The Apollo Lunar Surface Experiments Package consisted of a collection of experiments deployed by Apollo astronauts on the moon. While the specific instruments within the ALSEP varied each Apollo mission, the ALSEP always included a central processing station to which all of the peripheral experiments (and the RTG) were attached. It provided power distribution, communications with Earth, etc. The rest of the experiments connected to this station by cables. Power for all of the experiments was provided by the RTG.