The ESA ACES-PHARAO space program is the fruit of collaboration between several European organizations and laboratories. ACES-PHARAO is a space mission whose aim is to produce a time scale on board the International Space Station, for comparison with ground-based time scales produced by various metrological institutes. LTE is heavily involved in the production and processing of data for this mission.
ACES-PHARAO
The main objectives of this program are to :
- validate new on-board technologies for atomic clocks and clock signal transfer systems. These systems will be installed on the International Space Station.
- use these instruments to carry out time and frequency comparisons with unrivalled resolution and worldwide coverage. Comparisons will be made with all the clocks developed in the laboratories of the various nations. Time resolution will be of the order of ten ps from 1 to 10 days, and frequency resolution will be 10-16 to 10-17 in relative terms.
- study space-time on the basis of these comparative data. The aim is to constrain the fields of validity of the various relativity theories. In particular, we’ll be looking for instabilities in the fundamental constants of physics in time and space.
- on the instrumental side, CNES and SYRTE are also responsible for developing the heart of the system: the PHARAO cold atom clock.
- This innovative cesium clock will deliver the ultimate performance to meet mission objectives. Its construction has been subcontracted to several industrial companies. Assembly and final qualification were carried out at CNES in Toulouse, and the flight model was delivered to ESA in summer 2014.
