SOFIA or better yet the Stratospheric Observatory For Infrared Astronomy is a converted 747-SP that holds a telescope. The plane flies up to 40000 feet well above any atmospheric moisture for perfect conditions. The 747 SP #21441 began life as a special performance model of the 747 for Pan Am in 1977. Named in honor of Charles Lindbergh, The 'Clipper Lindbergh" was sold to United Airlines for its Pacific routes. NASA had the grandson of Charles rechristen the aircraft following its extensive modifications to honor the aviation pioneer. SOFIA carriers a 8.2 foot reflector telescope in the rear of the aircraft. A large moving door opens once the it reaches altitude and the observing begins! It replaced the Kuiper Airborne Observatory which can also be seen at Moffett Field. read more