|Quickly skimming through this: first, in the prologue, take out all those "had"s. Had is a passive verb. Either just cut it out of the sentence completely "...focus, they HAD recently joined..." change to "...they recently joined..." or re-write the sentence altogether. Little things like that make a big difference.
Also, you do a lot of "telling" as opposed to "showing".
You're telling how they feel. Only in the last five paragraphs do you really describe what is happening via what the character notices, hears, smells, etc. You need to focus on details of what the character experiences like hearing, seeing, smelling, rather than telling about the details.
One last thing. This story takes place in the near future, which is okay in sci fi, but it seems that this less sci fi than, say current suspense or general fiction. It sounds almost like a medical thriller, in the style of Robin Cook's "COMA".
While not bad, you need to really work on style and technique. Trust me, this only comes with reading reading reading and then writing writing writing. Practice makes perfect!