A unique astronomical observatory aboard a Jumbo jet is a step closer to winning a reprieve from Nasa.
The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a Boeing 747 that is due to fly a German-built telescope.
Nasa upset its partners at the German Aerospace Centre by failing to include the project in its budget request to Congress in February. The agency has so far spent £270 million ($500 million) on the project. It is close to completion, though over budget and behind schedule, and astronomers are appalled that it might be scrapped at such a late stage.
Now a senior review board, NASA’s Program Management Council, has decided that there are “no insurmountable technical or programmatic challenges” to completing SOFIA. It notes, however, that Nasa has still made no firm decision whether to continue the project or cancel it.
The telescope, with a 2.5 metre (8.2ft) mirror, is designed to fly into the stratosphere at a height of 41,000ft. That will place it above nearly all the water vapour in the atmosphere that blocks much infrared radiation from the stars.
The telescope views the sky from a large door in the side of the fuselage near the jet’s tail. The observatory has been tested on the ground but no flights have yet been made.