Providing critical testing support to the Nation’s Research and Development activities in hypervelocity aerodynamics, impact physics, flow-field structure and chemistry.
The facilities provide the Nation with unique, critical and mission-enabling test capabilities, allowing low-cost "flight tests" in ground based facilities. The Range Complex has a comprehensive suite of highly adaptable, world-class test hardware and a staff with extensive expertise garnered from a wide range of test experience. Together, they offer a unique set of testing possibilities for a wide variety of hypervelocity topics, including the aerodynamics and flow field characteristics of entry vehicles (either for Earth entry or other planetary atmospheres) and other hypersonic vehicles, meteor or asteroid impacts on a planet or moon surface, and micrometeoroid impacts on a spacecraft.
The HFFAF is the Agency's only aeroballistic capability and is the only ballistic range in the Nation capable of testing in atmospheres other than air.
The Test Complex currently consists of three ranges: the Ames Vertical Gun Range (AVGR), the Hypervelocity Free Flight (HFF) Facilities and the Electric Arc Shock Tube (EAST). Together, they enable a wide range of research, outlined below.
The Ames Vertical Gun Range (AVGR) was designed to conduct scientific studies of lunar impact processes in support of the Apollo missions. In 1979, it was established as a National Facility, funded through the Planetary Geology and Geophysics Program. In 1995, increased scientific needs across various disciplines resulted in joint core funding by three different science programs at NASA Headquarters (Planetary Geology and Geophysics, Exobiology, and Solar System Origins). In addition, the AVGR provides programmatic support for various proposed and ongoing planetary missions (e.g. Stardust, Deep Impact).
Using its 0.30 cal light-gas gun and powder gun, the AVGR can launch projectiles to velocities ranging from 0.5 to nearly 7 km/sec. By varying the gun’s angle of elevation with respect to the target vacuum chamber, impact angles from 0° to 90° relative to the gravitational vector are possible. This unique feature is extremely important in the study of crater formation processes.
Many projectile types including spheres, cylinders, irregular shapes, and clusters of small particles can be launched. They can be metallic (aluminum, copper, iron), mineral (quartz, basalt), or glass (Pyrex, soda-lime). Soda-lime spheres, for example, can be launched individually (for sizes ranging from 1.5 to 6.4mm diameter - 1/16 to 1/4 inch), in groups of three (0.2 to 1.2mm), or as a cluster of many particles (2 to 200-?m).
The target chamber is approximately 2.5 meters in diameter and height and can accommodate a wide variety of targets and mounting fixtures. It can maintain vacuum levels below 0.03 torr, or can be back filled with various gases to simulate different planetary atmospheres. Impact events are typically recorded with high-speed video/film, or Particle Image Velocimetry (PIV).
Right: The Range Complex specializes in hypervelocity aerodynamics and flow-field structure.
The Hypervelocity Free-Flight (HFF) Range currently comprises two active facilities: the Aerodynamic Facility (HFFAF) and the Gun Development Facility (HFFGDF). The HFFAF is a combined Ballistic Range and Shock-tube Driven Wind Tunnel. Its primary purpose is to examine the aerodynamic characteristics and flow-field structural details of free-flying aeroballistic models.
The HFFAF has a test section equipped with 16 shadowgraph-imaging stations. Each station can be used to capture an orthogonal pair of images of a hypervelocity model in flight. These images, combined with the recorded flight time history, can be used to obtain critical aerodynamic parameters such as lift, drag, static and dynamic stability, flow characteristics, and pitching moment coefficients. For very high Mach number (M > 25) simulations, models can be launched into a counter-flowing gas stream generated by the shock tube. The facility can also be configured for hypervelocity impact testing and has an aerothermodynamic capability as well.
The HFFGDF is used for gun performance enhancement studies, and occasional impact testing. The Facility uses the same arsenal of light-gas and powder guns as the HFFAF to accelerate particles that range in size from 3.2mm to 25.4mm (1/8 to 1 inch) diameter to velocities ranging from 0.5 to 8.5 km/s (1,500 to 28,000 ft/s). Most of the research effort to date has centered on Earth atmosphere entry configurations (Mercury, Gemini, Apollo, and Shuttle), planetary entry designs (Viking, Pioneer Venus, Galileo and MSL), and aerobraking (AFE) configurations. The facility has also been used for scramjet propulsion studies (NASP) and meteoroid/orbital debris impact studies (Space Station and RLV).
The Electric Arc Shock Tube (EAST) Facility is used to investigate the effects of radiation and ionization that occur during very high velocity atmospheric entries. In addition, the EAST can also provide air-blast simulations requiring the strongest possible shock generation in air at an initial pressure loading of 1 atmosphere or greater. The facility has three separate driver configurations, to meet a range of test requirements: the driver can be connected to a diaphragm station of either a 102mm (4 inch) or a 610mm (24 inch) shock tube, and the high-pressure 102mm shock tube can also drive a 762mm (30 inch) shock tunnel. Energy for the drivers is supplied by a 1.25-MJ-capacitor storage system.
NASA Ames has a long tradition of leadership in the use of ballistic ranges and shock tubes for the study of the physics and phenomena associated with hypervelocity flight. The Range Complex has provided critical testing in support of many of NASA's Space Transportation and Planetary Programs including: Mercury, Gemini, Apollo, Shuttle, Viking, Pioneer Venus, Galileo, Cassini, Stardust, Mars Odyssey, Mars Exploration Rovers, Mars Science Laboratory, International Space Station, and the National Aerospace Plane.
Above Right: Vertical Gun Range.
Below Right: Hypervelocity Free-Flight Facility.
This tradition of leadership in testing for aerodynamics impact physics and flow-field structure and chemistry, goes back to the NACA era of the 1940's. Today, the Range Complex continues to provide unique, mission-enabling support for the Nation’s programs in planetary geology and geophysics, exobiology, solar system origins, earth atmospheric entry, planetary entry and aerobraking vehicles, and various vehicle configurations for supersonic and hypersonic flight.