Impulse Space: Funding Rounds, Investors & CEO

About Impulse Space

Impulse Space builds spacecraft that move satellites and other payloads after a rocket drops them off in low Earth orbit. It sells these trips to satellite operators, the U.S. Space Force and NASA. Mira is a small, highly maneuverable spacecraft that carries and releases payloads. Helios is a kick stage, an extra engine stage, designed to carry large satellites from low Earth orbit to geostationary orbit in under a day.

Tom Mueller founded Impulse in 2021 and is its CEO. He was a founding member of SpaceX, where he led propulsion for the Falcon rockets and the Dragon spacecraft. Eric Romo is president and COO. The company is headquartered in Redondo Beach, California, and also has a factory near Boulder, Colorado, an office in Washington, D.C., and a test site in Mojave. Mira has launched four times since November 2023. Customers include SES, Astranis and Infinite Orbits, and the Space Force has ordered Mira spacecraft for its VICTUS SALO missions.

Funding Rounds (SEC Form D)

First sale	Filed with SEC	Amount sold	Investors	Avg. check	Terms	Filing
Apr 8, 2026	Jun 2, 2026	$499,832,346of $500.0M target	63	$7.9M	EquityRule 506(b)	Form D ↗
May 9, 2025	Jun 11, 2025	$294,526,573of $299.8M target	47	$6.2M	EquityRule 506(b)	Form D ↗
Jul 21, 2023	Aug 3, 2023	$38,749,892of $45.0M target	31	$1.2M	EquityRule 506(b)	Form D ↗
Mar 24, 2022	Apr 4, 2022	$19,999,997fully sold	38	$526K	EquityRule 506(b)	Form D ↗
Total, four offerings		$853,108,808

First sale is the date the first investor in the offering committed to invest. Companies must file Form D within 15 days of that date, so filing dates run later.

Rounds announced by Impulse Space

What the company said publicly about its funding. Announced amounts can differ from Form D figures: an announcement can combine several closings, and some money is raised without a Form D.

Announced	Round	Amount	Investors	Source
Jun 2, 2026	Series D	$500M	137 Ventures and BANNER VC (co-leads), Founders Fund, Lux Capital, Linse Capital; extended on Sept. 16, 2026 by $308M from 137 Ventures, BANNER VC, DFJ Growth, Linse Capital, Lux Capital and Valor Equity Partners, for $808M in all	impulsespace.com ↗ Reuters ↗ TechCrunch ↗ impulsespace.com (extension) ↗
Jun 3, 2025	Series C	$300M	Linse Capital (lead), DFJ Growth, Valor Equity Partners, Founders Fund, Lux Capital, RTX Ventures, DCVC, Airbus Ventures, Spring Tide, First Principles Group, Balerion Space Ventures, Tamarack Global, Trousdale Ventures	impulsespace.com ↗
Oct 1, 2024	Series B	$150M	Founders Fund (lead), Lux Capital, Spring Tide, DCVC, Airbus Ventures, Alumni Ventures, Balerion Space Ventures, RTX Ventures, Tamarack Global, 137 Ventures, Elysium, First Principles Group, Island Green, Overmatch, Trousdale Ventures	impulsespace.com ↗ CNBC ↗
Jul 24, 2023	Series A	$45M	RTX Ventures (lead), Founders Fund, Lux Capital, Airbus Ventures, Space Capital	impulsespace.com ↗
Mar 29, 2022	Seed	$20M	Founders Fund (lead), extended on June 16, 2022 by $10M from Lux Capital, for $30M in all	impulsespace.com ↗ impulsespace.com (extension) ↗

Why Investors Backed Impulse Space

Investors backed Impulse Space because it sells the step that comes after launch. Rockets now reach low Earth orbit cheaply and often, but many satellites must go much higher or move on short notice. Impulse builds spacecraft for both jobs, and the Space Force and large satellite operators have signed contracts. Its founder and CEO, Tom Mueller, also led propulsion at SpaceX.

The problem it targets

Impulse's case is that once a rocket drops off a satellite, moving it further is slow and expensive. An operator bound for geostationary orbit must pick between scarce heavy-lift rockets and electric thrusters that take months to raise the orbit. Military satellites face a second problem. People long assumed GPS and other key satellites were safe because their orbits were hard to reach, Impulse president Eric Romo wrote in 2025. That is no longer true, he argued. BANNER VC's Adam Ramada put it simply: “As activity in orbit increases, in-space mobility becomes foundational.”

What the product does

Mira carries up to 300 kg of payload and maneuvers with eight Saiph thrusters. On its first flight in 2023, it raised its orbit by 150 km in 75 seconds. Helios, the bigger vehicle, rides a medium-lift rocket such as Falcon 9 to low Earth orbit. Its Deneb engine, which Mueller designed, then pushes large satellites to geostationary orbit in under a day. Impulse also plans a yearly GEO rideshare, Caravan, from 2027. In July 2026 it unveiled Electra, an electric propulsion system.

Progress so far

In June 2026 Impulse had “hundreds of millions of dollars” in customer contracts, up from nearly $200 million a year earlier. SES signed a multi-launch deal for Helios in May 2025, and Astranis booked a Helios mission, both for 2027. Infinite Orbits has booked four flights through 2029, SatNews reported. The Space Force made three awards in 2026. Helios won a spot in its NSSL Lane 1 launch program. Two more contracts, worth $28 million each, cover Mira flights for VICTUS SALO and for a space domain awareness mission. Headcount more than doubled in the year to June 2026.

Who backs it

137 Ventures and BANNER VC co-led the $500 million Series D in June 2026. Reuters reported a $4.26 billion valuation. A $308 million extension in September took the round to $808 million. Founders Fund led the 2022 seed and the 2024 Series B. RTX Ventures led the 2023 Series A, and Linse Capital led the 2025 Series C. Linse founder Michael Linse is a director. His firm renamed itself Lithos Capital in October 2026. South Korea's Hanwha Asset Management also joined the extension, the Korea Herald reported.

How the market is moving

Rivals are raising large rounds. True Anomaly, a defense space startup, raised $650 million in April 2026 at a $2.2 billion valuation, SpaceNews reported. In March, Swiss startup Pave Space raised $40 million for a transfer vehicle much like Helios. The Space Force is also opening launch work to newer firms. In July it added Impulse and Relativity Space to NSSL Lane 1, bringing the field to seven companies, Via Satellite reported.

We wrote this summary from public statements by Impulse Space and its investors. It is not investment advice.