Flying

NASA Begins Flight-Testing Flying Observatory

posted: 12 October 2007 05:36 pm ET

: NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA) infrared observatory lifts off on the first of a series of test flights to verify the flight performance of the highly modified Boeing 747SP. SOFIA arrived at NASA's Dryden Flight Research Center at Edwards Air Force Base, Calif. on May 31, 2007. The heavily modified Boeing 747SP was ferried to Dryden from Waco, Texas, where L-3 Communications Integrated Systems had installed a German-built 2.5-meter infrared telescope and made other major modifications over a period of several years. Credit: NASA Dryden Flight Research Center
: NASA's SOFIA infrared observatory is seen here in flight on Oct 11, 2007, in the first of a series of test flights to verify the flight performance of the highly modified Boeing 747SP. SOFIA is scheduled to undergo installation and integration of mission systems and a multi-phase flight test program at Dryden over the next three years that is expected to lead to a full operational capability to conduct astronomy missions in about 2010. During its expected 20-year lifetime, SOFIA will be capable of \"Great Observatory\"-class astronomical science, providing astronomers with access to the visible, infrared and sub-millimeter spectrum with optimized performance in the mid-infrared to sub-millimeter range. Credit: NASA Dryden Flight Research Center

NASA has begun flight testing the highly modified Boeing 747SP that contains its Stratospheric Observatory for Infrared Astronomy (SOFIA).

The initial flight tests represent the first of several phases required to verify the aircraft is structurally sound for future science flights. The preliminary flight-test phase is scheduled to be completed by the end of this year.

"SOFIA is making tremendous progress toward the initiation of science observations in 2009, and this flight testing is another milestone along the path," said Jon Morse, director of the Astrophysics Division in the Science Mission Directorate at NASA Headquarters, Washington.

Engineers at L-3 Communications Integrated Systems' facility in Waco, Texas installed a 17-metric-ton telescope in SOFIA's aft fuselage. The telescope installation process included cutting a 16-foot-high telescope door into the fuselage.

After arrival at NASA's Dryden Flight Research Center, Edwards, Calif., the aircraft was outfitted with test instrumentation critical for the preliminary flight tests. It also was equipped with a telescope cavity environmental control system, which is designed to keep the telescope dry when the door is closed and the aircraft flies to the altitude required for operation of the observatory.

NASA is conducting the first series of flight tests with the cavity door closed. These flights will study the aerodynamics, structural integrity, stability and control, and handling qualities of the modified 747SP. Future flights will concentrate on the in-flight rotational motion and control of the German-built telescope.

After closed-door flight testing is complete, the SOFIA aircraft will undergo installation and integration of the remaining elements of the observatory before door-open test flights, which are scheduled to begin in late 2008.

"The largest technical challenges remaining are in 2008, with the remainder of the mission sub-system installation that will give the aircraft the ability to fly with the cavity door open," said John Carter, NASA's SOFIA aircraft project manager at Dryden.

After finishing flight testing and modifications, NASA plans to begin using the airborne observatory for "first light" infrared observations of the universe in 2009. The first-light flights will enable the mission to begin obtaining results several years before the observatory reaches its full capability in 2014. SOFIA will collect science data using a variety of specialized instruments developed by NASA and its German partners.

"Early observations will have significant science community involvement to initiate broad use of this unique astronomical observatory," said Morse.

When operational, SOFIA's 2.5-meter infrared telescope will conduct celestial observations while flying at altitudes up to 45,000 feet.

This height will place the instrument above almost 99 percent of the Earth's atmospheric water vapor, greatly enhancing its ability to observe the cosmos. The flying observatory is designed to detect the formation of stars in galaxy, determine the chemical composition of the interstellar medium, and peer through the dust that hides the black hole at the center of the Milky Way.

The SOFIA program is a partnership of NASA and the German Aerospace Center. Dryden manages SOFIA, and NASA's Ames Research Center at Moffett Field, Calif. manages the science elements of the program.