Space, at least the tiny area around our planet, is more accessible than ever thanks to a nascent boom in small satellites. While easy access to orbit has the potential to revolutionize all sort of fields from communications to agriculture, it has also increased the density of objects in low-Earth orbit and the attendant risk of collisions. In one well-known scenario called the "Kessler Syndrome," cascading collisions between space debris and satellites could turn orbit into a literal mine field, essentially closing off access to space (for a fictional depiction of the Kessler Syndrome in action, see 2013's Gravity.)
Tom Markusic, a propulsion expert whose resume includes time at SpaceX, Blue Origin, Virgin Galactic, and founding his current small satellite venture, Firefly Space Systems, thinks he has a solution for the growing threat of space junk. In short, he wants to recycle unused satellites cluttering up geo-stationary orbit above our equator by towing them to an entirely new planetary neighborhood to be born again as support equipment for missions to Mars and its moons.
You won't find mention of the project on Firefly's website or in any of Markusic's media appearances on behalf of the Austin startup, but over the past year he's been giving a talk called "Mars Now!" at conferences around the country. He proposes using solar electric propulsion-powered space tugs to capture spent satellites and transport them to Mars' over-sized asteroid moon, Phobos, transforming it into a staging base for a future human presence on Mars.
"We should build up a fleet of ion propulsion craft to start the process on Phobos," Markusic said during one of his talks last year.
He says geostationary satellites that go dark after their fuel is expended and are just left to drift endlessly still have functional equipment that can be utilized. Communications electronics, solar panels and thrusters are among the parts that could be salvaged for another mission, along with gold and platinum components, aluminum, titanium and empty propellant tanks that can be recycled.
Harvesting materials from dead satellites is potentially a much less expensive means of putting together support equipment for missions to Mars because it cuts out the costly process of getting materials off of Earth, which can cost up to $10,000 per pound according to NASA estimates. SpaceX and others are currently working to reduce that figure, but Markusic's approach to recycling space junk comes with the ancillary benefit of cutting down the risk of cascading Kessler-esque catastrophes that could set back space and other industries for decades.
The road between deploying robot recycling crews in orbit and setting up shop on Mars in Markusic's plan is a long one, however. The process of transporting spent satellite scraps to the neighborhood of Mars via solar-electric tug could take years in itself. Staging and resupply stops for crews headed to Mars also need to be setup along the way in orbit around the moon and on Phobos.
When everything is finally set, he thinks his plan could enable a mission to the surface of Mars lasting anywhere between 30-500 days on the Red Planet.
If it works -- and that's a big "if" since no one appears to be actively pursuing the plan at the moment, -- it could kill two very big birds with one stone by preserving operability in Earth orbit while also setting humans up to become a multi-planet species.
"Kids will see this happening," Markusic says. "It will engage people's imagination and create a momentum (towards getting to Mars) that I think would be unstoppable."