On January 28, 1986, at 11:38 a.m., EST, the space shuttle Challenger lifted off Pad 39B at Kennedy Space Center, Florida. The entire crew of seven was lost in the explosion 73 seconds into the launch. Today, on the 25th anniversary of this national tragedy, we honor in memory the brave crew who gave their lives for the exploration of space. Sharon Christa McAuliffe, a New Hampshire social studies