The European and French space agencies on Dec. 15, 2009, signed an agreement under which the French PHARAO atomic clock will be sent to the international space station in late 2013 along with a Swiss-built atomic clock using a different design, the two agencies announced.
Under the agreement, the PHARAO — or Atomic Clock Project from Atom Recooling in Orbit — laser-cooled cesium clock, built for the French space agency, CNES, will be fitted to the outside of Europe’s Columbus space station module as part of a package including the Space Hydrogen Maser clock being built by SpectraTime of Neuchatel, Switzerland.
CNES is investing about 100 million euros ($144 million) in PHARAO. SpectraTime is producing components of the Space Hydrogen Maser clock under a 2.5 million euro contract with the European Space Agency ().
The clocks together form ESA’s Atomic Clock Ensemble in Space (ACES) package that ESA expects to launch as part of a barter arrangement with NASA. In return for providing the launch services for ACES and four other payloads to be placed on Columbus’ outer shell, NASA is receiving the ESA-financed Cupola observation dome, to be launched to the station in February along with the Node 3 habitable module, built by ThalesAlenia Space Italy.
ESA said the ACES and other external payloads could be launched on a Japanese H-2 Transfer Vehicle cargo ferry, or aboard a space station cargo freighter being designed under NASA contract by Space Exploration Technologies of Hawthorne, Calif.