Why Did We Lose Challenger and Columbia Shuttles?

Why did we lose the space shuttles?

On January 28, 1986, the Challenger space shuttle was lost during a terrible explosion. This tragedy killed seven members who were on board and had such an impact on NASA, that they suspended shuttle flights for two years. But why did the shuttle suffer this devastating explosion?
The Challenger suffered several launch delays six days prior to liftoff. NASA officials overruled concerns that the engineers had, and ordered a liftoff at 11:38 a.m. “I found out later that the people who worked on the engines always had their fingers crossed on each flight, and the moment they saw the shuttle explode, they were all sure it was the engines. But of course, the TV replay showed a flame coming out of one of the solid rocket boosters” (Feynman27).
It was a mixture of structural failures that caused the shuttle to break apart. The cause of the explosion was the failure of O rings in the right (SRB) solid rocket booster due to the cold weather. This caused the O rings to allow hot gases to leak out of the booster through the joint. These rubber rings sealed the joint between the two lower segments of the booster. The combustion gas leak passed through the right Solid Rocket Motor aft joint and set off at ignition which eventually weakened and made its way into the External Tank. This broke up the shuttles structure and the Challenger Mission as a whole. The accident occurred 73 seconds into flight disintegrating the Challenger into a catastrophic ball of fire at an altitude of 46,000 feet and at about twice the speed of sound.

All in all, NASA's decision to launch the shuttle was imperfect. The top level decision makers had not been informed of problems with the joints and O rings or the possible damaging effects of cold weather. Shuttle designers made several technical alterations, including an improved O ring design and procedural changes which included stricter safety reviews and more restrictive launching conditions.
The Space shuttle Columbia disaster occurred in February 1, 2003, and was the second space shuttle misfortune to happen. The spacecraft broke up while re-entering Earth's atmosphere near the end of its mission. According the (CAIB’s) Columbia Accident Investigation Board report, the main cause of this disaster was a management one. Although the Challenger was said to be an engineering difficulty, both the Challenger and the Columbia missions had faulty communication and intense scheduling pressures.
These catastrophes could have been avoided with patience and management communication. Speculations of other management error for the Columbia mission were damages to the left wing were caused by a piece of foam debris falling from the shuttle. To have been safe, another shuttle should have picked the astronauts up which would have just taken as little as ten days. But the awareness was never dealt with properly. Therefore, the cause the both the shuttles disasters was stupidity on NASAs part due to serious flaw in the decision making process.