Scaled-down versions of Orbit Fab’s satellite docking and servicing technology during a demonstration at the new ISAM Test Facility in London. Credit: Paul Marks
Once famed for the technological prowess of the watchmakers and clockmakers who plied their trade there in the 19th century, leafy Northampton Square in London’s Clerkenwell district on Tuesday played host to a very different high-precision technological revolution.
In a lab based in the square, a beefy industrial robot — one that would look more at home building cars on a production line — gingerly approached a similar robot on a 10-meter-long steel track, both of them fitted with compatible docking interfaces. The robots met near the middle of the track, the docking systems latching together with a gentle click.
This outsized choreography was a technology demonstration at the opening of a new space autonomy test center at City St George’s, a college of the University of London.
Called the Hardware-In-The-Loop Space Robotics Facility, the site’s aim is to provide a raft of test equipment for startups building autonomous satellites for applications including refueling and deorbiting — the broad category formally known as ISAM, or in-space servicing, assembly and manufacturing. This emerging market is estimated to be worth $11 billion globally by 2031, according to market researcher Analysys Mason.
The brainchild of City St George’s robotics and autonomous systems professor Nabil Aouf, the facility comprises three lab spaces kitted out with a variety of robots, many of them industrial-strength droids from Germany-based KUKA.
The overarching aim, said Aouf, is for startups to partner with the lab’s experts in AI and autonomous systems and jointly simulate, with live robots, rendezvous and docking operations for their specific spacecraft across ISAM’s many possible applications. Underpinning these operations will be deep-reinforcement-learning-based navigation algorithms that allow these satellites to operate autonomously, because communication latency renders remote control from the ground far too challenging.
The test activities won’t be limited to navigation, Aouf told an audience of space technologists at the event. The facility will also allow users to assess and defend against simulated adversarial cyberattacks on their autonomous docking technology — which, if unaddressed, could lead to collisions that increase the amount of orbital debris.
“Let’s say you have an adversarial threat occur in a near-Earth orbit,” he said, “one that accesses the chaser satellite’s image sensor and tries to modify the stream of images that deep-learning-based strategies use to determine navigation and docking strategy. The impact could be very bad if it cannot retrieve the pose angle of the target.”
In Aouf’s view, the answer is yet more deep reinforcement learning: using the technology to spot when there is malicious meddling into with the docking imagery. City St George’s last year published a technical paper on its research in this area, conducted jointly with the European Space Agency.
“We developed algorithms that will detect those attacks and potentially mitigate them,” he says.
The U.K. arm of Colorado-based Orbit Fab will be the first company to make use of the ISAM facility, said Max Hogan, a research fellow in AI and autonomous systems at City St George’s, who investigates trust assurance in AI guidance technology for drones and spacecraft. The company is developing various craft for satellite refueling, scaled-down versions of which completed that docking demonstration: the RAFTI (short for Rapidly Attachable Fluid Transfer Interface) and its mateable “grasper.”
“We are derisking our own mechanisms here, making sure we know very carefully what precision we need in guidance, navigation and control to achieve safe docking,” said Tiago Amaral, Orbit Fab’s rendezvous and proximity operations mission lead in the U.K. and Europe. “Those are the things we can prove here and it’s helping us build confidence that our mechanism is solid.”
The UK Space Agency welcomed the lab’s opening. “It’s a really important asset that should be able to support the ISAM sector in the U.K., allowing firms here to develop their technologies and algorithms here on the ground before they get anywhere near space,” said Matt Archer, the agency’s director of launch and ISAM.
Massimo Casasco, head of guidance, navigation and control at ESTEC — ESA’s R&D lab in Noordwijk, the Netherlands — praised the fact that the new ISAM lab has a litany of new, high-precision robots, boosting docking accuracy. However, he noted that all such rendezvous simulation labs need upgrading in one important respect: They must also be able to simulate use of multispectral image acquisition for navigation.
The reason? Currently, once a chaser and its target satellite begin to orbit on the night side of Earth, they cannot find each other using optical cameras. “So they need to move to infrared and near-infrared, not just the visible spectrum, so they are not sensitive to illumination conditions,” said Casasco. This is crucial “because even the shadow of the chaser cast on the target can cause docking problems.”
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