What happened that day
The Challenger, officially STS-51L, was readied for launch on the morning of Jan. 28, 1986. The launch had been delayed several times, and NASA officials were anxious to get Challenger into space to meet a schedule of 16 planned missions for 1986.
With all systems registering “go,” the countdown began and the shuttle blasted off at 11:38 a.m.
The shuttle cleared the launch pad and headed into a brilliant blue Florida sky, performing perfectly, or so everyone thought.
Seventy-three seconds into the flight, witnesses began to see a flame move up the side of the external fuel tank, then what looked like an explosion as the tank collapsed and its contents -- the fuel propellants -- mixed and ignited.
The tank was ripped away from the body of the shuttle and it spun wildly out of the sky.
At first, Johnson Space Center officials in Houston were not aware of what happened and continued the routine of relaying trajectory and speed information.
Seconds later it was clear what everyone had seen was not what was supposed to happen, and NASA commentator Steve Nesbitt alerted those listening to the tragedy when he said, "Flight controllers here are looking very carefully at the situation. Obviously a major malfunction."
The fall back to Earth
The shuttle was 46,000 feet in the air when the accident happened, traveling at twice the speed of sound.
The craft continued its upward trajectory, reaching 65,000 feet about 25 seconds later.
The shuttle, having lost the other two fuel tanks, was at the mercy of physics and was quickly torn apart by aerodynamic forces.
Challenger, now in pieces, began its fall back to Earth, hitting the Atlantic Ocean at 207 mph some two minutes and 45 seconds after the breakup.
The shuttle pieces struck the ocean surface at 200 times the force gravity, ''far in excess of the structural limits of the crew compartment or crew survivability levels,'' a NASA report later read.
What caused it
The official report concluded that a leak in the solid rocket booster joint allowed superheated gas to escape and burn through the external tank, causing the collapse of the tank.
Many blamed the cold weather in Florida that day for the problem, saying the rings that helped seal the tank joints were not made to be used in weather so cold.
The official report of the accident lists weather only as a contributing factor.
The rings – called O-rings – meant to seal the segments of the booster had failed to do their job in the right-side solid rocket booster. That is where the superheated gas leaked through and burned the side of the rocket, starting the chain reaction that would bring the shuttle down.
Why didn’t they know about it
Engineers at the company that made the O-rings, Morton Thiokol, said they tried to warn their bosses the night before the launch that the seals could be brittle because of the cold and needed to be replaced.
They would later testify that they were overruled and told the launch would go on as scheduled.
Who we lost
The team on Challenger was different than any that had come before.
A "civilian" was to fly with the crew. Christa McAuliffe, a New Hampshire high school teacher, had been chosen to go into space and teach lessons from the shuttle.
She, Hughes Aircraft Co. satellite engineer Gregory Jarvis and physicist Ronald McNair were on the lower deck of the crew cabin at lift-off.
On the upper deck were engineers Judith Resnik and Ellison Onizuka, the shuttle’s pilot Michael Smith and the ship’s commander, Dick Scobee.
It was the first flight for Jarvis and Smith. The rest of the crew, save McAuliffe, had all flown on shuttle missions before.
Three facts and a cruel hoax
As with any tragedy, the facts sometime become blurred with the reality of the moment. Then, there are some who seek to capitalize on such events.
Here are a few facts and a cruel hoax that were born out of the Challenger disaster.
1. Few people actually saw the launch on live TV
While several national networks had reported from Cape Kennedy that morning, only CNN was carrying the launch live to a nationally-televised audience.
Some network affiliates also carried the launch live to local markets, but not many. The largest audience to watch the disaster that day was likely one made up of students. NASA had arranged a satellite broadcast of the full mission to be available to schools so students could watch the first teacher in space, McAuliffe.
While CNN had the event live, NBC was the first to break into regularly scheduled programming with the news at 11:42 a.m. ABC was on a minute later at 11:43, followed by CBS at 11:45.
2. The shuttle didn’t blow up
The shuttle did not explode, the external fuel tank collapsed because of the joint failure and the collapse resulted in the release of its liquid hydrogen and liquid oxygen propellants.
Those propellants mixing together created the fireball seen in videos of the disaster.
The shuttle itself – the craft minus the fuel tanks – remained intact and continued to climb.
Eventually, aerodynamic forces were too much for the shuttle to handle without the aid of the external tanks which had broken off the ship.
The tail section, the wings and the main engine section broke apart and began to fall to Earth. It was followed by the remaining pieces of the shuttle, including the crew cabin.
3. The crew died when the ship came apart
The crew likely survived the accident and even the shuttle being torn into pieces.
The question remains, however, were the astronauts conscious as the crew compartment fell from the sky and slammed into the ocean at 207 mph?
There was evidence that emergency oxygen tanks were manually activated, suggesting the crew tried to do something to save themselves.
A report presented in July of 1986 said there was no way to tell exactly how or when the astronauts died. The report was presented by Dr. Joseph P. Kerwin, director of life sciences at the Johnson Space Center in Houston and a former astronaut.
''The cause of death of the Challenger astronauts cannot be positively determined; the forces to which the crew were exposed during orbiter breakup were probably not sufficient to cause death or injury; and the crew possibly, but not certainly, lost consciousness in the seconds following orbiter breakup due to in-flight loss of crew module pressure.''
It was noted that the impact of the crew cabin with the surface of the Atlantic was so violent that it would have been nearly impossible to know the exact condition of astronauts after the craft broke apart.
Kerwin’s report also noted the shuttle’s seats “were in place and occupied at water impact with all harnesses locked.
This would likely be the case had rapid loss of consciousness occurred, but it does not constitute proof.”
4. The hoax of the crew's “final words”
Through the years, many have expressed their views that the crew was alive and taking action following the accident.
They point to what they have said was NASA’s reluctance to release the transcript of the audio recordings between the crew and the Johnson Space Center as proof that the agency was hiding the panic that Challenger’s astronauts were in as they hurtled toward the ocean.
An alleged transcript of the crew’s final moments has made the rounds on the Internet for the past 20 years, supposedly leaked to a tabloid called the Weekly World News.
While NASA’s official transcript stops when pilot Michael Smith says, “Uh-oh” at 73 seconds into the flight, this transcript reports the alleged on-going conversation as the crew cabin falls to earth at 207 mph.
NASA has debunked this “transcript.”
The official transcript from the final moments of the Challenger flight:
(NASA: SSME thrust level at 100% for all 3 engines.)
T+O............... Judith Resnik ..... Aaall riiight.
T+1...............Michael Smith..... Here we go.
(NASA: Vehicle motion.)
T+7...............Dick Scobee.............Houston, Challenger roll program.
(NASA: Initiation of vehicle roll program.)
T+11..............Smith..... Go you Mother.
T+14.............. Ellison Onizuka..... LVLH.
(NASA: Reminder for cockpit switch configuration change. Local vertical/local horizontal).
T+15.............. Resnik ..... (Expletive) hot.
T+19..............Smith..... Looks like we've got a lotta wind here today.
T+22..............Scobee..... It's a little hard to see out my window here.
T+28..............Smith..... There's ten thousand feet and Mach point five.
(NASA: Altitude and velocity report.)
T+35.............. Scobee..... Point nine.
(NASA: Velocity report, 0.9 Mach).
T+40.............. Smith..... There's Mach one.
(NASA: Velocity report, 1.0 Mach).
T+41.............. Scobee..... Going through nineteen thousand.
(NASA: Altitude report, 19,000 ft.)
T+43.............. Scobee..... OK we're throttling down.
(NASA: Normal SSME thrust reduction during maximum dynamic pressure region.)
T+57.............. Scobee..... Throttling up.
(NASA: Throttle up to 104 percent after maximum dynamic pressure.)
T+58.............. Smith..... Throttle up.
T+59.............. Scobee..... Roger.
T+60.............. Smith..... Feel that mother go.
T+1:02............ Smith..... Thirty-five thousand going through one point five
(NASA: Altitude and velocity report, 35,000 ft., 1.5 Mach).
T+1:05............ Scobee..... Reading four eighty six on mine.
(NASA: Routine airspeed indicator check.)
T+1:07............ Smith..... Yep, that's what I've got, too.
T+1:10............ Scobee..... Roger, go at throttle up.
(NASA: SSME at 104 percent.)
T+1:13.......................LOSS OF ALL DATA.
President Ronald Reagan’s response
President Ronald Reagan, who was supposed to give the State of the Union Address that night, spoke to a stunned country about Challenger instead.
Quoting from the poem “High Flight” by John Magee. Reagan said, “We shall never forget them nor the last time we saw them, as they prepared for their mission and waved goodbye and slipped the surly bonds of Earth to touch the face of God.”
What came out of it all for the Space Shuttle program
After months of investigation, the joints in the booster fuel segment were redesigned and an O-ring added.
The shuttle program was put on hold after the accident and wasn’t resumed until 1988 after the upgrades were completed and tested. The shuttle program ended in 2011.