Manchester mission to improve low altitude satellites

Funded through the EU’s Horizon 2020 programme, the €5.7 million DISCOVERER project aims to drive the development of smaller, lighter and more economical Earth observation satellites that operate in very low Earth orbits (under 450km altitude). Orbiting much closer to the Earth helps them to avoid space debris and improves the quality of images they can send back.

The University’s so-called Satellite for Orbital Aerodynamics Research (SOAR) - a type of CubeSat - will be launched on SpaceX’s CRS-22 mission on 3 June 2021 from Kennedy Space Center, Florida to the International Space Station from where it will be deployed into orbit.

Whilst in orbit the satellite will be controlled from a ground station based on the University campus where scientists will study the interactions between the residual atmosphere in these low orbits and new materials developed at the university that could reduce drag and increase aerodynamic performance.

Dr Peter Roberts, the scientific coordinator for DISCOVERER said: “We’re breaking new ground with a satellite designed specifically to explore aerodynamic effects in very low Earth orbits, whilst simultaneously measuring atmospheric parameters such as density and composition.”

The satellite features a set of fins that are coated with four different materials for testing and can be individually rotated to different angles. The fins will be folded and stowed against the spacecraft body for launch and are deployed once the satellite is in orbit enabling the interaction of the different test materials with the residual atmosphere to be investigated. The fins will also be used as control surfaces to demonstrate novel aerodynamic control manoeuvres in orbit.

Operating closer to the surface of the Earth significantly reduces latency for communications applications and improves link budgets, whilst remote sensing also benefits from improved link budgets, the ability to have higher resolution or smaller instruments, all of which provide cost benefits.

The Manchester team has developed several different advanced materials that will also be tested in a unique rarefied flow wind tunnel that mimics the atmospheric composition and speed that low altitude satellites will experience. The in-orbit phase of testing on SOAR is intended to validate the performance of these materials, enabling the much sought-after development of new, smaller, low orbit satellites.

The DISCOVERER project is also developing atmosphere breathing electric propulsion prototypes that could use the residual atmosphere in low orbits as a propellant. This has the potential to both keep the satellites in orbit indefinitely despite the drag acting upon them but also bring them back down to Earth more quickly at the end of their mission, thereby preventing them from contributing to the space debris problem experienced at higher altitudes.