NASA scientist isn't impressed with the new 'Star Wars' droid BB-8

BB-8 may look cool, but R2-D2 and C-3PO are the most plausible of the "Star Wars" drones, says Brett Kennedy, a roboticist at NASA's Jet Propulsion Lab.

In a video for Wired, Kennedy compares the three droids to NASA's robotics.

Kennedy says the physics behind BB-8 make it a flawed robot. While it's easier for it to travel on flat land, it would be "extremely difficult" for it to roll up and over something, inhibiting its movement.

As for R2-D2, Kennedy says it's something scientists can build today.

"A lot of what it does is perfectly possible with what we have," he said.

The same goes for C-3PO.

"If you married the capabilities of our humanoid systems with what you can get out of your phone today, marrying the two together shouldn't be particularly difficult," he said. "There are even some humanoid systems that we have today that can out-perform a C-3PO system.

The one thing C-3PO has that real robots have trouble emulating is spine flexibility, he added.

Watch the video below: