First In-flight Observations With the Stratospheric Observatory for Infrared Astronomy are Complete
The Stratospheric Observatory for Infrared Astronomy, a joint program by NASA and the German Aerospace Center, achieved a major milestone May 26, with its first in-flight night observations.
"With this flight, SOFIA begins a 20-year journey that will enable a wide variety of astronomical science observations not possible from other Earth and space-borne observatories," said Jon Morse, Astrophysics Division director in the Science Mission Directorate at NASA Headquarters in Washington. "It clearly sets expectations that SOFIA will provide us with Great Observatory-class astronomical science."
The highly modified SOFIA Boeing 747SP jetliner fitted with a 100-inch diameter reflecting telescope took off from its home base at the Dryden Aircraft Operations Facility in Palmdale, Calif. The in-flight personnel consisted of an international crew from NASA, the Universities Space Research Association in Columbia, Md., Cornell University and the German SOFIA Institute (DSI) in Stuttgart.
During the six-hour flight, at altitudes up to 35,000 feet, the crew of 10 scientists, astronomers, engineers and technicians gathered telescope performance data at consoles in the aircraft's main cabin.
"Wind tunnel tests and supercomputer calculations made at the start of the SOFIA program predicted we would have sharp enough images for front-line astronomical research," said SOFIA project scientist Pam Marcum of NASA's Ames Research Center in Moffett Field, Calif. "A preliminary look at the first light data indicates we indeed accomplished that."
The stability and precise pointing of the German-built telescope met or exceeded the expectations of the engineers and astronomers who put it through its paces during the flight.
"The crowning accomplishment of the night came when scientists on board SOFIA recorded images of Jupiter," said USRA SOFIA senior science advisor Eric Becklin. "The composite image from SOFIA shows heat, trapped since the formation of the planet, pouring out of Jupiter's interior through holes in its clouds."
The highly sensitive Faint Object Infrared Camera for the SOFIA Telescope, or FORCAST, was used for the initial observations in flight. A team led by Cornell's Terry Herter, which also built the instrument, operated it during the flight.
FORCAST captures in minutes images that would require many hour-long exposures by ground-based observatories blocked from a clear infrared view by water vapor in the Earth's atmosphere. The SOFIA's operational altitude, which is above more than 99 percent of that water vapor, allows it to receive 80 percent or more of the infrared light accessible to space observatories.
The flying observatory's platform 747SP also performed well.
"We have retired many of the threats and much of the risk with this first-light flight. This was a major accomplishment in terms of understanding the quality of our observations, for example how much image instability we encounter with airflow over the telescope. While improvements can be made, we exceeded expectations," said Bob Meyer, the SOFIA program manager.
The SOFIA program is managed at Dryden. Ames manages the SOFIA science and mission operations in cooperation with USRA and DSI.
- Expected lifespan: 20 years
- Diameter of primary telescope mirror: 98 inches (2.5 meters)
- Weight of telescope assembly: 44,100 pounds (20,000 kilograms)
- Operational altitude: 41,000 to 45,000 feet
- Observation time at altitude: eight hours or longer
- Ambient temperature in telescope chamber: from zero to -40 degrees Fahrenheit
- Up to 20 flight crewmembers will be aboard on missions, including flight crew, technicians, astronomers and educators
- Plans call for more than 120 flights a year when fully operational
Editor, X-Press Special Delivery
NASA Dryden Flight Research Center