Apollo 1 stars commemorated in US

January 27 is a sad day for NASA, marking the 50th anniversary of when a flash fire occurred during a launch-pad test of the Apollo/Saturn space vehicle, which was being prepared for its first piloted flight. Astronauts Virgil I "Gus" Grissom, Edward H. White II and Roger B. Chaffee lost their lives when a fire swept through the command module, or "CM."  

A nearly 10-week investigation determined that an electrical spark, occurring in an environment rich in pure oxygen inside the command module, ignited the fire. The blaze occurred during the early evening hours of Jan. 27, 1967 — also a Friday — at Cape Canaveral Air Force Station Launch Complex 34, Space.com reports. 

The flight of Apollo 1 was to be the first crewed mission of the Apollo program, with the ultimate goal of landing astronauts on the moon and returning them safely to Earth. Apollo 1 was scheduled to fly on a two-week mission on Feb. 21, 1967, but the tragic accident set America's space program back by some 20 months.