Fishing on other worlds
Could space fishing be the answer to a low-cost sample-and-return mission?
Despite a raft of probes and landers reaching the surface of far-off planets, moons, asteroids and comets, nothing quite beats having extraterrestrial samples in your hands to analyse. However, the high cost this entails has been extremely prohibitive up until now. Scientists have had to be able to find a spot to land, touch down gently on the surface, collect samples and finally have enough fuel left to escape the gravity of their landing site. This takes time, precision and money, so the quest to find a practical way to collect samples cheaply has been a high priority for a long time. Enter Professor Robert Winglee and his team from the University of Washington, who have come up with the concept of fishing for samples in space.
The idea is beautiful in its simplicity – a probe would near an object of interest, open up a tube and fire a tethered rocket to the surface of the planet or moon. This would smash into the ground, and hopefully a few metres into it. The impact would force material through an opening in the top of the harpoon, where it would be stored. The device would then be reeled back into the probe, much like a fisherman would reel in a fish. This would then be safely stored until the spacecraft’s return to Earth, where researchers could analyse data with their own eyes, hands and instruments, rather than relying on machinery millions of miles away.
Apart from the advantage of returning data to scientists, there are a number of pluses to space fishing – mainly that the spacecraft would no longer need to land on the surface of the planet and get trapped in its gravitational field. This would mean an awful lot less fuel would be needed. Missions could be completed on a far smaller budget, or the spacecraft could travel much further before returning home.
The time taken to prepare for the mission would also be reduced, as a safe landing spot would not need to be found. The mission itself would be much quicker too, as the spacecraft would only be passing by a place of interest rather than landing, stopping, collecting and launching back home again.
The main challenge to Winglee and his team has been the construction of the rocket that gets fired into the surface of the planet or moon. It has to be phenomenally strong to withstand the force that will accompany the firing, as well as the impact as it attempts to burrow into its target. Currently it’s made of steel and is able to power through 1.8 metres (six feet) of concrete, but it will have much tougher material to get through than that in outer space. The inner casing of the craft also has to withstand a huge shock and stay intact, as it will be carrying valuable samples back to Earth.
The project is currently at the Phase II stage, meaning that NASA’s Innovative Advanced Concepts (NIAC) program is providing Winglee with a further £300,000 ($500,000) to enable him and his team to research this project for two more years, having already funded it so far. However, should the team succeed in their fishing mission, the financial saving and return for science on NASA’s investment could be huge.