H2O

H2O was the denomination of a multi-payload mission which carried several instruments onboard, but all with a common scientific scope: to measure the amounts of water vapor in the stratosphere. Hence, the mission was dubbed H2O. The platform used to mount the instruments was developed by CNES for another experiment (the LPMA/DOAS spectrometer) following their well proven modular structure based on aluminum balls and bars. At left we can see an scheme of the gondola.

Onboard instruments were: the SawfPhy (Surface acoustic wave frost point hygrometer) developed by the LMD (Laboratoire de Météorologie Dynamique); the LOAC (Light Optical Particles Counter) developed by the Laboratoire de Physique et Chimie de l'Environnement etde l'Espace (LPC2E); a specific GPS unit to carry out preliminary measures for futures mission that need high-precision time measuruemnts and three versions of the instrument picoSDLA (Spectromètre à Diode Laser Accordable) a tuneable diode laser spectrometer designed for in situ measurements of water vapour and methane operated by the University of Reims. Two of the versions of Pico-SDLA were aimed to measure CH4 and CO2 while a third one devoted to measure H2O was located in a boom detached from the gondola.

Balloon launched on: 8/31/2015 at 19:45 local
Launch site: Timmins Stratospheric Balloon Base, Ontario, Canada  
Balloon launched by: Centre National d'Etudes Spatiales (CNES)
Balloon manufacturer/size/composition: Zero Pressure Balloon model 100z Zodiac 100.000 m3
Flight identification number: NIMBUS-3
End of flight (L for landing time, W for last contact, otherwise termination time): 9/1/2015
Balloon flight duration (F: time at float only, otherwise total flight time in d:days / h:hours or m:minutes - ): 10 h 36 m
Landing site: 236 km SE of Timmins, Ontario, Canada
Campaign: STRATO SCIENCE 2015  
Payload weight: 227 kg
Overall weight: 1197 kg

• Assessment of the Last Two STRATO SCIENCE Campaigns in Timmins, Canada SpaceOps 2016 Conference, SpaceOps Conferences, (AIAA 2016-2611)
• La nacelle H2O atterrit bien au sec... Coverage of the flight at CNES website