[Launch Alert] NASA Launches Satellite

[Launch Alert]

The following is a NASA news release.


NASA LAUNCHES SATELLITE TO STUDY HOW SUN'S ATMOSPHERE IS ENERGIZED

WASHINGTON -- NASA's Interface Region Imaging Spectrograph (IRIS) 
spacecraft launched Wednesday 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: 

http://www.nasa.gov/iris