I hesitate to sound like a creative writing cliche, but you're telling us everything. You should work on showing us instead. Don't list stuff out, rather have it revealed naturally. The first two paragraphs would be well served to be told as the dropship is circling the objective... "The hollow remains of the research center made Klasky frown. He sat in the Pelican, watching himself and his squad on approach from intel satellites. He brooded over the images. It seemed straightforward enough, but it never is..." And so on. I assume they have satellites in Halo.
When you use acronyms, you need to define them the first time so your reader knows what you're talking about. Don't assume they know.