Apollo XIII was scheduled to be the third lunar landing.
The crew was James A. Lovell Jr. (spacecraft commander), Fred W.
Haise Jr. (lunar module pilot), and John L. Swigert Jr. (command
module pilot). (That's a lot of juniors.)
All did not go as planned during the mission (you've probably
seen the movie):
an explosion damaged the oxygen tanks on board, forcing a
hair-raising return home in a crippled and dying spacecraft.
You will not need to go to such extreme lengths to find the
cache, however, you will have to find out some info:
AA = the originally specified heater voltage for the oxygen
tanks,
B = the number of unique space missions the crew of Apollo 13 flew
on during their careers at NASA,
CCC = the day of the year in which Apollo 13 was launched,
DD = the hours elapsed since launch when Jack Swigert informed
Mission Control: "OK, Houston, we've had a problem."
EE = the minute of the above hour and
F = the number of the first oxygen tank to fail.
Start at the above coordinates. Add AA-B to the latitude and
B+CCC+DD+EE+F to the longitude. Your ammo box awaits!
ad astra per aspera
ex luna scientia