I'm playing Crusader: No Remorse. I'd really like to get past the door shown in the_attached_screenie.jpg. I know that to do this, I have to operate the flashing red panel shown in the_other_screenie.jpg (thanks, Jassica!).

Problem is, there's a thermatron next to it. Thermatrons can occasionally be shot, but that doesn't work on this occasion. You can squash them with elevators and I once got one to fall into water, but this one stays rooted to the spot, so that isn't an option. Spider mines detonate at the entrance to the room. I've never heard that thermatrons ever run out of bullets. I don't see how doing things beforehand another way could make a difference. I started from a much earlier point hoping that the thermatron would then be somewhere else, but no joy.

Assistance would be most welcome.

Whoa! I did it! I used one medikit beforehand and then another as I was blasting away. It would be nice to hear of a way of doing it that didn't use these things that are all-too-scarce.

So that's what those three switches did. Lordy.

Missing a grenade launcher twice is very me. I read the thread about fighting thermatrons a while ago, so I realize how valuable they are. I don't remember the place in your screenie. Unfortunately, I don't still have a save for mission 3. Buying a grenade launcher from Weasel sounds like the best idea, but I don't remember him having any the last time we met. Admittedly, I wasn't thinking “GL-303” at the time, so mayhaps I just didn't recognize it. I don't remember his having a fission battery, so I guess that one comes at the end of mission 4. How do I see how many credits I have?

To see credits, you just have to rotate your inventory. The screenie attached shows I have 7960 credits. By the time I finished the 4th mission, I bought the BA-41 and the RP-32 (I missed the RP-22 in mission 3), I also wasted a few credits on GL-303 ammo (not recommended unless you're completely out) but still had around 4000 credits to spare so I'm certain you should have enough for the both the GL-303 and fission battery as long as you didn't waste too many credits on consumables.

Here's a handy little guide for you on what to buy from weasel to avoid wasting your hard pillaged credits

Projectile weapons

BA-41: Buy this after mission 2 but you'll be ditching it after the 5th mission
RP-22: Found in mission 3, don't bother buying
RP-32: If you already have the RP-22, this gun may not be worth the purchase, buy at your discretion
SG-A1: Found in mission 1, don't buy
AC-88: Buy this as soon as it becomes available, awesome weapon!!! (don't forget to drop your SG-A1)
AR-7: Excellent and very destructive weapon but don't purchase, can be found in mission 10. Before you start mission 10, make sure you're only carrying 4 weapons (I had to drop my RP-32 in the mission to pick this up).
GL-303: Found in several missions throughout the game, but you'll definitely need this from mission 4 onwards

Energy weapons

PA-21: Found in mission 6, don't bother purchasing
PA-31: I got lucky and had an enemy drop it but if you have the credits, definitely buy this and keep it the whole game
PL-1: Fun gun, but not a must buy, This gun disintegrates corpses so you can't loot them, bummer
EM-4: Found in the same container as the PA-21 in mission 6, also destroys corpses
UV-9: Another MUST HAVE, this gun replaces all energy weapons except for the PA-31 (PA-31 doesn't destroy corpses)

Other stuff

All consumables (ammo, medkits, mines etc): Don't buy unless absolutely necessary
Generators: Do not buy, loads are found throughout the game. In the mission where you have to rescue your informant. Don't forget the graviton generator on the table. (If you do forget it, you might need to purchase one from weasel)
Batteries: Buy as soon as they are available. You only need to buy 1 fission and 1 fusion battery, multiple batteries are a waste.
Inhibitor: Not essential, can be found late in the game anyways.

Remember to drop weapons you aren't using anymore at the rebel base as you can only carry 5 at a time. After mission 5, definitely drop your BA-40 and BA-41. They are useless from that point on and you will want to carry two other weapons instead of those two. Make sure you drop the weapons at the rebel base, you can always pick them up again from the container in the screenie. For most of the game at least, I don't want to give away any spoilers unless you first tell me it's okay ;)

Also, there is a fair bit of leeway on how to use your credits. In my last play through, I bought the RP-32 (2200 credits) and PL-1 (2250 credits). Looking back these two were a waste but I still had enough credits to buy the important weapons. So if you do buy the GL-303, you will still be able to buy the important stuff later on with credits to spare. Just don't miss the important stuff in the missions too often, especially at the higher difficulty settings ;)