CAPE CANAVERAL, Fla. — 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.

Ms. Grissom, 89, was at the memorial again on Friday, wearing a denim jacket with a large Apollo 1 patch in patriotic colors. She joined old friends, family members, and NASA officials and veterans, among them Charlie Duke, who took part in the Apollo 16 moon landing. With the recent deaths of the astronauts John Glenn and Eugene A. Cernan and the sea changes in Washington, the gathering felt like a memorial for an era as well as for three men.

At the ceremony, candles were lit for the dead astronauts by members of their families, including Cody Grissom, 22, a pilot, who is completing his last year at his grandfather’s alma mater, Purdue University. Representatives from the Navy, the Air Force and NASA spoke, and a Navy bugler performed taps after the sun went down.