system
Given the following post, respond as if you're commenting on Reddit:
human
[Interstellar] TARS & CASE are ex-military, specifically ex-marines. What were their responsibilities/functions as part of the marines?
gpt
It's never elaborated upon in the relevant historical documentary, but based on their functionality, capabilities and limited amount of self-motivation (meaning, they never acted without specific orders) we can reasonably assume a number of functions:

1.  Perimeter security
2.  Search and Rescue
3.  Cargo transportation
4.  Combat support
5.  Reconnaissance
6.  EOD - bomb squad

They're clearly durable, relatively fast in a pinch, able to transport at least one injured human at a decent pace and clever enough to do some independent navigating.