At their new speed, they had six hours to their destination, and almost everyone was intending to sleep as much as they could, in preparation for a long, sustained battle the moment that they arrived.
All the Mecha were being moved to their Cutters, and Terminus herself would stay well outside the destination system, hiding in an asteroid field so that they didn't alarm the Rebels that they wanted to wipe out.
When the Cutters arrived with the Mecha, the plan was to blast the Rebel transport vessel's engines so they couldn't flee or fight, and then force their way into the facility and fight it out.
There was air on the moon, but not of the breathable type or density, so they would have to suit up inside their Mecha to go into battle, just to be safe.
Having a small puncture in the cockpit suffocate the Pilot would be a tragedy, so the second layer of protection was standard procedure for all such fights.