A plaque carried by Pioneers 10 & 11, intended for intelligent life.
Symbols included: a hydrogen atom, solar coordinates of the sun and Earth, male and female figures, and Pioneer itself.
My Dad worked for the team that made the power supply for Pioneer (and Viking, etc.). The power supply is called an RTG, radioisotopic thermoelectric generator, but the concept is, in theory, trivial. You build a thermopyle (a bunch of thermocouples in series (or is it in parallel), and you put one pole of it towards the cold of space, and the other pole next to a small pile of radioactively hot material (which remains thermally hot, as well, from low-level nuclear fission). The temperature difference across the thermopyle produces a weak but steady current which powers all the satellite's functions. Of course, that job went with the passing of the Apollo program.
He had also worked on the team that did the original (post Sputnik) ablative heat shields for the KRONOS spy satellites. As I understand it, the idea was that the satellite was launched and made to orbitally fly over the target. It would take its photos and then reenter the atmosphere with the aid of the ablative heat shield and then pop a parachute at high altitude. An air force plane with what amounted to a hook would track the parachute, and grab the thing in mid flight (the size of the rentry vehicle was quite small) and fly it back to the AF base for film processing and sending off to the spooks. About 10 years ago, all this '60's stuff was declassified and the remaining members of the original team got recognized by DoD.
