Having had to cut or freeze several NASA programmes due to budgetary constraints, Obama sought to reassure Agency workers that their jobs were safe by announcing a new awe-inspiring mission for the coming years: landing astronauts on an asteroid and the conquest of Mars.

This deserves a brief explanation:

NASA has admitted it no longer remembers how to lift a manned spacecraft off the surface of the Moon ... yet it is expected to make one land on and take off from Mars, which is even more difficult to do given the stronger gravity of that planet.

The new goal is to reach Mars by using an asteroid, and no longer the Moon, as an intermediate landing site. NASA could circumvent the obstacle of take-off by choosing a smaller asteroid that would have a much weaker gravity. That wouldn’t solve the problem of take-off from the Moon, let alone from Mars, but it would keep the Agency busy for twenty more years.