URL copied ISRO to launch data relay satellites to track Gaganyaan The Indian Space Research Organisation will launch a data relay satellite that will help maintain contact with the Gagangyaan mission throughout after the launch, sources said. The satellite will be launched before the final leg of the Gaganyaan mission, which will send astronauts to the Lower Earth Orbit (LEO). The first leg -- the unmanned mission -- is to be launched in December. "We're planning to launch our own satellite, which will act as a data relay satellite before going for the first human space flight," the sources said.