Spacecraft developers today are limited by the size of their rocket fairing, folding up their hardware origami-style for launch and then carrying out a complex choreography of unfolding once on orbit. Engineers at a Warsaw, Poland-based startup are testing another possible solution: 3D-printing solar arrays and other components in space.
The company, Orbital Matter, in early July launched its Replicator 2 satellite. The spacecraft has four 3D printers, two of which are to generate 1-meter-long beams to support a small solar array. If all goes as planned, the demonstration will help validate the technique for larger structures. Orbital Matter’s eventual goal is to print beams that can support 100-meter-long, 100-kilowatt solar arrays.
The company views its potential customers as any operator that requires large structures from which to hang solar arrays and other components, said Jakub Stojek, CEO and co-founder. Chief among these are developers of orbital data centers, many of which are envisioning arrays 100 m or longer.
As of early August, one of the satellite’s printers had printed a rope-like strip of polymer — roughly enough material to create a 1-cm cylinder, said Robert Ihnatisin, Orbital Matter’s co-founder and chief technology officer. Engineers are now analyzing this test print to determine what adjustments to the printer settings are needed. For instance, he said, they have already concluded the printer head “over-extruded,” or pushed out more liquid polymer than needed for an optimal print.
Before uploading the new settings to Replicator 2’s software, engineers tested them on a “flatsat” model at the company’s facility in Warsaw. Plans call for resuming on-orbit printing the week of Sept. 14, Ihnatisin said.
“By taking the printer into microgravity, there were some variables that we had to adjust for, which we expected, and that’s why we have four of them on board,” he said.
Two of the printers are designated for fine-tuning the settings for the microgravity and vacuum conditions of space. By the end of September, one of those printers is to generate a 1-m-long cylindrical beam to extend an antenna, in a separate test for a space services company.
Orbital Matter’s primary demonstration is to resume by mid-October, when the other two printers are to generate 1-m-long beams in unison, Ihnatisin said. Each printer would extrude liquid polymer resin like a coiled rope, hardened by an ultraviolet light, that stacks upon itself in a lengthening cylindrical form as more and more material is printed.
Positioned between the two printers are folded up solar panels. As more and more beam layers are printed, these panels will unfold accordion style, forming a flat array.
Afterward, engineers will observe the twin beams via onboard cameras to see how much they expand and contract as they heat up and cool down in direct sunlight and in Earth’s shadow. Also of interest is how much the beams bend or otherwise deteriorate from solar radiation during the expected three-year life of the satellite.
“It’s basically how well the beam holds together,” Ihnatisin said. Engineers will also measure power output over time for the solar panels, which were built with off-the-shelf solar cells.
The company is also preparing a follow-up demonstration, in which a satellite would print two 3-m-long beams to deploy a 1-kilowatt solar array, he said. That launch is targeted before the end of 2027.
If successful, the Replicator 2 demonstration would mark the first publicly known instance of a 3D-printed structure generated on orbit outside the walls of a space station or capsule, said Advenit Makaya, an advanced manufacturing engineer with the European Space Agency in the Netherlands.
Building future large structures in space will likely require a combination of 3D-printing and robotic assembly methods, he said.
The “deployable” method for delivering structures that unfold origami-style in space has been the workhorse for decades for solar arrays, antennas and telescopes, Makaya said, but that approach only goes so far.
“Deployables will hit a certain ceiling,” he said. “The limitation you have when you want to make large structures in space is the size of your rocket fairing.”
Indeed, Ihnatisin said Orbital has a number of prospective customers, though the company declined to name them. Of particular interest, he said, is the ability to print beams to support 100-kW-plus solar panel structures — but “we need to demonstrate it first.”
“The blocker has always been: ‘It sounds like a great technology, but we want to see it working first.’ That was the motivation behind doing our own launch,” he said.
