BOZEMAN -- Montana State University faculty and students who designed and tested optics for a NASA solar mission are counting down the days when their work will head into space.
The Interface Region Imaging Spectrograph (IRIS) is scheduled to launch at 8:27 p.m. Mountain time Thursday, June 27, from the Vandenberg Air Force Base in California. The launch was originally set for June 26 and could be postponed at the last minute, but the MSU scientists are inviting the public to watch with them at the new planned time. The free event will run from 7:30 to 9:30 p.m. in the planetarium at MSU’s Museum of the Rockies.
“It’s very exciting to see the work of so many people come together,” said Charles Kankelborg, leader of the IRIS team at MSU. “A rocket launch like this is such a focal point and such a milestone.
“You know that things usually go just fine, but it’s always very stressful, and you always worry,” Kankelborg added. “It’s always very exciting. The only satisfying way to enjoy it is to hold a party and invite a lot of people.”
NASA will also offer the public several opportunities to follow the launch. Extensive prelaunch and launch day coverage will be available on NASA’s home page. To view the IRIS webcast and launch blog and learn more about the mission, visit http://www.nasa.gov/iris .
MSU became involved with IRIS in 2007 after Kankelborg attended a solar physics meeting in Honolulu and long-time colleagues at Lockheed Martin approached him about collaborating. Kankelborg had come to MSU in 1996 from Stanford University where he earned his doctorate in physics. In 1998, he moved to Maryland and spent eight months at the Goddard Space Flight Center, which housed the operations center for another solar mission called the Transition Region and Coronal Explorer (TRACE). During that time, before Kankelborg returned to Bozeman, TRACE was launched.
In the past six years, more than a dozen people at MSU have helped design and test optics that are part of the IRIS mission to answer some of the biggest questions about the sun, Kankelborg said.
Besides Kankelborg, the team includes program manager Larry Springer who worked at Lockheed Martin before coming to MSU. Other current or past participants are professor Joe Shaw, postdoctoral researchers Nathan Pust and Sarah Jaeggli, Keith Mashburn, Christy Dunn, Janet Glenn and Erica Lastifka. Angela Des Jardins, Randy Larimer and Joey Key in the Montana Space Grant Consortium organized education and outreach efforts, such as the recent National Student Solar Spectrograph competition held at MSU.
Stefan Eccles was an undergraduate student in physics when he joined the team, Kankelborg said. By the time he graduated in 2011, he had become such an expert at testing optics that he was invited to do the same during a summer at Lockheed Martin.
One of the biggest mysteries about the sun is why the corona is millions of degrees Celsius when a layer closer to the sun is much cooler, Kankelborg said. That layer, the photosphere, averages 6,000 degrees Celsius.
IRIS will focus on the layer between the photosphere and corona – the chromosphere. Expected to give the most detailed look ever of the sun’s lower atmosphere or interface region, IRIS will observe how solar material moves, gathers energy and heats up as it travels through this largely unexplored region of the solar atmosphere. The interface region, located between the sun’s visible surface and upper atmosphere, is where most of the sun’s ultraviolet emission is generated. These emissions affect the Earth’s climate and can interfere with satellite communications and the transmission of power.
IRIS will carry an eight-inch ultraviolet telescope, a spectrograph that contains MSU optics, and a “bus” carrying transmitters and batteries. It will fly 390 to 420 miles above Earth and pass over the poles every 90 minutes. The telescope is tentatively scheduled to open for the first time on July 17. The occasion, called “First Light,” is the next big thing after the launch, Kankelborg said.
Once the telescope opens, it will transmit ultraviolet light to the spectrograph. The spectrograph will then split invisible light into wavelengths like a prism splits visible light. This allows scientists to identify physical processes and measure such things as solar temperatures, velocity and composition. At the same time, IRIS will take high-resolution photos of the sun. Scientists will then match the photos and images and analyze the results.
“IRIS data will fill a crucial gap in our understanding of the solar interface region upon joining our fleet of heliophysics spacecraft,” Jeffrey Newmark, NASA’S IRIS program scientist, said in a NASA press release. “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.”
The satellite is the first mission designed to use an ultraviolet telescope to obtain high-resolution images and spectra every few seconds and provide observations of areas as small as 150 miles across 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,” Alan Title, IRIS principal investigator at Lockheed Martin, said in the NASA release. “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,” Title said.
IRIS is designed to operate for two years, but if it’s like TRACE, it will operate much longer, Kankelborg said. TRACE was launched in 1998 and retired in 2010. It was designed to operate for eight months.
IRIS and TRACE are both part of NASA’s Small Explorer (SMEX) Mission. The goal of the program is to provide frequent flight opportunities for world-class scientific investigations from space using innovative and efficient management approaches.
“It’s an exciting program to work with,” Kankelborg said. “The Small Explorer missions build up more quickly and generally they are lower-cost operations where you can get a lot of science done for relatively little money.”
IRIS was about a $100 million mission. By comparison, interplanetary missions can cost more than $1 billion, Kankelborg said. He noted that there are cheaper interplanetary missions, such as the upcoming Mars Atmosphere and Volatile EvolutioN (MAVEN). That mission is projected to cost half a billion.
Evelyn Boswell, (406) 994-5135 or firstname.lastname@example.org