Purpose of the flight and payload description
It is a UV-visible spectrometer able to provide vertical profiles of O3, NO2, OClO, BrO and H2O by solar occultation during ascent of the balloon (or descent) and from float at 30 km during sunset (or sunrise). The balloon version of the SAOZ instrument is very similar to the one used for ground-based measurements of total ozone and NO2.
It is composed by a commercial flat field, 360mm, holographic grating spectrometer equipped with a 1024-diode linear array and an entrance slit of 50 µm. A simple conical mirror replaces the gondola orientation or sun tracker systems generally used on large balloon platforms and is driven by an on-board computer, connected to a PTU (Pressure, Temperature and Humidity) sensor, a GPS (Global Positioning system ) for the localisation (Altitude, latitude and longitude) and an Argos transmitter for the recovery of the payload after cut-down and descent under parachute.
At left can be seen a picture of the standard package (click to enlarge).The weight of the instrument is 20 Kg and is contained in a insulated box with only a small aperture in the top for capture the solar rays. It's currently flown in three configurations, SaOZ-Standard, SAOZ-BrO and SAOZ-H2O each tuned to a different wavelength for measurements of different atmospheric constituents.
Details of the balloon flight
Balloon launched on: 3/17/1997 at 20:50
Launch site: European Space Range, Kiruna, Sweden
Balloon launched by: Centre National d'Etudes Spatiales (CNES)
Balloon manufacturer/size/composition: Montgolfier Infrared 40.000 m3
Balloon serial number: MIR Nº 6
End of flight (L for landing time, W for last contact, otherwise termination time): 4/8/1997
Balloon flight duration (F: time at float only, otherwise total flight time in d:days / h:hours or m:minutes - ): 21 d & 3 h
Landing site: Near Trondheim, Norway
Campaign: ILAS VALIDATION 97
Payload weight: 62 kgs
Gondola weight: 29 kgs