Impulse Space Secures $500 Million in Series D Funding at $4.26 Billion Valuation

Impulse Space raised $500 million in Series D funding on June 2, 2026, valuing the orbital transfer vehicle startup at $4.26 billion. The round was co-led by 137 Ventures and Banner VC, pushing total capital raised to over $1 billion. Founded by former SpaceX propulsion lead Tom Mueller, the Redondo Beach, California-based company develops spacecraft that maneuver satellites and payloads after launch. The investment underscores surging demand for post-launch logistics as commercial space activity accelerates beyond low Earth orbit. Impulse has flown three missions and holds hundreds of millions in customer contracts. Its Helios transfer vehicle, set for a 2027 debut, aims to drastically cut satellite travel time—offering same-day orbit placement versus months. The funding arrived amid heightened space-sector enthusiasm following SpaceX’s filing for a historic initial public offering, which sparked investor interest in startups led by ex-SpaceX executives.