BackForward Satellite: TRUTHS 

Satellite details
Acronym TRUTHS
Full name Traceable Radiometry Underpinning Terrestrial- and Helio- Studies
WIGOS Station Identifier ---
Satellite Description
  • Single satellite of the TRUTHS programme.
  • Main mission: measurements of incoming solar radiation and of radiation reflected from Earth that can be linked to an absolute standard.
  • Contribution to the Global Space-based Inter-Calibration System (GSICS).
  • Two instruments: a solar irradiance radiometer and a hyperspectral imager.
  • A novel onboard calibration system to enable the measurements to be traceable to a standard reference.
Mass at launch 1000 kg Dry mass 850 kg
Power 1300 W
Data access link no link provided
Data access information


Orbit Drifting orbit Altitude 610 km
Inclination 90 °


Space agency ESAUKSA
Status Planned
Details on Status
(as available)
  • Final approval by ESA expected at end-2022.
  • Launch envisaged by 2029.
Launch ≥2031 EOL ≥2041
Last update: 2023-11-16
Associated satellite programme and related satellites

Note: red tag: no longer operational , green tag: operational , blue tag : future

Satellite Payload

All known Instruments flying on TRUTHS

Acronym Full name
CSAR Cryogenic Solar Absolute Radiometer
HIS Hyperspectral Imaging Sensor
Show instrument status and calibration