Watch SpaceX launch NASA’s new planet-hunting satellite here

It’s almost time for SpaceX to launch NASA’s TESS, a space telescope that will search for exoplants more across nearly the entire night sky. The launch has been delayed more than once already: originally scheduled for March 20, it slipped to April 16 (Monday), then some minor issues pushed it to today — at 3:51 PM Pacific time, to be precise. You can watch the launch live below.

TESS, which stands for Transit Exoplanet Survey Satellite, is basically a giant wide-angle camera (four of them, actually) that will snap pictures of the night sky from a wide, eccentric, and never before tried orbit.

The technique it will use is fundamentally the same as that employed by NASA’s long-running and highly successful Kepler mission. When distant plants pass between us and their star, it cause a momentary decrease in that star’s brightness. TESS will monitor thousands of stars simultaneously for such “transits,” watching a single section of sky for a month straight before moving on to another.

By two years, it will have imaged 85 percent of the sky — hundreds of times the area Kepler observed, and on completely different stars: brighter ones that should yield more data.

TESS, which is about the size of a small car, will launch on top of a SpaceX Falcon 9 rocket. SpaceX will attempt to recover the first stage of the rocket by having it land on a drone ship, and the nose cone will, hopefully, get a gentle parachute-assisted splashdown in the Atlantic, where it too can be retrieved.

The feed below should go live 15 minutes before launch, or at about 3:35.