The Quantity Distance Measurement Tool is a GIS BASEP computer program that aids safety engineers by calculating quantity-distance (Q-D) relationships for vessels that contain explosive chemicals used in testing rocket engines. (Q-D relationships are standard relationships between specified quantities of specified explosive materials and minimum distances by which they must be separated from persons, objects, and other explosives to obtain specified types and degrees of protection.)

The program uses customized geographic-information- system (GIS) software and calculates Q-D relationships in accordance with NASA’s Safety Standard For Explosives, Propellants, and Pyrotechnics. Displays generated by the program enable the identification of hazards, showing the relationships of propellant storage-vessel safety buffers to inhabited facilities and public roads. Current Q-D information is calculated and maintained in graphical form for all vessels that contain propellants or other chemicals, the explosiveness of which is expressed in TNT equivalents [amounts of trinitrotoluene (TNT) having equivalent explosive effects]. The program is useful in the acquisition, siting, construction, and/or modification of storage vessels and other facilities in the development of an improved test-facility safety program.

This program was written by Keith Jester of General Dynamics for Stennis Space Center. Inquiries concerning rights for the commercial use of this invention should be addressed to

the Intellectual Property Manager
Stennis Space Center
(228) 688-1929.

Refer to SSC-00209.

NASA Tech Briefs Magazine

This article first appeared in the August, 2005 issue of NASA Tech Briefs Magazine.

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