US DARPA-funded project: Caltech's Astra robot performs first autonomous in-space structural assembly
The Astra robot developed by the California Institute of Technology (Caltech) successfully performed the first autonomous modular structure assembly in space, validating the feasibility of building large solar arrays and telescopes on orbit.
The Nom4d project, funded by the U.S. Defense Advanced Research Projects Agency (DARPA), has achieved a key milestone: the Astra robotic system, developed by the California Institute of Technology (Caltech), successfully performed the first autonomous structural assembly in space. This breakthrough aims to overcome the physical limitations currently facing the deployment of large structures into orbit—traditional methods require structures to be folded or disassembled on the ground, launched, and then manually reassembled.
Launched into space in March 2026, the Astra robot was tasked with autonomously constructing a 1.4-meter diameter reflector antenna using carbon fiber tubes and aluminum connectors, and covering it with a reflective film. According to DARPA, this assembly method resembles a high-tech version of children's building blocks, but the automation process proved highly challenging. Due to time constraints, the team only completed the first section of the antenna. As the mission is set to end in December 2026, the antenna may not be fully finalized, but the demonstration has sufficiently proven the feasibility of the concept of autonomous in-space assembly.
Sergio Pellegrino, the project's lead scientist, Professor of Aerospace at Caltech, and Senior Research Scientist at NASA's Jet Propulsion Laboratory (JPL), stated that this success lays the foundation for building giant mirrors for more powerful space telescopes or orbital solar power stations in the future. Andrew Detor, DARPA's Nom4d program manager, noted that the long-term goal is to enable the efficient, scalable construction of very large structures hundreds of meters or even kilometers in size on orbit, which is currently impossible to achieve through traditional launch methods.