Kuiper Airborne Observatory
United States
The Gerard P. Kuiper Airborne Observatory (KAO) was a national facility operated by NASA to support research in infrared astronomy. The observation platform was a highly modified Lockheed C-141A Starlifter jet transport aircraft (s/n: 6110, registration: N714NA, callsign: NASA 714) with a range of 6,000 nautical miles (11, 000 km), capable of conducting research operations at altitudes of up to 48,000 feet (14 km).
Observatory data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).