Impulse Space's in-space mobility bet scales to a $500M Series D

Impulse Space, founded by SpaceX engine guru Tom Mueller, builds highly maneuverable spacecraft for in-space mobility: Mira, an orbital transfer vehicle targeted at US Space Force and commercial customers, and Helios, a high-energy vehicle designed to carry satellites from low Earth orbit to higher orbits.

That as launch gets cheap, the bottleneck moves into space itself: payloads in the wrong orbit need tugs that deliver, deploy and rendezvous — a layer Impulse could own.

Cheap rideshare launches changed the economics of getting to space but not the destination: rockets like SpaceX's Transporter missions deliver dozens of satellites to a generic low Earth orbit, leaving each payload to reach its exact orbit by itself. Impulse Space, founded by the SpaceX engineer behind the company's engines, bet that in-space mobility was the missing layer — a business of moving, deploying and servicing satellites after launch, the way trucks handle the last mile on the ground.

Impulse's first Mira flew in November 2023 on Transporter-9, and the second launched January 14, 2025 on Transporter-12, a rideshare mission hauling 131 payloads. On LEO Express-2, Mira deployed two CubeSats — FOSSA Systems' FOSSASat TAT-0 and SatRev's Bluebon for RIDE! — hosted an imaging payload from HEO, and on February 27, 2025 completed two engine burns within a single orbit, a first for the vehicle that showed mission planners could fit several maneuvers into minutes or hours. Privately, the same spacecraft then executed the Remora mission: in late October 2025 it autonomously approached the first Mira to within about 1,250 meters using a single lightweight camera and Starfish Space's guidance software, a rendezvous the two companies revealed on December 15, 2025.

On June 2, 2026 Impulse announced a $500M Series D led by 137 Ventures and BANNER VC with participation from Founders Fund, Lux Capital and Linse Capital, to hire up to 200 engineers and build more vehicles. The round followed a setback — the third Mira flight in late 2025 lost much of its propellant early to a navigation problem — with the company preparing another Mira mission before the end of 2026.

Rideshare launch commoditized getting to space but left the destination unsolved, so Impulse built the vehicle that finishes delivery — a market that grows as launch prices fall.

Mueller's propulsion heritage let the company start with engines and expand into full spacecraft, keeping control of the thruster technology that makes precise orbital maneuvers possible.

Missions were the marketing: deploying satellites, hosting payloads and completing two burns in one orbit gave buyers observable proof of maneuverability before the company asked for scale capital.

The Remora rendezvous showed Impulse could perform autonomous proximity operations, positioning it for defense buyers like the US Space Force that need tugs to maneuver near other spacecraft.

In frontier markets, operational demos are the pitch: two engine burns in one orbit and an autonomous rendezvous earned Impulse credibility that a propulsion pedigree alone could not have bought.

As of June 2026 Impulse Space had flown two Mira vehicles on three missions, the latest in late 2025 marred by a navigation problem that consumed much of its propellant early. The $500M Series D announced on June 2, 2026 — led by 137 Ventures and BANNER VC with Founders Fund, Lux Capital and Linse Capital — was earmarked for hiring up to 200 engineers and expanding vehicle production, with president and COO Eric Romo arguing that hardware engineering still needed people, not just AI tools. A new Mira mission was expected before the end of 2026.