Press Release

ATK Provides Propulsion and Composite Structures for Successful Launch of Pegasus Rocket

By SpaceRef Editor
June 13, 2012
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ATK (ATK) supported the successful launch of an Orbital Sciences Corporation (ORB) air-launched Pegasus XL(R) rocket from the Ronald Reagan Test Site at Kwajalein Atoll in the Pacific Ocean. The Pegasus rocket carried NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) satellite, an Orbital-built spacecraft designed to study high energy X-rays in the universe.

ATK provided propulsion for all three stages, many of the composite structures of the Pegasus rocket, as well as the solar array and structures for the NuSTAR spacecraft. ATK’s Orion motors – manufactured in Magna, Utah – have provided reliable propulsion for the Pegasus since its first mission in 1990. The Pegasus vehicle’s payload fairing, interstage, raceways, and the filament-wound solid rocket motor cases were produced by ATK in Clearfield, Utah.

The Pegasus traveled under Orbital’s L-1011 “Stargazer” carrier aircraft to an altitude of approximately 40,000 feet, where it was released horizontally before the first-stage Orion 50 SXL motor ignited. Approximately 130 seconds into the flight, the Orion 50 XL second-stage ignited and a composite payload fairing was jettisoned. After a several-minute coast period, the third-stage Orion 38 motor burned until approximately 10 minutes into the flight, when the Pegasus released NuSTAR into orbit.

ATK in Goleta, Calif., provided the solar array for the NuSTAR X-ray observatory mission. This unique solar array consists of five solar panels that wrap around and connect to the hexagonal-shaped spacecraft with a yoke panel. The solar panels unfold sequentially, one panel at a time, upon reaching orbit. The five deployed panels align in a single plane and function as a total arraymuch like a door swinging out from a wall on hinges. When fully deployed, the solar array extends 10 feet out from the spacecraft. The 867 solar cells on the array generate 725 watts to power both the satellite and on-board sensors for the planned multi-year science experiments.

ATK-Goleta also provided the deployable, stable and weight-optimized instrument structure for the NuSTAR observatory. This structure consists of a 33-foot long deployable ADAM (ABLE Deployable Articulated Mast) and adjustment system manufactured at ATK’s Goleta, Calif. facility, with an integrated focal plane bench and optical bench manufactured at ATK’s Magna, Utah, facility.

The mast and adjustment mechanism are the backbone of the observatory and one of the primary enabling technologies for the NuSTAR mission. This mast provides the required separation distance between the focal plane assemblies and the tip-mounted optic modules. Stowed in a 34-inch canister during launch, the mast uses technology similar to ADAM, which flew on the Shuttle Radar Topography Mission in 2000 and demonstrated extreme stability and deployment repeatability capabilities.

The focal plane bench is a high-strength composite structure that serves as a multi-functional stable platform for the NuSTAR instruments and the primary interface to the satellite bus structure. It supports the stowed mast/canister and optical bench with its integrated X-ray optics during launch. Mounted to this bench are the focal plane assembly’s instrument electronics and metrology detectors performing mission-critical operations of instrument alignment, focus and data collection.

The optical bench, which attaches to the tip of the deployable mast, is a precision-engineered, highly stable, composite structure responsible for structurally supporting the binocular-like X-ray optics modules, metrology lasers, adjustment mechanism and star tracker. X-ray optics modules held stable within the optical bench will collect images as NuSTAR searches for black holes, maps supernova explosions and studies the most extreme active galaxies.

The NuSTAR mission was the 41st mission carried out by Pegasus rockets and the 27th consecutive successful launch. Pegasus, which has deployed nearly 80 satellites into orbit, has set the standard for reliable small launch vehicles using ATK’s Orion motors.

ATK is an aerospace, defense, and commercial products company with operations in 22 states, Puerto Rico, and internationally. News and information can be found on the Internet at

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SpaceRef staff editor.