Stargate Command officer who was pulled from inoculation duty to 865 to accompany SG-1 to Vagonbrei. Awake 18 hours at the start of the mission, Ackerman was the first among several to fall prey to an indigenous parasite. This native organism forced him to slip into a sleep state, and once it matured it created a fatal aneurysm in his brain.
Ackerman had been classified by Dr. Reimer as being in "Stage Four" sleep, also known as "delta wave" or "slow wave" sleep. His brain, which produced an overwhelming amount of melatonin, kept him there until his death.
Morpheus - Ackerman is the first of the Stargate team to fall victim to the native sleep-inducing organisms of Vagonbrei.