US Space Force Adds Impulse Space and Relativity Space to Launch Contract Bidders

This week the US Space Force brought two more companies into the pool of bidders eligible to compete for its launch contracts—Impulse Space and Relativity Space. For a rocket company, cracking into the lucrative US military launch market is both a sign of maturity, as well as an important source of revenue.

The inclusion of Relativity Space, which is making credible progress toward the launch of its heavy-lift Terran R rocket, is perhaps not a huge surprise. Under the leadership of former Google chief executive Eric Schmidt, the company has continued to work toward bringing the partly reusable rocket to the launch pad.

The addition of Impulse Space, however, was something of a surprise. The company specializes in building spacecraft for in-space operations, rather than launching from Earth.

“I think it’s fair to say that Phase 3 did not contemplate this,” said Eric Romo, president and chief operating officer of Impulse Space, in an interview. “However, the Space Force has been really clear that they’ve got a lot of demands for high-energy launch, especially at GEO, and they don’t have a lot of supply.”

How the competition works

Phase 3 refers to the third iteration of the military’s launch program, known as National Security Space Launch Phase 3. It allows companies to bid on “task orders” for launches between the period of 2025 and 2029. Launches typically take place one to three years after a contract is awarded. To further complicate things, there are two lanes of this program.

“Lane 2” is for more established rocket companies, SpaceX and United Launch Alliance, to handle the military’s most valuable payloads. “Lane 1” was created to bring newer launch companies into the competition and allow them to bid for more “risk tolerant” missions. The military has set aside about 30 launches to be awarded to Lane 1 bidders, worth a total of about $5.6 billion.

Romo said Impulse Space has been speaking with the government about the possibility of joining Lane 1 for a couple of years, and said US military officers have shown a great willingness to be flexible in order to meet their launch needs, particularly to reach high-energy orbits such as geostationary space.

Impulse Space is developing a “kick stage” it calls Helios, which can provide up to 9 km/s of delta-V to a payload, rapidly boosting it from low-Earth orbit to geostationary orbit about 36,000 km above the Earth’s surface. Essentially, this allows the company to transform a medium-lift rocket, such as SpaceX’s Falcon 9 vehicle, and give it the performance of a larger and more powerful rocket.

Helios still under development

Under Lane 1, Impulse Space will contract with the Space Force to provide end-to-end service, procuring a launch vehicle and then stacking the Helios stage and designated satellite into the payload fairing of the rocket. Helios is compatible with a range of rockets, from the Falcon 9 to boosters built by United Launch Alliance, Rocket Lab, Relativity Space, and more.

To be eligible to bid on Lane 1 contracts, Impulse Space must first successfully demonstrate Helios in flight. Following a post-flight review by the US Space Force, Impulse can seek to win task orders. Launches could follow 18 to 24 months later.

According to Romo, development of Helios continues to progress well. The company recently shipped a “run tank” to its test stand at the Mojave Air & Space Port in Mojave, California. A run tank is designed to be loaded with propellant many times and put through a series of rigorous tests to ensure its ability to hold pressure and perform in flight. A flight tank is typically lighter, as it will not be subjected to the wear and tear of multiple uses in flight.

Romo also said the “Deneb” engine that powers the Helios vehicle is doing well in testing. Powered by liquid oxygen and methane, Deneb has a thrust of 15,000 pounds. The company is targeting a 2027 debut of Helios in flight, launching on a Falcon 9 rocket.

Impulse Space and Relativity Space are the newest companies to be on-ramped to Lane 1 of the national security launch program. Rocket Lab, with its Neutron rocket, and Stoke Space, with the Nova vehicle, were added in March 2025. SpaceX, United Launch Alliance, and Blue Origin were the original awardees in 2024.