A NASA Small Explorer satellite launched in 2013 June to obtain high-resolution images and spectra at ultraviolet wavelengths of the Sun’s chromosphere, transition region, and lower corona. IRIS is in a Sun-synchronous polar orbit from where it makes continuous observations through a 0.2-m telescope equipped with a multi-channel imaging spectrograph operating in the near and far ultraviolet.

http://www.nasa.gov/mission_pages/iris Official mission website.