Impact Research: High Speed Cameras
The high speed cameras that are used at the HVIT are Cordin High Speed Shadowgraph Cameras.
They are capable of taking images at a rate of 2.5 million per second. These cameras are quite
unlike any conventional camera. The film is fixed around around a circular housing; at the center
of the circle is a rotating mirror powered by a compressed gas turbine.
There is no shutter; instead, the light source is a pulsed laser, timed to strike the rotating
mirror in such a way that it exposes one frame of film per pulse. Since the film is stationary,
each test is limited to only 80 frames of film. If you are operating the camera at 1 million
frames per second, that's 80 microseconds of filming. Fortunately, that's plenty of time, since
impacts last only a few microseconds.
Right Image: Projectile in flight prior to impact event.
Center Image: Debris and ejecta cloud formation right after impact.
Left Image: Space Station Remote Manipulator System (SSRMS).
Research Technologies
Diagnostic Tools
We can measure the velocity of the impacting projectile in a
hypervelocity impact test using several different techniques.
Other tools are also leveraged to ensure a quality test.
Light-Gas Guns
Launching projectiles at the velocities needed to simulate
impacts caused by orbital debris requires remarkable equipment,
and the two stage light-gas guns are what make it possible.
High Speed Cameras
The cameras we have are capable of taking up to 2.5 million
frames per second, giving us the ability to capture images
of hypervelocity impacts that last only a few microseconds.
Hydrocode Simluations
Hydrocodes are used to investigate impacts beyond the testable
regime. They are also used as a visualization tool, to help us
understand the physics that occur during an impact.