The AO named 'Nanosatellite constellations for Earth observation' addressed technical challenges driving new mission concepts involving a large number of cooperative nano-satellites operated in a distributed system (constellation or localised swarm) in order to acquire new or additional measurement data for Earth Observation applications.
In recent years, technology miniaturisation in particular in electronics, sensors and MEMS devices has enabled the development, qualification and successful flight heritage of many nano-satellite systems in orbit. The performance of such systems (in terms of attitude control, on-board processing, and communications) is now reaching a level sufficient for supporting potential Earth Observation applications. At the same time, there are numerous efforts ongoing to develop compact optical and RF instrument payloads that could be accommodated on such small platforms.
Whilst the individual payload performance may be degraded compared to conventional larger payloads, the satellite unit cost is significantly lower and therefore their deficit in performance may be compensated by the multitude of satellites operated together in LEO as a system. The AO therefore aimed to investigate concepts which take advantage of this aspect in order to provide significant contributions taking advantage of low-altitudes and large coverage.
Challenge No. 1
The objective of the Land challenge completed by ISIS BV was to perform measurements of land characteristics over a wide spectral range/resolution and at a high spatial resolution on timescales that are relevant to changes in the observables. The constellation system shall be equipped with nadir-pointed payload instruments that provide global coverage and will cover one or more channels in the visible, SWIR or thermal infrared wavelength bands.
Challenge No. 2
The objective of the Atmospheric Challenge undertaken by TAS UK was to perform measurements of the NO2 content in the troposphere with high temporal resolution over the diurnal cycle. The measurements should be achieved by a constellation of nano-satellites carrying optical payloads providing global coverage.
Challenge No. 3
The objective of the Weather challenge undertaken by both SSTL and Strathclyde University was to perform measurements of tropospheric properties (e.g. temperature, pressure, humidity and wind), on rapidly evolving timescales in support to weather forecasting of severe weather events such as convective thunderstorms, cyclones, hurricanes, etc. The measurements shall be achieved by a constellation of nano-satellites carrying RF payloads providing global coverage.