NASA is expected to announce this summer that it will stick with the U.S.-German SOFIA program, the airplane-mounted astronomy telescope that has been on the chopping block since the beginning of the year.

The U.S. space agency shocked the astronomy community and annoyed its German partners when it sent Congress a budget request in February that included no funding beyond this year for the Stratospheric Observatory for Infrared Astronomy (SOFIA). NASA has spent approximately $500 million to date modifying the 747 to serve as a flying observatory for scientists and teachers. The German Space Agency, DLR, contributed the state-of-the-art infrared telescope at a cost of just under $100 million.

SOFIA’s future was up in the air because the program is behind schedule and over budget at a time when NASA is looking for ways to save money.

NASA officials testified before Congress earlier this year that SOFIA’s first science flight had slipped at least three years to 2008, and that estimates of what it would cost to operate the flying observatory had risen substantially. NASA officials also said that SOFIA’s science value had been eroded by the delays since it is not expected to have much, if any, overlap with NASA’s Spitzer telescope, a space-based infrared observatory SOFIA was designed in part to complement.

Under fire from SOFIA backers and their allies in Congress, NASA said it would hold off on making a final decision about SOFIA until an outside panel had a chance to weigh in on the program’s science merits and determine what it would take to finish and fly the observatory.

NASA now has the SOFIA Options Review Team’s report in hand. The NASA Program Management Council, the agency’s highest-level program review board, is scheduled to discuss SOFIA when it meets June 15. NASA spokeswoman Erica Hupp said May 25 that the agency would announce its SOFIA decision this summer. She declined to release a copy of the SOFIA review report “because it is pre-decisional information.”

Congressional staffers following SOFIA also have been unable to get a copy of the report from NASA, according to sources, so Rep. Mike Honda (D-Calif.) and several California and Texas Democrats sent a letter directly to NASA Administrator Mike Griffin May 25 requesting the report.

NASA’s Ames Research Center in Moffett Field, Calif., is managing the SOFIA project. L-3 Communications and Integrated Systems is modifying the SOFIA aircraft in Waco, Texas.

David Black, president of the Universities Space Research Association — the Columbia, Md.-based private, nonprofit organization that was awarded the SOFIA prime contract in December 1996 — told Space News he had not seen the report but that he understands the review team found that SOFIA’s science is still highly pertinent, that there are no unresolved technical issues standing in the way of completion and that the program should be permitted to go forward.

Black said he expects NASA’s Program Management Council will elect to restore SOFIA when it meets in June.

“I will be very surprised if they don’t go ahead and go forward with the program,” Black said. “We see completion of SOFIA — when it is nearly complete, has no technical issues and the science is as timely now as it was when it was recommended in the Decadal surveys — as a fiduciary responsibility to both the taxpayers and the astronomical community.”

Other sources who follow SOFIA but declined to comment on the record said they too expect NASA to restore the program, but throttle back on the number of science flights SOFIA would be funded to conduct in any given year.

Another change widely believed to be in the works is moving SOFIA’s flight tests from Ames to NASA’s Dryden Flight Research Center, which is located at Edwards Air Force Base some 600 kilometers south near Los Angeles.

SOFIA must undergo nearly two years of flight tests before it can be cleared to carry scientists and teachers aloft for science flights. During science operations, a retractable door on the side of the 747 must be open to give the on board telescope a view of the sky.

Ames Research Center Director Simon “Pete” Worden said in an interview that the Dryden option is on the table but that no decisions had been made.

“We’re in discussion on how to move forward,” he said. “There hasn’t been a final decision. I expect that Ames is going to continue to play a major role regardless of what happens.”