5 mins read 30 Mar 2021

Valiant Space demonstrates its bi-propellant space thruster

Last month, a Brisbane based startup, Valiant Space, commenced testing of its “non-toxic” space-based thruster for use in small satellites. This testing marks the first step towards creating an Australian designed and manufactured liquid-fuelled rocket engine developed for this growing market. 

The bi-propellant thruster during testing. Valiant Aerospace hope that this new thruster design will appear to small commercial satellite companies looking for an alternative to hydrazine and ion based thrusters. Credit - Valiant Aerospace

Valiant Space is looking to develop a non-toxic space thruster aimed directly at the small satellite market. They are hoping to create an Australian designed and made liquid rocket engine. In 2019 Valiant Space, won $20,000 from the iLab Accelerator program, a startup accelerator run by The University of Queensland (UQ). 

The team at Valiant Space wanted to do something bold, and according to Co-Founder and CEO, Andrew Uscinski that bold thing was to “build a rocket engine before we graduate”. They also wanted to contribute to the wider space industry and grow Australian space capability. 

The team, who all met whilst studying engineering at UQ have taken a dream of contributing to the space industry and brought it a step closer with the successful test of their liquid fueled rocket engine. They hope that by the end of 2021 they will be able to start in space testing with the help of another local Queensland-based business, BlackSky Aerospace. 

What is the alternative?

Filling up spacecraft with Hydrazine is not only a dangerous process it is a costly one. Using Hydrazine can be a barrier to many small satellite companies which cannot afford the financial costs or the time costs due to the limited availability of companies willing to manage the fuel. Credit - NASA

One of the most common fuels used for spacecraft and satellite propulsion is Hydrazine. Hydrazine has been used as a propellant for over 100 years, and is still in use today. However there are many challenges with Hydrazine, including its toxicity to humans and it’s volatility. 

Hydrazine also requires careful handling and storage, which comes with great cost. Hydrazine is a hypergolic propellant, meaning that it requires no ignition once it is mixed with an oxidiser, this makes it ideal for small spacecraft where every extra system takes up valuable weight. 

However, Hydrazine is so toxic that on the return of Space X’s Crew Dragon capsule last year, the crew had to wait to disembark due to trace amounts of unburnt hydrazine being detected around the capsule. It does however produce a large amount of thrust, quickly, which is perfect for responsive on orbit maneuvers, like moving to avoid a collision for example. 

A current alternative to Hydrazine thrusters are electric or Ion thrusters, which require a lot less space onboard and have none of the risks associated with chemicals such as Hydrazine.The energy output of Ion thrusters is a form of electric propulsion, created by accelerating ions in an electric field before firing them out of a nozzle to create spacecraft movement. However, these kinds of thrusters, whilst very efficient and have a high specific impulse, do not have the instantaneous thrust capabilities of chemical systems. These low thrust, high specific impulse propulsion systems are great for highly efficient propulsion over long time frames and long distances but not so great for quick changes, which means it may take many months to get your satellite into the correct orbit. 

Green fuels are seen as the future, particularly in small satellites, and finding an alternative for the highly flexible Hydrazine, that gives similar acceleration performance with less risk, is a challenge that even NASA is looking to solve.

A customisable product

Valiant Space tested their first prototype engine out at the Funny Farm test range, Goondiwindi, late in 2020. Credit - Valiant Aerospace

According to the team, the time is now in the Australian space industry which has enabled Valiant Space to have the start it has. Government support, public awareness thanks to organisations such as SpaceX and the growth of opportunities to fill in niche products and services have all contributed to an opportunity for Valiant Space to grow.

Valiant Space are looking to develop “a real alternative to the current Hydrazine systems.” said Uscinski. This bi-propellant system will combine two different liquids which will produce thrust. This should be cheaper and easier to integrate with a higher thrust then electric or ION systems. 

Whilst the current test engine is a little larger than they hope the final product will be, they are already looking to more than just the engine itself. With a final customisable and scalable product they hope that their system will fit in CubeSats as small as 6U but they are aiming for the 50kg+ satellite market. Whilst they are aware they are not the only company looking at developing propulsion systems that use “green rocket fuel”, they believe they have some unique advantages. 

“What a lot of other “green propellants” struggle with is that they have the caveat of [needing] to be warmed up over an extended period of time before they can be used. [Which leads to] losing the commercial viability of really giving a fast response time.” said Uscinski. The aim for Valiant Space’s engine is to be ready to go with no lead time and be easy for satellite owners to fuel themselves. 

The team at Valiant Space will be using this year to refine their product and understand the needs of this growing marketplace. But it is not just the engine itself they are considering. According to Uscinski, they are also looking to develop custom tankage and feed systems, which all add up to contribute a significant mass and volume to many satellites. 

Uscinski went on to say, “the density of our propellant compared to Hydrazine is a little bit less but what we really have as our advantage here is that our propellants are self pressurising that means we mitigate the need either in the tank itself, any pressurisation, let alone a separate tank that we store on board”. This lack of a requirement for pressurisation, means they are able to save a lot of tank space and significantly reduce the complexity of the system. 

The Valiant Space team is made up of Uscinski and CTO Michael Douw, with an advisory board including the founder of Saber Astronautic, Jason Held and Andrew Barton, who has spent time with Southern Launch, Fleet Space and the European Space Agency.