With the Hycon camera down, Roosa would have to step in and use a Hasselblad with a 500 mm lens, to take detailed photos of the Apollo 16 potential landing site. If Roosa did nothing else, he had to return to earth with pictures of Descartes that would be good enough to plan a lunar landing.
The mortar package contained a set of grenades which were planned to be fired to distances of 500, 1000, 3000, and 5000 feet to the north of the ALSEP site.
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