The identities of the seven were announced at a press conference at Dolley Madison House in Washington, D.C., on April 9, 1959: Carpenter, Gordon Cooper, John Glenn, Gus Grissom, Wally Schirra, Alan Shepard, and Deke Slayton. The magnitude of the challenge ahead of them was made clear a few weeks later, on the night of May 18, 1959, when the seven astronauts gathered at Cape Canaveral to watch their first rocket launch, of an SM-65D Atlas, which was similar to the one that was to carry them into orbit. A few minutes after liftoff, it spectacularly exploded, lighting up the night sky. The astronauts were stunned. Shepard turned to Glenn and said: "Well, I'm glad they got that out of the way."