Back in his days as a test pilot at Wright-Patterson Air Force Base in Ohio, Gus Grissom had a message for his wife, Betty.

“If I die, have a party,” he said.

Betty Grissom never did have that party. But on Friday, as for the past 25 years, there was a solemn observance at the little-known memorial for her husband and two crewmates who were killed in the Apollo 1 disaster. Mr. Grissom, Roger Chaffee and Ed White died in a flash fire that engulfed their capsule atop a Saturn 1B rocket during a routine training operation on Jan. 27, 1967. Mr. Grissom was 40.