Key facts
- Impulse Space is developing a "kick stage" called Helios.
- Helios can increase a payload's velocity by up to 9 km/s.
- The stage is designed to be integrated with existing medium-lift rockets.
- Successful flight demonstration is required for Impulse Space to bid on Space Force contracts.
- The company targets a 2027 flight debut for Helios.
Impulse Space is developing a "kick stage" named Helios, designed to enhance the performance of existing rockets for military launch contracts. This technology allows a medium-lift rocket, such as SpaceX's Falcon 9, to achieve the capabilities of a larger vehicle, providing up to 9 km/s of delta-V to boost payloads from low-Earth orbit to geostationary orbit.
Under Lane 1 of the national security launch program, Impulse Space will contract with the Space Force to provide end-to-end launch services, integrating its Helios stage with a chosen rocket and satellite. Helios is designed for compatibility with a range of launch vehicles, including those from SpaceX, United Launch Alliance, Rocket Lab, and Relativity Space.
To be eligible for Lane 1 contracts, Impulse Space must first successfully demonstrate Helios in flight. Following a review by the US Space Force, the company can pursue task orders, with potential launches occurring 18 to 24 months later. The company is currently progressing with development, having shipped a "run tank" to its test stand in Mojave, California, and is testing its liquid oxygen and methane-powered "Deneb" engine, which produces 15,000 pounds of thrust.
Impulse Space and Relativity Space are the latest companies to join Lane 1 of the national security launch program. They join Rocket Lab and Stoke Space, added in March 2025, and the original awardees from 2024: SpaceX, United Launch Alliance, and Blue Origin. Impulse Space is targeting a 2027 debut for Helios in flight, launching on a Falcon 9 rocket.