A Startup Is 3D Printing Solar Beams in Orbit for the First Time

A Warsaw-based startup called Orbital Matter is running a real test that sounds like science fiction: 3D printing structures in the vacuum of space. Its Replicator 2 satellite, launched in early July, carries four 3D printers. Two of them are generating 1-meter-long polymer beams to support a small solar array. If the demonstration works, the technique could scale to 100-meter beams supporting megawatt-class power systems for orbital data centers.

Why print in space at all

Spacecraft have always been limited by the size of their rocket fairings. Solar arrays, antennas, and telescopes must fold up like origami for launch, then deploy once on orbit. That approach hits a ceiling. Very large structures need too much mechanism, too much mass, and too much risk.

Printing directly in orbit removes that constraint. Parts do not need to survive launch loads. They do not need to unfold. Build them in place, and the only limit is how much raw material you carry. Orbital Matter's long-term goal is to become a construction company in space, manufacturing beams and panels on the Moon, Mars, and in Earth orbit.

How the printer works in a vacuum

Orbital Matter's process does not rely on heat to fuse material. In a vacuum, there is no air to cool a hot print. Without convection, a heated part would take months to cool by radiation alone. The company's extruder pushes liquid polymer resin that hardens under ultraviolet light. No furnace, no hotend, no thermal management nightmare.

As of early August, one printer had produced a rope-like strip of polymer, roughly enough material for a 1-centimeter cylinder. The team found the printer head over-extruded in microgravity and is adjusting settings. They tested the new parameters on a flatsat model in Warsaw before uploading them to the satellite. On-orbit printing is set to resume the week of September 14.

The first structure outside a space station

If successful, Replicator 2 will mark the first publicly known instance of a 3D-printed structure generated on orbit outside a space station or capsule. The two main printers are to extrude 1-meter beams in unison by mid-October. Ultraviolet light cures each layer as it stacks into a cylindrical form. Folded solar panels will unfold accordion-style between the beams as they grow.

Cameras will track how the beams expand and contract through sunlight and eclipse cycles. Engineers also want to know how much the polymer degrades from solar radiation over the satellite's expected three-year life.

A follow-up mission targeted before the end of 2027 would print two 3-meter beams to deploy a 1-kilowatt solar array. Orbital Matter sees orbital data centers as a primary market. Those facilities will need 100-meter-plus solar structures. The company has prospective customers but has not named them.

ESA advanced manufacturing engineer Advenit Makaya said large space structures will likely combine 3D printing with robotic assembly. Deployable mechanisms have served well for decades, but rocket fairing size remains a hard wall. In-space manufacturing is one way to move past it.