AEDC improves solid rocket motor test process
By Capt. Roger Burdette
/ Published May 14, 2007
ARNOLD AFB, TENN --
Moving a seven-ton rocket motor loaded with explosive fuel can be a tricky proposition, but that task just became easier, safer and more efficient at Arnold Engineering Development Center (AEDC).
Jan. 10, AEDC employees used a new transport system to move two such rocket motors - stage two and stage three motors for the Minuteman intercontinental ballistic missile - into place at the Rocket Preparation Area on a remote part of Arnold Air Force Base.
Moving the motors into the preparation area is the first step of testing the motors at AEDC. Once in the prep area, the motors are fitted with testing instruments and otherwise prepared for testing in AEDC's J-6 test cell, which can test solid-propellant rocket motors with up to 500,000 pounds of thrust at simulated altitudes up to 100,000 feet.
"It's a big day," said Aerospace Testing Alliance (ATA) employee Dwight Crosslin as he prepared for the first operational use of the new transport system. "I never dreamed I'd see this," added the 24-year AEDC veteran.
A truck and an enclosed, climate-controlled trailer had transported the two Minuteman motors to Arnold from the Minuteman System Program Office at Hill Air Force Base, Utah. The truck backed up to preparation bays that house the new rail system. After inspecting the motors, lining up the rails and making other preparatory actions, workers rolled the first motor onto the rails and into the rocket preparation area.
Previously, motors were moved into AEDC's rocket preparation area using a heavy-duty crane. The now-defunct lifting procedure included three critical lifts that moved the motors from the truck-drawn carriage into the preparation bay.
"The implementation of the rail system reduces two critical lifts of a live motor," said Lt. Col. Curt Amble, chief of the AEDC Space and Missile System Test Division. He explained that a "live" motor is one that is loaded with solid rocket fuel.
The rail system had been tested in the fall of 2004 using an "inert" motor that simulated a live motor, but Monday's procedure was the first movement of a live motor. "It seemed to go very well," Colonel Amble said of the initial use of the rail system.
The old lifting system required more manual labor and posed more risk to the motor, he explained. "Using the rails, we just pull the motor off the truck. It's much quicker and safer. The unloading operation takes about 20 minutes, compared to about 3 hours before."
The first use of the rail system for live motors is a "swan song" for Colonel Amble, who is scheduled to retire from the Air Force this week after a 22-year career.
In 2003, Colonel Amble led a team of six AEDC people to the Minuteman Special Program Office at Hill Air Force Base. "We conducted an audit, looked at procedures, and identified best practices we could implement in operations here at Arnold," he said. "Our whole test process has been refreshed as a result of this audit, and we've implemented a number of best practices and safety countermeasures," he said.
In addition to installing the rocket rail system and safety countermeasures - including better lighting, work stations and a procedure for eliminating foreign objects from the preparation area - all support equipment unique to the Minuteman III motor was replaced or refurbished.
Colonel Amble said that he received exemplary support to institute changes to the rocket testing procedures at AEDC, and as a result was able to install the new rocket rails transport system quickly.
"We were ready to go 70 days after we got clearance to proceed," he said. "We designed the modifications, procured them, refurbished the bay, and were ready to go - all in 70 days."
In November 2004, Mike McBride, an executive from the Minuteman System Program Office, visited the rocket prep area and viewed the new rocket rails system. He applauded AEDC's efforts to make the moving of rocket motors and engines more safe and efficient.
"We appreciate all the effort you put into this," he said. "We couldn't survive without the tests you do here. We look forward to a continued great relationship with you in the future."