For the first time in space, a humanoid robot makes "a firm handshake" with an Earth man.

International Space Station (ISS) Commander Daniel Burbank on Wednesday became the first man to shake hands with a humanoid robot, which has been subjected to plenty of technical tests since it was launched into space to join Expedition 30 Commander Burbank and the crew of the ISS this time last year.

The tests have culminated to a 'man and machine' handshake, which Burbank described to be "firm."

The handshake happened after ground controllers uploaded software that enabled the robot to extend its right hand, an act that is recognized on Earth as a handshake offer.

Robonaut was launched in the shuttle Discovery to see how it could help NASA's missions in space.

In its Twitter profile, the robot describes itself as "a humanoid robot designed to work side by side with humans, or go where the risks are too great for people."

Robonaut, which is into microblogging, has made tens of thousands of followers on Twitter (@AstroRobonaut) by giving humans updates on its condition in the space.

Burbank was pleased with the humanoid milestone, and praised the programmers for an impressive work.

"For the record, it was a firm handshake. Very nice. Nice job on the programming and all the engineering," he said on NASA's video of the grand space event.