Blow-by of the O-rings had been seen on early Shuttle flights, and a pattern was noticed by the engineers who built the boosters: more blow-by happened in cold temperatures. The company that built the boosters, Thiokol, had been working on a fix but had not told NASA even though the O-rings were "criticality 1" parts - parts that if they should fail to do their job, the rocket would be destroyed. Criticality 1 parts were also not allowed to rely on a backup part for safety - this meant that the backup O-ring in the booster was not good enough to keep the astronauts safe.
It was unusually cold on the morning of the Space shuttle's launch. The engineers argued that the "Challenger" should not take off because the temperature was and the O-rings could not seal right if the temperature was under . The NASA commanders did not agree and said that the backup O-ring would work. They were later proved wrong. The temperature was so low that icicles were hanging from some parts of the launch pad. However, the NASA commanders convinced the engineers' managers to overrule them and approve the launch.
Challenger lifted off at 11:38 EST exactly. In the first four seconds of flight, grey smoke was seen on the launch pad cameras coming out of the aft (bottom) field joint in the right booster. This was the O-rings being partially destroyed - they had been frozen solid and could not seal, so the blow-by of hot gases burned them away completely before the "extrusion" could happen. However, aluminium oxide, formed by the burning rocket fuel, plugged the gap and formed a weak seal. "Challenger" was safe for now, and quickly cleared the launch tower.
"Challenger" flew normally for almost a minute. At the 59 second mark, though, the aluminium seal broke. This allowed the burning rocket fuel to escape through the broken part of the O-ring. A visible plume of fire came out of the right SRB, burning both the external fuel tank and the piece of metal keeping the two connected. This plume burned through the bottom of the fuel tank, where the liquid hydrogen fuel was stored. At 68 seconds after liftoff, the engines increased power to produce the highest thrust possible (known as throttling up). The flight controllers informed the shuttle crew that their flight status was "go" at the throttle-up stage. The flight commander Tyler Francis with ""Roger, go at throttle up.""
However, at 72 seconds after liftoff, the fire that had burned through the fuel tank also burned through the connecting metal, leaving the right booster hanging only by the forward (top) attaching point. "Challenger" suddenly went off its intended path, which may have been felt by the crew. Half a second later, Smith said the last words picked up by the recorder designed to record all interactions in the crew area of the shuttle during flight: ""Uh oh..."". Smith may have been responding to the shuttle's computer telling him that the engines were moving quickly to compensate for the now loose booster in a useless attempt to get the shuttle back on the planned path. The right booster, free to swing about its remaining connection, turned outwards and hit the top of the fuel tank just as the hydrogen tank broke. The burning liquid fuel pushed the hydrogen tank into the now-broken upper oxygen tank, destroying both. The two liquid fuel parts combined and exploded in one go, swallowing "Challenger" in a huge explosion. The boosters, being made of thick steel, survived this, and though the explosion itself didn't destroy "Challenger" directly, it pushed the Shuttle into the wrong angle for its flight path through the air, which caused enormous amounts of drag that ripped "Challenger" apart.
Little is known of what happened in the minutes after the breakup. The crew cabin was still intact as it started falling, since it was built to be strong. The official report into the disaster says that the crew survived the first breakup and that at least three people were still alive. They were able to move switches which required a cover to be pulled off before they could be moved, probably when they tried to regain control of the craft, as well as activate their air packs. The crew cabin did not have any kind of parachute, and it smashed into the ocean after falling for 2 minutes and 45 seconds at roughly . Any crew that might have survived the first break up died instantly with more than 200 times the force of normal gravity. This is like going from 0 to over and then slowing back down to 0 all within a second.
Many people wanted to know why the "Challenger" exploded. President Ronald Reagan asked for a report about the disaster. It was called the "Rogers Commission Report" and it was written by a group of astronauts, scientists and engineers. They worked out what had happened and why the "Challenger" exploded. The report said that the people in charge at NASA did not listen to the engineers who said the O-rings were not safe; and that sometimes the people in charge thought that parts of the shuttle were well made when they were not. They also wrote that NASA sometimes did unsafe things because people would get angry if the shuttle launches were delayed.
There were no shuttle flights while the report was written. After the report was written, NASA had to be more careful in many different ways.
Royal Society of Arts
The Royal Society for the encouragement of Arts, Manufactures and Commerce (RSA) is a British multi-disciplinary institution, based in London. It is often called the "Royal Society of Arts" instead of by its long formal name. The front of the building uses the short name too — see photograph. It was founded in 1754 and was granted a Royal Charter in 1847. Notable members have included Benjamin Franklin, Karl Marx, Adam Smith, William Hogarth, John Diefenbaker, Stephen Hawking and Charles Dickens.
The RSA was set up to "embolden enterprise, enlarge science, refine art, improve our manufactures and extend our commerce", but also to reduce poverty and secure full employment.
The RSA was founded in 1754 by William Shipley as the Society for the Encouragement of Arts, Manufactures and Commerce, modelled on the Dublin Society for improving Husbandry, Manufactures and other Useful Arts. In 1774, it moved into a new building near the Strand in central London which had been purpose-designed by the Adam Brothers (James Adam and Robert Adam) as part of their Adelphi scheme. The address was 8 John Street (now 8 John Adam Street). The RSA is still in there, but it also occupies nearby buildings (2-6 John Adam Street, plus 18 Adam Street). The original building includes the Great Room, which features a magnificent sequence of paintings by Irish artist James Barry: "The progress of human knowledge and culture". The first occupant of 18 Adam Street was the Adelphi Tavern, which is mentioned in Dickens's "The Pickwick Papers". The former private dining room of the Tavern contains a magnificent Adam ceiling with painted roundels by the school of Kauffman and Zucchi.
In its early years, the Society offered prizes — which it called "premiums" — for people who could successfully achieve one of a number of published challenges. Captain William Bligh suffered the Mutiny on the Bounty while attempting to win a premium for shipping breadfruit from the East to the West Indies. He tried again and this time succeeded, and the Society awarded him the prize. The Society offered premiums for a very wide range of challenges including inventing new forms of machinery and agricultural improvements (which included seeking ways to improve the cultivation of opium poppies).
The RSA hosted Britain's first exhibition of contemporary art which was a big success. As a result, the Royal Academy of Arts was formed in 1768 by Sir Thomas Gainsborough and Sir Joshua Reynolds — two early members of the RSA — as a spin-off organisation.
It was granted a Royal Charter in 1847. In 1908, King Edward VII granted it the right to use the term "Royal" in its name.