NASA's InSight Mars Mission_ Countdown to T-Zero
NASA's InSight Mars Mission_ Countdown to T-Zero

InSight, NASA's next Mars explorer, has arrived at Vandenberg Air Force Base in California - a big step forward in the countdown to T-zero on May 5, 2018.

The spacecraft is called InSight - short for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport - and it's being tested, fueled and encapsulated for launch aboard the powerful United Launch Alliance Atlas V rocket.

The upcoming liftoff will mark the first time an interplanetary mission has launched from the West Coast.