A joint European-Japanese mission to the tiniest planet, Mercury, has been successfully blasted off from French Guiana on its long journey. That mission, BepiColombo, will spend seven years cruising toward its target, where it will separate into two spacecraft and orbit Mercury for a year. The measurements taken there could not only solve lingering mysteries about the innermost planet, but also about the formation of our solar system and neighboring ones. The whole mission cost the European Space Agency (ESA) and Japan Aerospace Exploration Agency (JAXA) almost $2 billion. GTD played a main role in the validation of the on board software of BepiColombo spacecraft, the AOCS and its sophisticated payload. Impressive view of the Ariane5 rocket during transfer to launch area Why is it so complicated to go to this planet? Obviously because of the high temperatures, but also because of the high difficulty of breaking and entering orbit. ABOUT GTD AT KOUROU SPACE CENTER Since 2003, each time an Ariane 5, a Soyuz or a VEGA are launched from the spaceport in Guiana, as well as the payload, many hours of work are required from GTD’s technical teams. GTD supplies services and software in practically all steps of an Ariane 5 mission – from the launcher's flight program to the responsibility of ground systems that control the launching operations, as well as the radars, telemetry and mission control systems. Each launch is also a challenge for GTD’s team, who is responsible for all the computer systems at the launch site. Each launch is a fresh new project; there is no routine, which means our engineers always embark on an adventure than goes beyond technical jobs that require a lot of responsibility. Countdown: The campaign to prepare a launcher takes about 22 - 30 working days, and a campaign to prepare the payload (satellite) takes from 4 weeks to 5 months (depending on the mission and its magnitude). Our teams are currently able to launch up to seven double Ariane 5, up to four soyuz and up to two Vega per year, that is, 14 telecom satellites and 4 to 6 EO and scientific spacecraft every year. Launch day: The end of the countdown is near. The final operations to fill the liquid propellants on the Ariane 5, and then the ground operation tests are carried out on the launcher. During this stage, gtd's staff is working hard all round the Spaceport. In the launch site's bunker, the technical centre, in Des Pêres Mountain where the radar and telemetry installations are, in the meteorological centre where the last conditions before the launch is authorised. At the same time, a support team is configuring a backup of the computer systems in Barcelona, 8,000 km away from the Ariane 5, which is already letting out oxygen steam. Ariane is launched: Once the launcher is in the air, it is controlled on board (by the embedded computer) and from the Jupiter Control Centre (CDC). These two systems were also designed by GTD’s engineers and are currently being operated by GTD’s engineers, too. Once the launcher releases the payloads (at a height of 500 - 600 km), everyone breathes a sigh of relief and starts clapping and cheering and congratulating each other; but our engineers are already thinking about the next mission that starts the following morning.