Today is our Day of Remembrance. We remember all who made the ultimate sacrifice while furthering the cause of exploration and discovery. Those we honor today include the crews of Apollo 1, Challenger STS-51L, and Columbia STS-107. The Apollo 1 tragedy took place on Jan. 27, 1967. Astronauts Gus Grissom, Ed White, and Roger Chaffee were sitting atop the launch pad for a prelaunch test when a fire broke out in their Apollo capsule. All three astronauts perished in the fire. The Challenger explosion occurred just 73 seconds after launch on Jan. 28, 1986, when a booster engine failed and caused the space shuttle to break apart. This accident claimed the lives of seven crew members: Ellison Onizuka, Michael Smith, Christa McAuliffe, Dick Scobee, Gregory Jarvis, Judith Resnik, and Ronald McNair. The space shuttle Columbia was lost on Feb. 1, 2003. Foam loss during launch had opened a hole in one of the shuttle’s wings, causing the orbiter to break apart upon re-entry. Seven crew memb...