CHELOSBA (CHEmistry of the LOwer Stratosphere with BAlloons) was an European sponsored balloon launch campaign performed between 1996 and 1998 to study the seasonal cycle of the vertical profiles of a major part of the relevant stratospheric odd nitrogen and halogen components by remote sensing balloon-borne measurements at middle and high latitudes.

The program included the participation of research groups from France and Germany and was based on remote sensing of the species vertical profiles by means of three different spectroscopic methods: differential optical absorption spectroscopy (DOAS), Fourier transform infrared spectrometry (FTIR), Michelson interferometer for passive atmospheric sounding (MIPAS). These instruments were accomodated in two different balloon platforms.

In all nine flights -of the eleven originally planned- were performed under operative control of the French Space Agency (CNES) ballon group, from four different places in Europe: in 1996 and 1998 from Leon, Spain, in 1997 from Kiruna, Sweden and Gap, France and finally from Aire Sur L'Adour, France in 1998.

Launch base	Date	Flight Duration	Experiment	Payload landing place or cause of the failure
León	11/23/1996	2 h 8 m	LPMA (Limb Profile Monitor of the Atmosphere) + DOAS	--- No Data ---
Gap-Tallard	6/19/1997	8 h 23 m	LPMA (Limb Profile Monitor of the Atmosphere) + DOAS	--- No Data ---
Gap-Tallard	7/1/1997	6 h 13 m	MIPAS-B2 (Michelson Interferometer for Passive Atmospheric Sounding - Balloonborne)	--- No Data ---
León	3/19/1998	3 h 15 m	LPMA (Limb Profile Monitor of the Atmosphere) + DOAS	--- No Data ---
Aire Sur L'Adour	5/8/1998	6 h 14 m	MIPAS-B2 (Michelson Interferometer for Passive Atmospheric Sounding - Balloonborne)	--- No Data ---