Impulse Space announced a $500 million Series D funding round on Tuesday, bringing total capital raised to over $1 billion since its founding five years ago. The company, established by SpaceX veteran Tom Mueller, focuses on improving spacecraft mobility through advanced propulsion systems.

Impulse has already completed three missions using its Mira small spacecraft, which launched in 2023 with a novel propulsion system powered by non-toxic propellants—nitrous oxide and ethane. After unveiling the larger Helios kick stage, commercial customer demand exceeded expectations, prompting investors to push for rapid expansion despite the company not actively seeking new funding.

The US Space Force has shown growing interest in satellite mobility capabilities, viewing them as essential for countering potential threats from Russian and Chinese spacecraft in low-Earth and geostationary orbits. Impulse also aims to provide landing services for NASA's lunar initiatives, targeting the 1-ton-class payload market.

President and COO Eric Romo noted the rapid evolution of space markets, pointing to sudden demand for concepts like orbital data centers. This funding positions Impulse to scale operations amid increasing competition in the orbital maneuvering sector.