The Use of Extraterrestrial Resources to Facilitate Space Science and Exploration

by Paul Gilster on June 10, 2016

We get to the stars one step at a time, or as the ever insightful Lao Tzu put it long ago, ​”You accomplish the great task by a series of small acts.” Right now, of course, many of the necessary ‘acts’ seem anything but small, but as Ian Crawford explains below, they’re a necessary part of building up the kind of space economy that will result in a true infrastructure, one that can sustain the exploration of space at the outskirts of our own system and beyond. Dr. Crawford is Professor of Planetary Science and Astrobiology in the Department of Earth and Planetary Sciences, Birkbeck College, University of London. Today he brings us a report on a discussion of these matters at the Royal Astronomical Society earlier this year.

By Ian A. Crawford

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There is increasing interest in the possibility of using the energy and material resources of the solar system to build a space economy, and in recent years a number of private companies have been established with the stated aim of developing extraterrestrial resources with this aim in mind (see, for example, the websites of Planetary Resources, Deep Space Industries, Shackleton Energy, and Moon Express). Although many aspects of this economic activity will likely be pursued for purely commercial reasons (e.g. space tourism, and the mining of the Moon and asteroids for economically valuable materials), science will nevertheless be a major beneficiary.

The potential scientific benefits of utilising space resources were considered at a Specialist Discussion Meeting organised by the UK’s Royal Astronomical Society on 8 April. This meeting, which was attended by over 60 participants, demonstrated widespread interest in the potential scientific benefits of space resource utilisation. A report of the meeting has now been accepted for publication in the RAS journal Astronomy & Geophysics and videos of the talks are available on the RAS website.

The participants agreed that multiple (and non-mutually exclusive) scientific benefits will result from the development of a space economy, including:

  • Scientific discoveries made during prospecting for, and extraction of, space resources;
  • Using space resources to build, provision and maintain scientific instruments and outposts (i.e. in situ resource utilisation, or ISRU);
  • Leveraging economic wealth generated by commercial space activities to help pay for space science activities (e.g. by taxing profits from asteroid mining, space tourism, etc);
  • Scientific utilisation of the transportation and other infrastructure developed to support commercial space activities.

Specific examples of scientific activities that would be facilitated by the development of a space economy include the construction of large space telescopes to study planets orbiting other stars, ambitious space missions (including human missions) to the outer Solar System, and the establishment of scientific research stations on the Moon and Mars (and perhaps elsewhere).

In the more distant future, and of special interest to readers of Centauri Dreams, an important scientific application of a well-developed space infrastructure may be the construction of interstellar space probes for the exploration of planets around nearby stars. The history of planetary exploration clearly shows that in situ investigations by space probes are required if we are to learn about the interior structures, geological evolution, and possible habitability of the planets in our own solar system, and so it seems clear that spacecraft will eventually be needed for the investigation of other planetary systems as well.

For example, if future astronomical observations from the solar system (perhaps using large space telescopes themselves built and paid for using space resources) find evidence suggesting that life might exist on a planet orbiting a nearby star, in situ measurements will probably be required to get definitive proof of its existence and to learn more about its underlying biochemistry, ecology, and evolutionary history. This in turn will eventually require transporting sophisticated scientific instruments across interstellar space.

However, the scale of such an undertaking should not be underestimated. Although very low-mass laser-pushed nano-craft, such as are being considered by Project Starshot, could conceivably be launched directly from Earth, the scientific capabilities of such small payloads will surely be very limited. Initiatives like Starshot will certainly help to develop useful technology that will enable more capable interstellar missions later on, and are therefore greatly to be welcomed, but ultimately much more massive interstellar payloads will be required if detailed scientific studies of nearby exoplanet systems are to be conducted.

Even allowing for future progress in miniaturisation, a scientifically useful interstellar payload will probably need to have a mass of at least several tonnes, and perhaps much more (as I have discussed in this recent paper in the Journal of the British Interplanetary Society). Moreover, in order to get this to even the nearest stars within a scientifically useful timescale (say ≤100 years) then spacecraft velocities of order 10% of the speed of light will be required. This will likely require vehicles of such a size, with such highly energetic (and thus potentially dangerous) propulsion systems that their construction and launch will surely have to take place in space.

The potential long-term scientific benefits of an interstellar spacefaring capability are hard to exaggerate, but it seems certain that it is a capability that will only become possible in the context of a well-developed space economy with access to the material and energy resources of our own solar system.

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Bender772 June 10, 2016 at 13:14

Are there any fundamental physical limits to how big an optical space telescope could be? Given availability of cheap space resources and advanced robotic construction ability, could we build a 100km main mirror space telescope, to resolve about 3000 km wide features on a planet 30 light years away?

john walker June 10, 2016 at 19:05

Antoine Labeyrie has been working for years on a concept he calls hypertelescope. Here’s a grab from 20 years ago:http://articles.adsabs.harvard.edu/full/1996A%26AS..118..517L

Michael T June 11, 2016 at 9:10

I would love to read this, bur sorry that link seems to be incomplete and doesn’t work.

Michael T

Michael June 11, 2016 at 13:50

Copy it all up to 517L and then pasted it into the web section, mine worked but the link did not.

Christopher Phoenix June 13, 2016 at 17:11

This is a question that intensely interests me as well. Sten Odenwald addressed this question in his book, The Astronomy Café, which was what first introduced me to the idea of hyper-resolution astronomy. Ironically, it was in the section devoted to questions that interest Mr. Odenwald but no one ever thought to ask him.

Sten discussed things in terms of maximum available resolution. If I recall correctly, one micro-arcsecond technology would allow us to see planets orbiting other stars as clearly as we can now see Jupiter with a six-inch telescope. One nano-arcsecond would allow us to map planets orbiting Alpha C with as much detail as Magellan saw Venus, and could resolve the disks of stars and spot Jupiter-like worlds in the Andromeda Galaxy.

There are major difficulties with developing instruments capable of doing this, but even the lower end of this scale portends a view of the universe we can hardly imagine today. One micro-arcsecond imaging technologies will someday allow us to map the nearer exoplanets even before our first probes can reach them to study them up close.

All the same, no telescope will ever be able to gather even a fraction of the information a probe or astronaut can gather in-situ. A solar-system based telescope may someday map the continents of a nearby exoplanet, but it will never see microorganisms swarming in an alien pond. A field microscope could do so easily. In the long run, we will have to get there… somehow.

Hop David June 10, 2016 at 15:57

I fully agree that a space economy is a prerequisite to getting to the stars. I like it that the four entities listed are targeting the moon or near earth asteroids. If we successfully achieve a return on investment, expansion into space will occur as a matter of course. Until then, government programs won’t have adequate funding to achieve settlement of space.

While necessary, I’m not sure it’s sufficient. Sunlight falls with inverse square of distance from the sun so it will be harder to harvest solar energy as move into the outer solar system. I think the Main Asteroid Belt is close enough we could build mirrors to concentrate sunlight. I suspect to settle the Kuiper Belt and Oort we would need fusion power (manmade, not from the sun).

Alex Tolley June 10, 2016 at 16:09

I think this is where power beaming technology makes sense beyond just pushing spacecraft or transmitting power from SPSs to earth. With relatively cheap, scaled facilities, it should be possible to beam power efficiently to the outer solar system, rather than trying to generate it locally.

Hop David June 11, 2016 at 11:00

Even with lasers you have power density falling with inverse square of distance. And the power beaming stations in the inner solar system as well as the receiving stations in the outer system are both constantly moving.

I know I wouldn’t be comfortable relying on a power source 30 or 40 A.U. away.

Michael June 13, 2016 at 13:56

We could also use particle beams, not only can they transmit kinetic energy they can also transmit fuels such as nuclear and chemical energy and they can also transmit information.

Alex Tolley June 10, 2016 at 16:17

Privat5e scientific research is likely to be prodigious with commercial space activities as part of their R&D. The problem is that this may remain private rather than public. It would be good if there was a way to incentivize transferring at least some of it to the public domain, rather than only disseminating it commercially, via products and services.

R&D should also encapsulate knowledge in products, and it will be a great benefit if these products allow cheaper exploration and settlement of space. I can see a future of branded “life support systems in a box”, sold by a number of competitors. Also off the peg spacesuits tailored for different environments, all in your choice of color, pattern, and style.

Andrew Palfreyman June 10, 2016 at 17:03

When it comes to considerations about interstellar ventures, it sharpens the mind wonderfully to have a clear destination in mind. Despite the recent cornucopia of exoplanet discoveries, what is missing is a catalogue of exoplanets that are both reasonably close by, and whose atmosphere, if any, is understood to some degree. Without any atmospheric characterisation, every one of the roughly earth-sized habitable zone exoplanets discovered to date, or to be discovered in the future, may well be either a Venus or a Mars.

I believe missions are planned to address these concerns.

Hop David June 11, 2016 at 11:08

If we expand into the solar system as the O.P. suggests, we will be paraterraforming the new real estate.

In many ways paraterraforming small bodies is much easier than the deep gravity wells. The asteroids and KBOs represent much more real estate and available resources than the thin outer crusts of rocky planets and large moons.

By the time we fill our solar system, planetary chauvinism will be a quaint notion from ancient history.

Christopher Phoenix June 14, 2016 at 1:40

>In many ways paraterraforming small bodies is much easier than the deep gravity wells. The asteroids and KBOs represent much more real estate and available resources than the thin outer crusts of rocky planets and large moons.

For the people back home in the solar system, maybe. But for the starship crew it will be much easier to survive on a planet with a thick atmosphere and gravity well. Paraterraforming is a fairly massive technology-heavy effort, and one that requires continual effort. If you give a moon-sized body an artificial atmosphere, you must continue to replenish it as the gasses inevitably escape into space. Giving it that atmosphere in the first place will require some serious industrial effort.

In the solar system, we will have space infrastructure and support from nearby Earth to get these efforts started. Even in the best of cases, a pioneering starship will have a much smaller population, arrive with diminished resources, and cannot rely on support from home. Even entire skill-sets may be lost in transit. The crew of an arriving starship probably won’t be in any position to begin paraterraforming.

Furthermore, they will not be able to use technology that they do not have the resource and skill base to support. It’s quite possible they could be forced to rely on a much more basic tool set than their ancestors built their starship with. It’s possible that entire skill-sets may be lost in transit, and even if the crew knows in theory how to create certain technologies, they may simply not have the tools and resources they need to create them. The problem with space habitats is that they do not permit you to survive with anything but a high level of technology. A paraterraformed moon’s atmosphere may last for a while, but if you lose the capability to maintain your atmosphere, you will be trapped on a slowly dying world.

Keeping all this in mind, I argue that we should not dismiss Earth-like exoplanets as our primary target for crewed starships. By their very existence, they will offer us a potential zone of habitability that does NOT require a constant high level of technology for us to survive. A starship could arrive in quite scrappy condition after centuries of maintaining a habitable environment in space. Having somewhere to go will make all the difference.

Habitable in this case does not have to mean “having a breathable atmosphere”. Just having a gravity similar to Earth, temperatures in the range for liquid water to be present, and an atmosphere and oceans would be quite inviting. No spacesuits or pressure vessels would be required. “Terraforming” such a planet could just mean introducing algae and planet life, not trying to maintain a livable environment on a celestial body that cannot naturally support one.

Grandiose schemes to terraform or paraterraform planets and moons are fine when you have the resources of a solar system wide infrastructure behind you, but not for lone starship crews!

Christopher Phoenix June 14, 2016 at 1:40

In many ways paraterraforming small bodies is much easier than the deep gravity wells. The asteroids and KBOs represent much more real estate and available resources than the thin outer crusts of rocky planets and large moons.

For the people back home in the solar system, maybe. But for the starship crew it will be much easier to survive on a planet with a thick atmosphere and gravity well. Paraterraforming is a fairly massive technology-heavy effort, and one that requires continual effort. If you give a moon-sized body an artificial atmosphere, you must continue to replenish it as the gasses inevitably escape into space. Giving it that atmosphere in the first place will require some serious industrial effort.

In the solar system, we will have space infrastructure and support from nearby Earth to get these efforts started. Even in the best of cases, a pioneering starship will have a much smaller population, arrive with diminished resources, and cannot rely on support from home. Even entire skill-sets may be lost in transit. The crew of an arriving starship probably won’t be in any position to begin paraterraforming.

Furthermore, they will not be able to use technology that they do not have the resource and skill base to support. It’s quite possible they could be forced to rely on a much more basic tool set than their ancestors built their starship with. It’s possible that entire skill-sets may be lost in transit, and even if the crew knows in theory how to create certain technologies, they may simply not have the tools and resources they need to create them. The problem with space habitats is that they do not permit you to survive with anything but a high level of technology. A paraterraformed moon’s atmosphere may last for a while, but if you lose the capability to maintain your atmosphere, you will be trapped on a slowly dying world.

Keeping all this in mind, I argue that we should not dismiss Earth-like exoplanets as our primary target for crewed starships. By their very existence, they will offer us a potential zone of habitability that does NOT require a constant high level of technology for us to survive. A starship could arrive in quite scrappy condition after centuries of maintaining a habitable environment in space. Having somewhere to go will make all the difference.

Habitable in this case does not have to mean “having a breathable atmosphere”. Just having a gravity similar to Earth, temperatures in the range for liquid water to be present, and an atmosphere and oceans would be quite inviting. No spacesuits or pressure vessels would be required. “Terraforming” such a planet could just mean introducing algae and planet life, not trying to maintain a livable environment on a celestial body that cannot naturally support one.

Grandiose schemes to terraform or paraterraform planets and moons are fine when you have the resources of a solar system wide infrastructure behind you, but not for lone starship crews!

Giuseppe Proietti June 15, 2016 at 13:23

In my opinion in the case of a starship coming in a new solar system we should not consider a limited number of colonists as a limit.
We must take in count technology advancements like auto-replicant machines and artificial intelligence.

Auto-replicant machines can help to build a strong infrastructure, specially in case of they are able to use asteroids as resources for their first phase develop and later on landing to a terrestrial planet for a second phase where terraforming will start by use of the same technology plus introduction of terrestrial species like algae and plants.

So, a limited resource starship which includes an auto-replicant machines technology and a complete knowlegde database may permit the development of a complete colonized extra-solar system in the time scale of some centuries.

Astronist June 10, 2016 at 18:50

Ian, your JBIS paper is interesting, and repeats in more detail what you were saying at the Starship Century meeting in London in October 2013. A useful reminder that miniaturisation of the payload can only go so far.

Clearly, the first step on the way to using the resources of the Solar System is to reduce the costs of launch into space. It is very disappointing that Europe, with the exception of the private UK firms Reaction Engines and Bristol Spaceplanes, seems to have decided to leave this work up to America. I hope you will be able to point this out in European forums that discuss how to make progress in space!

Stephen
Oxford, UK

tchernik June 10, 2016 at 19:29

I like this kind of post, talking about what can happen now or in the short term, in our way to the stars. We probably won’t be seeing any such mission in our lives, even less going there ourselves, but we may witness the start of it.

And let’s admit it, it will be quite fun to watch how humans start going into the Solar System for commercial purposes, generating some branches of life and civilization in space along their trips.

Also the great concepts of interstellar travel are wondrous and amusing things to think and talk about, but in the end, it all reduces to how are you going to build the starships and how and who is paying for them. Currently any such undertaking would demand unrealistic amounts of money and resources, always better spent on Earth.

Unless placing the required parts and machinery in space isn’t that expensive or complex anymore, because we have already placed a whole ecosystem of extraction, refining, production of goods and assembly of complex machinery out there. If we had an industrial civilization with full production cycles and people living in the Solar System, making a starship would still be a great project, but certainly not an impossible one.

And the only way to make such a thing possible, passes through developing a solid economy in space with small steps now. With things like launchers and mining space drones/factories being paid by customers, making some gain in return.

Exploration of space can very well pay for itself. Because there is no conflict between mining an asteroid and seeing how it’s made; and between understanding how we can build a production chain of refined/complex products up there, how to make it as efficient and automated as possible and using that knowledge to assemble a realistic starship and remain within our budget and means.

But, don’t get too pragmatic and commercial either: even if we go to the Solar System for business and settlement, it doesn’t mean we will automatically start feeling motivated to build starships shortly thereafter.

We can have a bustling economy and plenty of room for expansion in the Solar System for millenia, without ever venturing outside of it. The Solar System is Big, and it seems there are many worlds and worldlets in the outskirts of the Sun’s domain. Enough for keeping us busy for a long, long time.

The drive

Hop David June 11, 2016 at 11:22

“The Solar System is Big, and it seems there are many worlds and worldlets in the outskirts of the Sun’s domain. Enough for keeping us busy for a long, long time.”

Indeed.

Should we expand into the Oort, that will change the paradigm of star ships. One of the major stumbling blocks to a generation star ship is establishing self sufficient city states that can endure for millennia while cut off from the rest of humanity.

Well, unlike the inner solar system, the Oort bodies are farther apart and essentially isolated. Inner system bodies can rely on trade between neighboring asteroids and rocky planets and large moons. That’s less of an option in the Oort. So if we expand into the Oort, self sufficient city states will come to pass as a matter of course.

But self sufficient biomes is only one of the stumbling blocks for reaching other solar systems. Achieving the necessary delta V is another (huge) obstacle.

Michael T June 10, 2016 at 21:44

The requirement for large interstellar probes (vs the minute ones of Starshot) mentioned in this post, again brings up the idea of sending small devices via the Starshot system, but of coordinating them at their destination. Could we also physically join them at the destination to make larger functional structures? Maybe even make something that can synthesise other large things there (similar to Von Neumann probes).

Michael T.

Michael June 13, 2016 at 12:55

If we had radioactive fragment films on each sail to move them about i see no problem bringing them together over time, could be used to make a very large scope if say they are hexagonal.

david lewis June 13, 2016 at 17:47

I wonder how well we’ll handle pollution in space. Creating a space-based economy will mean a lot more satellites and such, which will increase the chances of Kessler’s Syndrome taking place. If that occurs then we lose everything in earth orbit at that time, and could be barred from operating in space for decades.

I’m sure we could adapt to life without satellites through using high-altitude balloons and solar-powered drones for wireless communications and earth observation. But after such an event, what then would be the motivation to return to space? The facilities we use for launching rockets would have been neglected for decades with the cost to rebuilt them being astronomical. The same with facilities for building those rockets.

As for taxation, how do you tax an organization that’s based in space? I expect we would see very little revenue from them as what little of their infrastructure remains on earth moves to locations with the lowest taxes. Heck, with 3D printing they might move to international waters and build rockets and such out there.

Here’s to hoping we can take that next step to being a space-faring species, but I expect there’re quite a few filters ahead.

Christopher Phoenix June 13, 2016 at 17:52

I definitely agree with Mr. Crawford that in the long run, we need payloads massing tonnes or more to get useful data return. Things like Starshot will help open the way, but the data micro flyby probes can gather is limited. And, obviously, sending humans to the stars will require ships massing thousands of tonnes or more.

Such craft will be built on such a scale and make use of such energetic and dangerous propulsion systems that we cannot launch them from Earth. Even building starships in sections and launching them piece by piece (like the current ISS) is probably impractical. Furthermore, the energy resources required by a starflight program may simply outstrip what we can gather on the Earth. This makes a mature space infrastructure a prerequisite for a robust interstellar exploration effort.

Consider raw materials. It will be much easier to source raw materials from the Moon, which has a much smaller gravity well. Instead of rockets, a mass driver could be used like was suggested for constructing O’neill colonies. Another possibility is a space elevator, which could be built on the Moon using modern materials. Asteroids are another vast source of minerals. Perhaps a starship could be built near Ceres instead of in the Earth-Moon system.

Energy resources are also abundant in space. At Earth’s distance from the Sun, every square meter of surface receives 1.4 kilowatts of power from sunlight, which can support many industrial activities. The magic of the inverse-square law allows us to intercept greater amounts of energy the closer we get to the Sun. Solar arrays in close orbit around the sun might someday capture enormous amounts of energy for our projects in space.

This is significant, since interstellar travel requires vast energy supplies. Whether we beam the energy to a sail of some sort or use it to power an antimatter factory, capturing even a minute fraction of the 384.6 yottawatts released by the Sun will liberate us from the Solar System.

If we use more traditional nuclear rockets, we will still require vast amounts of nuclear fuel and propellant. The Project Daedalus designers found the question of fueling their behemoth probe to be a thorny problem. They turned the outer gas giant planets as a promising source of the required Helium 3. Mining the outer planets and exporting fusion fuel requires a very mature space infrastructure.

It is pretty clear that we will have to have a mature space infrastructure in place in this solar system before we venture to other solar systems. That infrastructure will probably be built with other ends in mind (commercial activities, space colonization efforts, etc.), but by following this path current space programs and corporations will build the springboard from which we can someday depart for the stars.

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