Space Cover 551: Rocket SledWhen collectors think of rockets, we think of them launching something – crewed missions, satellites, scientific experiments, and military warheads. Covers exist for thousands of launches from around the world.
An interesting sideline to collecting launch covers is to collect "launches" of horizontal rockets. One of these areas for collecting is related to rocket sleds.
The rocket sled is a system that was designed to experiment with G-forces. In its simplest form, a rocket sled consists of a chair attached to a sled on a long stretch of railroad track with a rocket engine strapped to the back. The rocket ignites, the sled fires forward, the chair and occupant go along for the ride.
Rocket sled tracks have been built at multiple places around the world. Some of the United States government/military tracks were built at Edwards AFB, Kirtland AFB, Holloman AFB, and Redstone Arsenal. There are also private tracks such as the one in Socorro, NM – run by Energetic Materials Research and Testing Center (EMRTC), a research division of New Mexico Tech.
Extensive aviation research was conducted on the ground at Edwards AFB. Two rocket sled tracks there pioneered important developments and research for the United States Air Force. The first 2,000-foot track was built by Northrop in 1944 at what was then Muroc Army Air Field. The track was originally intended to help develop a V-1 flying-bomb-style weapon that ultimately never left the drawing board. After the war, the track found use as a test area for V-2 rockets captured from Nazi Germany in Operation Paperclip.
Later, Lt. Col. John Stapp appropriated the track for his MX981 project and installed what was believed to be one of the most powerful mechanical braking systems ever constructed. The sled weighed 1,500 pounds, could hold a person and had room for a number of rocket engines in the rear.
At first the "Gee Whiz" rocket sled was tested with a crash test dummy, known as "Oscar Eightball." Eightball would suffer a violent ejection that sent him flying 700 feet, as well as other work-related "injuries."
These problems were fixed, however, and then they strapped a chimpanzee in the seat. Finally they needed a human volunteer.
After 35 unmanned test runs, Stapp himself rode the sled with a single rocket propelling it, hitting 10 Gs of force in the process. He was hooked. The image above shows Stapp riding Gee Whiz.
Within months, Stapp had hit 35 Gs of force, blowing away the previously believed 18 G fatality point. This research changed the way airplanes were designed nearly immediately, accounting for additional safety measures and new capabilities.
Captain Ed Murphy, an Air Force Engineer, briefly came out to Edwards Air Force base to try to test some sensors he had created on the sled run. He believed that they would grant quantifiable insight into the amount of force applied to Stapp during deceleration.
An assistant installed the sensors on the restraints and — while the exact details of the event remain contested — something went wrong.
By either malfunction, mistakes in wiring, or an error setting the system up, the gauges that Murphy had installed had no readout after Stapp's run on the sled.
At that point, Murphy — either out of anger at the assistant who configured the device or as a commentary on engineering and design — said something to the nature of "If there's any way they can do it wrong, they will," according to a witness.
After a test failure, the result spreads around the staff very quickly. Murphy's sensor failure and subsequent quip were no exception. The notion was eventually distilled to a catchier "If anything can go wrong, it will."
"Murphy's Law" caught on, everyone was talking about it. The key moment where it entered the mainstream was at a press conference Stapp was holding. When asked how such dangerous testing had never caused a fatality, Stapp commented that he and his team always kept Murphy's Law in mind when working, and planned to prevent mistakes. The rest is history.
Similarly, "Stapp's Law," written during the rocket sled tests, states that "The universal aptitude for ineptitude makes any human accomplishment an incredible miracle."
The results from the first track prompted the Air Force to build a second in 1948. Located just south of Rogers Lake, the 10,000-foot track was capable of supersonic speeds. Its first project was the development of the SM-62 Snark cruise missile. This track was so successful that an extension was constructed, and on May 13, 1959, the full 20,000-foot track was opened. After the United States Navy had conducted research on the UGM-27 Polaris ballistic missile, the track was used to develop ejection seats that could be used at supersonic speeds.
Pictured at the top of this post is an image of a carried rocket sled cover and it states it is the "First transportation of mail at the AIR FORCE FLIGHT TEST CENTER by rocket propelled sled on the High Speed Track." The cover was "Carried by the Parachute Test Vehicle on 18 Jun 59 at a maximum speed of 875 mph."
Though this program was a success, a budgetary review concluded that the track was too expensive to maintain and the track was decommissioned on May 24, 1963. Before it was closed, a trial run set a world speed record of Mach 3.3 before the test car broke up.
Stapp's deceleration test runs at Edwards AFB and Holloman AFB led the press to nickname him the "fastest man on earth" and the "bravest man in the Air Force". Stapp, one of the most frequent volunteers on the runs (29 of 77 total human runs), sustained a fracture of his right wrist during the runs on two separate occasions, also broke ribs, lost fillings from his teeth and bleeding into his retinas that caused temporary vision loss; in one run he survived forces up to 38 Gs.
The image above is Milestones of Flight cover Number 22 for the 20th anniversary of Stapp's 38 Gs ride. This was written up in Space Cover of the Week 392.
So while you are on the hunt for space covers consider looking for some horizontal rocket launch covers...
posted 02-08-2020 11:13 PM
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