Uncrewed Systems Technology 046

58 Insight | Space vehicles for mounting instruments, PCBs, battery trays and other electronics that absolutely have to fit inside that shape. Compared with, say, a five-axis aluminium milling machine, making the structure through AM gives the end-user freedom to mount their subsystems in ways that might not otherwise have been possible.” CRP materials currently in use in Earth orbit include its Windform XT 2.0, SP and LX 3.0. This last one is a non-conductive composite of mineral glass fibres and polyamide, whereas the first two are carbon microfibre-based (also with polyamide matrices) with conductive properties. “The first step in qualifying our materials and properties for spacecraft was out-gas testing, to ensure the polyamides weren’t going to be off- gassing polymer molecules into space, as they would then be attracted to flat, shiny surfaces like lenses, solar panels or other critical devices that need to stay clean in space to avoid endangering the satellite,” Davis says. “We have also exhaustively tested our materials against UV radiation and in vacuum conditions, and proven that they have no issues with enduring those environmental factors.” Although details about actual customers cannot be disclosed, Davis adds that CRP’s materials and processes are contributing to a wide range of small satellites and uncrewed rockets, and that the company is likely to explore alternative AM approaches such as fused deposition modelling or techniques for metal AM to supply parts with the properties needed for future orbital spacecraft. “We expect to have parts in use on the Moon relatively soon, based on what our customers are doing,” he says. While the use of satellites of all sizes for comms, mapping, surveys and more is well-established, there remains a gap in capabilities for inspecting the satellites themselves, which could be critical regarding proper maintenance and safely de-orbiting ageing space structures. HEO Robotics, based in Australia, is one company aiming to resolve this, given the benefits of well-maintained orbital spacecraft as well as the risks to orbital industries posed by the growing amount of space junk. Its proprietary HEO Inspect software is programmed to use existing Earth observation satellites as in-orbit inspection cameras to visually examine other satellites, generating critical data in real time for satellite owners and operators. “We are primarily a software company, working with satellite operators with existing assets in space, currently 33 satellites in LEO,” says David Balson, managing director of HEO Robotics in the UK. “And in summer 2023, we’ll be partnering with operators launching satellites into geostationary orbit, which opens up opportunities to inspect and protect an enormous range of comms and military satellites that provide critical infrastructure for life on the ground.” Partnering with satellite operators gives HEO Robotics the ability to access and programme the necessary patterns of thruster movement and camera operations for such spacecraft to zoom in on and provide close scrutiny of others. The partnerships also give critical real- time locations of where different satellites are so that HEO can calculate the angles and directions to enable each camera to track their targets precisely. Also, as of this September, the company has unveiled the Holmes Imager, a telescopic space camera designed to be hosted as a secondary payload on spacecraft. It is a 2.3 kg system that consumes 6 W in normal operation, with a 94 mm aperture and a 0.4 º field of view. So far, HEO has partnered with three space companies to have four Holmes cameras launched into orbit by the end of next year, with a target of 2500 cameras in orbit by 2027. “We have development plans beyond that too,” Balson adds. “EO data is very useful, but IR and NIR sensing can identify material qualities and deeper signs of damage to other spacecraft, so we’ll almost certainly develop solutions based around those, as well as adopting more edge computing for real-time or post- processing of in-orbit image data.” While the ability to perform persistent, autonomous, high-resolution inspections of spacecraft stands to help satellite operators keep track of the conditions of their growing numbers of orbital assets, HEO notes that the number of satellites in space is already extremely high, and that the hope is that HEO Inspect and Holmes will encourage operators to use individual assets for longer, rather than continuously launch more and more. October/November 2022 | Uncrewed Systems Technology Two TubeSats and an additively manufactured TuPOD during their integration phase, made using CRP’s Laser-Powder Bed Fusion technology (Courtesy of GAUSS)