A document discusses a lightweight, functional mockup of the Pistol Grip Tool for use during underwater astronaut training. Previous training tools have caused shoulder injuries. This new version is more than 50 percent lighter [in water, weight is 2.4 lb (≈1.1 kg)], and can operate for a six-hour training session after 30 minutes of prep for submersion.
Innovations in the design include the use of lightweight materials (aluminum and Delrin®), creating a thinner housing, and the optimization of internal space with the removal of as much excess material as possible. This reduces tool weight and maximizes buoyancy. Another innovation for this tool is the application of a vacuum that seats the O-rings in place and has shown to be reliable in allowing underwater usage for up to six hours.
This work was done by Michael Liszka, Matthew Ashmore, Mark Behnke, Walter Smith, and Tod Waterman of ATK Spacecraft, Systems and Services for Goddard Space Flight Center. GSC-16060-1