June 27, 2013
IRIS Launches, Now On Way To Investigate The Sun
[ Watch the Video: IRIS Launch ]
Lee Rannals for redOrbit.com – Your Universe OnlineNASA successfully launched its new Interface Region Imaging Spectrograph (IRIS) aboard an Orbital Sciences Pegasus XL rocket at approximately 7:27 pm (PST) tonight.
IRIS and the Pegasus rocket were both flown aboard Orbital's Stargazer L-1011 commercial transport aircraft, which has been modified to serve as the launch platform. This launch design helps to keep the cost low for smaller missions, opening up the door for spacecraft like IRIS to take flight within budgetary means.
NASA's new spacecraft 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.
"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 now on a path to reach an altitude of 390 miles to 420 miles above the Earth, allowing it to pass directly over the poles and cross the equator at the same time each day. Earth orbit will take IRIS around 97 minutes to complete. NASA said this orbit was selected because it provides nearly eight months of eclipse-free sun viewing and also maximizes the spacecraft's ability to downlink data by traveling over several ground receivers.
Now that the spacecraft has launched, the IRIS team will be performing post-flight checkouts for about 60 days before the official science campaign begins. Once this campaign starts, IRIS will join a host of other spacecraft, including NASA's Solar Dynamics Observatory and the joint NASA-Japan Aerospace Exploration Agency's Hinode. IRIS, along with these other spacecraft, will explore how the sun's corona and solar wind are powered.
"Relating observations from IRIS to other solar observatories will open the door for crucial research into basic, unanswered questions about the corona," said Joe Davila, IRIS project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md.
The region of the sun IRIS will be investigating has historically been difficult to study for scientists. However, gathering more data about this region will help improve scientists' understanding of our host star.
"Understanding the interface region better improves our understanding of the whole corona and, in turn, how it affects the solar system," said Davila.