Skip to navigation | Skip to content

Telescope-toting jet has trial run

space mirror

Polishing the telescope's 2.5 metre wide primary mirror(Source: DLR)

Testing has started of a jet modified to house a sensitive infrared telescope that the US space agency says will offer astronomers a new window on the ever-evolving Milky Way. The Stratospheric Observatory for Infrared Astronomy, or SOFIA, is intended to operate at altitudes up to 13,000 metres. That would put it above 99% of earth's atmospheric water vapour, which blocks wavelengths from reaching the ground. "In the visible and ultraviolet, you're mainly looking at stars," says SOFIA chief scientist Professor Eric Becklin, an astrophysicist with the University of California, Los Angeles. "When you look in infrared you see stars, but also see the dust and gas those stars formed from or are throwing off as they die. You really get a different view of the universe," he says. "The most exciting science is really trying to understand the chemistry and, potentially, the biology that's going on in space, and really getting to the heart of the question, did life form here on earth, or did it form out in space?" SOFIA's scientific agenda includes studying star formation in the Milky Way, determining the chemical composition of the interstellar medium and seeing through the dust hiding the black hole at the centre of the galaxy. "We can open up some wavelengths that are impossible to see from any ground-based observatory," says SOFIA science program manager Ed Austin, with NASA's Ames Research Center in Moffett Field, California. Cheaper and flexible SOFIA also is less expensive to build and operate than space-based observatories and can be quickly positioned to view cosmic phenomena such as approaching comets. "We can position the aircraft anywhere in the world to take advantage of some really unique things that ground-based observatories are likely not able to get," Austin says. SOFIA scientists can take advantage of newer, but potentially riskier, technologies than those typically onboard space-based platforms that cannot be retrieved or modified. With its 2.5 metre diameter primary mirror, the 20 tonne observatory is a bit bigger than the Hubble Space Telescope, which observes primarily visible and ultraviolet NASA modified a Boeing 747SP aircraft for SOFIA, cutting a 5 metre opening in the fuselage so the telescope can view the cosmos. It also added a door to keep the observatory safe and dry during take-offs and landings. Test flights of the jet with the telescope's door closed are under way at NASA's Dryden Flight Research Center at Edwards Air Force Base in California. Open-door excursions are scheduled to begin next year. NASA hopes to have its first images from the telscope in 2009. "As soon as possible, we want a science instrument on the plane," says SOFIA program manager Bob Meyer. SOFIA, which is being built in cooperation with the German Aerospace Centre, is a follow-on program to the successful Kuiper Astronomy Observatory aircraft, which flew for 21 years. NASA provided the aircraft and will conduct flight and mission operations, while the Germans contributed the telescope. Germany also provided upgraded engines and subsystems for the aircraft, as well as a new coat of paint.
