Nasa's latest solar solar observatory takes to the skies on a real hot mission.
It's attached to the nose of a Pegasus rocket which is slung underneath an aircraft for launch.
The IRIS - Interface Region Imaging Spectrograph - will point a telescope at the area between the sun's surface and its outer atmosphere.
The plan is to find out how the sun creates such intense energy that creates heat ranging from 6, 000 degrees to millions of degrees celsius.
The probe will concentrate on the interface region where most of the sun's ultraviolet output is generated.
That affects things like the Earth's climate.
The IRIS mission may also help spacecraft designers work out new ways to protect instruments and electronics from solar flares