Our structural model is the physical metalwork forming the satellite, with dummy masses representing onboard equipment attached in the correct relationships. The centres of gravities of all the components are correctly oriented around the structure. So when all that comes together, it s representative from a mass and a mass location point of view. And that s quite complex, even in little satellites, to get right. Accelerometers are on-board the model, critically placed to measure how it s reacting to the forces, said Chris.
Shakers come in two main types, electromagnetic and hydraulic.
They resemble giant versions of the paint-tin shakers in hardware stores, except their movements are much more precise, and usually limited to one plane only. It s moving so fast you can t see it, said Chris, but if you put your hand on it you can feel the vibration. All you ve got to do is watch the accelerometer outputs on the oscilloscopes. But in general you could see that it was coping and surviving in the environment. Once they start shaking, you can physically see them moving.