ACES GS Acceptance

Space Applications Services has supported the Final Acceptance of the ACES Ground Segment in CADMOS/CNES, Toulouse. The acceptance of the ground segment is a first step towards the full end-to-end acceptance of the ACES Payload and Ground Infrastructure. ACES will be launched to the International Space Station in early 2017.

The ACES (Atomic Clock Ensemble in Space) is an ESA payload which accommodates two high precision clocks - a laser cooled caesium clock (for long–term stability) and a hydrogen maser (for short term stability. The purpose of the payloads is to conduct experiments in the domain of fundamental physics.

Space Applications Services is involved as a subcontractor to Airbus DS in the design and development of many of the ACES Ground Segment facilities, under overall ESA responsibility:

  • Experimental Phases planning
  • ACES specific enhancements to the standard real-time monitoring and control system (CD-MCS) used for European payloads.
  • Monitoring and control system for the remote MWL (Micro-wave link) ground and SLR (satellite laser ranging) stations via secure links over the Internet.
  • Archiving and completeness check of all the flight and ground data with automatic recovery of missing data using various mechanisms.
  • Implementing algorithms for scientific data processing allowing space to ground clocks comparison down to the 10-16 uncertainty level. This includes detection and elimination of multipath effects, compensating for ionospheric and tropospheric delays, correcting relativistic effects based on orbit data and gravity field, etc.
  • Internet portal for raw, engineering and scientific data dissemination to the engineering support centres and to the time & frequency analysis scientific community.