TRUTHS: a new potential ESA Earth Watch mission
29 May 2019
With ESA’s Space19+ Ministerial Council meeting set for November, a new satellite mission called TRUTHS will be added to the list of missions to be financed in the Earth Observation Earth Watch programme.
On 27–28 November, government ministers responsible for space activities in ESA Member States will gather in Seville, Spain, to decide on ESA’s programmes and funding for the coming years.
As well as the two main proposals, FutureEO and the Copernicus space component, that will be put forward for Earth Observation, TRUTHS will be proposed as an additional operational mission.
TRUTHS is short for Traceable Radiometry Underpinning Terrestrial- and Helio- Studies.
Proposed by the UK, the mission would establish an SI-traceable space-based climate and calibration observing system to improve confidence in climate-change forecasts – a kind of ‘standards laboratory in space’.
To do this, TRUTHS would carry a hyperspectral imager to provide benchmark measurements of both incoming solar radiation and outgoing reflected radiation with an unprecedented accuracy achieved through a novel on-board calibration system conceived by the National Physical Laboratory of the UK.
These benchmark measurements would improve our ability to estimate radiative imbalance underlying climate change – importantly, in a shorter time than is currently possible.
Reference datasets from TRUTHS would also serve to calibrate other satellite sensors, such as those carried on the Copernicus missions and the emerging constellations of small satellites.
Furthermore, TRUTHS would contribute to the Global Climate Observing System, the Committee on Earth Observation Satellites, the World Meteorological Organization, the Copernicus Climate Change Service and the Group on Earth Observations by offering an important element of an international space-based climate observing system proposed in the Strategy Towards an Architecture for Climate Monitoring from Space.
It would also provide observations that meet requirements for the key radiation balance essential climate variables and underpin many others, particularly those related to Earth’s carbon cycle.
ESA’s Director of Earth Observation Programmes, Josef Aschbacher, said, “ESA is happy to include the TRUTHS mission in our package of programme proposals for Space19+. It is a very interesting mission that will bring many benefits to better understand climate change and offer well-calibrated measurements for cross-reference with other missions.
“It is now up to ESA Member States to take up this offer and participate in this exciting programme.”