Small Spacecraft Design and On-orbit Performance for the IRIS Mission

In June 2013, the Interference Region Imaging Spectrograph (IRIS) launched from Vandenberg AFB for a two year solar observing science investigation to study the interface of the solar photosphere to the corona. IRIS is a NASA Small Explorers mission that is in a sun-synchronous, low-Earth orbit. It is obtaining high-resolution images and spectra of the chromosphere and transition region that, combined with advanced computer models, will explore how matter, light, and energy move from the sun’s 6,000 K surface to its million K outer atmosphere, the corona. This paper describes the design, development, and test of the 183 kg observatory along with a summary of the on-orbit performance. IRIS was designed and built at the Lockheed Martin Space Systems STAR Labs in Palo Alto, Calif., with support from the company’s Civil Space line of business and major partners Smithsonian Astrophysical Observatory and Montana State University. NASA Ames is responsible for mission operations and the ground data system. The Norwegian Space Agency provides the primary ground station at Svalbard, Norway with scientific modeling performed by the University of Oslo. The science data is managed by the SDO Joint Science Operations Center, run by Stanford University and Lockheed Martin