I cannot help with information concerning the exercise itself.
As you assume that it was an aviation related matter i can tell, that photoflash cartridges had been used by RF-4 Phantom II aircraft for illuminating the target area during night low level recce missions.
RF-4C_2_zps5b5108c1.jpg Photo by hairoldcut | Photobucket
The pic shows the ejector rack (both sides had one) for 26 M112cartridges, another rack with 10 bigger M123 cartridges was available as well. We dropped them only occasionally outside of life firing ranges during major exercises. The area was notamed as the cartridges were pretty bright and blinding.
MACDONNELL DOUGLAS F-4 PHANTOM II: MANUAL FLIGHT 7 - Museu Pedagogico Luso Brasileiro - Google Books
Those cartridges have been used with other equipment as well.