Now Did IPX exist prior to the Earth-Minbari War?
Yes, IPX has been around for quite a while. Though they only came into their present incarnation around 2175 or so, when the EA started expanding into a major power after their encounter with the Cenaturi. As they realized that most of their neighbors have better tech, the EA initiated a aggressive R&D program to raise their tech base, and one of the tricks was to have IPX try to find technology among the ruins of dead civilizations, from mars (the shadowship Dr. Kirkish found on mars wasn't the first find of shady artifacts - and the "mouse" Dr. Sheridan examined wasn't either. Read the Psi-Corps trilogy, part 1) to any dead world they could reach.
What kind of ship would they use to move teams from world to world?
This is of course in the Time period prior to the E-M War
Well, the small "Icarus" type science ship does not seem like a terribly new design (it shares more similarities with the old -Hyperion, Kestrel shuttle, Skylark Transport, Olympus, Aries-to-Aurora Starfuries- then the new -Omega, Warlock, Thunderbolt- designs); I'd assume it had been around since before the Dilgar war, quite possibly even since the first days of EA interstellar exploration. The earliest design I know of that has some similarities dates back to 2168...
For more understanding - IPX Modus Operandi:
First regular Explorers ("Explorer" class ships after the Minbari war, "Oracle" and "Pathfinder" -a Nova variant trading many big guns and half the fighters for a rotational section and long-range stores, looks almost like an Omega, most likely the ones seen in "ItB"- class ships before) find the new system and establish a reliable jump route. If they report any ruins...
...an IPX ship comes, carrying a science team (see "Thirdspace" or the scenes about the "Icarus" landing on "Alpha Omega Three" aka "Z'ha'dum"; and read "The Shadow Within" for more info) to investigate and maybe find something of interest - or some info pointing to something usable.
Since they don't usually risk their people in first investigations (after all, IPX specialists are too higly paid to check out all planets, they get sent only once indication of an ancient civilization has been found), they don't usually need big and jump-capable ships (though they might have some - or they just ask Earthforce to help them if they need something with a jump engine).
Sooo... if any mongoose guy sees this, how about doing a "IPX Science Vessel" part complete with stats and deckplans for "S&P" or some other supplement? :wink: