The 3D-printed metal engine, designed and built entirely by Space Machines Company’s (SMC) propulsion team, has achieved burn times of up to 65 seconds, with more than 1,200 seconds of cumulative testing and over 40 successful restarts. The engine will power SMC’s upcoming rapid response vehicle, Optimus Viper, a satellite platform built for orbital manoeuvring and space domain awareness missions.
The Scintilla produces 50 newtons of thrust at 92 per cent efficiency, surpassing the company’s original target of 90 per cent, with engineers confident they can push performance closer to 100 per cent in future versions.
“We’ve made faster progress than even our most ambitious schedules predicted,” SMC co-founder and chief executive Rajat Kulshrestha said. “The engine has reached steady-state conditions and shown it can operate for extended periods – limited only by the propellant we feed it. We can now run this engine for minutes at a time, which is essential for our satellite missions.”
Unlike most satellite manufacturers, which typically buy in propulsion systems, SMC has opted to build its own. The move reflects the company’s view that propulsion is central to satellite capability.
“Propulsion is absolutely core to what Space Machines needs to do,” said Ian Partis, SMC’s vice president of engineering and mission operations.
Partis added, “The better the propulsion system and the more delta-v available, the greater the range of orbits we can access – and the faster we can get there. In many ways, the Optimus Viper is essentially a propulsion system with a payload on top.”
The Scintilla engine has passed through all design and testing milestones, including critical design review. Its final capabilities include:
- Extended burn times: 65 seconds continuous operation, with potential for longer runs.
- High efficiency: 92 per cent, with a pathway to 99 per cent and beyond.
- Scalability: engine architecture able to deliver up to 10 times more thrust with minor adjustments.
- Restart capability: multiple ignition cycles, enabling complex orbital manoeuvres.
- Robustness: proven reliable under varying test conditions.
Engineers say the system can be scaled up from its current 50 newtons to between 100 and 500 newtons with relatively modest modifications.
Kulshrestha credited the success to SMC’s “build-to-learn, learn-to-build” philosophy, underpinned by the company’s fully integrated in-house design, manufacturing and testing set-up.
“When our team found an issue during testing, they could diagnose it within 10 minutes and implement fixes immediately,” he said. “That kind of responsiveness just isn’t possible when you’re dependent on external contractors.”
With Scintilla now complete, SMC is moving into full subsystem integration, including flight-ready valves and propellant management systems, ahead of deployment on Optimus Viper.
“This achievement shows that small, focused teams can deliver world-class propulsion on accelerated timelines,” Partis said. “By putting propulsion at the heart of satellite design, we’re taking a fundamentally different approach – one that prioritises manoeuvrability and rapid response.”