In 1985, scientists confirmed the existence of an "ozone hole"--a phenomenon in which the amount of ozone over Antarctica varied on an annual cycle, with significant depletion in winter months. Such depletion allowed greater penetration of ultraviolet radiation from the Sun to the Earth's surface, detrimentally affecting biological life.
This discovery led to scientific research to determine causes of the ozone hole.
The Middle Atmosphere High Resolution Spectrograph Investigation (MAHRSI) was one research response. In the 1990s, MAHRSI flew twice on the space shuttle. It measured amounts of ozone-destroying hydroxyl (OH) and nitric oxide (NO) in the middle atmosphere, aiding understanding of the processes of ozone production and depletion. It also yielded the first complete global maps of hydroxyl in that region.
This object flew in space and was donated by the Naval Research Laboratory to the Museum in 2014.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.