Interview: Game-Changing Spacecraft Propulsion with Phase Four

Simon HalpernOff the back of their successful attendance at Space Tech Expo USA 2018, we caught up with Simon Halpern, Founder and CEO of Phase Four to learn more about their game-changing propulsion system. 


Phase Four develops propulsion systems for small satellites, a part of the satellite industry that is set to expand rapidly in the coming years. What made Phase Four specialize in propulsion systems for small satellites, rather than all satellites?

In fact, Phase Four’s propulsion systems are designed to meet demand from the entire satellite industry. Designed with tomorrow’s satellites and constellations in mind, our electrode-less RF thruster is the smallest plasma propulsion system available today, and can be scaled for use from cubesat to smallsat to school-bus-sized satellites. By eliminating the most common failure points in incumbent technologies – electrodes, high-voltage electronics and complex fabrication – we’ve built a system that is inherently scalable, reliable and offers high performance with baked-in manufacturability.


The space industry is miniaturizing electronics and other components to fit smallsats. What were the challenges for Phase Four when it came to propulsion system miniaturization?

One of our inherent strengths – and key differentiators – is that we anticipated the need for small, modular propulsion from the beginning. As a result, our RF thrusters are built around the cubesat standard and leverage decades of advances in telecom to accelerate our ability to mass manufacture a small, high-performance system.

 Phase four propulsion


Phase Four recently signed contracts with NASA and Astro Digital, a startup based in Silicon Valley; two very different organizations, both requiring an advanced propulsion system for small satellites. The small-satellite industry is open to many more professionals than the ‘traditional’ satellite market. How will this diversified market change the industry?

We welcome the diversification of the satellite market and believe this is one of the key areas that will help to drive the swift growth and iterations we need to meet the market opportunity. As the industry attracts talent from different fields – large-scale manufacturing, machine learning and design – it begins to look much more like Silicon Valley, which values innovation, scalability and maximizing different skill sets to achieve incredible goals.


What are Phase Four’s next steps in terms of technology development?

We are firing on all cylinders, so to speak, here in El Segundo. We’re working to deliver thrusters to our first set of commercial and government customers, which will ultimately be used on spacecraft missions to demonstrate their ability to support future operational small-satellite missions. In tandem, we’re in the final stages of our most recent performance testing. The last tests in April, done in cooperation with the Aerospace Corporation, showed that our thrusters offer the same performance as today’s state-of-the-art Hall thrusters, but without all the pain points of those systems. And finally, we are focused on demonstrating our thruster capabilities in a soon-to-be-announced launch, so stay tuned for that!


You recently exhibited at Space Tech Expo USA. How was your experience at the show?

The show was (and always is) a great opportunity to meet face to face with everyone in the industry. Our booth was busy all day, every day, where we were fielding increasingly sophisticated questions around the performance and use cases for our thrusters.

Phase Four