In RELAGAL we aim to use the data obtained by the errant GALILEO navigation satellites GSAT0201 and GSAT0202 for a precision test of relativity theory. In August 2014 the two satellites GSAT0201 and GSAT0202 have accidentally been injected into an orbit of high eccentricity. The onboard atomic clocks thus are now subject to a daily modulation of the gravitational potential, with a height difference of approximately 8000 km between apogaeum and perigaeum. This provides us with an excellent opportunity to determine the modulated gravitational time dilation these clocks experience and to perform an accurate test of this fundamental prediction of general relativity.


This project is supported by the German Space Agency DLR with funds provided by the Federal Ministry for Economic Affairs and Energy (BMWi) under grant number 50WM1547.