Spaceflight
 

Info please on derivation of electrical power on manned spacecraft. I know that the ISS is solar, deep space probes nuclear, but the shuttle for example, or Apollo/Soyuz vehicles. I understand that they use fuel cells, combining hydrogen and oxygen but how is the electrical energy actually derived, how is it regulated etc.etc.
Also, with ref to navigation, I assume they use some sort of inertial system, but obviously cannot use lat/long as co-ordinates so what is used instead?
Thanks in advance.