On board of the Phobos-Grunt mission (Mission Roskosmos destined for Phobos), "GAP", (Gas Analytic Package) is the main experiment to characterize the composition of the soil of the molecular point of view. To this end, this experience will include:
- aPyrolyzer - Analyzer thermal differential (TDA),
- a Laser (TDLAS) spectrometer.
- Mass spectrometer (MS),
- a gas chromatograph (GC)
The gas chromatograph (GC) is developed jointly by laboratory atmospheres, environments, space Observations (LATMOS) and laboratory Inter-university of atmospheric systems (LISA) under the aegis of the National center for space studies (CNES).
The purpose of the GC is to separate and analyze before further analysis by MS (mass spectrometer), the permanent gases on the one hand, and organic gases on the other hand, from the upstream processing of samples. This analysis is made using two analytical channels, each channel being dedicated to one of the two families of previous compounds.
Take-off at the end of 2011 for an arrival on Phobos in the spring of 2013 !
Figure 1: View of Phobos, satellite of Mars, Phobos-Grunt mission target. This mission should notably allow to respond to issues related to its origin, and be the seat of the second return for a sample of a planetary surface on Earth (after lunar surface samples, Apollo mission)
Figure 2: View the instrument GAP_GC CAD. 2 Circular parties first match housing where the chromatographic columns, true "heart" of the instrument.
The LATMOS/LISA consortium is in charge of achieving two independent pathways each one incorporated of:
- a trap injection, which allows gas to analyze before injection in the column
- a GC chromatography column, dedicated to the analysis of a specific family of compounds and who will be chosen depending on the nature of the gas analysis
- universal gas chromatographic detector (Thermal Conductivity Detector), which allowseven before analysis by mass spectrometer, the detection of compounds present in the sample on the level of ppm up to a couple of percent and a first identification of gas eluted by the column from calibrations of the latter.
- final integration of GC pneumatic systems (connection of different sub systems of the GC by soldering).