The Air Force's 846th Test Squadron conducted a world record rocket sled test on the Holloman High Speed Test Track (HHSTT) at 0033 on 30 April 03. The sled obtained a velocity of 9,465 feet per second or 6,453 miles per hour, delivering a 192-lb. payload into a target. The test culminated the Hypersonic Upgrade Program (HUP) which began in 1998. The HUP significantly increased the capabilities at the HHSTT to meet a variety of hypersonic test needs for the Department of Defense. The test demonstrated improvements in rocket sled design, rail alignment, rocket propulsion, and modeling and simulation. These new capabilities will be used on an upcoming missile defense warhead test program. The HHSTT is the only ground test facility capable of achieving the speed/payload combinations necessary to simulate full-scale intercepts of missile defense systems. The previous world record of 8,974 feet per second, or 6,119 miles per hour, with a 25-lb. payload was also set at the HHSTT 5 October1982.The sled was propelled by a four-stage sled train. A Super Roadrunner (SRR) rocket motor, developed specifically for the HUP program, powered each of the last two stages. The SRR motor produces 228,000-pounds of thrust for 1.4 seconds and only weighs 1,100 pounds. The maximum acceleration of the sled was 157-g's or 157 times the force exerted by gravity. When the payload impacted the target it had 363 megajoules of energy or the energy of a car impacting a brick wall at 2,020 miles per hour.The HHSTT is the world's premier rocket sled test track. The HHSTT at Holloman AFB, New Mexico, is an aerospace ground test facility that conducted its first sled test in 1950. During tests, payload and instrumentation are moved along a straight-line path by means of rocket sleds, which operate on a set of heavy-duty crane rails. These rails span a total linear distance of 50,988 feet. They are continuously welded and aligned to rigid tolerances with respect to straightness and surface smoothness.The Test Track provides a critical link between laboratory-type investigations and full-scale flight tests. The Test Track provides an efficient, safe, and cost-effective ground test alternative to expensive developmental flight tests. Complementing the Test Track itself, the overall HHSTT complex encompasses ancillary facilities for artificial rain simulation, an accurately surveyed ejection test area, captive and free-flight blast test sites, impact test sites, and a horizontal rocket test stand. Support facilities include buildings for electronic and photo-optical instrumentation, a telemetry ground station, and engineering and shop facilities for design and fabrication of test sleds.Both military and civilian professionals operate the HHSTT and have the skills needed to design, fabricate, instrument, launch, photograph, and analyze the performance of test vehicles and payloads.