NASA’s IRIS Solar Mission Launch Moved To Thursday
June 25, 2013

NASA’s IRIS Solar Mission Launch Moved To Thursday

[ Watch the video IRIS Science Overview ]

Lee Rannals for - Your Universe Online

Update (June 25, 2013 3:10 p.m.)

NASA announced on Tuesday that its planned launch for its Interface Region Imaging Spectrograph (IRIS) mission has been moved due to the "recent central California power outage."

The launch window has moved from Wednesday, June 26 to Thursday, June 27. Stay tuned for further updates.

Main Story (June 24, 2013 12:43 p.m.)

NASA's Interface Region Imaging Spectrograph (IRIS) mission is gearing up for its long-anticipated launch this week.

IRIS will be launching Wednesday between 7:27 and 7:32 pm pacific daylight time from the Vandenberg Air Force Base in California. The mission will help to provide insight into energy transport into the Sun’s corona and solar winds.

The mission will ride aboard Orbital's Pegasus XL rocket, which is a more affordable way to launch a spacecraft into orbit because it is released from a carrier aircraft initially.

IRIS will observe how solar material moves, gathers energy and heats up as it travels through unexplored regions of the solar atmosphere. It will be looking at an area located between the sun's visible surface and upper atmosphere called the interface region. This region is where most of the sun's ultraviolet emission is generated.

“IRIS data will fill a crucial gap in our understanding of the solar interface region upon joining our fleet of heliophysics spacecraft,” said Jeffrey Newmark, NASA’s IRIS program scientist in Washington. “For the first time we will have the necessary observations for understanding how energy is delivered to the million-degree outer solar corona and how the base of the solar wind is driven.”

Scientists hope the IRIS program will help better understand how energy and plasma moves from a lower layer of the sun's surface called the photosphere. Observation into this movement has been a fundamental challenge in Solar and Heliospheric science, and the mission is expected to open up a window of discovery into this region by producing observations necessary to pinpoint physical forces at work in the interface region.

“With IRIS, we have a unique opportunity to provide significant missing pieces in our understanding of energy transport on the sun," said Dr. Alan Title, IRIS principal investigator and physicist at the ATC Solar and Astrophysics Laboratory in Palo Alto. "The complex processes and enormous contrasts of density, temperature and magnetic field within this interface region require instrument and modeling capabilities that are now finally within our reach."

IRIS is the first mission designed to use an ultraviolet telescope to obtain spectra and high-resolution images every few seconds. It will be able to look at areas as small as 150 miles across on the Sun.

“Previous observations suggest there are structures in this region of the solar atmosphere 100 to 150 miles wide, but 100,000 miles long,” said Alan Title, IRIS principal investigator at Lockheed Martin. “Imagine giant jets like huge fountains that have a footprint the size of Los Angeles and are long enough and fast enough to circle Earth in 20 seconds. IRIS will provide our first high-resolution views of these structures along with information about their velocity, temperature and density.”

After Wednesday's launch, IRIS will be orbiting around Earth at an altitude of 390 miles to 420 miles and in such a way it passes directly over the poles and crosses the equator at the same time each day.