New Delhi, Jan. 24 -- Families of the astronauts lost in the space shuttle Challenger accident gathered back at the launch site Thursday to mark that tragic day 40 years ago.

All seven on board were killed when Challenger broke apart following liftoff on Jan. 28, 1986.

At the Kennedy Space Center memorial ceremony, Challenger pilot Michael Smith's daughter, Alison Smith Balch, said through tears that her life forever changed that frigid morning, as did many other lives. "In that sense," she told the hundreds of mourners, "we are all part of this story."

"Every day I miss Mike," added his widow, Jane Smith-Holcott, "every day's the same."

The bitter cold weakened the O-ring seals in Challenger's right solid rocket booster, causing the ...