This new space engine could power up cheaper missions and reduce space debris
Up until a decade ago, a NASA space shuttle launch cost on average $450 million per mission, and it cost between $50 and $400 million to launch a single satellite, making it traditionally difficult for smaller players to access space.
In recent years, new developments such as the commercial launch of multiple satellites at a time and the miniaturisation of satellite components have contributed to a steady decline in launch costs — now 40 times lower than in the 1980s — and created more opportunities for technological innovation.
Conception X alumni Mohamed Ahmed, PhD student in Space Engineering at the Surrey Space Centre, is developing an electric propulsion system that reduces mission weight by 80%, works with a variety of non-conventional propellants to ignite the system — such as air and water vapour — and could extend the lifetime of space missions.
“The cost of launch per kilogram is in the hundreds of thousands of dollars,” Ahmed says. “Yet, in recent years, Elon Musk’s Space X has shown a new space economy is possible, and this has motivated me to use my research to improve space accessibility.”
Ahmed’s research project focuses on developing reconfigurable, low-power electric space engines to assist small-to-medium-sized satellite manufacturers and operators. His solution is an external discharge plasma thruster that uses electric and magnetic fields for acceleration.
“Existing solutions are expensive to acquire — with lengthy lead times, complex system assemblies and limited performance metrics at low power,” Ahmed says. “We have achieved a significant reduction in the mass and volume of our thruster head, eliminating assembly difficulties to enable mass production.”
The team’s system aims to give access to both lower and higher orbits, and could extend mission lifetime for interplanetary travel and deep space exploration.
“Electric engines have been commonly used for decades, but we’ve developed a technology that can have the longest lasting lifetime,” Ahmed says.
“In deep space exploration, each satellite that is deployed with an electrostatic engine has an expiration date because the engine eventually expires. This means the mission has an expiration date. Mitigations need to be factored in early on to ensure the satellite is brought back to Earth, and this increases manufacturing costs. By extending the engine’s expiration date, mission costs go down.”
The goal is to also collaborate with satellite manufacturers to reduce space debris, eventually building electric propulsion systems that can support unlimited mission lifetime.
“What we’ve done on Earth, we’re doing in space as well,” Ahmed says. “We’re polluting it with a lot of unnecessary space junk that harms us indirectly. Space debris is another reason why it’s so expensive to access space.”
In the second year of his PhD, Ahmed is in the process of testing a further iteration of the technology and has been talking to small satellite manufacturers and an asteroid mining company that have expressed interest in the team’s plasma engine. The initial prototype was tested at the Japan Aerospace Exploration Agency.
Ahmed joined Conception X to explore the commercialisation potential of his idea and acquire new business skills.
“I learned everything you would need as a scientist looking to transition into the commercial world,” he says. “Initially, we were hoping to apply plasma technology to space as well as clinical medicine, water sterilisation and agriculture. One of the biggest lessons was understanding that you can’t just launch a business and start implementing your concept in every sector. It was a reality check and some much needed grounding.”