Modernization effort underway to keep Holloman High Speed Test Track on the rails Published Oct. 8, 2021 By Bradley Hicks AEDC/PA HOLLOMAN AIR FORCE BASE, N.M. -- To ensure the Holloman High Speed Test Track at Holloman Air Force Base, New Mexico, continues its record-setting ways and serves as a hub for testing to enhance pilot safety and hypersonic systems development for decades to come, 846th Test Squadron personnel are exploring the modernization of the HHSTT rail system. Operated by the 846 TS, a unit of the 704th Test Group of the Arnold Engineering Development Complex, or AEDC, headquartered at Arnold Air Force Base, Tenn., the HHSTT serves to bridge the gap between laboratory analysis and full-scale flight tests by providing a ground test capability to simulate selected portions of the flight environment under accurately programmed and instrumented conditions. The facility is in continuous use by various offices of the Department of Defense and Department of Energy and for commercial activities. The goals of this modernization effort are to increase the viability of the facility by bolstering infrastructure to prevent deterioration and catastrophic failure along the rail system and to provide an unprecedented capability for testing hypersonic systems into fiscal year 2070 and beyond. The 846 TS is studying three feasible courses of action, or COAs, to accomplish the modernization. “These COAs range from all-new construction to a combination of new construction and repair to the possibility of only repairing the existing track infrastructure,” said Capability Development Element Chief Lee Powell. The caveat, Powell said, is that each COA should provide for the extension of the narrow-gauge system to span the entire 10 miles of the facility. The narrow gauge, or NG, system consists of two parallel rails spaced approximately 26 inches apart and currently only runs for 4 miles. The facility currently hosts a 10-mile-long dual rail, or wide-gauge system, that is mainly used for egress, dispense, and guidance testing. “The extension of the NG system will allow for larger, operationally-representative test articles and fielded weapons systems to test and push the boundaries of their systems in a controlled and highly-instrumented environment at velocities previously unattainable in the world,” Powell said. Currently, recovered high-speed – those of Mach 3 or more – and rain erosion tests are limited to one of the 10-mile-long rails in a monorail configuration. The monorail configuration limits the size of test articles to small, light test articles, or coupons, due to roll stability issues at high velocities. Several congressional, general officer and VIP visits to the HHSTT in 2018 spurred research into the modernization enterprise. Later that same year, a team began studying the three COAs to gather cost and schedule estimates for each. “The report was published in August 2019 and used to start discussions with the local civil engineering unit and higher headquarters – AEDC and AFTC [Air Force Test Center],” Powell said. “The project idea reached TRMC [the Office of the Secretary of Defense’s Test Resource Management Center] and other Air Force Test and Evaluation offices and is continuing to garner interest and support.” How the modernization effort will be funded has not yet been determined. The 846 TS is currently pursuing military construction funding, but there is a chance of receiving funding through other agencies, such as TRMC. Because the 35 percent architecture and engineering, or A&E, design is not yet completed, a preferred COA has not yet been chosen at this time. U.S. Air Force policy and Congress require the completion of a 35 percent A&E design before the project is funded to help avoid cost overruns due to inadequate planning. “Once the 35 percent is complete, we will select a preferred COA and get approval from the chain of command to proceed with developing the 100 percent A&E design,” Powell said, adding this design effort will also be accomplished through a contracted effort. From there, the 846 TS will await the allocation of funding by Congress or another source which will trigger a request for proposal from a set of Air Force Civil Engineer Center contractors for the actual construction. And while the range of potential funding is uncertain at this point, Powell said the HHSTT modernization is a worthy project due to both the track’s celebrated past and its importance in the future. “The Holloman High Speed Test Track is a truly unique national asset with a 70-plus year history that is worthy of preservation and modernization to continue its test and evaluation heraldry into the next century,” he said. The HHSTT was constructed in five distinct sections between 1949 and 2002. The first section was around 3,400 feet long, and the first sled tests were performed on this portion of the track in 1950. The last section of the track added in 2002 brought the total length of the HHSTT to 50,971 feet and extended the narrow gauge to approximately 4 miles. Tests performed to assess the impacts of speed on the human body were performed at the HHSTT in its early years. On Dec. 10, 1954, Lt. Col. John Stapp climbed into a metal chair affixed to the top of a rocket-propelled sled preparing for launch at the HHSTT. After Stapp was secured, the sled was fired down the test track. The open-cockpit vehicle eclipsed speeds of 630 miles per hour. During the ride, Stapp endured around 40 times the pull of the earth’s gravity. He suffered several injuries, including broken ribs and a temporarily detached retina. But Stapp survived and, in the process, demonstrated the incredible forces the human body is capable of withstanding, thereby providing a greater understanding of human tolerance to high-speed aircraft ejections. This ride broke the land speed record, and Stapp was thereafter referred to as the “Fastest Man on Earth.” Stapp’s work also aided in the development of safety belts capable of tolerating a greater amount of force. In October 1982, the HHSTT became known as the “fastest place on earth” when an unmanned rocket sled delivering a 25-lb. payload to a target reached 6,119 miles per hour. This record would stand for a little more than two decades. The world land speed record was again set at the HHSTT in April 2003 when a rocket sled delivering a 192-lb. payload to a target reached speeds of 9,465 feet per second. This comes out to just shy of 6,500 miles per hour or around 8.5 times the speed of sound. Ejection testing, weather erosion testing, weapons dispense testing, impact testing and aerodynamic testing are among the variety of activities performed at the HHSTT over its first 70 years. Editorial note: This article includes information from the article, “A closer look at the Holloman High-Speed Test Track,” posted to the Holloman AFB website on Feb. 10, 2012.