Earth vibrates on the surface.
Everything above surface also vibrates. Think of it as a loudspeaker.
The waves travel out to the atmosphere and then outer space.
Assuming this vibration frequency occurs @ natural freq of a designed SAT's - which is ALWAYS measured prior to deploying it into space to ensure we never get into the nat freq range, its a possibility those got fucked up up in space from a particular freq which was in that range.