An anonymous reader writes: For three decades, retired NASA engineer Bob Ebeling blamed himself for being unable to stop the 1986 launch of space shuttle Challenger. He had warned that the shuttle might explode, and it did shortly after liftoff, killing seven crew members. Ebeling was one of five engineers at a NASA contractor then called Morton Thiokol who warned the space agency that cold temperatures predicated at the time of the launch could prove disastrous. The warning was ignored. The night before the launch, Ebeling reportedly told his wife, Darlene, "It's going to blow up." He told another daughter, Kathy Ebeling, that he had toyed with the idea of bringing his hunting rifle to work to threaten NASA not to launch, according to an article last month in The Washington Post. In the final weeks of his life, however, thanks to an outpouring of support following a National Public Radio story in January on the 30th anniversary of the disaster, Ebeling, 89, finally found peace. Ebeling died Monday in his home in Brigham City, Utah, after a prolonged illness with prostate cancer, NPR reported.