ATK Provides Composite Structures for Delta IV Rocket
ATK propulsion, composite and spacecraft technologies supported the successful launch of a United Launch Alliance (ULA) Delta IV rocket from Space Launch Complex 37 at Cape Canaveral Air Force Station.
This rocket carried a Wideband Global SATCOM satellite (WGS-6) into orbit for the U.S. Air Force and is the sixth satellite delivered by prime contractor Boeing as part of the WGS system that provides flexible, high-capacity communications for the nation’s warfighters. WGS is the Department of Defence’s highest capacity communications satellite providing high data rate and long-haul communications for soldiers, sailors, Marines and airmen worldwide.
This was the fourth time the Delta IV medium-plus rocket featured four ATK 60-inch diameter Graphite Epoxy Motors (GEM-60). The 53-foot-long motors were mounted in pairs on opposing sides of the rocket, with one fixed and one vectorable nozzle per side. They burned for 90 seconds and provided more than 1.1 million pounds of thrust to assist delivery of the WGS-6 satellite to its determined orbit. The composite cases, nose cones and aeroskirts for the GEM motors were fabricated at ATK’s Clearfield, Utah, facility. The solid rocket motors were produced at ATK’s Magna, Utah, facility. ATK has manufactured 58 GEM-60 boosters for the Delta IV launch vehicle since the initial flight in 2002.
For the Delta IV medium-plus launch vehicle itself, ATK supplied nine key composite structures, including:
The Interstage that provides the interface between the Common Booster Core and the cryogenic second stage;
A Centerbody that integrates the liquid oxygen (LO2) and liquid hydrogen (LH2) tanks;
A Thermal Shield that protects the RS-68 engine during ignition and flight, and an LO2 Skirt;
The five-meter-diameter composite payload Fairing; and
A variety of required hardware for payload integration, such as Nose Cap, X-Panels, Payload Attach Fitting, and Payload Attach Fitting Diaphragm. The structures are five meters in diameter and range from one to 15 meters in length. They are all produced using advanced hand layup, machining and inspection techniques at ATK’s manufacturing facility in Iuka, Miss., with the exception of the X-Panels, which are produced at ATK’s facility in Clearfield, Utah.
The nozzle for Delta IV’s RS-68 engine was designed and manufactured at ATK’s Promontory, Utah, facility. The Aerojet Rocketdyne-built RS-68 is the largest hydrogen-fueled engine in the world. ATK also designed and produced the nozzle’s thermal protection material, which is capable of shielding the nozzle from the extreme heat of launch when external temperatures can exceed 4,000 degrees Fahrenheit.
ATK also provided the propellant tank for the Delta IV upper stage roll control system. The tank was manufactured at ATK’s Commerce, Calif., facility.