Why should we, as a race, support human spaceflight? This is one of the key questions hanging over the world's space agencies in these hard economic times. It turns out that one answer is very simple: to protect Earth from civilization-ending asteroid impacts .

Recently, President Obama spoke at NASA's Kennedy Space Center (KSC) to announce his new proposed direction for the US space agency: skip the moon, send man to a near-Earth asteroid (NEO) by the mid 2020's and use this new technological know-how to get humans to our ultimate goal — Mars.

Although the reasons for landing astronauts on asteroids are sound, NASA's proposed redirection has been met with fierce opposition. Most of this opposition is purely political, but the message is clear: We're no closer to replacing the space shuttle and there's no clear incentive to support an expensive manned space program. Just because we've proven we can live in space for long periods, for many policy makers, it doesn't mean we need to do it. Unfortunately, we probably won't understand the need to push into space until it is far too late . [ MSNBC ]