SMALL SATELLITES FOR EARTH OBSERVATION: A PERSPECTIVE FROM JPL/NASA

In the cost-constrained environment of NASA, the need for an acceptable compromise between science objectives and mission affordability is informing the decadal surveys. The rising credibility of SmallSats and CubeSats as science platforms has changed significantly in the last few years while access to space and the ability to deploy multiple spacecraft have inspired people to develop mission concepts that exploit the new capability. Interestingly, new scientific observations are possible, via constellations, formation flying, and sensor disaggregation. This talk reviews ongoing missions such as CYGNSS, and technology demonstration experiments such as RainCube and TEMPEST-D, and discusses the value added to Earth science measurements by single smallsats and constellations. As general characteristics of smallsat constellations, instrument resolution (strength, direction) is dictated by spatial sampling in the measurement, and high sensitivity in the frequency band of interest is dictated by temporal sampling, leading to novel requirements in instrument bandwidth. Exploiting such richness in spatial and/or temporal sampling allows for observations of physical processes thus far precluded, such as highly dynamic changes needing high resolution, as in the case of seismic event detection. Additionally, the talk discusses new concepts rapidly emerging as part of the Designated Observables architecture studies following the Decadal Survey report of 2018, which calls for smallsats as part of the NASA observation strategy in the next decade.