Confederation6 books in series
The Heart of Valor Publisher's Summary
So, of course, she'd jumped at the chance to go to Crucible---the Marine Corps training planet---as a temporary aide to Major Svensson. The major had been reduced to little more than a brain and a spinal cord in his last combat, and he and his doctor were anxious to field-test his newly regrown body. It should have been an easy 20-day run. After all, Crucible was only set up to simulate battle situations so that recruits could be trained safely. But they were barely on-planet when someone started blasting the training scenarios to smithereens. Suddenly, Kerr found herself not only responsible for the major and his doctor but caught in a desperate fight to keep a platoon of Marine recruits alive until someone could discover what was happening on Crucible.