(AP) — NASA has launched a satellite on a mission to examine a little-studied region of the sun that it hopes will improve space weather prediction.

The Iris satellite rode into Earth orbit on a Pegasus rocket, which was air-launched over the Pacific Ocean Thursday evening. The airplane carrying the rocket and satellite took off around sunset from Vandenberg Air Force Base along California’s central coast.

Mission controllers clapped after receiving word that Iris separated from the rocket as planned 13 minutes after launch. It will begin its two-year mission after a checkout period.

Iris will focus on a region of the sun between the surface and the corona, the sun’s outer atmosphere that’s visible during eclipses.

The mission will last two years and costs $182 million. That’s cheap by NASA standards.