For the first time, a structure in space was assembled by an autonomous robot - without the participation of astronauts. This was reported by the California Institute of Technology (Caltech), whose team created the ASTRA apparatus. It operates under the NOM4D (Novel Orbital and Moon Manufacturing, Materials, and Mass-efficient Design) program of the US Defense Advanced Research Projects Agency (DARPA).
ASTRA is a robotic manipulator that takes rods and connectors from adjacent compartments and sequentially assembles identical frame sections. The idea is that such frames should support large reflecting surfaces - for example, antennas or telescope mirrors.
The demonstration lasted about six months. The robot was supposed to build a reflector antenna 1.4 meters in diameter from composite tubes, aluminum nodes and Kapton film. Due to a lack of time, only the initial section was assembled. Nevertheless, according to the researchers, the experiment showed the viability of the idea itself: the design can scale to very large frames with giant reflectors.
"This is the first time a structure has been autonomously built in space," said project leader Sergio Pellegrino, professor of aerospace and civil engineering at Caltech.
The apparatus, about one cubic meter in size, went to low Earth orbit on March 30, 2026 aboard the Vigoride 7 spacecraft of Momentus Inc. as part of the SpaceX Transporter-16 mission. In orbit, ASTRA, on commands from Earth, released the restraints, extended two pre-assembled sections and began assembling the third. The commands were transmitted by engineers Charles Sommer, Alan Chuong and graduate student Tara Venkatadri, and the results were verified using photographs from space.
The operation had to be repeated because of unforeseen problems. "There are many differences in the space environment compared with Earth. There are always lots of little surprises," explained Jaden Su, a former Caltech postdoc and now a professor at the University of Texas at Austin. To debug solutions, a "twin" of the apparatus - a spare flight unit - remained in Pellegrino's laboratory. Communication with space is possible only during about seven or eight short sessions of 15 minutes per day.
The perforated reflective film was created jointly with colleagues from the University of Pennsylvania under the leadership of Professor Igor Bargatin. Unlike a conventional metal mesh, it requires less pre-tensioning, which makes it possible to make structures lighter.
The complete frame is supposed to consist of 11 sections, but the mission ends in December and, apparently, it will not be possible to assemble them all. The scientists say they have obtained enough data to confirm the viability of the approach and now intend to simplify and refine the design.
According to Pellegrino, when the dimensions of a structure exceed the capabilities of rocket fairings, one has to think about assembly directly in orbit. This could be useful not only in astronomy and astrophysics, but also in communications, as well as in creating very large solar panels for space energy.