Impulse Space: Powering the Space Economy

TL;DR: Impulse Space is transforming space logistics with breakthrough propulsion systems and a veteran team to enable fast, flexible orbital operations.

Main points:

• Cuts orbital transfer from months to hours with Saiph & Deneb engines
• Enables satellite servicing, repositioning, and collision avoidance
• Supports GEO, MEO, and cislunar missions with same day delivery
• Founded by SpaceX propulsion pioneer Tom Mueller
• Building the logistics layer for the next era of the space economy

Redefining Space Logistics to Accelerate the Orbital Economy

Rethinking In-Space Mobility

Accessing Low Earth Orbit (LEO) has never been easier. Reusable launch systems, led by SpaceX’s Falcon 9, have dramatically lowered costs and increased launch cadence. But beyond LEO, space remains slow, costly, and underserved.

Delivering satellites to higher-energy destinations requires significantly more delta-v. Delta V is the change in velocity needed to reach more distant or demanding orbital regimes. Higher energy destinations include:

• Geostationary Orbit (GEO)
• Medium Earth Orbit (MEO)
• cislunar space

Reaching GEO typically involves first inserting a satellite into a Geostationary Transfer Orbit (GTO). This orbit is elliptical and extends nearly 36,000 kilometers at its highest point. The satellite then uses orbital propulsion to circularize at GEO.

Electric propulsion systems, today’s dominant solution for orbit-raising. It can take up to nine months for satellites to fully circularize into GEO. Electric propulsion is very efficient but produces low thrust.

This slows missions, delays service, ties up satellites, and increases operational risks. A satellite stuck in transfer can delay tens of millions of dollars in revenue.

When several satellites face delays, losses can reach hundreds of millions. This also leads to missed contracts and unused capacity.

Recent examples show how long orbit-raising can take. SES-15 took over six months to reach operational orbit. Inmarsat's I-6 F1 satellite, which began electric orbit-raising to GEO in December 2021 and took over seven months.

These delays create major costs for both commercial operators and national programs. This is becoming even more acute as demand for GEO capacity accelerates.

Satellite operators face growing demand for bandwidth, Earth observation, and secure communications. They launch new satellites to meet this demand. They also replace older satellites, many launched over ten years ago and now close to end-of-life. Rapid growth of broader commercial space economy adds greater pressure on GEO systems, as new applications emerge:

• satellite-to-satellite communications
• persistent climate monitoring
• sovereign national space programs emerge

Structural Constraints Slowing Progress

The constraints are deeply structural:

• Limited Agility and Power-Constrained Thrust: Electric propulsion systems include ion engines and Hall-effect thrusters. They offer high efficiency but produce very low thrust, often only millinewtons. These aerospace propulsion systems also rely on steady onboard power to operate.
• Satellites launched into GTO use low-thrust maneuvers to raise their lowest point, or perigee. They repeat these burns until the orbit becomes circular at GEO¹. These extended transfer phases limit agility and responsiveness, hindering their ability to adapt to mission changes dynamically or avoid orbital hazards.
• Limited Maneuvering Agility: Electric propulsion systems are not well-suited for rapid or responsive maneuvering. Slow thrust makes satellites less flexible. They struggle to adapt to mission changes, avoid collisions, or move between orbital planes. This problem grows as space becomes more crowded.
• Exposure to Environmental Risk: Extended transfer periods leave satellites vulnerable to space weather events, radiation damage, and increased collision risk in crowded orbits. The longer a satellite remains in transit, the greater its operational exposure to environmental and orbital hazards.
• Operational Complexity and Cost: Managing months-long transfer phases introduces logistical complexity for operators. It requires extended ground support, increases mission planning burdens, and can impact insurance premiums due to prolonged exposure periods.

However, it is not just the launch of new satellites that is impacted. Refueling, repairing, or upgrading satellites could extend their service life. But major barriers still block these options. Although servicing could theoretically extend the operational lifespan of aging satellites, it has remained rare and prohibitively expensive.

Early commercial tests proved satellite servicing is possible.

But these missions remain complex and risky. They make economic sense only for a few high-value satellites. Recent efforts aim to cut the cost and complexity of satellite servicing. Much of this work targets small satellite maneuvering and life extension in LEO.

Next-generation servicing vehicles are now in development. They will inspect, reposition, and dock with satellites at far lower cost than older methods. Companies also plan to expand these services to GEO satellites. However, even as technical progress continues, the fundamental challenge of in-orbit logistics remains.

Reaching GEO and higher orbits takes a lot of energy, time, and money. These demands put heavy strain on mission budgets and slow broader adoption. Without faster, more flexible in-space mobility solutions, these challenges will only intensify.

Throughout history, the expansion of economies has been inseparable from advances in transportation and logistics. Trade routes enabled the rise of ancient civilizations:

• railroads unlocked continental economies
• container shipping transformed global commerce

New frontiers only opened when transport systems could move goods, people, and services reliably and at scale. Space is no different.

Moving between orbits is central to the orbital economy. It supports satellite launches, spacecraft repairs, and future space outposts. Addressing this need requires more than incremental improvements to legacy architectures.

It demands a new model for in-space transportation. That’s one built for speed, flexibility, and operational efficiency across Earth orbits and beyond.

Impulse Space was founded to solve the space mobility challenge. It builds an in-space logistics layer for the orbital economy. It speeds up commercial, civil, and defense missions.

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A Team That Helped Shape Modern Spaceflight

What makes Impulse Space distinct is not just the scale of its ambition, but the depth of experience embedded in its founding team. At the center is Tom Mueller, one of the most accomplished propulsion engineers in the world and a founding team member of SpaceX.

As employee #1 at SpaceX and the longtime head of Propulsion, Mueller led the development of the Merlin, Kestrel, Draco, and SuperDraco engines. These engines enabled reusable rockets and changed space launch economics. Over 30 years, Mueller grew into a leading figure in aerospace. He built teams able to work at the edge of space engineering and aerospace propulsion systems.

“You know, I like machines. I like high-energy, fast and dangerous. I’ve always liked motorcycles. I like fast cars. Rockets were the most appealing things to me because they are the most high-energy mechanical devices that you can do.” - Tom Mueller (source)

That force is now reflected in Impulse’s DNA. Stepping away after 14 years at SpaceX, Mueller initially planned to retire. Instead, he found himself designing a new thruster in his garage, which would become the Deneb engine. Word quickly spread across the aerospace community, and a new team began to form.

Impulse Space is now based in Redondo Beach, California. Its team includes former SpaceX engineers who helped grow the Falcon and Dragon programs from first flights to full operations. The team keeps the same culture that drove SpaceX’s early success:

• First-principles design
• Vertical integration
• Fast development cycles
• Strong technical ownership

But Impulse is not simply replicating the past. Impulse Space is preparing for the Starship era. In this future, orbital mobility, logistics, and infrastructure will form the base of economic activity beyond Earth.

Impulse’s leaders shaped timelines, roadmaps, and deployment strategies at SpaceX. Their experience gives them insight into future bottlenecks and how to solve them.

Their experience helps them predict new demand and design systems for the next wave of complex orbital missions. Eric Romo, now President and Chief Operating Officer, works with Mueller. He started at SpaceX then built companies in energy and virtual reality. He also held leadership roles at Meta’s Reality Labs.

Mueller, Romo, and the Impulse team combine proven experience with bold vision. They helped shape the first wave of private spaceflight and now aim to define the next.

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Infrastructure Designed for a New Era

Delivering rapid orbital maneuverability and high-delta-v capability required rethinking propulsion, avionics, and mission systems from the ground up. Impulse Space’s design starts with aerospace propulsion systems first.

The company builds engines, flight software, structures, and avionics in-house. This vertical approach supports fast and high-performance orbital missions. This system centers on two new propulsion designs. Each one solves different challenges for fast and flexible movement beyond LEO.

The Saiph Thruster

The Saiph thruster powers the Mira vehicle. It is a storable, non-toxic propulsion system that uses ethane and nitrous oxide. This makes it safer and easier to manage than hypergolic engines. Key features include:

• High cycle life and rapid restarts
• Thrust levels suited for agile orbital maneuvers
• Over 50,000 pulses and 65,000 seconds of test runtime, proving reliability
• Modular design that allows clustering for more thrust as needed

The Deneb Engine

The Deneb engine powers the Helios high-energy kick stage. It uses liquid oxygen (LOX) and liquid methane to produce 15,000 pounds of thrust. This engine supports rapid, high-delta-v transfers to MEO, GEO, and cislunar space.

Key features include:

• LOX/methane design matches modern launch propellant standards
• Compatible with future in-situ resource utilization (ISRU) concepts
• Accelerated qualification program for upcoming commercial and defense flights
• Torch igniter system³ with in-house spark ignition for precise, repeatable restarts
• Multi-burn capability for reliable, complex orbital missions

Emerging Needs

These aerospace propulsion systems form the backbone of a new generation of orbital vehicles designed for the emerging needs of the orbital economy:

• Mira: A high-agility, high-thrust vehicle built for fast orbital maneuvers, station-keeping, rendezvous, and hosted payload missions. It operates in LEO, MEO, GEO, and cislunar orbits, where quick response and agility are vital. Mira:
  • Uses the Saiph thruster array with custom avionics and adaptive flight software
  • Supports space domain awareness (SDA), satellite servicing, and rapid repositioning
  • Modular design allows upgrades for higher thrust and larger payloads

• Helios: A high-energy orbital transfer stage built for fast delivery to any orbit. It uses the Deneb engine to cut transfer times from months with electric propulsion to under eight hours. It:
  • Supports commercial constellations, lunar infrastructure, and national security missions
  • Enables rapid orbital mobility and long-range deployments
  • Designed for serviceability and future reuse, aligning with sustainable space operations

Impulse treats propulsion as the core of orbital infrastructure, not just another subsystem. This shift enables next-generation space mobility and mission design. Their approach builds on the same first-principles thinking that empowered SpaceX. Building propulsion, avionics, structures, and mission software in-house, Impulse creates a platform ready for fast-changing and contested missions in space.

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Unlocking Responsive Space Operations

As space activity moves beyond Earth orbit and toward cislunar and deep-space, spacecrafts need mobility infrastructure that can:

• respond rapidly
• maneuver flexibly
• work with less human supervision

Impulse Space’s propulsion-first platform enables same-day orbital delivery. It meets today’s mission needs and prepares for the future space economy. Immediate capabilities enabled by Impulse include:

• Dynamic Orbital Defense and SDA:
  In an increasingly contested space environment, Mira’s high-agility maneuvering is critical for national security operations, including persistent intelligence, surveillance, reconnaissance (ISR) coverage. Recent reports highlight Chinese satellites practicing "dogfighting" maneuvers, which aggressively shadow, intercept, and trail other spacecraft to simulate offensive actions. Russian assets have similarly demonstrated disruptive proximity operations. In this new environment, the ability to re-task, reposition, defend and deter satellites dynamically is no longer optional.
• Collision Avoidance in Congested Orbits:
  The growing population of debris and defunct satellites across LEO, MEO, and GEO raises real operational risks. High-delta-v mobility lets spacecraft avoid collisions on their own. This reduces the need for constant ground control, which is vital as orbits grow more crowded and active.
• Asset Servicing and Repositioning:
  Mira supports on-orbit servicing missions, asset inspection, and life-extension maneuvers. It lets operators reposition or repair assets without requiring expensive new replacements.
• Hosted Payloads and Platform-as-a-Service:
  Impulse provides maneuverable hosting platforms for surveillance, sensing, and communications payloads. This cuts mission costs and speeds time-to-orbit for customers.

While Impulse’s immediate focus is on dynamic orbital mobility, its propulsion-first platform architecture points toward broader strategic possibilities. As the orbital economy matures, high-agility vehicles like Mira and Helios could:

• enable autonomous on-orbit refueling networks
• debris interception and removal missions
• dynamic cargo transfers between satellites
• serve as power and resource distribution platforms for lunar surface operations

In future cislunar infrastructure, maneuverable vehicles will be critical for:

• delivering supplies
• repositioning assets
• supporting ground stations with energy relay or communications bridging

In under three years, Impulse Space has translated its vision into rapid execution. The company has successfully launched two Mira missions, demonstrating responsive maneuvering and autonomous collision avoidance capabilities. Vast selected Impulse to provide propulsion systems for the Haven‑1 commercial space station. This choice shows rising demand for flexible, high-performance mobility in commercial and government missions.

Impulse completed key propulsion system milestones on the Deneb engine, speeding Helios’s path to high‑energy demonstration flights. The first launch is set for mid‑2026. For defense, Impulse secured multiple large-value contracts with the U.S. Space Force’s Space Systems Command and the STRATFI⁵ initiative. These contracts focus on enabling dynamic, high-delta-v orbital operations.

Its partnership with Anduril Industries, integrates Mira into the Lattice autonomous defense network. This positions Impulse at the forefront of a new model for responsive, contested-space operations.

Companies must rethink how they operate in orbit, not just upgrade old systems. Much like SpaceX redefined launch by reimagining access itself, Impulse Space is rebuilding in-space logistics to grow the space economy and prepare for a new era of infrastructure and exploration.