Mike Power was a infantry soldier in Viet Nam who lost his legs and right arm in a land mine explosion.
While in Hospital he was approached by Joe Colton and Nick Fury and offered the choice of a radical experimental procedure which might be able to replace his lost limbs. The only condition was Mike had to join S.H.I.E.L.D as a field agent.
After the successful surgery and lengthy recuperation Mike was transferred into Joe Colton's Adventure Team as it's second member. He served several years and retired in the 90's. He still goes on the annual camping trip to hang out with his former team mates.