American space company Impulse Space has submitted plans to develop a new orbital transfer vehicle that could deliver satellites to geostationary and other orbits. The company announced on January 17 that it was working on the Helios stage. It will use a liquid oxygen and methane engine and will be able to deliver satellites weighing up to 5,000 kilograms to low or geostationary orbit in less than a day.

Tom Mueller, CEO of Impulse Space and co-founder of SpaceX, emphasized that Helios will significantly expand the capabilities of similar vehicles such as SpaceX’s Falcon 9, not just for higher orbits. “SpaceX got the party started by opening up access to low Earth orbit,” Mueller noted. “Impulse wants to achieve the same thing, but for all other orbits.”

Helios will be used as an additional stage for the Falcon 9 rocket, allowing satellites to be delivered to geostationary orbit in less than 24 hours. This will allow up to two-thirds of the Falcon Heavy’s capabilities to be used, which is more cost-effective and does not require abandoning the central unit, Muller said.

To accomplish this mission, the Helios stage will be equipped with an engine called Deneb that will provide 15,000 pounds of thrust (about 66,723 kN). The company plans to begin testing the engine this summer, and the first Helios flight is planned for early 2026. It is assumed that there will be four to six flights per year.

The company currently has an agreement with an unknown customer and is in positive discussions with other potential users. Martin Halliwell, former CTO of satellite operator SES and consultant to Impulse, said being able to deliver satellites to geostationary orbit in hours rather than weeks or months made a big difference for customers. This will allow satellites to start up faster, reduce radiation exposure and reduce payload mass. Halliwell emphasized that Helios will open new opportunities for MEO and GEO* operators beyond current limitations.

Helios is designed to be compatible with a wide variety of launch vehicles. Muller noted that Helios could significantly increase the capabilities of not only the Falcon 9 but also other mid-sized vehicles, including a rocket with striking features like the Vulcan.

Impulse is also considering launching Helios as a complement to its other spacecraft, called Mira, which successfully completed its first mission last November. Mira has been part of a joint mission with SpaceX called Transporter-9 and has already demonstrated its effectiveness in launching cubesats; currently in the process of testing the engines.

Impulse Space has approximately 100 employees and raised $45,000,000 in a Series A round in July 2023. The company is currently working on a Series B round to secure development of the Helios project. Mueller said they would need just one additional round to make the device and satellite business profitable.