kerbal space program

Via Engadget:

The first public version of the spacecraft building game was released in 2011, and it's been in a rough state ever since. At last, though, it's officially ready for action -- the developer has revealed that KSP 1.0 will be available on April 27th. This polished version will be very familiar if you've tried pre-release code on your Mac or Windows PC, although that's not a bad thing. As before, your only real goal is to explore the Kerbals' solar system using the best rockets, landers and probes that you know how to make, with (mostly) realistic physics...

They're special talent is Kerbal

Yeah, that Kerbal Space Program. The little space flight simulator with the tiny green men. According to a profile in Polygon,

Beneath its childish surface lies a complex physics system churning through mathematical calculations so expertly, real rocket scientists would blush to see it. KSP has even earned the respect of NASA — many of its employees play it regularly.

These past few months the team at KSP and the team at NASA have developed a professional, although distant, relationship. And this year they will begin to work together.

Soon the Kerbals will embark on the next phase of space exploration, more than a decade before their real-life human analogues. NASA hopes to land humans on an asteroid by 2025. It's their most daring mission in a half century, and they've asked the small team of eight developers headquartered in Mexico City to help promote that mission through their game.