Questions and Answers

DISCOVERER is highly innovative as it will open up a new low altitude flight regime for EO satellites. Current approaches to improve EO platforms focus on incremental improvement on proven technology (e.g. larger optics, more precise attitude determination and control, higher bandwidth communications) in order to increase image resolution and downlink data rates. However these platforms are fundamentally limited by their operational altitude.

DISCOVERER, in contrast, envisages a radical redesign of these platforms to operate at lower altitudes. For example, a VLEO platform orbiting at 300km could obtain the same resolution imagery as the current state-of-the-art WorldView-4 satellite, but with payload cost savings due to a telescope aperture less than half the diameter (or one quarter the area).

To our knowledge, there is no other ongoing research effort in our field anywhere in the world which pursues the same ideas as DISCOVERER, or would produce comparable data quality and quantity at the same extraordinary speed. It is our ambition to completely eliminate the lifetime limitation of EO platforms for sustained operation at significantly lower altitudes with the ultimate goal of reducing cost whilst achieving the same or even better resolution pictures and shorter revisit times.

This requires novel and foundational research to identify and develop low-drag materials which specularly reflect the incident gas, in satellite aerodynamic control, and in atmosphere-breathing electric propulsion. An experimental wind tunnel will be developed, built and operated. It will provide a unique, world-leading infrastructure for studying rarefied-gas aerodynamics and will enable the identification and characterisation of low-drag materials. Furthermore, the test satellite will be the first wholly devoted to the study of spacecraft orbital aerodynamics and will validate the performance of the most promising low-drag materials in the VLEO environment, and demonstrate aerodynamic attitude and orbit control manoeuvring.

The current TRL  of material aerodynamic characterisation for VLEO satellites and for active aerodynamic control is at best at around TRL1 or less, and the proposed activities aim to move this to TRL5. The concept of atmosphere-breathing electric propulsion will be taken forward by designing, building and testing intakes and thrusters with the ambition to experimentally demonstrate, in a relevant environment, the feasibility of these concepts, and will prepare for operational use and wide-scale marketing of the new technology. Due to the experience and capability of the DISCOVERER partners, these developments in the timeframe of the project are entirely plausible. If successful, DISCOVERER will have a highly foundational effect. With the innovative breakthroughs it aims to deliver, VLEO platforms will become commercially viable for Earth observation thanks to unlimited orbital lifetimes and reduced costs. They will set new standards for civilian Earth observation applications, delivering better value remote sensing for flagship EC programmes such as Copernicus

What do YOU want to know about the DISCOVERER project? Send us your questions!