... SOFIA s Window Seat . ... 25.02.2006 . ... Credit: Courtesy Dana Backman ( SETI Institute ), USRA , L-3 Explanation: Earlier this month, a 2.5-meter diameter infrared telescope was permanently assigned a window seat , looking through this opening in the fuselage of a historic Boeing 747 aircraft. ... Known as the Stratospheric Observatory For Infrared Astronomy ( SOFIA ), the airborne observatory is intended to fly at altitudes up to 45,000 feet - above more than 99% of the atmospheric water vapor. ...