CU Aerospace is committed to developing propulsion and mission optimisation solutions that utilise the newest ideas at a cost-effective price point while maintaining environmentally conscious and safe alternatives
As the space industry accelerates towards a future defined by smaller, more agile satellites, propulsion has emerged as a critical enabler of capability, safety, and sustainability in orbit. From collision avoidance and precision manoeuvring to orbital transfers and end-of-life deorbiting, advanced propulsion systems are transforming what small and nanosatellites can achieve.
At the forefront of this evolution is CU Aerospace (CUA) – a company that is committed to developing safer, more cost-effective satellite propulsion thrusters using innovative propellant sources. Two of its systems are currently being validated in-orbit as part of the NASA-funded Dual Propulsion Experiment (DUPLEX), marking a significant step toward widespread commercial adoption.
To learn more about CU Aerospace’s key values and its latest developments, The Innovation Platform spoke with David Carroll, President of CUA.
Can you elaborate on the potential of small and nanosatellite propulsion and outline CU Aerospace’s innovations in this area?
In-space propulsion provides satellites with many capabilities, including for collision avoidance, orbit transfer, orbital insertion, rendezvous, proximity ops, docking, station-keeping, precision pointing, deorbiting, and more.
CU Aerospace has invented and developed six new propulsion technologies over the past 14 years. We have 15 patents, both US and European. We developed the Fibre-Fed Pulse Plasma Thruster (FPPT), which uses a spool of Teflon filament fibre as its propellant and is vaporised in very short, high-energy discharge pulses. The Teflon molecules are dissociated, ionised, and electromagnetically accelerated at very high velocity to provide thrust to the satellite. We are currently performing on-orbit testing with the first FPPT flight unit on our DUPLEX satellite.
The second propulsion system on DUPLEX is the Monofilament Vaporisation Propulsion (MVP) system, which also uses a polymer filament – Delrin – as its propellant. The system draws from extrusion 3D printer technology to feed and melt the Delrin fibre propellant. MVP then uses a low-power resistojet to vaporise the Delrin propellant and provide continuous electrothermal thrust with a specific impulse of 66 s. The Delrin fibre is spooled in a cylindrical configuration surrounding a core containing all the electronics inside the package.
Our third system is the CubeSat High Impulse Propulsion System (CHIPS) – a more standard resistojet, also known as a superheater tube. This uses R-134a as its propellant, as opposed to alternatives like ammonia. R-134a is self-pressurising, meaning it stores well and is easy to work with.
The fourth of the systems is our Monopropellant Propulsion Unit for CubeSats (MPUC). This is our highest thrust option, which uses an ethanol and hydrogen peroxide monopropellant mixture. It is a very stable and dilute monopropellant, and it avoids a lot of the hazardous problems that the classic hydrazine has.
Our last and most recent system is our exciting Airbreathing Magnetoplasmadynamic (MPD) thruster. This is similar to a pulsed plasma thruster, but, rather than Teflon, air is injected as the propellant. We were recently selected by the Defence Advanced Research Projects Agency (DARPA) to provide the first airbreathing, very low Earth orbit (VLEO) electric propulsion system to ever fly. This is a major milestone.
How is CUA committed to reducing space debris?
There are now around 54,000 tracked objects in space over 10 cm in size, and 1.2 million space debris objects of 1-10 cm in size. As the Kessler scenario theorises, a possible situation could occur in which the debris field continually grows until it causes a cascade of out-of-control collisions between satellites and debris that creates a self-sustaining chain reaction. This situation would make low Earth orbit (LEO) unusable, and would substantially increase the collision risk for any vehicles trying to reach geosynchronous orbit or the Moon. If Kessler Syndrome were to happen, you would want to use VLEO altitudes because they’re self-cleaning orbits, meaning the density in the atmosphere is high enough that, unless you’ve got propulsion like the MPD system that we’re building, the drag would become so large that the debris would fall and decay really fast.
To meet different customer needs, CUA has developed the family of thruster options that I described earlier. A key benefit of the FPPT system is that it comes in different sizes to suit different needs – we have small ones about the size of a litre, and then large ones of around 30-40 litres in size. The small ones can work as deorbit systems for small satellites like CubeSats, whilst the big ones can carry out active debris removal. In preparation for future demand, CUA is AS9100D certified. This means we have a rigorous quality management system to deliver flight hardware and software to the aerospace industry. We also have a clean room where we can perform precision cleaning, and we are about to expand with 15,000 square feet of new facilities. We will add some new CNC machines, lathes and mills, allowing us to produce larger parts at a faster rate.
As you mentioned earlier, the DUPLEX satellite launched in 2025 as part of a mission to demonstrate two new micropropulsion systems in orbit. Can you elaborate more on the on-orbit operations so far?
The CubeSat is fitted with two of our propulsion systems, the FPPT and MVP. The huge advantage of these systems is that they use polymer filaments as the propellant. As I mentioned earlier, these are friendly for packaging because you can spool them, but another important factor is that these propellants are completely benign inside the satellite and launch vehicle, posing no threat.
In terms of status, the satellite was launched on a Cygnus resupply vehicle to the International Space Station (ISS) in September 2025. We were deployed from ISS in December 2025, and were able to establish communications within an hour of deployment. We then carried out commissioning. We had to decay in orbit a certain amount away from the International Space Station before we could fire thrusters, so we spent the first few months doing a lot of attitude-control-type manoeuvres and reorienting to maximise power.
In March 2026, we began MVP thruster operations, and we’ve demonstrated orbit lowering and orbit raising and orbit maintenance with MVP. We also started operations with the FPPT very recently. So far the thruster is performing as expected, and we’re getting the flight heritage that we really need to reduce perceived risk to customers, help alleviate launch provider concerns, increase commercial potential, and increase customer confidence.
What are the main challenges to consider when designing and building satellites and propulsion systems for VLEO and how does CUA work to tackle them?
CUA is very proud and honoured to have been selected by DARPA for the airbreathing pulsed MPD thruster for VLEO. A major challenge of VLEO is that you have much higher drag at lower altitudes. To give you some perspective, the density at 200 km is about 100 times higher than at 400 km. Therefore, the VLEOSats must have an average thrust that’s greater than or equal to the average drag. One of the advantages of our pulsed MPD is that we can pulse or throttle the thruster faster in higher density regions where the drag is higher, and then dial it back to a slower pulse rate in lower density regions where the drag is lower, maintaining the altitude.
Another big problem for VLEO satellites is atomic oxygen, as opposed to the molecular oxygen that we breathe. Atomic oxygen is a high fraction of the atmospheric composition at VLEO altitudes and is notorious for attacking and damaging many materials. The spacecraft itself and thruster materials must be resistant to these effects.
For an airbreathing system, the mixture of oxygen and nitrogen changes by a factor of two over a 50 km range. Therefore, a thruster must be able to operate at different mixture ratios with minimal interference. One of the advantages of our MPD is that it doesn’t really care what you feed it. It will, for the most part, dissociate and ionise all species and then also electromagnetically accelerate the ionised atoms to very high velocities.
What are CUA’s priorities for the year ahead and beyond?
Our highest specific priority is getting our propulsion technologies flying so that they gain that flight heritage tag and boost customer confidence. As discussed, we already have two systems flying successfully now, and we’re going to be establishing flight heritage for the first airbreathing VLEO thruster with the MPD. All three of these are built on patented technologies. We delivered our first commercial sale of an FPPT system earlier this year, and we anticipate and hope that the orders for our thrusters will grow dramatically over the next five years as people gain confidence.
Last year, CU Aerospace received a 2025 Outstanding Small Business Award from Lockheed Martin, in recognition of our outstanding quality and performance in support of Lockheed Martin’s space programmes. Building on this, a general priority for us is to produce great products and continue to provide outstanding quality and performance to all of our customers.
Please Note: This is a Commercial Profile
