Galileo’s crucible

March 5, 2019  - By
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Photo: ESA-Anneke Le Floc’h

Inside the ESTEC Test Center, Galileo’s First Operational Capability first flight model, FM1, prepares for passive intermodulation testing in the Maxwell electromagnetic facility. (Photo: ESA-Anneke Le Floc’h)

Gazing through soaring plexiglass walls at the space simulation room of the European Space Agency’s Test Center in the Netherlands affords a glimpse into scientific history.

I felt a frisson, a highly regimented frisson if you will, of vicarious thrill for the rigors, rhythms and methods of research and testing as I toured the center after giving a keynote at the agency’s Navigation Days. Here, the final birthing touches were administered to transmitters beaming forth the Second Golden Age of satellite-based navigation.

One can debate which constellation combination will prove most fruitful to users: GPS plus GLONASS, GPS plus BeiDou, GPS plus Galileo (note the common term). I believe it will be the last, because of the close synergy and symbiosis of the two commercial arenas, North America and Europe.

All Galileo Full Operational Capability (FOC) satellites had their mettle and metals probed, radiated, bombarded, shaken and shocked here before they journeyed to space. The test center’s role is to verify, intensively and for months per satellite, that it can perform well for the whole of its planned lifetime.

A mass property test checks that the center of gravity and mass are aligned within design specifications, so that the satellite’s orientation can be accurately and economically controlled with thruster firings in orbit, prolonging work life by conserving propellant.

A five-week thermal-vacuum test runs inside a 4.5-meter diameter stainless steel vacuum chamber, the Phenix. An inner thermal tent heats to simulate solar radiation and cools with liquid nitrogen to create the chill of sunless space.

In the Maxwell test chamber, spiky radio-absorbent anechoic walls test electromagnetic compatibility to ensure that all systems operate together without interference. Noise horns generate more than 140 decibels to simulate a violent launch. A quad shaker table vibrates the satellite up, sideways and down, as accelerometers search for hazardous internal vibration, gathering data across hundreds of channels.

Altogether a severe trial, a crucible from which the FOC satellites emerge certified and ready for space.

Oh, that we humans were similarly tested before placement in positions of power.

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Alan Cameron is editor-in-chief and publisher of GPS World magazine, where he has worked since 2000. He also writes the monthly GNSS Insights column for the weekly Navigate! e-newsletter.

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