The last decade has seen NASA change tack quite a few times, mostly under the direction of different presidents who had very different ideas about how the venerable agency should function. Much of it came in the form of a lot of hand wringing about whether or not we should return to the Moon or simply go straight to Mars, with the current strategy to put NASA astronauts on our red sister sometime in the 2030s (although they might be too late if SpaceX has their way). This new direction included sending astronauts to a near-Earth asteroid by 2025 in order to vet some of the technology required to eventually send those astronauts to Mars and NASA has just detailed what that mission will be.
The initial mission was going to attempt to capture an entire asteroid, one around 8m in diameter, using an inflatable cylinder that would envelope the asteroid and then return it to a cis-lunar (between the Earth and the Moon) orbit. Now this wouldn’t have been a massive asteroid, probably on the order of 8m or so, but it still would have been a pretty massive endeavour to bring it back to a closer orbit. However there was another potential option for this mission: instead of retrieving the whole asteroid a probe would instead pluck a small boulder from the surface of a much larger asteroid and then return that back to the cis-lunar orbit. NASA announced today that the second option would be the one they’d pursue going forward with the mission timeframe still slated for sometime in the next decade.
Interestingly the second option is significantly more expensive, to the tune of $100 million, however the technology that will be developed to support it was seen as being of much more benefit than the other mission. Once a candidate asteroid has been selected the craft will be launched into orbit around it where it will identify and select a boulder for retrieval. It will then land on the boulder, capture it, and then lift it back off into orbit around the asteroid again. The craft will remain there for some time afterwards to see if the idea of a gravity tractor craft could work to divert a potentially dangerous asteroid from colliding with Earth. Then, depending on how successful that was, the craft will either remain there a little longer or begin the journey back towards earth, it’s newly captured asteroid boulder in tow. Then astronauts from Earth will embark on a month long mission to travel to the asteroid, study it and then potentially bring it (or at least samples) back to Earth.
It’s an ambitious mission but one that will be the proving ground for the vast majority of technologies required to get humans to Mars. Whilst we’ve learnt a lot about long duration spaceflights thanks to the International Space Station there’s a lot more we need to develop in order to support the same duration flights away from the protection of our Earth. Specifically this relates to the radiation shielding requirement (something which still doesn’t have a great solution) but there’s also numerous other questions that will need to be answered before we launch a craft towards Mars. A month to a nearby asteroid fragment might not sound like much but it will be another giant leap forward technology wise.
NASA is stil a far cry from its heydays during the cold war but its starting to rekindle that explorer spirit that drove them to achieve such great things all those years ago. Opting for the more ambitious mission profile means that our understanding will be more greatly increased as a result, hopefully fueling further exploration with a view to us one day becoming a multi-planet species. We’re still a while away from seeing this happen but it’s so good to finally see a light at the end of the tunnel.