ISPTech Raises €5.5M Seed Round to Redefine How Spacecraft Manoeuvre in Orbit

ISPTech, a German space tech company building propulsion systems that let spacecraft manoeuvre with speed and agility in orbit, has raised €5.5 million to deploy its advanced, non-toxic propulsion solutions for operational space missions.

The funding comes as demand for easy to use, cost-efficient and scalable propulsion solutions rises sharply. This shift reflects a broader industry transition towards safer, more flexible and more affordable in-orbit mobility, which ISPTech aims to take a defining role.

The round was led by Join Capital, with participation from High-Tech Gründerfonds (HTGF), Faber, First Momentum Ventures, Lightfield Equity, Final Frontier Liftoff, The German Aerospace Center (DLR), and Start-up BW Seed Fonds, among others. The Seed funding will be used to expand manufacturing capabilities, testing of critical infrastructure and to accelerate commercial deployment.

Satellite constellations are growing denser and missions are becoming more complex as spacecraft must reliably shift orbits and avoid collisions with zero tolerance for failure. Today, there is a lack of rapid, agile and high thrust maneuvering capabilities required for in our orbit.

With mobility in orbit becoming a hard operational constraint, ISPTech is building propulsion systems which are now ready for spaceflight and accelerating commercial traction with satellite manufacturers and mission operators. The technology also has applications across defense, servicing and even refueling.

“Regular, reliable and affordable access to space via reusable rockets is possible now,” said Lukas Werling, CEO and Co-Founder. “However, the true in-space ecosystem will only be unlocked by mobility solutions for satellites and spacecraft. We are building the propulsion systems that will power the space ecosystem and enable the expansion of humankind into our solar system.”

Meanwhile on Earth, regulatory pressure is accelerating the phase-out of conventional propulsion systems that rely on highly toxic propellants. Substances such as hydrazine are facing bans under proposed legislation due to its toxicity and carcinogenicity, which will increase costs and limit flexibility for existing operators.

As regulators and launch providers tighten restrictions on these chemicals, satellite manufacturers are being forced to rethink propulsion choices. This is creating demand for alternatives that can meet mission requirements without introducing new operational risk.

Enabling Mobility for Every Spacecraft

With the rapid expansion of satellites in orbit and an increasing need for dynamic, precision-controlled operations, propulsion has become a critical operational constraint rather than a background component. ISPTech’s propulsion portfolio spans HyNOx, an easy-to-use and affordable propulsion system designed for robustness, long continuous firings, and rapid availability, which is an ongoing limitation with competing systems.

“Too much space hardware looks great on paper and never proves itself where it matters, in orbit,” said Felix Lauck, CTO and co-founder of ISPTech. “Propulsion is foundational to everything that happens in space and needs to be executed without adding risk or complexity under real constraints. ISPTech is doing this today for every class of spacecraft and every mission profile.”

The company’s HIP_11 solution is a patented propulsion technology developed as a practical alternative to conventional toxic hypergolic propellants. It uses a unique, self-igniting propellant combination based on hydrogen peroxide and an ionic liquid fuel, offering a drop-in replacement for toxic hypergols without compromising reliability or maneuverability.

Furthermore, this technology allows for the seamless implementation of an electric mode, which enables efficient and fast maneuvers to be performed with the same system. This true multi-mode approach is only possible with HIP_11.

Together, the HyNOx and HIP_11 systems allow ISPTech to supply propulsion for spacecraft ranging from small CubeSats to large satellites, in-orbit service vehicles, and future mission architectures.

Built on more than a decade of propulsion research at the German Aerospace Center (DLR), ISPTech’s technologies address persistent challenges that still constrain satellite operators today.

In-Orbit Missions Set for 2026

ISPTech is currently preparing two customer missions, with a first small-sat mission using ISPTech propulsion scheduled to launch in 2026. Furthermore, CubeSat propulsion systems are undergoing acceptance testing, with deliveries planned for later this year.

ISPTech has already secured significant customer contracts for customer missions, reflecting early confidence from spacecraft manufacturers and mission operators. “Our contract with ISPTech is a testament to the short lead time, the capabilities of their propulsion systems, and the strength of the team behind them,” said Sebastian Klaus, CEO and Co-Founder of Atmos Space Cargo.

Development of HIP_11 and orbital refueling capabilities is further supported through projects backed by the European Space Agency, reinforcing the technology’s relevance for long-term European space infrastructure.

“Under the leadership of Lukas and Felix, ISPTech is set to enable truly dynamic and flexible space operations, redefining what’s possible in orbit with the breakthrough of their multimode propulsion system,” said Julia Flaig of Join Capital. “Their combination of deep technical expertise, commercial acumen, and extensive network across the space community is exceptional.”

ISPTech is building the mobility layer for the future space economy. Its ambition is to unlock propulsion capabilities that do not yet exist by giving spacecraft the freedom to move, adapt, and operate reliably over long missions. By turning propulsion from a constraint into an enabler, ISPTech is laying the groundwork for resilient satellite operations, new in-orbit services, and a fully functional in-space ecosystem.

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About ISPTech
InSpacePropulsion Technologies (ISPTech) is pioneering a new era of space mobility – delivering propulsion solutions for every spacecraft and every mission. As a spin-off from the German Aerospace Center (DLR), the company offers cost-effective, robust and quickly available in-space propulsion solutions based on more than 10 years of R&D.

ISPTech’s two technologies – HyNOx and HIP_11 – serve every spacecraft from small CubeSats to large landers and capsules. The propulsion technologies are designed to meet the growing demand for reliable and economical propulsion systems in the rapidly growing space market.

About Join Capital
JOIN Capital is an early-stage, pan-European venture capital fund with offices in Berlin, London, and Milan. Since 2017, we’ve been backing founders whose technologies strengthen Europe’s resilience and strategic autonomy through an asymmetric technological advantage. Our focus is on deep tech across enterprise, industrial, space, and defense sectors — solutions that strengthen economies, secure critical infrastructure, and create enduring strategic advantage.

JOIN Capital currently invests from its second fund generation, managing over €150 million in assets. Investors include NATO Innovation Fund (NIF), Isomer Capital, KfW Capital, and Cassa Depositi e Prestiti (CDP), leading funds-of-funds, and prominent family offices. To date, we’ve backed 36 portfolio companies and successfully realised five exits.

www.join.capital