what is the cause of the crash of space shuttle?

Answer 1

Which one... Challenger exploded after take off due to a defective seal on the booster rocket that burned through and allowed the fuel to spontaineously ignite. Columbia was attempting re-entry and the crew was not aware that on take off a piece of external fuel tank insulating foam had broken off and punched a hole in the wingtip. The super hot plasma gasses formed on re-entry attacked the shuttle at this point and she disintegrated.

Answer 2

The one over Texas a few years ago was caused by missing heat tiles. A piece of foam from the main tank had come off during launch and struck the shuttle. The tragedy is that NASA had seen some damage while the shuttle was in space and decided not to have a closer look before the astronauts returned home.

The original crash back in the 80's was due it is said by faulty O-rings connecting the booster rockets together. The launch was made when the temperature was too cold on the day of Reagan's second inaugural speech. I guess everyone had forgotten that a year previously NASA had announced that the shuttle could not launch if temps. were below 45 degrees since ice could form on the rockets during launch and break off tearing loose tiles and causing failure.

Answer 3

Challenger blew up one minute after launch because of a leak in a seal on the solid rocket booster.

Columbia broke up on reentry when a section of the heat shield burned through. It had been damaged days earlier, on launch, by loose insulation falling off the external tank and hitting the wing of the orbiter.

Answer 4

A defective O-ring

Answer 5

try this:
http://en.wikipedia.org/wiki/Space_Shuttle_Columbia_disaster.
and this:http://www.reuters.com/article/topNews/idUSN1337907120070616?feedType=RSS