UCGO cargos on an orbit - how to locate?

[malves61]

Greeting fellow orbiters. This is my first post on this forum hence I start by thanking Dan for all of his work - very well done!

Now to my great fellow flight commanders, here is a mission I was building up on complexity and I faced an ISSUE:
Imagine the following scenario:
- Long trip to Jupiter on a DGIV, running low on O2 (building mission). No specific cargo on the DGIV.
- Previous missions (actually scenario editor) would have left O2 cargo and other modules on Jupiter's orbit.
- EVA to capture modules into DGIV.
- ISSUE: How to track the UCGO cargos on Jupiter's orbit by themselves? They don't seem to have a transponder. I was thinking about associating the cargos with a probe, but once the probe is activated starts to deorbit.
- O2 ressuply from cargo, and then haul the modules to Europa (and find the hi-res base area).
- Meanwhile have an Arrow with more cargo lauched from Earth to Jupiter with the main mission components: More passangers (research crews) and modules.
Sorry if I am asking something that I should know...