CHEOPS in a nutshell

 
 

Science

Top-level Objectives

  • First-step characterisation of super-Earths and Neptunes à insight into physics and formation of planets; identification of planets with atmospheres; constraints on planet migration
  • Identification of golden targets for spectroscopic characterisation
  • Probing atmospheres of hot-Jupiters (phase curve measurements), study of physical mechanisms and efficiency of energy transport

 

  Spacecraft Rendering    

 

Key Science Requirements

 

  • Photometric precision (stability) over 48 hr timescale: 20 ppm (6 hrs) for G-type star, 6≤ V≤9; 85ppm (3 hrs) for K-type star, V ≤12
  • Sky coverage, target observability/visibility
  • Temporal resolution  (1 measurement/min; timing precision (1s))
  •  Mission lifetime of 3.5 years (5 years goal)

 

   

Programmatics 

Mission Flavour and Partners

 

  • S (small)-class mission in ESA’s Science Cosmic Vision Programme in partnership with Switzerland, with important contributions from Austria, Belgium, France, Germany, Hungary, Italy, Portugal, Spain, Sweden and the United Kingdom

 

       

Instrument

Design

 

  • Single high accuracy photometer, VIS/NIR range (0.35-1.1 um)
  • Compact Ritchey-Chrétien telescope, dia = 320 mm.
  • 60 kg / 60 W / 1.2 Gbytes per day.
  • Single, frame-transfer, back-illuminated and back-thinned CCD (AIMO), 1k x 1k pixels, op. temp -40 deg C (stabilised to 10mK).
  • Baffle to meet stringent stray-light requirement.
  • Developed by a consortium led by the University of Bern (CH).

 

   

Spacecraft

Design

 

  • Recurring design based on AS-250 (~1 m3, ~ 290 kg, ~ 200 W).
  •  3-axes stabilised, APE < 4 arcsec (rms).
  • Roll around Line of Sight (LoS) to maintain radiators pointing to cold space.
  • LoS within 60 deg half-cone around anti-Sun direction.
  • Developed by Airbus D & S Spain.

 

Ground Segment

Organisation

 

  • Mission Operations Centre (MOC) development by GMV (ES); operations at Torrejon de Ardoz by INTA (ES).
  • Science Operations Centre (SOC) at University of Geneva (CH).
  • Ground stations at Torrejon, Villafranca and Kiruna (LEOP only).
  • All operations incl. LEOP and commissioning executed from MOC.
  • Mission Planning System under SOC responsibility.

 

 

Observing Opportunities with CHEOPS

Guest Observing

  • 20% of total observing time available to the Science Community through ESA Announcements of Opportunity, with competitive review by an independent Time Allocation Committee.

 

Launch and Orbit

 Planned

  • Launch from Kourou on Soyuz rocket operated by Arianespace, co-passenger under ASAP-S.
  • Launch readiness end 2018.
  • Sun-synchronous orbit, Local Time of the Ascending Node 6am, altitude of 700 km.