Officers at F.E. Warren Air Force Base feared the disabled MX missile that slipped in its silo last June might accidentally launch or explode while they were trying to remove it from its silo.
They worried that the solid fuel might have been cracked when the missile dropped 6 to 8 inches to the bottom of the silo."If you have cracked propellant and you start moving it, you can get friction within the crack, and there was concern that it could cause ignition," Lt. Col. Charles R. Banta, deputy commander at the Wyoming base, told Air Force investigators.
Also, static electricity might have posed a danger of igniting the fuel while technicians struggled to remove the missile.
"Part of our concern, again, was the grounding system on the stage because of the potential for electrostatic discharge. So, we went down the raceway and checked all the raceway ground clips to make sure they were intact. Which they were."
Most of the MX's 192,000 pounds rested on the missile's nozzle, due to its internal slippage. So another fear was that this tremendous pressure might cause it to shift suddenly while work was going on to extract it.
"Thiokol eventually came up with a procedure to remove the igniter (the part of the missile that ignites the solid rocket fuel) and put a lifting adapter into the igniter hole."
A device was lowered through the hole where the igniter had been, and attached so it could lift the missile.
Meanwhile, technicians feared that if the missile were lifted, the damaged nozzle might fall off. Any kind of movement in that area of the fuel tank might cause the fuel to ignite.
To solve this problem, a "fish hook" was invented _ a long device lowered through the center of the stage. Controlled by two cables, it was rotated into place, to keep the nozzle stable.
This amounted to pulling the stage from above and from below, by way of the lifting device on top and the fish hook at the bottom.
"When we tried the movement operations, they did not feel comfortable with having a crew there doing that," Banta said. "They wanted to do those critical operations, as they called them, from a remote location."
In other words, it was to be done from a distance in case the missile blew up.
A dry run was decided upon. Banta described it this way: "So, we hooked up video cameras to be able to watch what we were doing. To run the cables over . . . we just coiled them on ground rather than run them out and attract a lot of attention. But we did run the full length of the cable and hooked them into a support truck to see what was happening."
The experiment worked well. Next it was time to actually move the MX itself.
"At that point in time, we went out to the site and hooked up our equipment and began the pull operations. It went very smoothly.
"We did the critical tasks from remote, and we'd go back in and take care of the things we had to do in local and go out remote and work more critical tasks.
The Strategic Air Command "supported us with some security police to block the roads off at the time we were doing the remote operations to make sure the public wasn't driving through out there."
The missile came out safely, and only the first stage was damaged, where it had slipped because of the failure of the bond.