Airbus Space has been awarded a €109.3-million (including options) contract by the European Space Agency (ESA) for the latest phase of its Traceable Radiometry Underpinning Terrestrial and Helio Studies (Truths) satellite mission. This phase includes mission design definition as well as payload design definition, and the development of the industrial partners needed to deliver the payload, which will be complex. It also includes the development of expertise in optical Earth instrumentation in the UK, which is the lead ESA member country in the Truths mission (ESA is not part of the European Union).

“We are glad to award the contract to Airbus in the UK to take their work on developing Truths into the next all-important phase,” affirmed ESA Earth Observation Programmes director Simonetta Cheli. “We see here at [the] COP28 [climate change conference] that the world is committed to climate action and having reliable data on which to base decisions is of the utmost importance. Truths will be used as a benchmark so that data from other satellites can be compared more easily, thereby improving reliability.”

Truths will be a space-based climate and calibration observation system. It will measure solar radiation and the sunlight reflected off the Earth’s surface, relative to an accurate reference. This will allow both the calibration of sensors on other satellites, through co-imaging activities, and the improvement of climatological data sets. It will increase the standards of data harmonisation and so improve the accuracy of climate change forecasts.

“This contract takes us one step closer to building a mission that will enable scientists and climatologists to cross reference their measurements and data, enabling much more accurate forecasts and analysis in a shorter time,” highlighted Airbus Space Systems Hhead Jean Marc Nasr. “Truths will provide the gold standard of calibration for space-based Earth observation – a kind of ‘standards laboratory in space’.”

Truths will measure both incoming radiation from the Sun and outgoing radiation reflected by the Earth, using a Hyperspectral Imaging Sensor. This data will be calibrated, with unprecedented accuracy, by a Cyrogenic Solar Absolute Radiometer. This combination will allow the estimation of the radiative imbalance, which underlies climate change, more accurately and more rapidly than can currently be done.

In addition to the lead funder, the UK, Truths is also being financially supported by other ESA member States, namely the Czech Republic, Greece, Romania, Spain and Switzerland. On the industrial side, Airbus Space is supported by Surrey Satellite Technology Ltd, Teledyne e2v, the National Physical Laboratory (UK), Rutherford Appleton Laboratory (UK), Deimos Space UK Ltd and AVS-UK Ltd, Deimos Space SRL, Thales Alenia Space Switzerland, Sener, and Integrated Systems Development.