Description of the payload

Is a spectrometer with six tunable diode lasers dedicated to in situ measurements of trace compounds in the upper troposphere and the stratosphere up to 35 km altitude.

The 6 laser beams circulate in a multipass HERRIOTT cell located below the gondola. The lower mirror of the two-mirror cell is fixed at the top of a deployable mast. The distance between mirror is about 3.50 m. Given the curvature of the two identical mirrors, two stable optical configuration can be used : first 86 reflections and 300 m optical path, second 156 reflections and 554 m optical path, by moving the lower mirror 5 mm up.

The mast is deployed during the flight to have the first measurements at the tropopause. Around the instrument, a rigid metal frame encompasses it, in order to have a instrument-safe landing.

Inside the instrument, three liquid nitrogen cryostats, hold the six diode lasers and the 12 detectors.

Vertical profiles of concentrations of a great number of species like O3, CH4, CO, CO2, N2O, HNO3, NO2, NO, HCl, HOCl, H2O2, and COF2, are measured with a very high vertical resolution, a high sensitivity and a high precision.

Details of the balloon flight and scientific outcome

Launch site: Centre de Lancement de Ballons CLBA, Aire Sur L'Adour, Landes, France  
Balloon launched by: Centre National d'Etudes Spatiales (CNES)
Balloon manufacturer/size/composition: Open balloon model 150z Zodiac - 150.000 m3
Campaign: ENVISAT  

The balloon was launched in the morning of October 2th, 2002 by dynamic method with the help of an auxiliary balloon.

No additional data is available.

During this flight several in-situ measurements (both in ascent and descent) were acomplished measuring the species : CO, O3, CO2, HCl, N2O, CH4, COF2, HOCl, H2O2, NO, H2O, NO2 and HNO3. These measurements were destinated to validate three instruments located onboard the ENVISAT satellite. The day of flight was choosed to allow ENVISAT close overpass of the balloon path, but it matched poorly with SCHIAMACHY, fairly well with MIPAS and none with GOMOS (due to the daytime).

External references and bibliographical sources

Images of the mission

Gondola preparation SPIRALE's launch