On June 27th 2013, IRIS satellite was successfully launched at 7:27 pm Pacific Time after deploying from the Vandenburg Air Force Base in California within the Pegasus rocket aboard the Stargazer plane. As a part of the MSGC (Montana Space Grant Consortium), we all proudly watched the launch from the newly rebuilt planetarium at Bozeman, Montana’s very own Museum of the Rockies. The Pegasus rocket was dropped over the Pacific Ocean at coordinates 36.0 north, 123.0 west. At deployment, the IRIS satellite was dropped for 5 seconds within the the Pegasus rocket from the Stargazer plane at an altitude of 11.89 kilometers (39,000 ft) and flying at a velocity of 243 meters per second (797 ft/sec). The 3 stage booster rocket than began its sequence to reach its target orbit in the earth’s LEO (Lower Earth Orbit). The target orbit for spacecraft separation was a perigee of 620 kilometers and an apogee of 670 kilometers (385 by 416 miles), giving a semi-major axis of 7,023 kilometers (4,364 miles), 97.89 degrees inclination and a mean local time of the ascending node of 06:02:30.
The MSU (Montana State University) personal involved in this mission includes:
Charles Kankelborg, Larry Springer, Christina Dunn, Janet Glenn, Stefan Eccles (undergrad), Joseph Shaw (EE), Nathan Pust (EE), Angela DesJardins (MSGC), Randy Larimer (MSGC)
Designed for a two-year mission, IRIS carries an ultraviolet spectrometer attached to a telescope with a diameter of 20 centimeters (8 inches). IRIS fills a crucial gap in our ability to advance Sun-Earth connection studies by tracing the flow of energy and plasma through this foundation of the corona and heliosphere. The satellite will return images and spectra produced every few seconds, allowing material to be tracked as it passes through the chromosphere. IRIS is the eleventh mission to launch as part of NASA’s Small Explorer (SMEX) program, which is part of the wider Explorer program. The launch of IRIS was the forty-second flight of the Pegasus rocket, and the thirty-second of the Pegasus-XL. The HXLV was an air-launched rocket, using the first stage of the Pegasus dropped from the Stargazer aircraft that carries the registration number N140SC, to boost a hypersonic flight experiment as part of NASA’s Hyper-X program. The aircraft is named Stargazer after the USS Stargazer from Star Trek, a ship formerly commanded by Captain Picard. Pegasus rocket made its maiden flight on 5 April 1990, carrying the Pegsat and SECS satellites for NASA and the US Navy respectively. Early launches were made using NASA’s NB-52B, nicknamed Balls 8, mostly flying from Edwards Air Force Base.
IRIS will be operated in this orbit, as does not carry any maneuvering thrusters or propellant to change its orbit. You can follow IRIS on their Facebook page :)