NASA Launches Satellite to Study How Sun's Atmosphere Is
Energized
WASHINGTON -- NASA's Interface Region Imaging Spectrograph (IRIS) spacecraft
launched Thursday at 7:27 p.m. PDT (10:27 p.m. EDT) from Vandenberg Air Force
Base, Calif. The mission to study the solar atmosphere was placed in orbit by an
Orbital Sciences Corporation Pegasus XL rocket.
"We are thrilled to add IRIS to the suite of NASA missions studying the sun,"
said John Grunsfeld, NASA's associate administrator for science in Washington.
"IRIS will help scientists understand the mysterious and energetic interface
between the surface and corona of the sun."
IRIS is a NASA 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 interface region also is where most of the sun's ultraviolet emission is
generated. These emissions impact the near-Earth space environment and Earth's
climate.
The Pegasus XL carrying IRIS was deployed from an Orbital L-1011 carrier
aircraft over the Pacific Ocean at an altitude of 39,000 feet, off the central
coast of California about 100 miles northwest of Vandenberg. The rocket placed
IRIS into a sun-synchronous polar orbit that will allow it to make almost
continuous solar observations during its two-year mission.
The L-1011 took off from Vandenberg at 6:30 p.m. PDT and flew to the drop
point over the Pacific Ocean, where the aircraft released the Pegasus XL from
beneath its belly. The first stage ignited five seconds later to carry IRIS into
space. IRIS successfully separated from the third stage of the Pegasus rocket at
7:40 p.m. At 8:05 p.m., the IRIS team confirmed the spacecraft had successfully
deployed its solar arrays, has power and has acquired the sun, indications that
all systems are operating as expected.
"Congratulations to the entire team on the successful development and
deployment of the IRIS mission," said IRIS project manager Gary Kushner of the
Lockheed Martin Solar and Atmospheric Laboratory in Palo Alto, Calif. "Now that
IRIS is in orbit, we can begin our 30-day engineering checkout followed by a
30-day science checkout and calibration period."
IRIS is expected to start science observations upon completion of its 60-day
commissioning phase. During this phase the team will check image quality and
perform calibrations and other tests to ensure a successful mission.
NASA's Explorer Program at Goddard Space Flight Center in Greenbelt, Md.,
provides overall management of the IRIS mission. The principal investigator
institution is Lockheed Martin Space Systems Advanced Technology Center. NASA's
Ames Research Center will perform ground commanding and flight operations and
receive science data and spacecraft telemetry.
The Smithsonian Astrophysical Observatory designed the IRIS telescope. The
Norwegian Space Centre and NASA's Near Earth Network provide the ground stations
using antennas at Svalbard, Norway; Fairbanks, Alaska; McMurdo, Antarctica; and
Wallops Island, Va. NASA's Launch Services Program at the agency's Kennedy Space
Center in Florida is responsible for the launch service procurement, including
managing the launch and countdown. Orbital Sciences Corporation provided the
L-1011 aircraft and Pegasus XL launch system.
For more information about the IRIS mission, visit:
NASA
Guillermo Gonzalo Sánchez Achutegui
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