So you made a new Temporal Agent, and you're finding out / being reminded that locating some of those temporal probes is a pain in the tribble.
This thread is meant to help.
There's an old thread on reddit here
that gives some helpful tips on finding the damned things,
Once you get close, you can type this command into chat to target the chingadera
/target temporal probe
A couple specific things about The Vault
1) At the start, when you board Starbase 39 Sierra, there's no map help. From the transporter pad where you appear, go forward to the desk, turn left through the doorway, go ahead until you cross the first white stripe on the blue carpet, and turn left again. You'll see a glowy door ahead. Go to that and you'll get two buttons, one is "Take Turbolift to Admiral's office". Once you're there, you can't miss DeSoto.
2) Once inside the Vault itself, opening the first door has been simplified, thank all gods great & small. Just blast the turret guarding it, scan the debris, and it'll give you the code 6750. Now when you do the opener puzzle, you will have three buttons. press the top one with the 3-part code until you get one with the string 6750 in it, then press the 6750 button, and voila, you're in like Flynn.
3) There are apparently multiple possible locations for the probe. I found it in the room with the Warbird on my way out
. I'd swear it wasn't there on my way in, but who knows. Open your Temporal Transponder and make SURE the icon for The Vault is lit up before you leave, You do not
want to have to do this TRIBBLE again.