Global warming. The future CO2 measurement satellite from space being tested in Toulouse
In 2023, CNES will launch MicroCarb, the first satellite capable of measuring atmospheric CO2 concentration across the globe. Its instrument, a grating spectrometer, has arrived at AirbusSpace in Toulouse to start thermal vacuum tests. Explanations
What are the main carbon sinks on our planet: the oceans or the tropical forests? How many tons of carbon dioxide (CO2) are emitted by cities, vegetation and oceans? As surprising as it may seem, we do not know today the quantities of CO2 delivered or issued in certain regions due to a lack of terrestrial measurement stations. Nor how they vary with the seasons.
However, this information is crucial for understanding the origins and impacts of global warming. CO2 is the main greenhouse gas produced by human activities.
To overcome this lack of data, NASA launched the OCO-2 satellite in 2014. In 2023, CNES takes over with the launch of MicroCarb. Its instrument, a grating spectrometer, will be able to measure the atmospheric concentration of CO2 over the entire globe with great precision (around 1 ppm). And it is this essential instrument that arrived in the clean rooms of Airbus Defense and Space in Toulouse in September for a test phase.
MicroCarb has thus started so-called “thermal vacuum” tests. 40 days during which the performance of the instrument will be tested under different conditions before delivery to Thales Alenia Space.
Elodie Cansot, instrument manager at CNES, explains:
The first objective concerns the qualification of the temperature control of the instrument in different conditions, operational or not. In particular, this involves checking the thermal performance of the cooling system, the cryostat (passive cryogenic cooling system), by reaching a temperature of 150 Kelvin, i.e. -123.15° Celsius whatever the temperature. environmental. Once the temperature is reached on the cryostat, validation and verification of the optical performance of the MicroCarb instrument could be performed.
Élodie Cansot, head of the MicroCarb instrument at CNES
The last objective is to ensure the proper functioning of the instrument during scenarios representative of flight conditions. For this, two tests will be carried out. The first consisted of illuminate the instrument by a signal having passed through a gas cell containing CO2, the second is a sun sight test where sunlight will be brought to the input of the instrument through a set of telescopes and optical fibers.
Once the thermal vacuum tests are complete, the teams will move on to the next big step, delivering the instrument to Thales Alenia Space United Kingdom located in Harwell in the UK.