Bodycote Thermal Processing Inc. retained sole source status for the main rocket booster on the NASA Space Shuttle. Bodycote Los Angeles plant continues to actively heat treat solid rocket booster segments for NASA's Space Shuttle Program. Bodycote uses a Gantry type furnace to accommodate the weight of the massive booster (the largest cylinder is 12,000 lb). The rocket booster material is D6AC (medium carbon, chromium, nickel and molybdenum high tensile strength steel) and is heat treated to 225/245 KSI, fracture critical. Bodycote is considered a single heat treat source for processing these rocket boosters and has been since the program's inception during the mid 1970s.