Modification and development of the external tank hydrogen vent umbilical system for the space shuttle vehicle

The design and development of a new T-O lock and secondary release mechanism which is being introduced to the ET Hydrogen Vent Umbilical System for the next launch of the Space Shuttle Vehicle is described. Critical analysis of the system in early 1986 indicated the need for an improvement in the secondary release system. The new T-O lock increases the clearance with the vehicle during secondary disconnect and is described.