More Treasures From Asteroids

The recent announcement of a potential NASA plan to robotically capture an asteroid, transport it to lunar orbit and use it as a target for a human expedition is amazing. Admittedly, it sounds more than a little crazy at first, but the mission plan is more realistic than some may suspect. It is technically feasible, but still advances technological development. It is practical and useful for scientific, engineering and industrial reasons. It's also feasible in the near-term, and would serve as effective stepping stone for more ambitious projects. The current NASA plan calls for capture of a small asteroid in 2019, followed by a human visit by the crew of an Orion capsule in 2021. It's possible that these target dates will not be met, but the overall structure of the plan looks good, and it should pursued and advocated. Hopefully this plan will come to fruition. It's probably the best plan for deep space exploration we have encountered in a long time. A basis for the plan is laid out in a recent report from the Keck Institute for Space Studies (KISS), and can be found online with a Google search. Some of the details in the KISS report have been modified in recent statements by NASA, and we can expect that the plan will probably evolve in the future. The KISS plan is filled with ideas for all the good things that astronauts can do when they finally reach the asteroid, such as taking samples, performing experiments and testing extravehicular procedures for working on small celestial bodies. If the plan goes ahead as advertised, it will be an outstanding mission. But this analyst is considering ways to add to the bounty. For obvious reasons, most of the human activity focuses on the asteroid. That's the way it should be, but mission planners could consider adding a few additional tasks. This would be icing on the cake for the mission, and it could broaden the appeal of the whole plan to areas beyond simply exploring and mining asteroids. Let's consider the first step of the mission. A large robotic space tug will fly into deep space to capture the asteroid, then steer it like a tugboat to a high lunar orbit. The mission will be conducted at a leisurely pace and could take years to complete its initial mission. The KISS report paints the capture/tugboat spacecraft as almost exclusively utilitarian, designed to retrieve the asteroid but not examine it. That's understandable when a crew of skilled astronauts is expected to follow in its wake. However, as the Apollo missions demonstrated, there's more to do in deep space than simply examine celestial bodies. Additional science and engineering can be performed, and the robotic tugboat is integral to these plans. This analyst proposes that a small experiment package should be attached to the exterior of this spacecraft. The experiments would travel into deep space for an extended period before they were finally inspected or retrieved by astronauts. Similar experiments have been performed by astronauts in the past on spacewalks to the exteriors of space stations. What would we send aboard the package? One option would be biological samples. Seeds, spores and microorganisms could be sealed in small vials and exposed to the harsh conditions of interplanetary space. Some could be protected from radiation and vacuum. Some could not. The results of these experiments could be useful for biomedical studies of astronaut health on long interplanetary missions and also for the rapidly advancing discipline of astrobiology. Materials could also be useful. Small patches and samples of foils, plastics and coatings that could be used on future spacecraft could be tested. A small collection panel could also sample dust and debris collected in deep space, as previous missions have done. These could be particles quite distinct from the collected asteroid. A compact panel containing these experiments could be easily bolted to the exterior of the spacecraft, together with a cover that could be hermetically sealed by a spacewalking astronaut. The panel could then be stowed aboard the Orion spacecraft for the return to Earth. A close engineering examination of the tugboat could also be useful. This could be done by simply parking the Orion spacecraft in close proximity to the tugboat and photographing its exterior with high-resolution cameras. How well has the spacecraft stood up to its epic journey in deep space? Has anything weathered or discoloured? How many hits from space debris have been sustained? Again, these are engineering questions that will be useful for future missions. By the time the mission is finally ready for launch, there will probably be numerous modifications, and some probably can't even be guessed at the present. There's a long way to go, but it's not too early to consider how we can make a great mission even better. Hopefully this plan will be more than just a great engineering study. We want to see it fly!