The Kuiper Airborne Observatory (KAO), named after the Dutch-American astronomer Gerard Kuiper (1905–1973), was operated by NASA, beginning in 1974. It was a modified C-141 Starlifter military cargo aircraft and carried a 36-inch (0.9-meter) diameter telescope weighing about 6,000 pounds (2,700 kilograms). It was based at the NASA Ames Research Center near Moffat Field, California, and flew about seventy scientific flights per year.

The KAO was retired in 1995, after more than twenty years of scientific service. Among the many discoveries it fostered were planetary rings around Uranus; water vapor in Jupiter’s atmosphere; the thin atmospheric layer that sometimes surrounds Pluto; and pioneering studies of comets, asteroids, and the interstellar medium.