VV27: behind the scenes at Europe’s spaceport as MicroCarb and CO3D get ready for lift-off

A fragile satellite: handle with care

MicroCarb, the French space agency’s satellite, is the first European satellite for measuring carbon dioxide (CO₂) in the atmosphere. To do so, it uses a spectrometer that captures sunlight reflected off the Earth. Its built-in detector is extremely sensitive to temperature and humidity.

“The average temperature in French Guiana is 27°C. To protect the detector, we decided to transport MicroCarb to the launch area at the end of the day, when the temperature is lower,” explained Philippe Landiech, senior MicroCarb project leader at the French space agency (CNES).

When the container was opened in the clean room, a pack of nitrogen was used to prevent humidity during transport. The team had to wait two hours for complete diffusion of the gas before handling the satellite.

Europe’s spaceport supplied clean, dry nitrogen for the satellite throughout the preparation phases. A special nitrogen supply pipe was designed by fluid systems experts at the payload preparation facilities to guarantee optimum conditions and protect the satellite until it was placed in the payload fairing.

Calculated to the nearest millimetre

Once it was ready, MicroCarb was disconnected just before it was moved into the payload fairing of the Vega-C launch vehicle. The race against the clock began: how long could the detector withstand being cut off from its nitrogen supply?

“We had a 700-hour window without nitrogen from delivery of the detector until it reached orbit, and the final phase in the payload fairing takes up most of that,” Philippe Landiech explained.

When we talked to him on 17 July, the satellite had already used up 400 hours of its allotted time. MicroCarb is now in passive stand-by mode. It will be switched back on automatically when the launcher separates, in orbit. No "red alert" problems are expected during lift-off for this satellite.

CO3D: well-oiled logistics for an electric satellite

The main passengers of mission VV27, taking up most of the room inside the payload fairing, are the four CO3D satellites developed jointly by Airbus and the French space agency. With an all-electric propulsion system (as opposed to chemical thrusters), they were filled with xenon (their fuel) in Toulouse, to simplify the process during the launch campaign. When they arrived in French Guiana after a long journey, the satellites simply needed to have their batteries recharged before being installed on their dispenser, with no need for further functional tests.

“CO3D was designed to optimise its production cycle: no fuelling in French Guiana, just a check and close monitoring of the batteries, and no need for health monitoring tests on site. It allowed us to secure the campaign and improve efficiency,” explained Philippe Chéoux Damas, head of the CO3D programme at Airbus Defence and Space.

From a logistics standpoint, the CO3D constellation required special equipment such as extra platforms and ladders, and of course, cleanliness had to be closely monitored at all times, with contamination sensors added by the project team and Europe’s spaceport, to meet the needs of an optical observation mission.

A bespoke adapter for a unique constellation

Lastly, to accommodate the four CO3D satellites on the Vega-C launch vehicle, a special flight adapter known as CLESSIDRA was designed specifically for the purpose by Airbus Defence & Space Madrid on behalf of Avio, the rocket’s Italian manufacturer.

“Our mission is to adapt the resources available at Europe’s spaceport to the specific needs of each satellite. For MicroCarb and CO3D, we had to be flexible when it came to preparing the payload preparation facilities, and make sure teams liaised effectively, especially on issues like cleanliness, logistics and the technical environment,” confirmed Emmanuelle Sainte-Rose-Fanchine, in charge of payload resources at the French space agency.

See you on 25 July for lift-off of mission VV27!
You can watch the launch live from the Carapa observation site, or online on the French space agency and Arianespace YouTube channels.