Later versions of the B-58 provided each crew member with a novel ejection capsule that could eject at an altitude of at speeds up to Mach 2. Unlike standard ejection seats of the period, a protective clamshell would enclose the seat and the control stick with an attached oxygen cylinder, allowing the pilot to continue to fly even "turtled up" and ready for immediate egress. The capsule was buoyant; the crewmember could open the clamshell, and use it as a life raft. Unusually, the ejection system was tested with live bears and chimpanzees; it was qualified for use during 1963. The XB-70 would use a similar system with capsules of a different design.