You're approaching Hell, a frozen moon orbiting Gaigan. Elysium, a research facility on Hell, has sent no transmissions for the past 18 hours. Aida describes the layout of the base--four research modules (each focusing on a different area of weapons research) located around a central hub.
Walk into the armory and speak with Isaak. He's got some weapon briefs for you. Isaak removed a limiter on the shock lance, increasing its power. The alt-fire is an EMP, and it screws up machinery. The marine shotgun is lethal up close and decent at midrange. Its alt-fire launches explosive, incendiary slugs at limited range. Finally, he's got the toxic grenade, which releases a cloud of neurotoxic gas that eats through armor. When you're finished, return to the drop deck and board your vessel to begin Hell.
Objective: Enter the installation. Investigate to determine why contact was lost.
You must reach that bridge in the distance, but you can't get there by going forward. Instead, turn around toward your ship. Hang a right under the ice overpass. There's the bridge. Cross it. There's a sleeping beast lying on the bridge. When it awakes, kill it or just run by it (better to save your ammunition). Drop down into the small recess on the other side, and you're automatically lowered into the facility.
At the bottom of the lift, move forward. You'll enter a security-clearance area. Despite some nervous moments and a bit of sweat, Aida disables the security system in time. Once the system is disabled, head forward into the next area.
Go left. The far door is locked, and Aida can't get you inside. Don't worry; you'll be back. Take the first door on your left and ride the lift down. Cross the room. Take care to avoid the fire by sticking to the right side of the room. Grab the flamethrower off the ground (it's near a corpse). It's a great weapon for this level. Enter the large doorway and follow it until a fire blocks your path. Turn left and proceed into the doorway, which leads to the medical bay.