Impulse Space said on June 2 it has raised $500 million in Series D funding at a roughly $4.26 billion valuation, bringing the Redondo Beach, California startup's total capital raised to more than $1 billion. The round was co-led by 137 Ventures and BANNER VC, with participation from existing backers including Founders Fund, Lux Capital and Linse Capital.
Building the highways between orbits
Founded in 2021 by Tom Mueller, the first propulsion engineer hired at SpaceX, Impulse is positioning itself as the company that connects launch with destination. Its flight-proven Mira maneuvering spacecraft has flown three missions to date, executing record-setting orbit changes and autonomous rendezvous and proximity operations. The upcoming Helios kick stage is designed to move large payloads from low Earth orbit to medium, geostationary, heliocentric and lunar trajectories on dramatically shorter timelines than legacy upper stages.
A vertically integrated engine family
Alongside its vehicles, Impulse is industrialising a family of in-house engines: Saiph for precision maneuvering, Deneb for high-energy long-distance transport at the core of Helios, and Rigel for throttleable applications such as landers. The company calls Deneb "the most efficient hydrocarbon engine ever built" by a US private company.
From three missions to a manufacturing flywheel
Impulse has more than doubled its headcount in the past year and currently lists more than 200 open roles. New funding will scale propulsion, avionics, autonomy, and manufacturing across facilities in Redondo Beach, Boulder, Washington, D.C., and a growing Mojave test site. "From Earth orbit to the Moon and beyond, the ability to move quickly, precisely, and affordably on orbit is the fundamental capability that will unlock a true space age," said founder and CEO Tom Mueller.
A vote on the post-launch economy
The raise is one of the largest single private rounds in the in-space services category to date. Backers see Impulse as the missing layer beneath the rapidly expanding constellation and on-orbit servicing markets, where customers increasingly need a way to move spacecraft after launch as orbits get more congested and missions get more time-critical. Coverage from Alphabet's $80 billion equity raise and the Anthropic IPO filing shows just how much capital is flowing into the physical infrastructure that AI and the new space economy now require.
Reporting based on coverage from Impulse Space (GlobeNewswire), SpaceNews and Bloomberg.