sea level on Earth’s surface, not far from what the capsule was designed to tolerate. Since about 25 Earth atmospheres are what most contemporary scientists estimated about the density of Venus’s air, it was logical (and politically expedient) for the Soviets to conclude that Venera 4 had reached the surface of the planet while still transmitting data – yet another space first.

The next day, October 19, Venus received the other mechanical emissary of 1967 from the inhabitants of the third world from the Sun. Although Mariner 5 carried neither an imaging system nor its own lander capsule (the latter was considered but never implemented, as the probe was under tight budget and time constraints), the vessel would use its radio signal to greatly refine the then current information about the atmosphere of Venus. This revised data would also let the scientists on both sides learn if Venera 4 did indeed survive intact and functioning to the planet’s surface – or not.

Flying past the veiled planet much closer than Mariner 2 did at a distance of just 2,480 miles, Mariner 5 spent 26 minutes behind Venus as seen from Earth. As the robotic explorer was being eclipsed by the bulk of the planet, Mariner’s radio signals cut through Venus’ atmosphere on their way to Earth, revealing new details on that planet’s mantle of air.

The atmospheric pressure of Venus at its very bottom was much higher than the majority of scientists expected, ranging from 75 to 100 Earth atmospheres. There appeared to be two different cloud layers over Venus, one approximately 37 miles above the surface and the other at 31 miles in altitude. The global ground temperature was even higher than recorded by Mariner 2, approaching up to 981 degrees Fahrenheit. Tracking Mariner 5 also helped to refine the planet’s mass at 81.5 percent that of Earth’s. This meant that an object weighing one hundred pounds on Earth would weigh just nine pounds less on Venus.

Over the next two years, American and Soviet scientists met formally several times to discuss the data results from their indirectly joint space mission to Venus. The Soviets initially argued that Venera 4 could have landed on a very high mountain or plateau to account for their readings, but the Mariner evidence and later Earth-based radar observations showed Venus’ crust to be relatively flat overall. The conclusion was that Venera 4 had been crushed into radio silence by the increasing air pressure just sixteen miles above surface. Eventually the capsule would have landed on the face of Venus in any event, just not in working order.

The Soviets would eventually succeed in reaching Venus with a functioning lander and refine the planet’s air pressure and temperature even further. Venera 7 touched down on December 15, 1970 in the southwestern section of what would one day be called Tinatin Planitia. There the instrumented capsule spent the 23 remaining minutes of its working life letting scientists know that the temperature of its landing site averaged 887 degrees Fahrenheit, while about ninety Earth atmospheres of pressure weighed down upon its hull (the Soviets had designed Venera 7 to withstand double that amount, just to be safe). One would have to dive over three thousand feet beneath the oceans to find an equivalent natural pressure on Earth. Any lingering thoughts of a cool and watery Venus brimming with life were finally crushed with Venera 7, the first probe to transmit from another planet.

Venus Exploration Heats Up

The robotic exploration of Venus reached its peak in the 1970s and 1980s, thanks largely to Soviet efforts but also with several notable American missions in those same decades.

Between 1972 and 1985, the Soviet space program succeeded in landing eight more probes on our celestial neighbor. These technologically superior Veneras, while lasting no more than a few hours in the very harsh conditions of the planet, returned the first (and so far only) optical images of Venus’ rocky surface and the first data on the composition of the crust.

These Veneras revealed that much of Venus is covered in various types of basalt, a mineral produced by volcanic lava. The surface readings and images, along with other data returned by that generation of Soviet probes, gave a pretty clear indication that most of the face of the second planet has been long shaped by intense volcanic activity, past and very likely present. The images also showed that daytime on Venus is not as gloomily dim as thought and that atmospheric refraction turns the sky bright orange in color, compared to Earth’s blue skies and the salmon pink ones of Mars.

Image: Color images of Venus, first obtained by Venera 13 and 14.

The last two space probes in the Venera series remained in orbit about Venus upon their arrival in 1983 and conducted the most sophisticated radar mapping of the planet until the American Magellan probe arrived there seven years later. The Soviets also succeeded in placing two instrumented balloons into the atmosphere of Venus with the twin Vega missions in 1985. These balloons spent two days traveling over five thousand miles among the thick and turbulent cloud layers.

While not quite as ambitious as the Soviets, the United States did send several more space probes to Venus, among them the last of the robot vessels officially part of the Mariner series.

Although its primary goal was to become the first probe to flyby the planet Mercury, Mariner 10 utilized Venus for a historic first gravity assist to reach the world closest to the Sun. Launched from Cape Canaveral in Florida in November of 1973, the probe flew by Venus on February 5, 1974. Equipped with an imaging system, Mariner 10 proved that scientists could see physical features in the planet’s clouds, especially in the ultraviolet range of the spectrum. The visiting probe revealed that hurricane-level winds whipped the Venusian clouds around the planet in just four Earth days, much faster than the global rotation rate of over 243 days, which is longer than it takes for Venus to go once around the Sun!

Four years later, the United States lofted its own armada of Venus explorers towards the planet as the last official members of the Pioneer family of deep space probes. While one spacecraft would circle the planet and return the first radar map of its surface made from orbit, the other member of the fleet would drop four small probes onto the planet itself. They would directly examine the atmosphere from four different regions over Venus until impact with the ground.

Along with determining that Venus has three distinct cloud layers instead of two as indicated by Mariner 5 eleven years earlier, the Pioneer Venus Multiprobes greatly added to the planet’s reputation as a hellish place when it was realized they were plunging through an atmosphere saturated with droplets of sulfuric acid!

Although none of these drop probes were designed or expected to survive their encounters with the surface, one called Day did manage to keep functioning after its rough landing. The vessel transmitted for 67 minutes before being overcome by the intense heat of its surroundings. The Pioneer Venus Multiprobes were the first American craft to land on the veiled world and remain the only ones to do so to this day.

A Mariner Called Magellan

The last American robotic probe mission dedicated to the exploration of Venus was a spacecraft named Magellan. Other later deep space machines built and launched by NASA such as Galileo, Cassini, and MESSENGER would fly by and aim their scientific instruments at the second planet from the Sun in the 1990s and 2000s, but their ultimate goals lay elsewhere in the Sol system. For them, Venus was primarily a gravity boost to save on fuel and costs. Magellan’s focus was Venus, namely to radar map its entire surface in unprecedented detail.

Although Magellan was never officially listed as a member of the Mariner family of space probes, the automated craft did more than just emulate the spirit of the Mariners that went to Venus: Magellan was actually put together from the spare parts of previous space probes, including Mariners and their kin.

The main body of Magellan came from a spare bus of the Voyager probes, which famously explored the outer Sol system from 1979 to 1989 and are expected to keep returning data from the fringes of our planetary neighborhood until 2025. The twin Voyager craft were originally going to be known as the eleventh and twelfth Mariners until NASA officials wanted them to have what they considered to be a more dynamic nomenclature. Despite the change of labels, if one looks at the structural design of Voyager 1 and 2, it is not hard to see their Mariner family heritage going all the way back to the first two Mariner probes to Venus.

Other features that Magellan literally shared with the Mariner probes were the large white high-gain antenna that also came from the Voyager mission and a medium-gain antenna that was originally a spare for the Mariner 9 probe that became the first spacecraft to orbit Mars back in 1971.

Whether anyone considered Magellan to be an actual part of the Mariner family or not, the craft did honor to that historic legacy by revealing the face of Venus as never before from 1990 until its demise in the planet’s atmosphere in 1994.

Many thousands of volcanoes of wondrous variety cover the surface of that planet, an unknown number of which may be active at present. Lava channels thousands of miles long snake across the landscape. By contrast, no impact craters smaller than a few miles wide exist due to the very thick atmosphere preventing all but the largest planetoids and comets from getting through to the ground.

Image: Color information from the Soviet Venera landers and radar data from the Magellan spacecraft were used to construct this striking perspective view of the Venusian landscape. (In this computer generated image, the vertical scale has been exagerated.) In the foreground is the edge of a rift valley created by faulting in the crust of Venus. The valley runs all the way to the base of Gula Mons, a 2 mile high volcano seen here on the right, some 450 miles in the distance. On the left is another volcano, Sif Mons. Using radar to pierce the dense clouds continuously shrouding the Face of Venus, Magellan was able to explore over 98% of the Venusian surface, revealing a a diverse and tantalizing topography. Credit: The Magellan Project, JPL, and NASA.

The Magellan radar data also seems to indicate that the face of Venus is about 800 million years old – rather young in geological terms for a planet created about 4.6 billion years ago. While there seems to be no evidence for plate tectonics, the planet’s interior may erupt in massive lava flows onto the surface, completely reshaping it over and over. Scientists also wonder if Venus has a rotating iron core, a lack of which would explain the very weak magnetic field that was later discovered by probes with much more sensitive detectors than the early Mariners.

Venus Now and in the Future

Other nations have since gotten into exploring Venus with their own robotic probes. The European Space Agency (ESA) built their first Venus craft called Venus Express, which they based on the Mars Express probe design, equipped with seven scientific instruments and launched on a Russian rocket in November of 2005 to go into polar orbit around the planet the following April. The primary goal of Venus Express is to monitor the atmosphere for a long time period, at least through the end of 2014. Scientists also hope to use what they learn about the climate of Venus to better explain Earth’s atmosphere and climate and ensure that what happened to our neighbor does not happen to our world.

One interesting finding from Venus Express is that the second planet may have slowed down its rotation rate by over one minute since Magellan measured this activity in the early 1990s. Scientists think if this is a real phenomenon, then the high winds and other harsh conditions of Venus turgid atmosphere may make an important contribution to this relatively pronounced rotational slowing.

Japan is another nation with a long and vibrant space program which has attempted to send their first probe to Venus, which they call Akatsuki, the Japanese word for “dawn”.

Launched from Japan in May of 2010, Akatsuki was supposed to go into orbit about Venus that December, where among other things the probe would attempt to learn if the planet has lightning storms and if any of its many volcanoes are active. Unfortunately, something went wrong with the critical braking burn when the probe arrived at Venus and Akatsuki and its mission team found themselves adrift in solar orbit. The hope is that when Akatsuki comes into the vicinity of Venus in 2015, it can be placed into orbit around the shrouded world using a different set of rockets on the probe.

Image: Launch of the Akatsuki Venus Probe. Credit: JAXA.

Not all was lost with Akatsuki. Riding along with Japan’s first Venus orbiter was a satellite named IKAROS, which stands for Interplanetary Kite-craft Accelerated by Radiation Of the Sun. When IKAROS arrived at Venus just one day after Akatsuki’s less than triumphant attempt to orbit the planet on December 8, 2010, the sail craft successfully flew 80,000 miles past Venus and demonstrated the feasibility of solar sailing in interplanetary space.

Talk of future plans for Venus include balloon probes and landers with methods to extend their life on the planet into months instead of just days. Other talk includes nuclear-powered rovers, gondolas, and aircraft on and just above Venus. Even a surface sample return mission has been considered. When and if these and other missions come to pass in the next few years and decades is up to those in charge of humanity’s future in space.

Scientists have even shown some confidence in the last few years that life might exist on the hellish world of Venus after all. Certain layers in the Venusian atmosphere are rather mild in comparison to other layers of air above that planet. It is considered possible that colonies of microbes may live up there in the more biologically friendly zones, floating, eating, and reproducing on the winds. Others think that just below the roasting and crushing realm that is the Venusian surface, the temperature remains milder and fairly constant, a better place for native organisms. Perhaps certain space agencies will be intrigued and encouraged enough to test these theories by sending missions to Venus equipped to answer the questions about life on or maybe under that world.

As for future humans living on Venus, the planet would have to undergo some pretty sophisticated terraforming to make conditions comfortable enough for people to live on Venus without protective gear. One possible method for making Venus more like Earth is to strategically slam comets into the planet. They may be able to provide the water and other elements necessary to cool Venus down and thin out its acidic and roasting atmosphere. Properly directed comet impacts may also speed up Venus’ rotation rate, which at the moment is painfully slow. Genetic engineering and other future technologies may provide life forms that will hasten Venus’ transformation into a place terrestrial organisms could call home one day.

For those who want to see an actual rendition of the probe that started it all for deep space exploration, the Smithsonian National Air and Space Museum in Washington, D.C. has a full-scale model of Mariner 2 hanging from its ceiling, as shown in the image below:

The spacecraft on display was constructed from test components by engineers from NASA’s Jet Propulsion Laboratory. Until the day that someone goes out into interplanetary space and recovers the original Mariner 2, this replica made of actual test components will have to suffice for now.

No matter how far we eventually go into space, or what forms our space vessels may take as they evolve to handle the new and strange celestial environments they will encounter, they will all owe their existence and success to a rather primitive and ungainly probe named Mariner 2 that was first to succeed in exploring another world fifty years ago. And humanity will continue to be grateful for the vast amounts of knowledge that Mariner 2 and all its mechanical descendants have delivered to us about the amazing Universe we live in.


The Magicians of Confidence

Centauri Dreams regular Al Jackson responded to yesterday’s post about Neil Armstrong with reminiscences of the Apollo program, but because the first of these ran as a comment to the story, I was afraid a lot of readers wouldn’t see it — we have far more subscribers through RSS than any other medium, and many of them do not see the comments. When Al submitted a second comment, I decided to merge them into a single post here. The author of numerous scientific papers and a widely known figure in the interstellar community, Al saw the Apollo program up close as astronaut trainer on the Lunar Module Simulator. Here he talks about Armstrong and Aldrin and the antics of the crew that followed Apollo 11.

by A. A. Jackson

I spent almost 4 years in the presence of Neil Armstrong and Buzz Aldrin. I came to the Manned Spacecraft Center (MSC) in 1966, where I was placed as a crew training instructor. I had degrees in math and physics at that time. Seems engineers were pressed into real engineering work or had been siphoned off into the DOD. Spaceflight attracted a lot of physicists who could be put to work on all kinds of stuff.

It’s funny, I met Buzz first, I think as early as 1966. At MSC in those days I used to be in Bldg. 4 (my office) or Bldg. 5 (the simulation facility) in the evenings. Sometimes we worked a lot of second shift and I was unmarried at the time with a lot time on my hands. Anyway Buzz would come to Bldg. 5 to practice in a ‘part task’ trainer doing manual rendezvous , something he had pioneered. So I kind of got to know Buzz, but I can’t remember much but small talk and later talk about the Abort Guidance System which was my subsystem.

Image: Al Jackson (facing the camera at the main console of the Lunar Module Simulator) performing a checkout of LMS systems with his colleagues. Credit: A. A. Jackson.

When the Lunar Module Simulator (LMS) got into operation I started seeing Neil, but never talked to him much. Of all the Apollo crews Neil and Buzz were the most quiet. I remember the time when we had them in the cockpit from about 8am to nearly noon and they had not said anything for like 3 hours, someone wondered if we ought to go up and check if they were all right! I do remember Neil from the trips to MIT and TRW, to go to briefings on the Primary Guidance and Navigation and the Abort Guidance System.

I had seen Buzz do a little ‘chalk talking’ about technical stuff, but on the TRW trip Neil got up and gave a short seminar about rendezvous in orbit, some math stuff and all. He really knew his stuff. I remember being kind of surprised because I knew about Buzz’s doctorate in astronautics, but did not know Neil knew that much engineering physics. I do remember Neil coming to the LMS the morning after the Lunar Landing Training Vehicle crash, I think the backup crew were there, and them asking him how he felt and he said “O I’m just a little sore.” Actually he had bitten his tongue badly.

The Apollo 11 crew were the backup crew for Apollo 8, except for Fred Haise — that crew too could have been first on the moon. I puzzle these days whether Deke Slayton and higher ups arranged that it would be Neil and Buzz or not. All the astronauts I worked with were very unusual and able men… but Neil and Buzz had more than the Right Stuff, they were kind of magicians of confidence. It would be years before the astronaut corps had anyone quite like them.

You know working Apollo, nearly 24 – 7 for five years, in those days we had our heads down in the trenches, so it is strange to think back, a lot of odd things and lore escaped my attention. I was never a diary keeper, but wish I had been. I do remember how seat-of-the-pants everything was. Everything became much more formalized in the Shuttle Era and I was glad I did not stay in crew training for all but 5 years of my tenure at JSC.

It was the Apollo 12 crew who were the most fun. Pete Conrad was the most free spirited man I ever met. He bubbled with enthusiasm and humor, a thinking man’s Evel Knievel. He was an ace pilot who kept us in stitches all the time. Conrad and Bean spent a lot of time in the LMS (I think Neil and Buzz spent the most) and we instructors really got tired of wearing our headsets , so when crews were in the LMS we would turn on the speakers we had on the console since the crew spent most of their time talking between themselves. When Conrad was in the cockpit we had to turn the speakers off, since we would unexpectedly have visitors come by.

The reason why: Conrad, an old Navy man, could string together some of the most creative blue language you would ever want to hear. The main guidance computer aboard both the Command Module and Lunar Module was called the Primary Guidance, Navigation and Control System (PGNCS), but the crews called it the PINGS. Conrad never called it that. I can’t repeat what he called it, but he never, in the simulator called it that. The instructors remembered the trouble Stafford and Cernan caused on Apollo 10 with their language, and we thought lord! Conrad is gonna make even Walter Cronkite explode in an oily cloud! Yet on Apollo 12 he never slipped once, that’s how bright a man he was.

A month or two before Apollo 11 Conrad and Bean were in the cockpit of the LMS and John Young was taking a turn at being the pilot in the CMS (Command Module Simulator). We were running an integrated sim. Young had learned that the CM would be named Columbia and the LM Eagle. Conrad being his usual individualistic self said that must have pleased Headquarters. (Of course Mission Control needed those names when the two vehicles were apart for com reasons).

So Conrad could not resist. He told Bean and Young right then and there that they were going to name the CM and LM two names that I also can’t repeat. Bean and Young had a ball the rest of the sim giving those call signs, but that only lasted one day. Conrad, as you might suspect, never used the language in an insulting way or even to curse something — he was a very friendly and funny man. But it’s so second nature in the military to use language like that, and those Navy men, well, they never said “pardon my French!” Later the three Navy men (Conrad, Bean and Gordon) gave their spacecraft proper Navy names! Remember them?


On Neil Armstrong

“Neil Armstrong may well be the only human being of our time to be remembered 50,000 years from now.”

— J. G. Ballard, “Back to the Heady Future,” Daily Telegraph, 17 April 1993.

If anything, Neil Armstrong was almost too perfect for the role he played. If I had been asked to script the kind of character I’d like to have seen as the first man on the Moon, Armstrong would have walked into the role effortlessly, a quiet, even diffident man who had the courage to ride rockets. Flyers come in all descriptions, but those I used to hang around with in my own flying days (far tamer than any of Armstrong’s, to be sure!) were generally raconteurs, full of improbable tales that could never be verified, jongleurs seasoned in the arts of extroversion.

Not so Neil Armstrong, and therein lies the reason for my own sense of pride in the man and his accomplishment. July 20, 1969 was, inevitably, a hot day in St. Louis. I had driven to Webster Groves that afternoon to watch the moon landing with my future wife along streets that shimmered with heat. A native of the city, I was used to the humidity and it wasn’t because of it that my hands were sweaty. Like so many around the world, I was jacked up and nervous as a cat. We watched the landing to the sound of distant thunder, not learning until later just how pulse-pounding the actual touchdown became, though hearing about computer alarms during the descent made it clear this was one script that hadn’t proceeded precisely by the book.

Later that night, back at my own house after the first steps had been taken on the Moon, I looked at the LEM on TV and knew I was in the middle of history and that someday I would be explaining how it felt to my grandchildren. I slept little that night, my thoughts — now and then turning into dreams — playing the landing sequence over and over again. The next day, which was a Monday if memory serves, I drove downtown to buy tobacco at my favorite pipe shop and saw a huge banner draped across one of the buildings. Its words were simple: ‘We Made It!’ That sense of collective exaltation is something that’s hard to describe to those who weren’t fortunate enough to experience it. It transcended an Asian war and the era’s violent politics.

Image: A time like no other: Collins, Aldrin, Armstrong amidst an exultant crowd in August of 1969.

The details of Armstrong’s life are all over the media — this Washington Post story is a good summary, especially in its comment by James Hansen, who wrote Neil’s biography First Man (Simon & Schuster, 2005). Hansen’s take is that Neil didn’t want any part of what would surely have become blatant commercialism growing out of Apollo 11’s accomplishments. Thus the withdrawal from public life that grew out of the natural instincts of a loner. The analysis helps to explain a man some saw as mysterious and others as mythic.

He was both those things, of course, but like all human beings, he transcended easy description. Armstrong would become the space program’s Garbo, elevated and magnified by virtue of his very untouchability. I wondered last night what his final thoughts were as the end approached. Would he have played over in his mind the dramatic moments of July 20, 1969? Maybe, and that’s how it would probably be scripted in a movie. But it’s just as likely that what he was perceiving in those last moments was deeply personal, a childhood Christmas, perhaps, or a favorite song during flight training, or the face of a woman he loved.

None of us can know how anyone else approaches death, but we are all creatures of bone, sinew and nerve and we live the truest part of our lives in the kind of deep emotional privacy that Neil Armstrong came to exemplify. This quietly dignified man vaulted into prominence only to remind us that great achievement does not have to walk hand in hand with ego. Indeed, Armstrong’s legacy will couple the Sea of Tranquility with the collected bearing of an individual who never elevated himself over others, whose gift of focused passion offers deep truths in the meaning of courage and character.