In a hangar at Vandenberg Air Force Base, a solar observatory named IRIS is preparing for launch.
Like a transistor in the sun, IRIS will go on to fill a "crucial gap in our ability to advance studies of the sun-to-Earth connection," NASA explains on its website.
IRIS will open a new window of discovery by tracing the flow of energy and plasma through the chromospheres and transition region into the sun's corona using spectrometry and imaging.
Or, put another way by NASA:
NASA will launch a new set of eyes to offer the most detailed look ever of the sun’s lower atmosphere, called the interface region. This region is believed to play a crucial role in powering the sun’s dynamic million-degree atmosphere, the corona. The Interface Region Imaging Spectrograph or IRIS mission will provide the best resolution so far of the widest range of temperatures for of the interface region, an area that has historically been difficult to study.