The Advanced Crew Escape Suit (ACES), or "pumpkin suit", is a full pressure suit that Space Shuttle crews began wearing after STS-65, for the ascent and entry portions of flight. The suit is a direct descendant of the U.S. Air Force high-altitude pressure suits worn by the two-man crews of the SR-71 Blackbird, pilots of the U-2 and X-15, and Gemini pilot-astronauts, and the Launch Entry Suits (LES) worn by NASA astronauts starting on the STS-26 flight, the first flight after the Challenger disaster. The suit is manufactured by the David Clark Company of Worcester, Massachusetts. Cosmetically the suit is very similar to the LES. ACES was first used in 1994. History In 1990, the LES was nearing the end of its service life, so a program to produce a successor was initiated. Favorable crew evaluations of a prototype led to full scale development and qualification that would run until 1992. Production of the completed design began in February 1993, and the first suit was delivered to NASA in May 1994. After 1998, it became the only suit used during launch and re-entry on the Space Shuttle. The ACES incorporates gloves on disconnecting lock rings on the wrists, liquid cooling and improved ventilation, and an extra layer of insulation. The ACES suit is analogous to the Sokol suits used for Soyuz missions and its functions are virtually the same – the primary differences being the ACES suit having a detachable helmet and survival backpack, while the Russian suit has an integrated helmet and no backpack (due to the limitations in space aboard the Soyuz, and that the spacecraft is an entry capsule, not a winged spacecraft or lifting body). Design A one-piece pressure garment assembly with integrated pressure bladders and ventilation system. Oxygen is fed through a connector at the wearer's left thigh and is transmitted to the helmet, via a special connector at the base of the neckring. The helmet and gloves are connected to the suit, via locking rings, a metallic gray in color (Gemini suits featured a gray neck ring and red and blue anodized glove rings). The suit has a Nomex cover layer in international orange color, instead of silver or white as in previous David Clark suits. The orange color allows rescue units to easily spot the astronauts in the case of an Orbiter bailout over the ocean. Underneath the suits, astronauts wear Maximum Absorbency