SOFIA

SOFIA consisted of a 2.7-meter infrared telescope mounted in a modified Boeing 747SP aircraft. The aircraft allowed the telescope to be flown above the interference of the Earth's lower atmosphere. It was a joint mission between NASA and the German Aerospace Center (DLR).

By flying at altitudes above 40,000 feet, SOFIA was able to observe above approximately 99% of the water vapor in Earth's atmosphere. This altitude was absolutely crucial for infrared astronomy. The atmospheric water vapor would otherwise block infrared light from reaching the telescope.

The SOFIA mission officially concluded its science flights in September 2022. The retirement was largely due to the high operational costs of maintaining a flying observatory. The scientific yield, while valuable, was deemed insufficient to justify the mission's continued funding by NASA and the DLR.

SOFIA observed the universe primarily in infrared light, which allowed it to see through dense cosmic dust clouds. It made significant discoveries regarding the formation of new stars and the composition of planetary atmospheres. It famously detected water molecules on the sunlit surface of the Moon in 2020.