Lucas was director of the Marshall Space Flight Center in Huntsville when the Challenger exploded on Jan. 28, 1986, just 73 seconds after liftoff from Cape Canaveral, Florida. It was the deadliest U.S. space flight disaster at that time.
The explosion killed all seven crew members, including schoolteacher Christa McAuliffe, who had been tapped to become the first U.S. civilian to travel to space. Her inclusion on the flight meant thousands of schoolchildren across the country were watching the Challenger's launch and witnessed the televised disaster in real time.
A presidential commission charged with investigating the cause of the explosion pointed to the shuttle's solid-fuel booster rockets as the likely culprit and criticized NASA managers for not taking safety concerns surrounding the rockets more seriously. The Marshall center had supervised development of the rockets.
Lucas pushed back on the criticism, telling reporters a month after the explosion that it was too soon to pinpoint the cause of the explosion, adding, “I think it was a sound decision to launch."
But within months he had resigned, just days ahead of the release of a commission report blaming faulty design of the booster rockets.
The explosion and resulting shakeup within NASA overshadowed what was an otherwise stellar career for Lucas, who was born and raised in rural western Tennessee and graduated from high school in 1939 as the class valedictorian. He earned a bachelor of science degree from Memphis State College, served in the U.S. Navy during World War II and later earned a doctorate in metallurgy from Vanderbilt University.
Lucas began his career in the guided missile development division of the U.S. Army's Redstone Arsenal near Huntsville. He became a charter member of the Marshall Space Flight Center when it was established in 1960 before rising through the ranks to become its director in 1974.