STE-QUEST will address some of the most fundamental and puzzling questions of physics as we know it today: The Einstein Equivalence Principle (EEP), dark matter and tests of the foundations of quantum mechanics.
It will do so by making use of advanced quantum sensors for ultimate precision. Thereby it will not only lead to unprecedented advances in science at the interface between general relativity and quantum mechanics, but also pave the way for the use of quantum technologies in space, be it in fundamental physics or Earth observation, time-keeping and navigation. As such, it is an integral part of the recent community roadmap for cold atoms in space, authored by over 200 scientists worldwide.