All systems are go for the launch of IRIS -- a seven-foot spacecraft that will orbit Earth and study a small but mysterious region of the sun.
You can watch IRIS take off for space Thursday evening, live, right here. Coverage of the launch provided by
When NASA's newest scientific satellite leaves Vandenberg Air Force Base, it will be riding in the belly of a rocket that in turn will be flying under an aircraft.
At 7:27 p.m. Pacific time, the carrier aircraft -- an L-1011 -- will drop the rocket 39,000 feet above the Pacific Ocean. The rocket will launch into space from the air, firing for about 13 minutes after its release, and then IRIS will continue its journey alone.
You'll find video at the bottom of this post on how it is all expected to go down.
At the time the rocket gets dropped from the carrier, it will be about 100 miles northwest of Vandenberg, not far from Big Sur, according to a NASA release.
The IRIS satellite is designed to keep a close eye on a thin sliver of the sun's lower atmosphere known as the transitional region.
The light emitted by the transitional region is in an ultraviolet range that is filtered out by Earth's atmosphere, so it is impossible to get a good look at this region with ground-based telescopes.
But the soon-to-be-space-based IRIS is equipped with a powerful ultraviolet telescope that will snap images of this mysterious and violent region every two seconds.
Scientists hope the data provided by IRIS will help them answer the long standing mystery of why the sun's surface is significantly cooler than its upper atmosphere.
The launch of IRIS was originally scheduled for Wednesday, but was delayed one day because of a power outage at Vandenberg earlier in the week.
If this launch is successful, IRIS should start sending back data to Earth in a month, said Pete Worden, the center director of NASA's Ames Research Center, and a co-investigator for the IRIS mission.