UK Startup Plans Cubesat Swarms to Defend Western Satellites in Orbit

British startup Shield Space is developing swarms of up to 100 small, low-cost autonomous spacecraft designed to defend Western satellites in orbit. The firm plans to demonstrate the core maneuvering technology in late 2027, marking what its founders describe as a next step in the evolution of orbital warfare.

The push follows a May 2026 incident in which four Russian military satellites came close to ICEYE-X36, a private synthetic aperture radar satellite widely believed to be providing battlefield intelligence for Ukraine. The maneuver, described as an aggressive and risky grey zone operation, brought the Russian craft close enough to jam the satellite's signal, blind it with a laser, fire a metal dart at it, or force it to burn fuel by maneuvering. In October 2026, one of those same four Russian satellites passed within 500 meters of the same ICEYE satellite.

Shield Space proposes to release microwave-sized cubesats from a car-sized carrier in Earth orbit, using them as interceptors. The company says the spacecraft will employ effectors such as lasers or microwaves, or kinetic standoff techniques, and will be able to defend satellites even if controllers lose contact with them. "We're talking about deploying 100 cubesats on a protect-and-defend mission for less than 100 million pounds, which is how much you would pay for one satellite previously," said Graeme Ritchie, co-founder and CEO of Shield Space.

In the fourth quarter of 2027, the company plans a mission called Project Broadsword, launching on SpaceX's Transporter-21 rideshare. It will send up an 8U cubesat and a smaller 3U target craft, maneuvering them from 100 kilometers apart to within 100 meters of each other through four stages of autonomy, from human-in-the-loop to approximately fully autonomous. Shield Space has commissioned EnduroSat to build the autonomous 8U cubesat, which has chemical propulsion and its own imagery-collecting capability. "The good thing about cubesats is they're very standardized and they're very off the shelf," said Dan Molland, co-founder and CTO.

The founders acknowledge major challenges in fitting propulsion, power, AI compute, sensors, and weapon systems onto small platforms with only about 100 cm by 100 cm of space. Ritchie said data scarcity is a central obstacle. "It takes an extraordinary amount of data to train the models and algorithms to achieve a fully autonomous mission, and the problem is that data is not readily available," he said. Molland noted that controlling a swarm for a military mission poses a far more complex set of questions than NASA's Starling demonstration, which showed four small satellites cooperating autonomously on a civilian science mission.

Bleddyn Bowen, associate professor of astropolitics at Durham University, was more cautious. He compared the plans to Brilliant Pebbles, a late Cold War missile-defense scheme under the Strategic Defense Initiative that envisioned thousands of small orbiting interceptors. "With enough investment, a lot is feasible," Bowen said. "But you're looking at many years of development and testing, solving the problem of testing kinetic weapons in space without leaving debris, and finding someone to buy the system."

Shield Space hopes to move quickly from the first rendezvous and proximity operations demonstration to testing two full-sized 16U cubesats, then a full carrier of 10 such cubesats, and then a super carrier of 10 carriers deployed across multiple orbits. Ritchie called the eventual vision space-based carrier strike, in which responsive launch or pre-positioned carriers would give the ability to protect and defend entire orbits.