DISCOVERING DISCOVERER

How many of us can say that our jobs are out of this world? For Nicholas Crisp (OW 2008), that’s an everyday reality. Nick has been a researcher in Orbital Aerodynamics for the DISCOVERER project since 2017 and has recently started lecturing in Aerospace Engineering at the University of Manchester.

Based at the University, Nick is currently working on the Satellite for Orbital Aerodynamic Research, SOAR, as part of the wider, European-funded DISCOVERER project. The project aims to enable the commercially viable operation of spacecraft in very low Earth orbits (VLEO), particularly focussing on missions for Earth observation.

SOAR, a 3U CubeSat, is used to study the interaction of the atmospheric gases on the satellite’s surface, while testing new materials to help increase the satellite’s aerodynamic performance and reduce drag in lower altitude orbits (below 450 km). The project looks to develop technologies to enable earth observation satellites to operate more effectively in VLEO.

The Aerodynamics Payload, developed at the University of Manchester, features a set of fins coated with four different test materials. The fins can be independently rotated with respect to the oncoming flow and, once in orbit, the interaction between the test materials and residual atmosphere will be recorded and studied by Nick’s team. Since the start of the Cold War, when they were used for reconnaissance, VLEO satellites have been employed very little. This is a result of various challenges that limit their useful lifetime, including increased aerodynamic drag experienced in orbit, due to reduced atmospheric density at lower altitudes, and their need to carry enough fuel to last the duration of the mission. Longer missions would need more fuel storage, requiring larger, more expensive satellites, meaning that they were not seen to be economically viable.

Nick explains that the obvious benefits of VLEO satellites are that they can be smaller, lighter, and able to provide equivalent or improved resolution; thus, being more economical. The images captured can be used to provide valuable infrastructure and environmental monitoring; for defence and security intelligence, disaster monitoring and response; alongside facilitating higher bandwidth and lower latency communications.

There are also wider environmental and social benefits to the success of the DISCOVERER project and increased use of VLEO spacecraft. The positive environmental implication of operating satellites in lower altitudes is the sustainability of space for future generations. VLEO satellites can be naturally disposed of rather than adding to the ever-increasing amount of space debris. Use of atmospherebreathing propulsion systems, rather than fuel-based, mean that the satellites do not need to store as much fuel for the duration of the mission and can be smaller.

The recent increase in demand for higher-resolution satellite imagery has led to a boom in the commercial market for earth observation (EO) data but the costs of procuring such data is high. This is currently pricing lowerGDP countries, with smaller aerospace budgets, out of global collaboration projects, leaving them unable to access the same level of data. Nick’s work is contributing to making VLEO satellites more durable and commercially viable. The increased use of VLEOs would help enable the ‘democratisation of space-based information globally’. If a cost-effective way of sending VLEO satellites into orbit is found, collecting data becomes cheaper. This would allow the types of data mentioned above to be collected more cheaply, thus encouraging collaboration and information sharing with lower socioeconomic countries.

From September, when not in the lab, Nick has been lecturing in Aerospace Engineering, travelling full circle since joining the University in 2008. Although not necessarily considering research or academia as a career on leaving school, Nick began his PhD straight after finishing his undergraduate degree and hasn’t looked back since. When asked what advice he would give to his younger self, Nick said: "See where the curiosity takes you and take opportunities as they come."

We can’t wait to see how the SOAR project and Nick’s career develops, watch this space – no pun intended!