A quartet of the European Union’s Galileo navigation satellites, being prepared to be flown to space
Satellites are among the most complex machines ever built, so the process of putting them together is far from straightforward.
Dedicated teams work on a satellite’s subsystems – such as its power resources, onboard computer and mission payloads – while system engineers are entrusted with focusing on the mission as a whole, ensuring that all these elements work properly together. First the satellite structure is assembled, serving as the backbone of the mission, then the various subsystems are integrated onto it and linked together, which can involve multiple kilometres of wiring and cabling being threaded through the satellite body.
Once a satellite is complete, the job of preparation is only half-done. The next stage is an exhaustive test campaign, using specialist facilities to simulate every aspect of the space environment: a satellite is placed on a shaker table then blasted with noise to simulate launch, run in hard vacuum for weeks on end and subjected to radio frequency testing as if communicating with the ground. The intention is to verify all the various subsystems operate as specified and validate the mission as a whole will meet user needs.
Of course the very best way of guaranteeing a system is ready for space is to test it in space. The European Union’s In-Orbit Demonstration and Validation initiative makes launch services available for the in-orbit testing of small satellites such as ‘CubeSats’ and other new technologies to be, in the process giving flight heritage to the space equipment of tomorrow.