A small plutonium source was used to power the Radioisotope Thermoelectric Generator (RTG) that would provide electric power for the ALSEP experiments. Ed Mitchell performed the delicate maneuver of inserting the fuel capsule into the RTG.
“Al is on the surface. And it’s been a long way, but we’re here.” Alan Shepard
Suddenly the caution lights went out and the radar signals began to transmit. Within seconds the astronauts could see that its data was good. Seconds later in mission control, a jubilant Will Presley shouted, “Flight, we got radar lockup!”
While checking the lander’s guidance software, during a final practice run for the landing, engineers in mission control detected that the computer was receiving an errant signal from the abort pushbutton.