It's heartening to consider that the two Voyager spacecraft, though built for a 4 ½ year mission, have continued to function ten times longer than that. This fact, and data from other missions, will help us get a handle on longevity in spacecraft systems as we contemplate pushing out beyond the heliosphere with a spacecraft specifically designed for the job. Mission longevity is mysterious for it often seems to surprise even the designers, who would like to have a more concrete sense of how to ensure operations continue for decades. Voyager 2 broke Pioneer 6's record of 12,758 days of operation way back in 2012, but we can also consider spacecraft like Landsat 5, launched in 1984 and carrying two instruments, the Multispectral Scanner System (MSS) and the Thematic Mapper (TM). Managed by the U.S. Geological Survey (USGS), Landsat 5 completed over 150,000 Earth orbits and sent back more than 2.5 million images of Earth's surface, with operations lasting almost three decades. Design...

One of these days we'll have a spacecraft on a dedicated mission into the interstellar medium, carrying an instrument package explicitly designed to study what lies beyond the heliosphere. For now, of course, we rely on the Voyagers, both of which move through this realm, with Voyager 1 having exited the heliosphere in August of 2012 and Voyager 2, on a much different trajectory, making the crossing in late 2018. Data from both spacecraft are filling in our knowledge of the heliosheath, where the solar wind is roiled by the interstellar medium. A new study of this transitional region has just appeared, led by Jamie Rankin (Princeton University), using comparative data from the time when Voyager 2 was still in the heliosheath and Voyager 1 had already moved into interstellar space. Leaving the heliosheath, the pressure of the Sun's solar wind is affected by particles from other stars, and the magnetic influence of our star effectively ends. What the scientists found is that the...

The arrival of an apparent interstellar visitor, the comet now designated C/2019 Q4 (Borisov), invariably calls to mind the all too swift passage of 'Oumuamua through our skies in 2017. Detected 40 days after perihelion, the object was headed out of the Solar system when discovered, making observation time limited and the prospects of visiting it with a probe problematic. Nonetheless, Andreas Hein and colleagues at the Initiative for Interstellar Studies put out a mission concept we reviewed in these pages. To refresh your memory, see Project Lyra: Sending a Spacecraft to 1I/'Oumuamua (formerly A/2017 U1), the Interstellar Asteroid). Image: C/2019 Q4 (Borisov), in the center of the image. Note what appears to be a short tail extending from the coma. Credit: Gennady Borisov. The mission the authors described stretched the boundaries of the technologically possible, not to mention the resources that would be available for such an attempt. But now we have a second interstellar wanderer,...

You would think that heading toward the Sun, rather than away from it, would not necessarily fall under Centauri Dreams’ purview, but missions like the Parker Solar Probe have reminded us that extreme environments are ideal testing grounds for future missions. Build a heat shield that can take you to within 10 solar radii of our star and you’re also exploring possibilities in ‘sundiver’ missions that all but brush the Sun in a tight gravity assist. Or consider the two proposals NASA has just selected in the area of small satellite technologies, which grow directly out of its heliophysics program. Here, the study of the Sun’s interactions with the Solar System, and the consideration of Sun, planets and heliosphere as a deeply interconnected system, takes pride of place. Let’s start with a mission called SETH -- Science-Enabling Technologies for Heliophysics. One of its two technology demonstrators, called the HELio Energetic Neutral Atom (HELENA) detector, involves solar energetic...

Al Jackson shares more memories of Apollo this morning in his account of a little known spacecraft component, the Abort Guidance System. A NASA historical document on computers aboard the Apollo spacecraft refers to the Abort Guidance System as "...probably the most obscure computing machine in the manned spaceflight program to date." The AGS was a backup computer system offering the capability of aborting the mission if the Lunar Module's primary guidance system failed during descent to the lunar surface, ascent or rendezvous. The very invisibility of the system is in its way a tribute to the primary guidance and navigation systems, for while the AGS could abort a landing, it was never needed for that purpose. But NASA's abort policy made its presence mandatory -- an abort would be ordered if one additional system failure could potentially cause the loss of the crew. Thus a loss of either the primary guidance and navigation control system or the AGS would have caused an abort....

One of the many legacies of the Voyager spacecraft is the Interstellar Mapping and Acceleration Probe (IMAP). Scheduled for a 2024 launch, IMAP has as part of its charter the investigation of the solar wind's interactions with the heliosphere, drawing on data from an area into which only the Voyagers have thus far ventured. Let me hasten to add that IMAP will stay much closer to home, orbiting the Sun-Earth L1 Lagrange point, but like the Interstellar Boundary Explorer (IBEX), it will help us learn more about a region physically reachable only by long-duration craft. The fact that we're still talking about Voyager as an ongoing mission is the story here. Launched in 1977, the doughty probes have kept surprising us ever since. In terms of their longevity, I noted in 2017 that when Voyager 1's thrusters had begun to lose their potency (they're needed to keep the spacecraft's antenna pointed at Earth to return data), controllers were able to fire a set of backup thrusters that hadn't...

I'm staying in Apollo mode this morning because after Friday's piece about the Lunar Module Simulator, Al Jackson forwarded two further anecdotes about his work on it that mesh with the discussion. Al also reports that those interested in learning more about the LMS can go to the official Lunar Module familiarization manual, which is available here. I've also inserted some background on the LMS, with my comments in italics. by Al Jackson A couple of funny anecdotes about the Lunar Module Simulator. It took some effort to get the LMS up and running … we could do a little simulation when it was first installed, but I had a very irregular schedule. I always worked at the LMS crew training 8 am to Noon, but for most of 1967, because the crew did not train after 5 pm, I came many the night with the Singer engineers to test the LMS, sometimes 6 to midnight, sometimes midnight to 7 am, and yeah I had to stick around for the 8 am to noon shift, and then go home and sleep. There was a...

While compiling materials for a book on Apollo 11, Neil McAleer accumulated a number of historical items that he passed along to me (thanks, Neil!), and I'm thinking that with the 50th anniversary of the first landing on the Moon approaching, now is the right time to publish several of these. Centauri Dreams has always focused on deep space and interstellar issues, but Apollo still carries the fire, representative of all human exploration into territories unknown. In the piece that follows, Neil talked to Al Jackson, a well known figure on this site, who as astronaut trainer on the Lunar Module Simulator (LMS) worked with Neil Armstrong and Buzz Aldrin before Apollo 11 launched, along with other Apollo crews. McAleer finalized and synthesized the text, which I'll follow with a piece Al wrote for Centauri Dreams back in 2012, as it fits with his reminiscences related to McAleer. I've also folded in some new material that Al sent me this morning. by Al Jackson and Neil McAleer In the...

Recent tests of a 'wafer-craft', an early prototype for what may one day be the 'starchip' envisioned by scientists involved with the Breakthrough Starshot project, have been successful. The work grows out of a NASA-funded effort led by Philip Lubin (UC Santa Barbara), whose investigations into large scale directed energy systems began in 2009. Lubin went on to perform multiple studies for NASA's Innovative Advanced Concepts program developing the idea that would become known as DEEP-IN (Directed Energy Propulsion for Interstellar Exploration). His NIAC Phase 1 report studied as one option beamed propulsion driving a wafer-scale spacecraft. Renamed Starlight, the proposal went on to Phase II funding as well as support from the private sector. A subsequent review by Breakthrough Initiatives led to endorsement of the concept within its Breakthrough Starshot effort. Breakthrough is devoting $100 million to studying the viability of sending a 'starchip' to a nearby star such as Proxima...

The exuberance of images like the one below captures the drama of Solar System exploration. Scenes like this are emblematic of the early reconnaissance of the Solar System. We saw similar enthusiasm with missions near and far -- I'm thinking back, for example, not just to Voyager, but the Viking landings on Mars, and I'm sure Russian controllers were equally jubilant when their Venera craft touched down on Venus. Space is indeed the 'final frontier,' as James T. Kirk reminded us on Star Trek, and it's a frontier that goes on without end. Image: Celebration in full swing as scientists react to the view from New Horizons after the Ultima Thule flyby. Credit: NASA / JHUAPL / SwRI / Henry Throop. Let's keep in mind, then, that New Horizons is not just returning Ultima Thule data, but continuing to push into the Kuiper Belt doing good science. In terms of future missions, we need to learn as much as we can about radiation, gas and dust as we assess the environment. New Horizons will get...

We've just learned that New Horizons is intact and functional, with a 'phone home' message at about 1530 UTC that checked off subsystem by subsystem -- all nominal -- amidst snatches of applause at the Johns Hopkins Applied Physics Laboratory. The solid state recorders (SSR) are full, with pointers indicating that flyby information is there for the sending, even as the spacecraft continues with outbound science. New Horizons will pass behind the Sun in early January, giving us a break in communications for a few days this weekend. Over the next 20 months we will get the entire package from Ultima Thule. Patience will be in order. Here's the approach image that was released yesterday. Image: Just over 24 hours before its closest approach to Kuiper Belt object Ultima Thule, the New Horizons spacecraft has sent back the first images that begin to reveal Ultima's shape. The original images have a pixel size of 10 kilometers (6 miles), not much smaller than Ultima's estimated size of 30...

Despite the various governmental breakdowns attendant to the event, the New Horizons flyby of Ultima Thule is happening as scheduled, the laws of physics having their own inevitability. Fortunately, NASA TV and numerous social media outlets are operational despite the partial shutdown, and you'll want to keep an eye on the schedule of televised events as well as the New Horizons website and the Johns Hopkins Applied Physics Laboratory YouTube channel. Image: New Horizons' path through the solar system. The green segment shows where New Horizons has traveled since launch; the red indicates the spacecraft's future path. The yellow names denote the Kuiper Belt objects New Horizons has observed or will observe from a long distance. (NASA/JHUAPL/SwRI). We're close enough now, with flyby scheduled for 0533 UTC on January 1, that the mission's navigation team has been tightening up its estimates of Ultima Thule's position relative to the spacecraft, key information when it comes to the...

Voyager 2 has now gone interstellar, making it not only NASA's single longest-running mission but one of only two spacecraft that have crossed over from the heliosphere to true interstellar space, what scientists call the Local Interstellar Medium (LISM). On that note, it's interesting to put the Solar System in context. Depending on how you define the term, the Solar System takes in a great deal of interstellar space. Many astronomers put its outer edge at the outer Oort Cloud, perhaps 100,000 AU away, and both Voyagers have yet to reach the inner Oort. At an estimated 1,000 AU, the inner boundary of the Oort Cloud is where the vast cometary cloud around our star becomes apparent, housing in its entirety trillions of comets and extending about 40 percent of the way to the Alpha Centauri stars. The Voyagers will keep going, of course, and will reach the inner Oort in perhaps 300 years, though without working instrumentation. The steady diminishment of power from the crafts'...

I never saw the 2008 film WALL·E, which was all the rage not long after its release. A computer animated science fiction movie, WALL·E won a slew of awards including a Golden Globe for best animated feature, a Nebula for best script, and an Academy Award, as well as making Time's list of best movies of the decade. Bringing it to mind this morning, though, is the recent success of the InSight mission at landing on Mars, and the support technologies that flew with it. Thus the image below, which in its own way is iconic. It's from a craft nicknamed WALL·E after the star of the film, a CubeSat no larger than a briefcase that flew all the way to Mars in a seven month journey that demonstrated what miniaturized technologies can do. WALL·E is formally known as MARCO-B, the partner to MARCO-A (nicknamed EVE, another star of the film). Both these craft proved successful at their mission, which was to offer Earthside engineers the opportunity to monitor the InSight landing in ways that hadn't...

Over the sound system in the grocery store yesterday, a local radio station was recapping events of the day as I shopped. The newsreader came to an item about the Parker Solar Probe, then misread the text and came out with "The probe skimmed just 15 miles from the Sun's surface." Yipes! I was in the vegetable section but you could hear him all over the store, so I glanced around to see how people had reacted. Nobody as much as raised an eyebrow, which either says people tune out background noise as they shop or they have little knowledge of our star. The correct number is 15 million miles (24,1 million kilometers), and it's still a hugely impressive feat, but I hope the station got the story right later on. I go easy on this kind of thing because it's easy enough to make a mistake when reading radio copy (I've done this myself). Anyway, there is always some listener who calls it in, which I should have but didn't. I was pushed for time that morning, making choices about squash and...

As we continue to track the Voyagers into interstellar space, the spacecraft have become the subject of a new documentary. Associate editor Larry Klaes, a long-time Centauri Dreams essayist and commentator, here looks at The Farthest: Voyager in Space, a compelling film released last year. Larry's deep knowledge of the Voyager mission helps him spot the occasional omission (why no mention of serious problems on the way to Jupiter, or of the historic Voyager 1 photo of Earth and Moon early in the mission?), but he's taken with the interviews, the special effects and, more often than not, with the spirit of the production. That spirit sometimes downplays science but does give the Golden Record plenty of air-time, including much that was new to me, such as the origin of the "Send more Chuck Berry!" quip, John Lennon's role, NASA's ambivalence, and an odd and insulting choice of venue for a key news conference. Read on for what you'll see and what you won't in this film about our longest...

I want to talk about the Voyagers this morning and their continuing interstellar mission, but first, a quick correction. Yesterday in writing about New Horizons' flyby of MU69, I made an inexplicable gaffe, referring to the event as occurring on the 19th rather than the 1st of January (without my morning coffee, I had evidently fixated on the '19' of 2019). Several readers quickly spotted this in the article's penultimate paragraph and I fixed it, but unfortunately the email subscribers received the uncorrected version. So for the record, we can look forward to the New Horizons flyby of MU69 on January 1, 2019 at 0533 UTC. Sorry about the error. Let's turn now to the Voyagers, and the question of how long they will stay alive. I often see 2025 cited as a possible terminus, with each spacecraft capable of communication with Earth and the operation of at least one instrument until then. If we make it to 2025, then Voyager 1 would be 160 AU out, and Voyager 2 will have reached 135 AU or...

Last Monday's article on the Trillion Planet Survey led to an email conversation with Phil Lubin, its founder, in which the topic of Breakthrough Starshot invariably came up. When I've spoken to Dr. Lubin before, it's been at meetings related to Starshot or presentations on his DE-STAR concept. Standing for Directed Energy System for Targeting of Asteroids and exploRation, DE-STAR is a phased laser array that could drive a small payload to high velocities. We've often looked in these pages at the rich history of beamed propulsion, but how did the DE-STAR concept evolve in Lubin's work for NASA's Innovative Advanced Concepts office, and what was the path that led it to the Breakthrough Starshot team? The timeline below gives the answer, and it's timely because a number of readers have asked me about this connection. Dr. Lubin is a professor of physics at UC-Santa Barbara whose primary research beyond DE-STAR has involved the early universe in millimeter wavelength bands, and a...

The image below intrigues me. It's the first image of the Earth and the Moon together taken from a CubeSat, one of a pair of such tiny spacecraft NASA has despatched to Mars as part of a mission called MarCO (Mars Cube One), which will work in conjunction with the InSight lander. Taken on May 9, the photo was part of the process of testing the CubeSat's high-gain antenna. But to me it's a reminder of how far miniaturized technologies continue to advance. Image: The first image captured by one of NASA's Mars Cube One (MarCO) CubeSats. The image, which shows both the CubeSat's unfolded high-gain antenna at right and the Earth and its moon in the center, was acquired by MarCO-B on May 9. Credit: NASA/JPL-Caltech. As of this morning, we are 66 days away from InSight's landing on Mars, at a distance of 65 million kilometers from Earth and 16 million kilometers to Mars. I don't usually focus on Mars and lunar missions because this site's specialty is deep space, which for our purposes...