If that's the case, I'm really looking for something with a bit more potential as part of a mini-campaign. So far it sounds like Kafer Dawn is getting the highest recommendation. I think I'll have to see if I can scrounge up a copy. Thanks!
Another suggestion I'd have (which requires a bit of legwork on your part, but a lot of GDW packaged adventures aren't really much better than outlines anyway):
If you're setting your game in the circa 2300 period (not 2320) and your players are die-hard Travellers, I would suggest getting a copy of the Colonial Atlas and Invasion. Why?
In my campaign, I decided to find some reason for my players to be on Kolonie Zwei when the Kafers smear it from the map.
If they're military/merc types they can be on their way to Aurore to be advisors or just guns-for-hire to the TANSTAAFL government.
If they're of a more merchant bent, perhaps they're on Kolonie Zwei to sell widgets from the Core and pick up exotic stuffs on their way back to Alpha Centauri.
You can use it opportunity to show your players the differences 2300 and Traveller:
* No anti-grav. Make those merchants really look closely at the costs of moving goods planetside (cheap) and getting it up to orbit (hugely expensive).
* That ships aren't so often held by private individuals.
* Nationalist tensions that run rampant in 2300.
* People nervous about the Kafer threat (but more scared of the local administration's "Cry Wolf" policy).
* Corporate intrigue (if you're playing more of the "Rotten to the Core" style).
Let them get into barfights, meet attractive members of the opposite sex (or the same sex if they're that way), intrigues, and so on. Let them get a feel for Kolonie Zwei.
Then spring the Kafers on them. There's actually quite a bit of time from when the Kafers are sighted to when they arrive at Kolonie Zwei. If the players don't have a ship, make them sweat finding a ride off of the planet along with hundreds of thousands of other murderously desperate people, all of whom will be dead in a few days.* If they have a ship, make them fend off attempts by the authorities to commandeer it, have rich people offer them outrageous amounts of money for space, desperate armed men and women trying to seize their ship by force, families trying to at least get their kids on board the ship even if they cannot. No matter what they do, they can't take everyone. Make them agonize over it no matter which choice they take. Make them realize the Kafers are playing for keeps. This isn't the TI where the Zhodani are going to be content making the TI spend its power and taking a few planets, Vargr raiders are just annoying, the Solomani are more Hogan's Heroes than Waffen SS, etc. At some point the players are going to return to Kolonie Zwei (maybe after getting to Aurore and doing "Kafer Dawn") and they'll know that all those people they left behind are dead.
* The Kafers don't wipe out every dome on Kolonie Zwei, either. If your players can't get off of the world, you could also make a fun adventure having your players trying to survive in some smaller, partially destroyed dome. Though it says the Kafers attempt no landings, perhaps curious or bored Kafers do land on the world for salvaging human tech for study or just to see if there's survivors to fight. Eventually some passing blockade runner should rescue them, but make 'em sweat it with supplies, oxygen, and power running low. If you're really sadistic, let them stay in contact with a few other scattered groups of survivors via radio and make them be too far away to help as they're overrun by Kafers, run out of basic requirements (food/water/oxygen/power) and die off before rescue comes.