Survey modules come from the Sensors tech line, not life support. You really shouldn't have much of a use for them during the first campaign mission anyway, as far as I know.

As for the invasion numbers, yes they are randomly generated (but not entirely randomly... they are generated within set ranges that are determined based on each side's advantage, soldiering, and tech factors, I believe). I think that it's always invader vs invadee, but it might be player vs computer, I'm not sure. However, it should be relatively obvious because the name of each race involved should be displayed on opposite sides of the screen. The random number belongs to the race whose name appears on the same side of the screen.

First, relax a little. GalCiv is a little different from other turn based strategy games. There is a learning curve. It's not that steep but it can be a bit daunting at first. One basic thing to remember is that if what you're doing doesn't work try something different! Don't try to do the same thing better.

Generally, you want to build a few factories on your home world and the first worlds you colonize. In sandbox games specialization becomes more important but I've found in the campaign games that it helps to build a base of factories and fill out the rest with research buildings (so you get more technology) and banking buildings (so you go into debt slower). First and foremost, set your spending to %100. Research planetary improvements (for bonuses) then enough to get the basic buildings then move to weapons tech.

More campaign specifically, the Drengin are in the upper right corner. To get there you'll need to settle the worlds leading in that directing. This will increase your ships range. You'll want to build weapons up fast to defend yourself. Defend forward. Meaning push the fights more toward the Drengin planet. Don't just keep defending. After you get the ability to make troop transports keep researching that line so you get an advantage (those random numbers you were talking about depend on your soldering and technology level). By researching technologies that increase your soldering you will increase your advantage factor. Take any planets and build a few constructors to create a military starbase to get you to the last Drengin planet. This may not be necessary but I did it.

There are technologies that are blocked out in the campaigns. You don't need what you can't research so don't worry about it. The first two or three techs you research should be for your planets. Get things that give you bonuses and give you buildings. Then research your beam weapons. As you have beam weapons build fighters with two laser cannons. Next go for planetary invasion and when your building transports go after soldering bonuses. As you get your more advanced laser technology (which you should do before planetary invasion) design newer ships with three cannons and start building them. You won't need defences for this mission.

That might help. I don't really remember a lot about that mission but I do remember it was a little more difficult then the next few. Other than that read through the forums to get some more strategies. Just remember to try different things and to analyse why the enemy is stomping you. That will help you adapt to GalCiv and eventually become an addict.

I'm sorry by the way if this is poorly organized but I'm trying to remember this mission and I'm writing as it's coming to me.

Thanks for the response.

I understand the sensors part. But when you look at the ship requirements, it says 4 techs required (or something similary). I researched the other three but there was never an option for advanced life support (the 4th). I guess, as previously stated that I don't need sensor ships so the tech won't be available.