NASA has awarded the University of Colorado at Boulder $2 million for graduate students to design, build and launch four payloads on sounding rockets from the White Sands Missile Range in New Mexico to study X-ray emissions from the edges of the solar system and beyond.
Centered in CU-Boulder's Center for Astrophysics and Space Astronomy, the project is funded by NASA's Sounding Rocket Program, which provides universities with a low-cost test bed for validating new space instruments and developing novel technologies. The first sounding rocket launch funded by the new NASA award is slated for June 2009, said CASA Professor Webster Cash, principal investigator on the project.
Cash, who noted that the CASA student sounding rocket program has been active for more than 30 years, said CU's X-ray sounding rocket missions traditionally are led by doctoral students. The lead students for each flight generally receive their doctorates about a year after the launch of their rockets, using scientific data gathered by the payload as the basis for their theses, said Cash, also a faculty member in CU-Boulder's astrophysical and planetary sciences department.
The 2009 suborbital payload, dubbed EXOS, is a slightly modified instrument package flown by CASA from White Sands in 2006, said CASA doctoral candidate Phil Oakley, who is leading the project. The idea of the missions is to tease out more information about the origins and implications of soft X-ray emissions from sources like the "hot bubble" surrounding the solar system and nearby stellar objects.
"Our spectrograph basically splits light, allowing us to deduce the composition, age, and temperature of our targets," said Oakley. "The thing that appeals to me most about this program is the exploratory nature of these missions. We point our instruments at interesting targets, take data and make new discoveries with a very broad focus."
The team will be observing a number of targets, from a tattered supernova remnant known as the Cygnus Loop located about 1,500 light-years from Earth to hot, ionized gas clouds in the spherical halo of the Milky Way. Subsequent CASA launches featuring even more refined instrumentation will focus on fainter and fainter targets, as well as the role the solar wind plays in creating soft X-rays, he said.
While some soft X-ray emissions have been linked to solar activity and other more persistent emissions to further reaches of the Milky Way, "there is still a lot we don't understand about them," said Cash. "That's why this is an exciting piece of science."
Subsequent launches of CASA's X-ray payloads from White Sands will take place in 2011, 2012 and 2013, Cash said. Researchers will compare X-ray emissions from different times in the solar cycle to measure the influence of the sun's activity.
NASA's Black Brant sounding rockets used for the launches will reach an altitude of about 200 miles and the payloads will provide about five minutes of data per launch, said Oakley. It takes about one year to analyze data from a single launch, he said.
"After going through the experience of designing, building and flying a payload on a NASA rocket, our students are in very high demand when they graduate," said Cash.
"As an undergraduate looking around at graduate schools, I didn't really see the kinds of hands-on research opportunities provided by CASA anywhere else in the country," said Oakley, who received his bachelor's degree from the University of California-Berkeley. There will be several other graduate and undergraduate students involved in the effort in the coming years, said Oakley.
Oakley also is involved in the New Worlds Observer effort, a proposed NASA mission led by CASA's Cash to zero in on Earth-like planets in other solar systems. Astronomers would use a gigantic, daisy-shaped space shield to block out glaring starlight and image fainter light from distant planets with a trailing space telescope and identify planetary features like oceans, continents, polar caps and cloud banks and even detect biomarkers like methane, oxygen and water.
CASA also has an active ultraviolet sounding rocket program led by Professor James Green of CASA. Last year NASA awarded CASA $1.2 million to design and build a UV rocket payload to probe a nearby interstellar cloud with new technology that may help scientists better understand the mass and evolution of distant galaxies.
Two of the 12 astrophysics sounding rocket programs around the country currently funded by NASA are at CU-Boulder, Cash said. CASA has launched roughly 20 sounding rockets in the past three decades.