Space Resources

Right now the most valuable and scarce resources in space are the RF spectrum and geosynchronous orbital slots. In this introductory post, I'll talk about other resources found in space which companies have yet to profit from, such as ice and solar energy.

Solar Energy

There is abundant supply of solar energy in space (duh), and there is ample demand for remote energy transmission to tactical locations on Earth for military and civilian purposes. The military use cases are obvious, but the civil opportunities which excite me the most, like a hybrid gas/solar electric trans-pacific airliner powered in part by an intense laser beam which tracks the vehicle through the stratosphere. If you could supply energy to any point on the globe, people would buy it.

The concept of space-based solar power transmission has been under heavy research since 1976 but has always been one of those "in five to ten years" technologies. What is the hold-up?

  • Transmission efficiency? Probably not, since we have been able to get 45% efficiency since 2002.
  • Global coverage for non-stop service? No, we have been able to provide global radio for decades.
  • Build and launch costs? This is probably the major concern. How massive do the solar arrays need to be, and how do you fit them inside a typical 4-5 meter launch fairing? If only someone had a plan to make this happen more cheaply... (look for a future post on this topic)

Of all the resources we will mention in this post, solar energy is the most readily usable resource. All it takes is an active pointing receiver and a decent battery, and boom you have a 5-meter-diameter power plant in your back yard. Incipient capability with emergent benefits is I think how the comb-overs describe it.

Ice (and Water)

You can find ice in the permanently shadowed areas of the Moon's polar craters and probably in some asteroids and definitely in comets. Water exists in several forms on Mars. H₂O is valuable as source of hydrogen and oxygen to create rocket fuel and for life-support systems in human missions.

You can't just buy a rock hammer and a pair of Levi's to bootstrap your ice mining operation, unlike the gold rush of the 1800's. Our ability to mine, refine, sell, and use products derived from space ice is non-existent today, and I expect the cost of building this infrastructure would include the following components.

  • Cheap, disposable prospectors are needed to locate usable ice deposits
  • Mining robots
  • Ice storage facilities
  • Refineries
  • Fuel storage facilities with minimal leakage or out-gassing
  • Vehicles to transport the fuel to the customer
  • Customer vehicles which can accept fuel from you
  • The command and control ground services for remote operation from Earth for all of these parts

It may be far off at this point, but I don't think I've seen a mission architecture to put humans on Mars that doesn't use water and ice to create additional rocket fuel for the trip there or back. Until the cost of building the infrastructure comes down, I think we will be stuck with sending up fuel from the Earth.

Platinum Group Metals

Who knows how much valuable gold and platinum there is on near-Earth asteroids. The idea behind mining this space resource is to send it back to Earth to become instantly rich, which is a way simpler plan than trying to refine ice into fuel and sell it to non-existent customers. But still this concept is only in the power-point stages of infancy. What is the hold-up?

  • Prospecting gold? Should not be an issue since we can identify candidate asteroids with telescopes from Earth, and then companies like Deep Space Industries have designed small spacecraft which they plan to send to investigate the top picks.
  • Bringing back the gold to Earth? Nope, we can get some pretty big people back to Earth from space, so it would probably be doable to bring back about a thousand pounds of gold, worth about $1 billion, in a single trip.
  • Building an asteroid drill? Probably not a big challenge for engineers, though the limiting factor might be power availability.
  • Refining the gold in space? Probably a big hurdle. You don't want to be bringing home worthless rocks, so you need a way to isolate and separate the gold.
  • Regulations and politicians? Not any more. There is language in the US Space Act of 2015 which allows companies to own and sell space resources, which I personally think is in violation of the Outer Space Treaty of 1967, but that's a topic for another post.

I think we will either see a surge of interest in gold or a sharp decline, depending on the results of the first prospecting missions.

Rocks and Dirt

Though you wouldn't want to bring rocks and dirt back here to Earth, you can use rocks and dirt on the Moon and Mars to make concrete for buildings, landing pads, and other planetary infrastructure needs. Once again this is a resource which is included in every single human mission to Mars and the Moon, but since either of those destinations are a little out of reach at the moment we'll just mention it with a playful air of imagination and creativity.

  • "Laser sintering of lunar regolith" is a process by which you melt Moon dust into hard surfaces, creating landing pads and sidewalks for a Moon village.
  • Similarly, you could use solar ovens to sinter and anneal lunar regolith into bricks to construct thick-walled buildings with ample radiation shielding for human occupants.
  • There is an ongoing competition for the best idea to print houses on Mars, and many of the concepts use regolith as feed stock.
  • And more! Everybody has an idea, but they're all dreams until we make advances in the areas which actually do matter: heavy lift rockets and systems to land lots of mass on the Moon or Mars.


The conclusion I would like to leave you with, which may be different than what you actually take away, is that the only feasible resource to use in the near term is solar power. It's the only capability with a clear and achievable path towards profitability due to the large amount of potential customers, both in space and on Earth. For the other resources, their place is still in presentation slides around the world, though I think things will change with the availability of more heavy-lift rockets.

See you next time, and please get in touch on facebook or linkedin if you'd like to talk to me about what I think an achievable system for space-based solar power looks like.

© Peter Brandt 2019 | all images in public domain unless otherwise stated