Robot Assembles Truss Segment for Space Antenna in Orbit, Marking Step Toward Large-Scale In-Orbit Construction

IT Home news on November 10, sending large equipment into Earth's orbit is not easy. If a large number of small components are first sent into space and then assembled into large structures in orbit, the difficulty might be lower, but traditional solutions often still require astronaut participation.

Considering that the space environment is full of radiation, the time astronauts spend working in orbit is naturally the shorter the better. A robot developed by the California Institute of Technology (Caltech) and funded by the Defense Advanced Research Projects Agency (DARPA) recently demonstrated a new space construction scheme: it successfully assembled independent components into an antenna truss structure in orbit.

Researchers called it the first autonomous structure construction achieved in space. This achievement is expected to provide a new technical path for building large space facilities in orbit in the future.

According to IT Home, this robot is one of the core pieces of equipment for the “Autonomous In-Space Tensioned Reflector Assembly” (abbreviated as ASTRA).

The project originally planned to use composite material pipes, aluminum connectors, and reflective film to assemble a reflective antenna with a diameter of 1.4 meters.

Due to time constraints, the robot was only responsible for assembling one of the support structures this time. Before the task began, two truss sections had already been pre-assembled and transported to space, after which the robot completed the assembly of the third section in orbit.

Although this is not yet a complete antenna that can be directly used for communication, it has proven that the robot can step-by-step assemble scattered components into larger structures in a space environment.

Andrew Detor, the head of the “New Orbital and Lunar Manufacturing, Materials, and Efficient Mass Design” (NOM4D) project at the U.S. Defense Advanced Research Projects Agency, stated that this demonstration is an important step toward constructing large structures in space, with future goals even including the construction of facilities reaching scales of several thousand meters.

“Currently, no structure of this scale can be realized through existing technology,” De Tolle said.

The larger vision of the NOM4D project is to transport raw materials into orbit and then manufacture structures adapted to the space environment directly in space.

In this way, facilities such as antennas, optical devices, and solar arrays can be designed according to the actual working environment, without having to first consider how to withstand the huge loads during rocket launches like traditional spacecraft.

DARPA compares this construction method to assembly toys such as Tinkertoys or K'Nex: robots only need to repeat relatively simple assembly steps to have the opportunity to manufacture structures much larger than their own dimensions.

De Tolle explained that, inside the automated assembly equipment, each structural component is manufactured one by one, followed by the installation of a reflection net. Once all parts are finished, they are then unfolded and connected together step by step.

He stated that the entire process does not rely on complex robotic systems or advanced algorithms; the key lies in the Caltech team's solid engineering design, which integrates various operations into a scalable process.

However, the “automation” in this demonstration cannot yet be fully understood as robots being able to independently complete all work.

During the period when the robot performed assembly tasks, the ground support team still undertook a large amount of work. Since there were only a few communication windows per day between the ground and the robot, each lasting only 15 minutes, engineers needed to use this time to check the photos sent back by the robot, troubleshoot problems in the laboratory using a completely identical model, and then send operation instructions to the robot in space.

In other words, the robot could perform actual assembly actions in orbit, but task planning, fault judgment, and operation instructions still required the involvement of ground personnel.

In fact, using robots to build structures in outer space is not a new concept.

The assembly of the International Space Station once relied heavily on the Canadian robotic arm 2 (Canadarm2). It could move large components and deliver them to specified locations, where astronauts would then complete the installation work. However, this method assembled components that were already manufactured on the ground, rather than having robots start from a large number of small parts and gradually manufacture larger structures.

In 2014, a 3D printer on the International Space Station once printed the panel for its own extruder. This was an important attempt in the field of space manufacturing, proving that small manufacturing workshops in orbit have practical value by printing replacement parts for the equipment itself.

NASA subsequently pushed forward a project named Archinaut One, also known as OSAM-2, which planned to conduct space manufacturing outside the International Space Station, using 3D printing technology to manufacture structural beams in orbit and deploying solar arrays through robotic operation. The project showed some potential in ground tests, but was ultimately terminated in 2023.

In contrast, ASTRA this time provided a true on-orbit validation case, proving that robots can gradually assemble multiple independent parts into larger structures in space.

Although there is still a long way to go before achieving fully autonomous construction of large space facilities, space manufacturing has already taken a new step, starting from the assembly of the first truss component. After all, when building large facilities in space, the nearest hardware store is far away, hundreds of kilometers away.