Conceptual illustration of the European Space Agency's (ESA) TRUTHS (Traceable Radiometry Underpinning Terrestrial- and Helio-Studies) mission. This mission will evaluate the incoming solar radiation and radiation reflected from Earth back out into space, using a cryogenic solar absolute radiometer and a hyperspectral imaging spectrometer as well as a novel onboard calibration system. TRUTHS mission is expected to launch in 2030 on a Vega-C rocket.