Weather A Strong Factor Behind Space Shuttle Challenger Disaster

1200px-Space_Shuttle_Challenger_(04-04-1983).JPEGLike most kids of my generation, I loved watching rocket ships blast off into space.

As a young kid, I sat in mute rapture watching on July 20, 1969 when Apollo 11’s Eagle landed on the Moon and Neil Armstrong boldly went where no man had gone before and took that one step for man and a giant leap for mankind.

I believed it then, and I believe it now. In 66 short years, we, as human beings had gone from the secretive flights of the Wright Brothers about their Wright Flyer as the first heavier-than-air aircraft to fly to propelling and aiming and actually landing on another planetary body.

How cool are humans?

Of course there were all those wars in between and improper treatment of race, sex and religion, but scientifically speaking, that leap in technology was immense.

I really thought that by the time I was in my 30s we would actually each and every one of us have our own jet-packs or flying cars.

Still… at least with those multiple trips to the Moon by Apollo 11, 12, 14, 15, 16 and 17, I figured it was only a matter of time before we colonized Mars, traveled to the rings of Saturn and exited beyond the confines of our solar system en route to visit the Andromeda galaxy and meet up with our space cousins who could help take humanity to another level of science and wonderment.

That’s what space flight meant to me. That’s what I saw when arch enemies USSR and the USA said screw politics and lets meet up in a joint Apollo-Soyuz mission. I watched it happen live in 1975 down in the basement of the house I am in right now.


The Apollo-Soyuz spacecrafts joined together in the US National Air And Space Museum. Until this moment, because I watched on a black and white TV, I had no idea the Soyuz craft was green. For the model kit I built in ’75, I painted it a ruby red… probably because that was what it was in my head.

And then when the missions to the Moon were halted, and there was naught else going on for about five years until the space shuttle—Columbia—was launched on April 12, 1981… my dream for that human utopia was kindled once again.

I was in university studying for that useless political science degree I have (the journalism has served me better), visiting a friend’s dorm when I realized that the space shuttle Challenger was about to launch that morning of January 28, 1986… and went to the common room and convinced the guys actually living at the dorm to switch to the TV station showing the launch.

And like when Buddy Holly died in a plane crash, when the Challenger exploded 73 seconds into its flight, my dreams of mankind achieving that space utopia within my lifetime died.

I swear that after it happened, I turned to my friend Patrick and said I would still go up on the space shuttle today if they would let me.

I wasn’t afraid of the technology. Those astronauts – every one of them, even the ones who never made it to space – my heroes.

I then went to my car and cried, wondering if I could ever be as brave as those astronauts.

challenger.gifAnyhow… I recently came across an article written by a meteorologist who wrote that the cause of Challenger shuttle disaster back in 1986, while found to have occurred because of faulty O-Ring, less publicized was that the faulty O-Ring was only faulty because of the weather.

You could have knocked me down with a feather.

So… on January 28, 1986 when seven astronauts:

  • Francis R. Scobee, Commander;
  • Michael J. Smith, Pilot;
  • Ronald McNair, Mission Specialist;
  • Ellison Onizuka, Mission Specialist;
  • Judith Resnik, Mission Specialist;
  • Gregory Jarvis, Payload Specialist;
  • Christa McAuliffe, Payload Specialist, Teacher.

… were aboard Space Shuttle Challenger (OV-99) for orbiter mission STS-51-L , it turns that the O-Ring near the base of the solid rocket boosters that seals the gap between two sections of the booster to stop exhaust gases from being emitted.

The problem is that those O-Rings were not rated for safe operation below 4C (39.2F).

But weren’t the space shuttles being launched from Cape Canaveral in Florida?

Yup… on January 12, 1986 – two weeks before the launch, it was a balmy 13C – but on January 28, it was well below freezing. Nearby Atlanta, GA had dropped to an overnight low -14C, while Montgomery, AL hit -9C.

Challenger Temperature map of Florida.jpg

Cape Canaveral is on the islands to the right. Image by NOAA NCDC.

Melbourne, Fla, located about 35 miles away from the launch site experienced hit -3C (26F ).

No biggie for Canada or those in the northern climes of the U.S., but those lows in the are remain records to this day.

And, even for the launch at Cape Canaveral, it was no biggie, as by the 11:37AM—launch time—it was no longer below freezing, getting up to about 2C… and if there was ice anywhere the ground crew addressed any ice build-up.

Now… because you realize that when the sun shines down from one direction onto (say) a building warming up that side quicker, the opposite side side of said building has not yet received the benefits of the sun’s heat.


This is a photograph taken of a frozen-over component on the launch tower of the space shuttle Challenger on January 28, 1986. Photo: NASA.

The same thing happened to the Challenger.

The solid rocket booster where that O-Ring failed… it was still in the shadow as the sun rose. While it did gain some warmth from the sun’s heat, it did not get as much as was required.

I know… holy crap, right?

The investigation into the disaster wrote that: “[a] warm O-ring that has been compressed will return to its original shape much quicker than will a cold O-ring when compression is relieved,” and “[a] compressed O-ring at 75 degrees Fahrenheit (23.9C) is five times more responsive in returning to its uncompressed shape than a cold O-ring at 30 degrees Fahrenheit (-1.1C).”

I added in the metric measurements. You know that only the superpowers of the United States, Liberia and Myanmar (Burma) continue to avoid the Metric system. Epic. Come on… though admittedly I understand Imperial far better than I do Metric.

Anyhow.. so despite the temperatures moving above freezing, part of the booster rocket containing the so-called faulty O-Ring was still within the cooler embrace of the shadows.
Because the O-Ring still hasn’t warmed up, it is stiffer and thus less capable of providing its sealing duties.

Challenger Ice on launch tower

Cold in Florida? Yup … here you can see icicles on the Challenger’s launch tower. Photo: NASA.

And, when Challenger lifted off the launch pad, that cold and stiffer O-Ring could not respond quickly to the stresses being exerted on the right solid rocket booster.

With the O-Ring unable to provide the perfect seal, gaps opened up between the two parts on the rocket booster allowing hot exhaust gases to vent.

Now you might wonder why the hot gases being vented did not warm up the O-Ring and force a seal after some of it was vented… and it’s true… it could have, and could have prevented the space shuttle from exploding… but again the cold weather caused that O-Ring to be unable to warm up quickly enough, meaning too much of the exhaust gases to be released… and in this instance the heat caused the O-Ring to have parts of it become vaporized.

NASA says that even still, with the booster rocket having had one of its O-Rings become partially vaporized and had some of the exhaust gases leaking out, Challenger should still have been able to reach space safely, more than likely have performed its mission without a problem, and thus returned safely at the scheduled time.

Really, couldn’t those venting gases have caused an explosion anyway?

Well, the rocket fuel when burned during flight creates aluminum-oxide by-products which would actually have re-created a seal between the two parts of the booster rocket ensuring an adequate seal was maintained long enough for the booster rocket to have expelled its fuel and been jettisoned… so what the heck happened?

Like most disasters, it takes more than one confluence of events to happen.

The next contributing factor to the demise of the seven astronauts aboard Challenger was the wind.

I don’t know if it’s weird or not, but the Challenger’s flight ended at the 73-mark, but at the numerically transposed mark of 37 seconds from lift-off, the spacecraft passed through a few wind shear events for 27 seconds (until 64 seconds into the flight) .

Wind shear is always a scary event for airplane pilots whereby the wind’s speed and direction can shift suddenly and dramatically… but surely the space shuttle aboard a firing bunch of rockets would easily overcome any sort of wind shear affect?

Mother Nature, unfortunately, doesn’t kid around. Watch the video below and see why all pilots should wear brown pants.

As the spacecraft thrust upwards through the near half-minute of wind shear, its on-board flight computers continued to adjust to the situation.

NASA, in a report on the disaster says: “[t]he wind shear caused the steering system to be more active than on any previous flight.”

The American Meteorological Society noted in its dispatch after the disaster that the there was some indication that there could be wind shear and clear air turbulence over north-central Florida that morning, there were no direct measurements of it, and therefore they could not have determined beforehand how strong the wind shear would be without prior knowledge of the conditions.

Truth of the matter, determining weather is based on pre-measured facts that change at the drop of a hat, which is why weather reports say it’s going to be sunny, while overhead your hair is being soaked by a sudden rain storm.

At least being a meteorologist is better than being a baseball hitter. In determining weather, you are only wrong 50% of the time, whereas you are a great simply for successfully hitting a ball 30% of the time.

Now all space shuttles are capable of handling wind shear up to a certain level—but how the hell do you determine if you are at that level when you can’t pre-determine how strong it is? You can’t.

With the wind shear and the spacecraft’s flight controls compensating for the wind shear, in combination with the weakened O-Ring seal around a booster rocket, the constant flight alterations by the flight control jostled the newly-formed aluminum-oxide stop-gap seal enough to break it allowing the heated exhaust gas to once again to be vented through the opening.

The exhaust gases ignited from the rocket’s booster.

When the spacecraft was past the wind shear at the 64-second mark, the fiery plume was larger—it’s theorized that at this time the flame had begun to burn a whole in the exterior fuel tank now… causing it to leak the hydrogen rocket fuel, which caused more smoke to appear to come from the craft.

Challenger 2.jpg

That glowing circle on the booster rocket… you can see it venting gaseous exhaust.

The sad part is that no one noticed… not the shuttle crew or the flight controllers down at Cape Canaveral… especially after the shaking and quaking undergone by the crew as the spacecraft maneuvered through the wind shear.

As such, within those next nine seconds, the order was given to throttle up for the rest of the journey into orbit, no one realized the the damaged O-Ring was no longer able to maintain its seal, as the extra throttle thrust caused the solid rocket booster and that fuel tank to fail, igniting the remaining fuel inside the breached fuel tank.

Now… people seem to think that that is what caused the space shuttle et al to explode… but it wasn’t.

That sudden loss of thrust because of the now-burnt rocket fuel threw the spacecraft off kilter… veering away from its safe trajectory into an angle that caused greater amounts of violent air to smash into the craft causing wind stress that was about 4x what the whole space craft was designed to handle.

The space shuttle Challenger essentially tore itself apart into thousands of pieces causing it arc and spiral back down to Earth.

Challenger 3.jpg

So… yes, one of the O-Rings failed on one of the shuttle’s rocket booster engines thanks to it being unable to function optimally at a colder temperature.

Did the manufacturer of the O-Ring know that it would not work optimally at temperatures below 4C (39F)?

Did NASA know pre-installation that the O-Ring works optimally at 4C (39F), but perhaps a higher fail-safe temperature minimum could have and should have been initiated?

We could blame NASA for not being quick enough on the uptick to perhaps measure temperatures where it could be both at its peak and lowest.

As far as weather goes, no one is able to predict it with any certainty, so it’s impossible to blame the weather.

Could anyone have known that the amount of wind shear was going to play so much havoc with the flight controls so as to to put undue stress on the already-compromised rocket to break apart the makeshift aluminum-oxide seal that formed after the O-Ring seal was partially vaporized?

Sadly, despite the cold weather causing the I-Ring to not work optimally, if there was less wind shear, that damaged rocket booster engine wouldn’t have made a damn bit of difference to the mission.

Yup… blame the wind shear, because that’s what was finally the straw that broke the camel’s back.

Now… as luck would have it, after I began writing this, I received a press release indicating that “Lockheed Martin begins construction on first Orion spaceship that will take astronauts into deep space”.

The release says that with the construction of the spacecraft, it will “achieve America’s goal of returning astronauts to the Moon.”

That’s the goal? Well, it does continue by saying that this will lay the groundwork for NASA’s lunar Deep Space Gateway, and ultimately for human missions to Mars.

About ‘effing time. But it still won’t be enough. I don’t think we’ll be leaving this solar system anytime soon within my compromised lifetime… and besides… where’s that personalized jet-pack we were all promised?


Oh… there it is. Where can I buy one?


About mreman47

Andrew was born in London, UK, raised in Toronto, Canada, and cavorted in Ohtawara, Japan for three years. He is married, has a son and a cat. He has over 35,000 comic books and a plethora of pioneer aviation-related tobacco and sports cards and likes to build LEGO dioramas. Along with writing for a monthly industrial magazine, he also writes comic books and hates writing in the 3rd person. He also hates having to write this crap that no one will ever read. Along with the daily Japan - It's A Wonderful Rife blog, when he feels the hate, will also write another blog entitled: You Know What I Hate? He also works on his Pioneers Of Aviation - a cool blog on early fliers. He also wants to do more writing - for money, though. Help him out so he can stop talking in the 3rd person.
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2 Responses to Weather A Strong Factor Behind Space Shuttle Challenger Disaster

  1. FFF says:

    Brilliant analysis … and writing.

    Wind shear. I’ve read about the O-rings and low temps but never heard about the wind shear and steering systems. Lord knows I’ve experienced plenty of landings that felt just like wind shear video and one or two where I put my head between my knees and thought I was kissing my @$$ goodbye.

    Years ago, right after I graduated from college and could not find a job that paid above minimum wage, I visited my local Air Force recruiter. I went through the process and was slated for their meteorology program until they found I was missing 1 required Physics course. They told me to come back if I ever completed the course and they would fast track me through the recruiting. Never did go back … got a job with an ad agency word processing dept (with some crazy madmen and women Copywriters and Art Directors) that paid a slightly better wage … which is where I was when the Challenger disaster happened. We were all quite stunned standing in the conference room watching the TV screen trying to come to terms with what we just witnessed.


    • mreman47 says:

      Isn’t it weird how we know where we were that day? It was one of those moments when the Earth stopped. I was going to the Army. Figured they’d whip me into shape, I could learn a decent trade… but I tried for the RCMP first… eyes… they suck. There was a minimum requirement even with corrective eyewear, which was met, but also one for w/o eyewear, which I was a long way from passing.
      I wanted to be an Ad man like Darrin and Larry Tate on Bewitched. Really. I did advertising and marketing at night school in College while I was IN university… and was one credit short… when I decided to go into journalism during day school in college. I have no idea why I never went back to finish it.


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