The Experimental Impact Laboratory (EIL) houses three different accelerators, each of which is used in its own way to simulate the effects of impact and shock on planetary surfaces and materials. Impacts in the EIL typically occur under near-vacuum conditions (pressures well below 1 torr).
The 5.56-mm Light-Gas Gun is mounted on the red rail to the right in the upper photograph. It is capable of accelerating a variety of projectiles smaller than 5 mm in diameter to speeds above 7 km/s (4.2 miles/s).
The Flat-Plate Accelerator, on the white rail to the left in the upper photograph, is used to shock targets to stresses that can exceed 700,000 atmospheres (70 GPa). Those targets can be recovered after they are shocked to be analyzed in any number of ways.
With a variety of different barrels, the Vertical Gun can launch projectiles as small as grains of sand and as large as 6.35 mm (1/4 inch) in diameter at speeds approaching 3 km/s (almost 2 miles/s). Its impact chamber (in the lower picture) can be refrigerated to support experiments involving targets of H2O ice.
While most of the research conducted in the EIL addresses questions related to planetary impacts, work involving spacecraft components has also been conducted on occasion. The aerogel collectors flown on the Stardust spacecraft to Comet Wild-2, for instance, were tested and flight qualified with the Light-Gas Gun.
Inside the Experimental Impact Laboratory: Photograph of the EIL taken from the mezzanine floor that shows the flat-plate accelerator on the left and the light-gas gun on the right.
A look into the impact chamber: A wide range of target sizes and configurations can be accommodated by the three accelerators in the EIL, spanning the range from small aliquots of powder to much larger, specimens of competent rock. This picture shows research scientist Christopher Cline and Mark Cintala examining the impact chamber of the vertical gun after an experiment, during which a coarse-grained granular target was impacted. Data from vertical-gun experiments like this routinely include measurements of ejecta kinematics and the creation of high-fidelity topographic maps of the cratered targets.