HYPERVELOCITY BALLISTIC RANGES G AND I

Hypervelocity Ballistic Ranges G and I are used to conduct kinetic energy lethality and impact phenomenology tests, hypersonic erosion testing, wake phenomenology studies, and other unique hypersonic test programs. Both launchers are two-stage light-gas guns with the Range G launcher being the largest gun of this type in the United States.

FACILITY DESCRIPTIONS

Range G

This launcher provides an unequalled capability to fire projectiles up to 8 inches in diameter at speeds ranging from 4,900 to 23,000 feet per second. Projectiles are launched into a segmented 10-foot-diameter, 930-foot-long instrumented chamber that can be maintained at pressure altitude from sea level up to 225,000 feet. Three sizes of interchangeable barrels - 3.3 inches, 4 inches and 8 inches are available for use on the Range G launcher. A four-rail guidance system can be mated to the barrel to guide the projectile into a specified point on the target in order to obtain precise hit point accuracy. This track system can also be installed the full length of the range on the 3.3 inch launcher, which allows a projectile to enter a recovery tube for post shot inspection. The 3.3-inch launch tube is typically used to support one-fourth scale testing (projectile and target one-fourth the size of the full-scale system), track guided erosion testing, and free flight wake phenomenology testing.

Range G also has the capability to launch larger scale projectiles at higher velocities and low acceleration loads in an 8-inch launch tube. This "soft launch" capability offers much lower acceleration loads than have previously been achievable at any other ground-test facility allowing a greater level of projectile and target fidelity for tests conducted with a two-stage, light-gas gun.

Range I

Range I facility, a smaller version of the Range G launcher, uses either a 2.5-inch (standard) or 1.625-inch-diameter barrel that fires into an 8-foot-diameter segmented test chamber that is 79 feet long. Test conditions inside the chamber can be maintained at pressure altitudes from sea level to 225,000 feet. Range I is ideal for testing space debris impact scenarios and firing projectiles capable of withstanding high acceleration loads. The chamber tank features a large rear door that allows quick installation and removal of the test article. The facility's capability provides customers with a quick turnaround and can allow multiple shots over the course of a single day.

"HIGH FIDELITY" PROJECTILE LAUNCH CAPABILITY

Projectiles launched from two-stage, light-gas guns experience acceleration loads that are typically greater than that of the actual missile defense system. These acceleration loads can cause design compromises in projectile geometry and mass-density distribution. AEDC has developed a "high fidelity" projectile design technique through the use of specialized software and years of experience. The current software suite provides accurate predictions of the launcher acceleration loads and can optimize the projectile configuration for many launch scenarios. This capability allows high speed launches of projectiles with geometry and mass-density distributions very similar to actual flight vehicles, thus resulting in a more representative simulation of the flight vehicle kinetic energy release at impact.

The ranges also offer several other unique capabilities that can accommodate exceptional test requirements. A specialized pitching system using custom built rocket motors can be affixed to a projectile allowing it to pitch to a certain angle of attack before impacting the target. Projectiles can be fabricated with unique gas generation systems that allow the study of high speed wake effects. Several types of proven rod penetrator designs are also available for hypervelocity impact test scenarios.

INSTRUMENTATION

Extensive instrumentation is available for both the Range G and Range I facilities. Capabilities include high speed digital cameras, digital X-rays, high speed data recorders and laser triggering systems. All digital imaging systems can be calibrated to provide a precise location of the projectile during flight. A state-of-the-art Position Angle Velocity (PAV) system using laser light can also locate the projectile attitude, speed and position in space during the course of flight. Range G also operates a very unique X-ray cinematography system that can capture six to 17 images at a rate approaching one million frames per second. Additional instrumentation using multispectral/infrared signature measurements is available to further aid in kill assessment analysis. Instrumentation can be placed at nearly any spot along the projectiles flight path.

HISTORY

Range G opened in 1963 following the successful operation of the pilot facility known as K Range. The initial Range G configuration was a 2.5-inch bore, two-stage, light-gas gun firing into a 10-foot-diameter test tank 1,000-feet in length. This gun was in operation until 1994 when the larger 3.3-inch gun was installed and the older 2.5 inch gun became the Range I launcher. The Range G launcher has performed more than 9,000 shots, several of which are unique tests that could only be performed at AEDC. For example, in 2001-2003 an axis-symmetric scramjet projectile was designed and launched in AEDC's Range G Facility. The test demonstrated, for the first time, that a scaled supersonic combustion was possible in a ballistic range environment and that powered acceleration could be measured with the current instrumentation suite.