The mission objectives for Argent in the Rough are some of the most complicated you will come across. Several of your new employer's agents are being held in this facility - they must be rescued before you can carry on. The mine has a relatively large concentration of robots, despite its small size.
You must rescue as many of the hostages as possible, then blast a trigger behind a grate at one end of the level. In a room behind this is the blue key, which you will need before you can reach the red key. Once you blast the trigger behind the red door, you can now access a network of triggers that you have to blast in sequence. The last one will unlock several doors, including the one which you must enter to destroy the mine.
Look for weapons such as the Plasma Cannon, Smart Missile, Smart Mine and Fusion Cannon.