Components for satellites must withstand the pressure and temperature conditions in outer space for years. In order to test whether the materials can withstand these extreme conditions, the French manufacturer of electronic components Radiall places its trust in vacuum chambers by Weiss Technik.
Before a component may be used for a satellite, it must undergo intensive testing. It is of vital importance that all components remain stable in a vacuum and do not ignite spontaneously due to overheating. The pressure in space is up to 10–6 millibars. This corresponds to a billionth of earth‘s atmosphere. The pressure conditions inside a satellite are the same as outside.
Many materials change phase in underpressure conditions and become unstable. In the worst case the components could self-destruct. “The vacuum chamber TVC Space Simulator 240 L was tailored especially to the strict specifications of Radiall and customised to the needs of the customer,” explains Herve Salmon, Sales Manager for the Special Products department at Weiss Technik. “We can build devices in horizontal and vertical orientation. It can create a vacuum of 10–5 to 10–7 millibars and simulate extreme temperature conditions.” Satellites usually stay in space between two and ten years. Since it is not possible to do maintenance work during this time, all components must be fully reliable. The Company Radiall mainly builds electronic components for satellites, which must meet the strict requirements of the European Space Agency (ESA).
Solar radiation, UV and cosmic rays age materials at a record pace. The side of satellites, which is exposed to the sun, heat up to +200 °C. On the shadow side the temperature can drop down to –200 °C. The temperatures are compensated by the rotation of the satellite, as the individual sides are exposed to the sun only for brief periods due to the rotation.
The electronic devices on a satellite also generate heat. In order to ensure that electronic components in space do not heat up to the point that they ignite spontaneously, their behaviour is also tested under extreme temperatures in the vacuum chamber. For the tests, the components are first affixed to a heatable metal plate that acts as heat exchanger. After the dooris closed, the pressure set by the testers is generated and the tests begin.
Since the simulation takes place in a vacuum, there is no temperature transfer through air. The test object is heated and cooled through the heat exchanger. In addition, liquids such as silicon oils or liquid nitrogen are used for temperature testing, and are fed into the heat exchanger through a specially constructed circulatory system. The temperature impact of the sun can also be simulated with the help of infra-red lights.
Coolness is regulated through the heat exchanger and the wall plates on the inside of the chamber. The temperature is measured and regulated through sensitive sensors in the vacuum chamber, on the heat exchanger, and on the test object itself. In this way, the vacuum chamber can simulate all temperature and pressure conditions that can exist in space.