Gallery: Space shuttle Discovery's non-human passenger

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

These aren't ray guns but tools that R2 expects to be using in space. One of the robot's principle tasks will be to assist astronauts during their space walks.

R2 does need to be dressed.

R2 can lift 20 pounds but NASA hopes testing at the space station will prove whether or not it can work with humans.

R2 has a cell phone but does it know how to use it?

Of course, R2 can text and Tweet according to NASA.

R2 is placed on a pedistal for testing.

Technicians are tweaking R2's robotic arm.

The long-range plan is to have robots like R2 land on hostile places and drive a buggy like this one called the Centaur 2.

R2 drives its buggy to the top of the hill.

At a NASA press conference R2 is the center of attention.

R2 steals the show from NASA deputy director Ellen Ocho.