Spaceium Successfully Demonstrates In-Space Refueling Actuator

Spaceium has just achieved a landmark milestone in space-based technical abilities . In just five months, two founders built and flew the most precise robotic actuator ever tested in orbit – over 70x more accurate than the robotic arms currently operating in space. 

This wasn’t a concept or ground test. It flew. It worked. On SpaceX’s recent Transporter-15 mission, our refueling actuator achieved a verified 0.003° rotation accuracy in orbit. When paired with a robotic arm the size of those already used in space today, that level of precision would translate to less than a millimeter of movement at the far end. That degree of control has never been demonstrated in space before.

Spaceium is the first to develop and prove this level of precision hardware on orbit – technology that forms the backbone of future in-space refueling, this actuator allows us to precisely grapple a spacecraft and carry out fuel transfer with extreme accuracy. That level of control has never been demonstrated in space, until now. This is a breakthrough that moves in-space refueling from ambition to reality.

We built this actuator to solve a fundamental problem in space: when a spacecraft runs out of fuel, it retires. Right now, operators are forced to plan missions around propellant limits. When the tank’s empty, the mission ends. We believed that was a technical gap, not a law of physics.

So we started building. No massive team. No multi-year roadmap. Just two founders, working around the clock. And in five months, we went from design to orbit – and proved our hardware performs in space.

The actuator is a key part of the robotic arm system we’re building to enable in-space refueling. It’s the precision driver – the part that makes sure every small movement is stable and reliable. In orbit, it delivered consistent results even in the harsh environment of space, where conditions like vacuum, radiation, and temperature swings can push hardware to the limit. When paired with a full-length arm, this actuator gives us the control needed to gently and accurately align with another spacecraft at the moment it matters most. We’ve now proven that this critical component works exactly as designed, and right where it needs to: in orbit.

This level of precision is what unlocks in-space refueling. Fuel transfer between spacecraft requires tight alignment – small errors can mean missed connections or failed missions. Our actuator gives us the fine control needed to make that process safe, repeatable, and fully autonomous. And the fact that we reached this milestone in five months with just two people isn’t just unusual; it shows what’s possible when you move fast, stay focused and build with urgency.

Next, we’ll be moving toward full refueling missions and sharing even bigger milestones. The journey here wasn’t easy — it took fast iteration and lean execution; we had to make bold decisions, move without bureaucracy, and stay locked in on our solution. This isn’t just something we’re building. It’s something we’re obsessed with getting right.

In the near future, we’ll be demonstrating actual fuel transfers and scaling up to a full‑scale refueling system that can extend mission lifetimes, reduce costs, and open up new mission profiles from orbital tugs to manufacturing. Spacecraft will carry less propellant and more payload, and the space industry will have a truly sustainable infrastructure for the first time.

We’ve proven it works.

Now we scale.