Kathryn Grove Shipp, 73, a retired research chemist who was named one of the top six career women in the federal government in 1967, died Oct. 14 at her home in Tiburon, Calif. after an apparent heart attack.

She received the Federal Woman's Award that year for her discovery of a new high explosive, hexanitrostilbene (HNS) while working at the Naval Ordnance Laboratory in White Oak, Md. The honorees were chosen by the Civil Service Commission.

Besides its use as a weapon. HNS has the unique ability to withstand high altitudes and re-entry heat. Used in exploration of the moon, it was thrown, grenade-style, at different distances. This helped scientists to take seismic readings and determine the composition of the moon's crust, its depth and constitution.

Dr. Shipp worked as a research chemist at the naval laboratory from 1958 until she retired in 1970. Besides her discovery of HNS, she wrote 13 technical reports and held six chemical patents, all classified under government security.

She was born in Annandale, Pa. Although she earned a bachelor's degree in chemistry at Mills College and a doctorate in organic chemistry from Yale University, and spent a year as a fellow at Oxford University, she did not put her education to immediate use.

From 1931, until her divorce in 1957, she was the wife of Dr. Harrel Shipp of Wilmington, Del. For 26 years she was a housewife and mother, who would later be known to her grand-children as "Mum-Mum."

After he divorce. Dr. Shipp came to Washington to work on explosives at the naval laboratory.

In an interview with The Washington Post in 1967, Dr. Shipp spoke of those days,"I was very far behind and am still behind." She pointed out that her previous work in chemistry, more than 25 years before at Oxford, had involved nothing more explosive than the coloring matter of plants and flowers.

But she caught up with her colleagues. Speaking of her work with the government, she said that research involved "long periods of drought, despair and discouragement - then happy heights like the chance to make history on the moon."

Dr. Shipp is survived by her sister, Ruth Kimball, with whom she was living at the time of her death; two daughters, Lisl Urban, of Arlington, Mass., and Sarah Cox, of McLean; two sons, Howard, of Bend, Ore., and Richard, of Silver Spring; nine grandchildren, and her former husband.