ATK's (ATK) Composite and Propulsion Technologies division supports launch of a United Launch Alliance Delta IV rocket carrying the GPS IIF-3 satellite.

The Delta IV medium-plus rocket that was used on this flight is in the 4, 2 configuration, which features two ATK 60-inch diameter Graphite Epoxy Motors (GEM).

The 53-foot-long motors were mounted on opposing sides of the rocket, with one vectorable motor per side, and provided additional lift capability for the Delta IV medium plus configuration rocket.

The GEM 60s burned for approximately 90 seconds and provided 560,000 pounds of thrust to deliver the GPS IIF-3 satellite to its predetermined orbit.

The composite cases for the GEM motors were fabricated at the ATK Clearfield, Utah facility and the motor was built at ATK's facility in Magna, Utah.

ATK also designed and produced the nozzle for the Delta IV's RS-68 engine. The Pratt and Whitney 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 4,000F. The nozzle is manufactured at ATK's Promontory, Utah facility.

ATK supplied seven key composite structures for the Delta IV Medium plus launch vehicle: the interstage that provides the interface between the Common Booster Core (CBC) and the cryogenic second stage, a centerbody that integrates the liquid oxygen (LO2) and liquid hydrogen (LH2) tanks, a thermal shield that protect the RS-68 engine during ignition and flight, and a LO2 skirt.

The payload was encapsulated by a 4-m (157-in) diameter composite payload fairing, along with a Payload Attach Fitting and Payload Attach Fitting Diaphragm required for payload integration.

The composite structures are four to five meters in diameter and range from one to eight meters in length. They are produced using advanced hand layup, machining, and inspection techniques at the ATK manufacturing facility in Iuka, Miss.

For the GPS IIF-3 satellite ATK provided a host of products including solar arrays, antennas and titanium propellant tanks. ATK designed, manufactured and delivered 12 satellite solar arrays (24 wings) for the Boeing-built GPS IIF-3 satellite.

Each array provides up to 3.5 kilowatts of continuous power over the 12-year mission. The arrays were manufactured at ATK's Goleta, Calif., facility. ATK has achieved 100-percent on-orbit success on all solar arrays and deployable systems delivered and launched to date.

The composite solar array substrates were manufactured at ATK's San Diego, Calif. facility. Additionally, ATK Goleta manufactured, tested and delivered 12 deployment booms for the Burst Detector Antennae (BDA) for the GPS IIF satellites. ATK's Rancho Bernardo, Calif. facility performed final assembly and RF (Radio Frequency) test of the antenna suite for GPS IIF between 2003 and 2010. Antennas tested were the TT and C (Telemetry, Tracking and Command), LBS (L-Band System)/ITS (Integrated Transfer System) and BDA (Burst Detection Augmentation), for which gain and antenna pattern data were verified.

The Reaction Control System (RCS) propellant tank for the Delta IV rocket was manufactured at ATK's Commerce, Calif. facility.

The GPS IIF has an ullage tank, for which ATK Commerce has responsibility for the blankets, heaters, thermistors and pressurant lines. This tank is a spherical vessel constructed of titanium.

The mission will deploy the third satellite in the Block IIF series of the U.S. Air Force's next generation GPS spacecraft that will have improved accuracy, enhanced internal atomic clocks, better anti-jam resistance, a civil signal for commercial aviation and a longer design life.

This newest spacecraft will replace the GPS 2A-21 satellite that was launched by a Delta 2 rocket on June 26, 1993. The IIF series incorporate various improvements to provide greater accuracy, increased signals, and enhanced performance for users.