The "Cheops" mission to explore exoplanets was launched one day late. The Soyuz rocket lifted off German time from Kourou spaceport in French Guiana on Wednesday morning. In addition to the "Cheops" satellite, the nanosatellite "OPS-SAT", a small space laboratory, was also on board.
Four hours and 13 minutes after launch, the satellite detached itself from the rocket with the "Cheops" telescope. The start was originally planned for Tuesday. However, it had to be stopped due to technical problems.
The "Cheops" mission (Characterizing Exoplanet Satellite) is supposed to explore several hundred planets outside our solar system. Around 4000 such exoplanets are currently known.
It depends on the average density
To do this, the space telescope targets bright stars around the planets. When one of the planets pushes itself in front of its sun, it shields the sunlight and can be seen as a small black dot. "Cheops" records such changes in brightness to determine the size of the planet.
The scientists already know the weight of many planets through another method of observation from Earth. And size and weight together make up the average density. "With the medium density you can make statements about what the planet could consist of", says the "Cheops" chief responsible Willy Benz. Is it a gas planet? Or is the celestial body made of iron, stone or maybe even water? In addition, "Cheops" is intended to provide information about a possible atmosphere and thus indications of possible life.
The satellite will fly at an altitude of around 700 kilometers and will be controlled from Spain. The scientific operations center is in Switzerland. The joint mission of Esa and Switzerland includes a consortium from eleven other countries, including Germany. The German Aerospace Center (DLR) delivered two modules of the satellite; they were built in Berlin-Adlershof.