A Cold-Spray Deposition Unit for Orbital Repair and Coating of Aluminium Structures: Gas, Kinetic-Energy and Throughput Budgets

This paper presents a computed design study, SIMULATED, NOT MEASURED, for restored sealing faces, conductive coatings and repaired panels in orbit, using aluminium and copper powder, 15-45 micrometre grade. The operating principle is distinct from neighbouring production methods: heated nitrogen expands through a de Laval nozzle to supersonic speed and carries powder particles that bond on impact by severe plastic deformation, without ever melting. Because the feedstock stays solid, oxidation and thermal distortion are largely avoided, and the process suits repair of parts that cannot tolerate a melt pool. The energy ledger is dominated by gas heating and compression, not by any phase change. Sizing follows from budgets computed in the accompanying script rather than from analogy with terrestrial equipment. The headline figures are a specific energy of 2.49 megajoules per kilogram of product, an installed electrical power of 4.5 kilowatts, a production rate of 6.51 kilograms per hour, and an annual throughput of 5.16e+04 kilograms over 330 operating days. Rejecting 2.48 kilowatts of waste heat at 320 kelvin requires 4.73 square metres of radiator, a photovoltaic supply requires 11 square metres of array, and the installed mass is 453 kilograms. Moving feedstock from a 400 kilometre to an 800 kilometre orbit costs 217 metres per second of velocity change. The study is a computed study with no targeting or weapon application; it concerns civilian production equipment only, and none of its figures is a measurement.