The Solar Occultation in the Infrared instrument, called SOIR was launched in 2006 in the frame of the Venus Express mission. Working sucessfully until the end of the mission in 2014, SOIR delivered high spectral resolution spectra of the Venus' mesosphere.
Onboard Venus Express, SPICAV was a spectrometer measuring the ultraviolet and infrared radiation. The instrument was designed in the frame of an international cooperation between France, Belgium, Russia and the United States of America. It included one channel measuring the ultraviolet range, SPICAV-UV, and two channels measuring the infrared range, SPICAV-IR and SOIR. The latter was built at the Royal Belgian Institute for Space Aeronomy in close cooperation with two Belgian industrial partners: OIP and PEDEO. During the entire Venus Express mission, from 2006 until 2014, SOIR was fully operational and delivered high-quality scientific data and results.
The SOIR instrument included an Acousto-Optical Tunable Filter and an Echelle grating. It was a high-resolution spectrometer operating in the infrared region, from 2.2 to 4.3 µm. The measurements were mostly performed in the solar occultation viewing geometry. This means that SOIR enabled the characterization of the atmosphere at the terminator region above the clouds, i.e. in the mesosphere. Its high sensitivity led to the detection of several species of high interest to understand the Venus atmosphere, such as its main constituent CO2, but also some key trace gases, such as CO, H2O/HDO, HCl, or HF.
The data can be found on the VESPA platform.