April 21, 2010
Infrared Airplane Telescope Ready to Explore the Universe
A NASA Boeing 747 carrying a German-made infrared telescope is ready to scan the skies for the first time.
Project officials in a NASA hangar in Southern California's high desert showed off the 40,000-pound telescope on Tuesday.The telescope assembly is mounted in the rear of the former Pan Am jetliner. A huge hatch opens during flight to allow the 98-inch-diameter telescope to view the sky.
The Stratospheric Observatory for Infrared Astronomy (SOFIA) is expected to capture its first infrared images during flight in the next six to eight weeks. The initial target for the telescope will be a calibration mission aimed at finding planets.
Project officials say that SOFIA is a "near-Hubble-class" observatory. It is expected to last for 20 years and will bring scientists to Palmdale for long-duration, high-altitude flights.
"They'll be working on unlocking the secrets about the universe and our own solar system," said Bob Meyer, SOFIA program director for NASA's Dryden Aircraft Operations Facility and Ames Research Center at Moffett Field, Calif.
The German Aerospace Center, NASA's partner, will receive about 20 percent of observing time.
Telescope engineer Thomas Keilig said the German participants and media were unable to attend Tuesday's event due to the ash clouds from the Iceland volcano.
SOFIA is a big step for airborne astronomy. Planetary scientist Gerard Kuiper initiated the concept in the 1960s by pointing a 12-inch telescope out of a window of an airliner. From the 1970s to mid-1990s, NASA flew a 36-inch telescope in a former military cargo plane.
SOFIA will observe objects that emit radiation in infrared wavelengths, which are not visible to the human eye. Infrared telescopes can see through the huge clouds of dust in the universe that block visible light.
Officials said that airborne telescopes have an advantage over ground-based observatories because they do not have to peer through a moisture-laden atmosphere, and unlike satellite telescopes, they can be constantly updated and repaired and are not bound by the limits of a fixed orbit.
Project officials said SOFIA would fly above 99 percent of the water vapor in the atmosphere. The goal is to set flights at an altitude of 45,000 feet with about eight hours of observation time.
The telescope is planned to be cryogenically chilled before take off so the mirror can be prevented from undergoing thermal shock once the cavity door is opened at high altitude.
The Boeing 747SP was delivered to Pam Am in 1977 and was christened the Clipper Lindbergh by Charles Lindbergh's widow on the 50th anniversary of his historic flight across the Atlantic. It was sold to United Air Lines before NASA acquired it in 1997. Lindbergh's grandson Erik rechristened it in 2007.
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