A Pegasus Rocket is set to drop from the Orbital Sciences L-1011 carrier aircraft with NASA’s Interface Region Imaging Spectrograph (IRIS) mission. Launch is set for 7:27 p.m. PDT (10:27 p.m. EDT) Thursday, June 27, from Vandenberg Air Force Base in California. Live NASA Television launch coverage begins at 6 p.m. PDT.
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. The IRIS mission will observe how solar material moves, gathers energy and heats up as it travels through a largely unexplored region of the solar atmosphere. The interface region, located between the sun’s visible surface and upper atmosphere, is where most of the sun’s ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth’s climate.
Because of a significant power outage at Vandenberg earlier this week, certain Western Range facilities were not be ready to support the original June 26 launch date. Range officials believe they will be able to restore power to the affected facilities in time to support the launch Thursday evening.
IRIS is a NASA Small Explorer Mission to observe how solar material moves, gathers energy and heats up as it travels through a little-understood region in the sun’s lower atmosphere. This interface region between the sun’s photosphere and corona powers its dynamic million-degree atmosphere and drives the solar wind.
The drop of the air-launched Pegasus from Orbital’s L-1011 carrier aircraft will occur over the Pacific Ocean at an altitude of 39,000 feet, about 100 miles northwest of Vandenberg off the central coast of California, south of Big Sur.