The space shuttle Discovery rocketed into Earth's orbit Thursday with a different kind of passenger that isn't human. It's a humanoid robot called Robonaut 2 or R2 for short and will be carried by Discovery astronauts to the International Space Station where it will reside in a container, likely for several months, until it is unpacked and assembled for testing. Here's more from NASA about R2.
Probably the biggest difference between R2 and the astronauts is that R2 only has a one-way ticket.
Photo credits: NASA