Alliant Techsystems (NYSE: ATK - News) recently conducted a successful full-scale severance test of an Ares I-X first stage. The test is a milestone in the development of NASA's Ares I crew launch vehicle and is another step leading to the flight test of Ares I-X in Spring 2009.

The test consisted of a replicated Ares I-X first stage forward skirt extension and forward skirt stacked and suspended two feet above the ground. A linear-shape charge was detonated, detaching the two pieces of hardware horizontally.

During an actual flight, once the first stage separates from the upper stage, the solid rocket booster will start to fall and at a predetermined altitude the forward skirt extension joint will be severed to facilitate deployment of the parachute recovery system. The first stage is designed to land in the ocean where it can be recovered for reuse.

This ground test was ATK's first-ever demonstration of joint severance on a simulated first stage and was the first in a series of three Ares I-X First Stage tests scheduled to demonstrate elements of the launch vehicle's joint severance capability.

The next two demonstration tests of the system are scheduled for July 2008. During the second test, the system will sever the first stage forward skirt extension from the first stage frustum. The third test will again demonstrate severance of the forward skirt and the forward skirt extension joint.

Ares I first stage is comprised of a five-segment reusable booster developed from the twin four-segment boosters used to launch the space shuttle. Unlike the shuttle, Ares I is an in-line launch vehicle design with a crew capsule on top.

Instead of a nose cone, the booster will connect to the upper stage with an attachment called a frustum. This design requires the first stage to be separated at the top, rather than falling off the side of the external tank as with the space shuttle.

Ares I and the Orion crew exploration vehicle will become America's primary space transportation system after the space shuttle is retired in 2010. Ares I will continue to service the International Space Station and eventually send humans to the moon. ATK is the prime contractor for the Ares I first stage