Impulse Space Raises $300M for In-Space Propulsion
By Jane Doe – Jul 15, 2025
Funding Milestone Accelerates Expansion
This week, Redondo Beach–based Impulse Space closed a $300 million Series C round, doubling its valuation and cementing its position as a leader in in-space propulsion. Coming just nine months after a $150 million raise, this influx of capital is among the largest for a non-launch space startup to date. Investors include Prime Movers Lab, Valor Equity Partners, and strategic aerospace funds.
“This capital allows us to scale manufacturing, deepen R&D in electric propulsion, and expand our mission services portfolio,” said CEO Eric Romo.
Impulse Space’s technology portfolio—ranging from its initial Mira small satellite tug to the upcoming heavy-duty Helios kick stage—has attracted interest from NASA’s CLPS program and the U.S. Space Force. In May 2025, the company won a $50 million NASA contract to provide orbital transfer services for lunar cargo missions under Artemis logistics.
Company Growth and Facilities Upgrade
- Employees: 250 today, targeting 350 by year-end
- Current facility: 60,000 ft² in Redondo Beach, CA
- New HQ plan: 120,000 ft² manufacturing and test complex in El Segundo
Engineering lead Tom Mueller—founder of SpaceX’s propulsion team—notes that the new site will host a 500-kW Hall-effect thruster test bay and an additive manufacturing line for high-temperature electric propulsion parts.
Mira: High-Thrust, Rapid-Response Tug
Impulse’s first product, Mira, is a hypergolic-like chemical tug using nitrous oxide and ethane. Key specs:
- Dry mass: 180 kg
- Propellant load: 350 kg
- Max thrust: 250 N
- Delta-V (100 kg payload): 900 m/s
- Operational life: 18 months with redundancy in thruster valves
Since its debut in Q4 2023, Mira missions have delivered hosted payloads across GEO slots in under two days. The U.S. Space Force’s recent GEO surveillance exercise leveraged Mira to reposition electronic warfare sensors in hours—demonstrating rapid-response capability formerly reserved for government tugs.
Helios: Multi-Ton Orbital Transfer Vehicle
Building on Mira’s success, Helios is designed as a kick stage compatible with Falcon 9, Falcon Heavy, and potentially Vulcan Centaur. Highlights include:
- Thrust: 15,000 lbf from a high-efficiency bipropellant engine (MMH/NTO)
- Payload capacity: 2 ton to GEO, up to 11 ton to Mars transfer injection
- Specific impulse: 330 s (chemical mode), with optional 1,800 s Hall-effect electric upper stage
- Power subsystem: 100 kW solar arrays supporting electric thrusters and avionics
Three Helios units are slated for Falcon 9 launches in Q3 2026. Integration tests with SpaceX are ongoing, including a gimbal compatibility check and payload fairing separation sequence validation at SpaceX’s Hawthorne facility.
Market Landscape and Competitive Positioning
The in-space tug market has seen entrants like Astral Technologies and Orbital Access, but Impulse’s combined chemical and electric portfolio offers unmatched flexibility. A recent analysis by Space Capital forecasts a $4 billion market by 2030 for orbital transfer vehicles (OTVs) and “last-mile” services.
Key differentiators:
- Dual-mode propulsion (chemical for high delta-V, electric for long-duration stationkeeping)
- Modular hosting ports supporting 50+ payload adapters
- Rapid mission planning via onboard AI-assisted navigation
Technical Deep Dive: Electric Propulsion Systems
Impulse’s R&D team is scaling Hall-effect thrusters beyond 150 kW, targeting specific impulses over 2,500 s. Advanced materials like carbon-carbon grids and molybdenum discharge channels are being tested in thermal vacuum chambers at 10⁻⁶ Torr. A recent 1,000-hour life-cycle test showed over 95% efficiency retention, a benchmark few competitors match.
Expert Opinions
“Impulse Space is redefining on-orbit logistics with a multi-modal approach—this will be critical for large-scale lunar infrastructure,” said Dr. Maria Vasquez, senior propulsion engineer at NASA JPL.
“Their agile manufacturing and in-house testing capability give them an edge on lead times and cost structure,” added John Kim, aerospace analyst at Jane’s Defence.
Interplanetary Mission Implications
By boosting Mars injection payloads from under 2 tons to over 10 tons, Helios could catalyze a new wave of robotic explorers and even small crewed missions. Impulse is in discussions with the European Space Agency (ESA) for a demonstration mission to Phobos as early as 2028.
Looking Ahead
With new funding, Impulse Space aims to:
- Complete Helios test campaign by Q2 2026
- Deploy next-gen electric tugs by 2027
- Expand mission services into LEO depletion gliders and debris removal
As launch becomes commoditized, Impulse Space is staking its claim on the next frontier: precision mobility across cislunar space and beyond.