The last one is nearly perfect - it's a shame it doesn't have a beam in there.
Also, WTFOMGBBQ, are those green things explosion effects? Which ones? They're fantastic!
Then again, my backgrounds don't look anything like that, either...
Green explosions?

You mean in the second picture? Those are just part of the Perseus's thruster glows.
I also think the last one is overall the best. It has no effects but shows off the new models and specular lighting nicely.

Erm all of them suffer a great deal because of their native resolution.
They look great minimized by HLP's lvlshot, but when viewd as originals they're rather blurry and uncontrasted.
Might want to go down from the insane resolution and take them in the sensible 1024x786
I can easily size them down if they are worth considering for putting up on wikipedia, especially since it's an exact multiple of 1024x768. That's what lvlshot is showing them as anyway.
That green thing looks like a shot from some clouds in front of the sun, but I like it. Where is it from ?
The background graphics were made by Lightspeed I think. I made a few minor color changes to them for my use. The mission is from my PI campaign (available in my thread in the campaigns section).