Sea Water Immersion of Gem II Propellant
Abstract
Following the Delta II flight failure on 17 Jan 97, the question of continuing safety for solid propellant that had fallen into the Atlantic ocean arose. With this failure, approximately 200,000 pounds of HTPB solid propellant were released. While large amounts of propellant were consumed in burning fragments and ground impact explosions, considerable amounts of unburned propellant fell onto the land and into the Atlantic ocean. It was quickly found that propellant attacked by sea water became mushy, and ammonium perchlorate (AP) crystallized on propellant surfaces if it was allowed to dry. Concerns were raised that propellant washing ashore might present fire and/or explosive hazards. In response to these concerns, a program was initiated to investigate the effects of sea water on GEM II propellant as a function of time and its activity when burned, impacted, or subjected to friction. To date, results show that AP is leached out of the propellant at a straight line rate on a logarithmic plot. Friction and impact data on dried, sea water soaked propellant samples show no significant differences from virgin propellant. With wet sea water aged propellant samples, outer surface layers were found to be significantly less sensitive (friction and impact) than virgin propellant. The centers of these samples were found to be less sensitive than virgin propellant, but definitely more sensitive than their wet outer skin. In fuel Fires, no difference was observed between virgin propellant and dried, sea water aged propellant burning. These samples ignited immediately with burning over all exposed surfaces. In contrast, wet sea water aged samples all had experienced ignition delays. Ignition delay usually paralleled propellant sample time of water exposure. In addition, these samples only burned from one face.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 23, 1998
- Accession Number
- ADA404866
Entities
People
- C. I. Merrill
- J. D. O'drobinak
Organizations
- Air Force Research Laboratory