Firing Up the Future
The primary principle behind propulsion – Newton’s third law of motion – seems simple enough: for every action, there is an equal and opposite reaction. Rocket propulsion systems utilize combustion that in turn generates thrust.
But in reality, designing, building, and testing rocket propulsion systems is anything but simple. It requires extreme precision under high-stress, high-temperature conditions, often while integrating advanced materials and novel propellants, which put today’s engineering and manufacturing capabilities to the test.
Exploring the Next Generation of Propellants
As space missions become more ambitious and frequent, the need to accelerate innovation while reducing cost and environmental impact becomes more intense. New propellant technologies have great promise to make space flight more performant, affordable, and sustainable.
Traditionally, most rockets have relied on some combination of solid and liquid fuels. Solid propellants are energy dense and typically easier and safer to store. But they are difficult to control, and once ignited, they burn to completion.
On the other hand, liquid fuels are easier to control, are highly performant, and have been used for more than 60 years. However, they pose storage and handling challenges and can be very harmful to the environment.
A growing number of gel, hypergel, and hybrid fuels are emerging with the potential to improve safety, performance, and environmental impact in launch operations. NASA is also evaluating alternate space nuclear propulsion technologies for more efficient in-space propulsion options. However, these are largely experimental at this stage; additional testing is needed before they are used more widely.
Delivering Precision Testing for Our Nation’s Space Missions
Propulsion systems present unique challenges when compared to other space system testing. For example, when evaluating guidance, navigation, and control systems, teams can assess most variables and simulate entire launches on a series of avionics computers.
While some aspects of propulsion system testing can be simulated on computers, many variables can only be tested in live exercises that demonstrate how various components perform and react under real launch conditions.
As the space industry continues to evolve, the Department of Defense (DOD), NASA, and commercial providers rely on expert test and evaluation partners who understand the intricacies of various component materials and propellants and can design safe testing protocols to mitigate risk while evaluating emerging fuels that will power tomorrow’s space flights.
Astrion has extensive experience testing and evaluating myriad propulsion fuels and systems for DOD and NASA. We support the Arnold Engineering Development Complex (AEDC) under the Test Operations and Sustainment II contract, where we test and evaluate weapon, propulsion, aerodynamic, and space systems at realistic conditions through modeling, simulation, and ground and flight test facilities across eight states.
Astrion also provides the core hands-on fabrication, assembly, integration, and test capabilities critical to propulsion systems development for NASA Marshall Space Flight Center. For example, we supported the successful pressure test on a sub-scale version of an inflatable habitation module designed for the world’s first commercial space station. We also tested NASA’s Space Launch System liquid hydrogen tank to demonstrate it could withstand more than 260% of forces expected during Artemis lunar missions.
In these propulsion testing programs, we focus on several key factors:
- How does fuel type affect test design? It’s critical to understand how various fuels and oxidizers work together and how to develop and adjust tests accordingly. When testing a new fuel in development, we must evaluate the various properties or attributes. Are they corrosive? Are they stable? Do they require cryogenics? As we move into subscale testing, can we produce the required thrust? And importantly, as we progress to larger system testing, does our understanding scale?
- How can we work together to create the most representative environment? To be successful, propulsion testing initiatives must be very collaborative. As our team works with each new entity exploring test capabilities at AEDC, we make sure we have a complete picture of what they are trying to achieve – from the conditions they want to replicate to the performance metrics they want to measure. We work seamlessly across test engineering, facility operations, program management, and our customer teams to create an environment that is as close to the operational environment as possible.
- How do we protect mission confidentiality and security? Many programs have unique classification requirements. We understand and emphasize who must be involved, who can be involved, and specific requirements for transporting and storing classified materials and systems.
- How can we take advantage of synergies? While customer information is often proprietary, we look for opportunities to share test infrastructure or lessons learned across programs – saving time and resources without compromising confidentiality.
As the space industry pushes the boundaries of what’s possible, propulsion testing serves as a critical enabler of safe, reliable, and high-performance missions. By combining deep technical expertise with flexible, mission-focused test capabilities, Astrion is validating the next generation of propulsion systems that will carry us farther, faster, and more sustainably into space.

Author
Rusty Powell
Vice President
Space Integration and Technical Fellow