The European Space Agency (ESA), which is not part of the European Union, has signed a contract with Airbus UK to lead the system feasibility and predevelopment phase of the agency’s Traceable Radiometry Underpinning Terrestrial and Helio Studies (Truths) satellite mission. This programme was proposed by the UK as part of ESA’s Earth observation ‘Earth Watch’ programme. 

Truths will gather data on the amount of solar radiation hitting the Earth and the amount of that radiation that our planet reflects from its surface back into space, linked with an absolute metrological reference. The Truths satellite will thus collect data itself and allow the calibration of data from other satellites. 

“We are thrilled to have signed the contract with Airbus that will define the mission system implementation concept as well as focus on the preparation of critical technologies prior to implementing the mission’s full development, which we envisage in 2023,” enthused ESA Earth observation programme director Josef Aschbacher. “The benchmark data that Truths will supply are going to bring real benefits for climate science – and we will be extremely proud to have it in our suite of satellite missions.”

The focus of the mission is on monitoring Earth’s changing climate. Truths’ dual function will improve the climate datasets available to scientists. To fulfil its mission, it will be equipped with a cryogenic solar absolute radiometer (CSAR) and a hyperspectral imager. The CSAR will provide the primary calibration standard which will allow the benchmarking of the data, on both the incoming solar and outgoing reflected radiation, that will be collected by the satellite. The hyperspectral imager will measure the radiation.

“Validating data on Earth’s changing climate is at the heart of this exciting mission, which will have a profound effect on future studies,” affirmed Airbus Defence and Space UK MD Richard Franklin. “It will provide the gold standard of calibration for space-based Earth observation – a kind of standards laboratory in space. For the first time, the international scientific community will be able to cross-reference their measurements and data, enabling  much more accurate forecasts and analysis, especially from the European Copernicus programme.”

“We have to use every tool at our disposal to help understand and tackle major issues such as climate change, whether that’s locating harmful carbon emissions or tackling the effects of deforestation,” highlighted UK Science Minister (equivalent to Deputy Minister in South Africa) Amanda Solloway. “This ambitious mission to create a ‘climate laboratory’ in space – the first of its kind – will help increase the accuracy of future climate projections by arming our scientists with the most reliable data and insight we have ever had access to – helping us take action to tackle this here in the UK, and around the world.”