NASA's new asteroid capture mission, officially know as the Asteroid Initiative (AI), has gotten the cold shoulder from some scientists in the planetary community. However, if your research centers on the solar system's minor bodies, towing an asteroid into the Earth-moon system could be a bonanza. You get to meet an asteroid up close and personal. But, if you'd rather find life on Mars, there doesn't seem to be any obvious connection with the AI.
The technology that will be developed for pulling off the asteroid hijacking will no doubt have spinoffs. NASA will need advances in computer directed autonomous rendezvous, docking, and long-term electric propulsion capability.
A win-win for the planetary community would happen if the technology developed for the AI could be used for retuning rock and soil samples from Mars that might contain direct evidence for extraterrestrial life.
VIDEO: Four Biggest Asteroid Strikes Ever
A solar-electric powered clone of the asteroid retrieval vehicle could be dispatched to Mars to pick up and return rock samples to Earth. NASA's manned Orion vehicle would play a role in retrieving the samples from a lunar parking orbit and bringing them down to Earth. This would eliminate the payload penalty of launching and entire return canister to Mars with the ability of reentering Earth's atmosphere.
I think it might also mollify doomsayers who will inevitable get nervous about an automated probe returning a potential alien bug to Earth's surface. They would cite the crash-landing of NASA's Genesis sample-return capsule in 2004 as a precedent for the best plans going awry.