In an April 2010 speech at NASA's Kennedy Space Center, President Obama directed NASA to send astronauts to an asteroid as the next step in human spaceflight but that concept has evolved in the years since so instead of us going to an asteroid, we bring one here and send it into orbit around the Moon.
Recent NASA funding changes mean the project’s future now looks uncertain, but apart from the end of one of the coolest astronomical ideas ever, there’s still sound reasons for pressing ahead with it.
Once parked in orbit about the moon, the captured asteroid would provide an easily accessible target for a future crewed mission to practise landing on fast moving space boulders with an eye on asteroid mining but more importantly it provides opportunities to test ways of nudging asteroids out of their current trajectory which could be very useful when we find ourselves in the direct line of a lump of rock a few miles wide.
It would also be useful for working out how to extract water from asteroids and for hitching a ride by piggy backing on any set on a course of the far flung solar system.
If the NASA plan is in doubt due to cost, the European Space Agency and other nations should be chipping in and making it an international effort because it is something that we will all benefit from and it should not be left to whither away just because the USA alone are unable to fund it.