NASA marked 25 years since the Challenger disaster with a 45-minute ceremony at the Kennedy Space Center in Florida on 28 January, while across the US and around the world, a generation that grew up with spaceflight as a common event reflected and remembered where they were when they heard the news.

Challenger was destroyed 73 seconds after launch, when a failed O-ring in one of the shuttle's solid rocket booster joints failed, probably due to the unusually cold weather, and hot gasses from the shuttle's main fuel tank ignited at 48,000ft.

Under a load factor of up to 20G, the shuttle itself broke apart, with the main engines, left wing and crew cabin all identifiable as the pieces fell into the ocean at an estimated speed of more than 200mph (173kts).

All seven crew members died: Dick Scobee, commander; Michael J. Smith, pilot; Ellison Onizuka, mission specialist; Judy Resnik, mission specialist; Ron McNair, mission specialist; Gregory Jarvis, payload specialist and Christa McAuliffe, payload specialist and teacher.

 Challenger Crew


Shuttle flights were put on hold for 32 months.

The launch - the 25th for the US space programme - was the first aerospace tragedy to play out on live television. It received particular attention in American schools because of McAuliffe, the New Hampshire high school teacher selected for the mission as part of the Teacher in Space program.

It remains a "where were you?" moment on par with the Kennedy assassination and September 2001 terrorist attacks.

Challenger ignites 


Challenger smoke 


"This speech becomes much more than words as I reflect on the failings of the human safe-flight team," said Bill Gerstenmaier, NASA's associate administrator for space operations for since 2005, at the memorial. "They're not academic or simple lessons, but lessons that must be implemented and learned every day. The little things that seem harmless can become catastrophic events."

A quarter-century later, it is the little things that continue to burden the shuttle programme, as it struggles to launch its last few flights before closing down. The November 2010 launch of Discovery has been repeatedly postponed first because leaking helium and nitrogen gas lines on the Shuttle's orbital manoeuvring system pod, then electrical problems and bad weather and finally due to cracks in the stringers on its external fuel tank.

Source: Flight International