For the first time ever an astronaut and a robot shook hands — in space. After nearly a year of assembly aboard the International Space Station, Robonaut 2 — or R2 as it's also known — underwent a series of performance checks, which were followed by a handshake with Commander Dan Burbank. R2 went in a little low, but Burbank says the handshake was "firm." The robot then followed the shake by saying "Hello world" in sign language. R2 has since been powered down and placed into storage, but after some additional tasks — including vision characterization tests involving R2's camera-equipped eyes — the robot will eventually be used to help the ISS crew with various tasks around the station. That is, when it's not too busy tweeting.