Note: Only forum leaders may delete posts.
*HTML is ON
*UBB Code is ON
[i]The explosively actuated side hatch was used for the first time on the MR-4 flight. The mechanically operated side hatch on the MR-3 spacecraft was in the same location and of the same size, but was considerably heavier (69 pounds as installed rather than 23 pounds).
The explosively actuated hatch utilizes an axplosive charge to fracture the attaching bolts and thus separate the hatch from the spacecraft. Seventy 1/4-inch titanium bolts secure the hatch to the doorsill. A 0.06-inch-diameter hole is drilled in each bolt to provide a weak point. A mild detonating fuse (MDF) is installed in a channel between an inner and outer seal around the periphery of the hatch. When the MDF is ignited, the resulting gas pressure between the inner and outer seal causes the bolts to fail in tension.
The MDF is ignited by a manually operated igniter that requires an actuation force of around 5 pounds, after removal of a safety pin. The igniter can be operated externally by an attached lanyard, in which case a force of at least 40 pounds is required in order to shear the safety pin.[/i]
Contact Us | The Source for Space History & Artifacts
Copyright 2020 collectSPACE.com All rights reserved.