NASA has released new concept images and animations outlining one version of its plan to capture an asteroid with an unmanned craft and return it to lunar orbit for astronauts to study. The plan is part of an initiative by President Barack Obama for a US manned asteroid mission as outlined in his 2014 NASA budget request. The agency’s main objective at the moment is to come up with alternative approaches and evaluate them.
The purpose of the initiative is to gather more information on asteroids for mining, as well as learning more about how to divert potentially dangerous ones. It also provides the US manned spaceflight program with a new goal now that the International Space Station is completed and the Space Shuttle retired. The current program is still very much in the concept stage, but NASA has already come up with some broad outlines of what a mission might look like. Generally, it would be based on a solar electric propulsion system, the Space Launch System (SLS), and the Orion manned spacecraft, all currently under development
In the scenario presented by NASA, the SLS would lift a robotic asteroid redirect vehicle into orbit around the year 2025. This would then make a rendezvous with an asteroid using an ion propulsion drive (similar to that on the Dawn probe) powered by a solar array. Once on station, the vehicle would engulf the asteroid in a huge inflatable cylinder. Secured, the cylinder would collapse and cinch tight on the asteroid like a bag. The asteroid would then be despun and the ion drive used to redirect it to a stable, retrograde lunar orbit like a sort of interplanetary tug boat.
After the asteroid is in orbit, a Orion spacecraft with a crew of two would be launched, also using the SLS, and sent to the asteroid on a nine-day passage that would involve a slingshot maneuver around the Moon to place the craft in the correct intercept orbit.
At the asteroid, Orion would dock with the redirect vehicle and the astronauts would use a boom mechanism to go from Orion, past the redirect Vehicle and to the asteroid. The cocoon around the asteroid would have hundreds of metal rings, so the astronauts could secure themselves as they cut through the Kevlar-like fabric. They could then make observations and take samples for six days before returning to Earth after another ten-day passage and another lunar slingshot maneuver.
In July, a mission formulation review was undertaken to look at technical and logistical problems. NASA will host a workshop from September 30 to October 2 at the Lunar and Planetary Institute in Houston to further discuss ideas.
The NASA animation below outlines a possible asteroid mission scenario.