Author Topic: Article about Challenger  (Read 585 times)

Offline SunTracker

  • Silver Member
  • ****
  • Posts: 1367
Article about Challenger
« on: March 01, 2005, 03:01:24 PM »
http://msnbc.msn.com/id/3078062/

CAPE CANAVERAL, Fla. - The water was murky, swirling from surface winds, keeping divers Terry Bailey and Mike McAllister from seeing more than an arm’s reach in front of them. They had been diving for days, recovering Challenger’s debris, and, now, on this dive, they had only six minutes left in their tanks.

They were about 100 feet down, moving across the seafloor, when they almost bumped into what at first appeared to be a tangle of wire and metal. Nothing that unusual, nothing they hadn’t seen on many dives before.

Then, they saw it. A spacesuit, full of air, legs floating toward the surface. There’s someone in it, Terry Bailey thought.

No, that’s not right, he admonished himself. Shuttle astronauts do not wear pressurized spacesuits during powered flight. They wear jumpsuits. They carry along two pressure suits if they should be needed for a repair spacewalk.

He turned to his partner, Mike McAllister. They just looked at each other and thought, “Jackpot.” This is what we’ve been looking for. The crew cabin.

Low on air, the two divers made a quick inspection, marked the location with a buoy and returned to their boat to report the find.

A cabin intact
Early the next morning, the USS Preserver recovery ship put to sea. The divers began their grim task of recovering the slashed and twisted remains of Challenger’s crew cabin and the remains of its seven occupants.

On first inspection, it was obvious that the shuttle Challenger’s crew vessel had survived the explosion during ascent. A 2-year-long investigation into how the crew cabin, and possibly its occupants, had survived was begun.

Veteran astronauts Robert Crippen and Bob Overmyer, along with other top experts, sifted through every bit of tracking data. They studied all the crew cabin’s systems — even the smallest, most insignificant piece of wreckage. They learned that at the instant of ignition of the main fuel tank, when a sheet of flame swept up past the window of pilot Mike Smith, there could be no question Smith knew — even in that single moment — that disaster had engulfed them. Something awful, something that had never before happened to a shuttle, was upon them like a great beast.

Mike Smith uttered his final words for history, preserved on a crew cabin recorder.

“Uh-oh!”

An ultimate epitaph.

Immediately after, all communications between the shuttle and the ground were lost. At first, many people watching the blast, and others in mission control, believed the astronauts had died instantly — a blessing in its own right.

But they were wrong.

NASA’s intensive, meticulous studies of every facet of that explosion, comparing what happened to other blowups of aircraft and spacecraft, and the knowledge of the forces of the blast and the excellent shape and construction of the crew cabin, finally led some investigators to a mind-numbing conclusion.

They were alive all the way down.

Rise and fall
The explosive release of fuel that dismembered the wings and other parts of the shuttle were not that great to cause immediate death, or even serious injury to the crew. Challenger was designed to withstand a wing-loading force of 3 G’s (three times gravity), with another 1.5 G safety factor built in. When the external tank exploded and separated the two solid boosters, rapid-fire events, so swift they all seemed of the same instant, took place. In a moment, all fuel was gone from the big tank.

The computers still functioned and, right on design plan, dutifully noted the lack of fuel and shut down the engines. It was a supreme exercise in futility, because by then Challenger was no longer a spacecraft.

One solid booster broke free, its huge flame a cutting torch across Challenger, separating a wing. Enormous G-loads snapped free the other wing. Challenger came apart — but the crew cabin remained essentially intact, able to sustain its occupants.

The explosive force sheared metal assemblies, but was almost precisely the force needed to separate the still-intact crew compartment from the expanding cloud of flaming debris and smoke. What the best data tell the experts is that the Challenger broke up 48,000 feet above the Atlantic. The undamaged crew compartment, impelled by the speed already achieved, soared to a peak altitude of 65,000 feet before beginning its curve earthward.

The crew cabin, reinforced aluminum, stayed solid, riding its own velocity in a great curving ballistic arc, reached the top of its curve, and then began the dive toward the ocean.

It was only when the compartment smashed, like a speeding bullet, into the sea’s surface, drilling a hollow from the surface down to the ocean floor, that it crumpled into a tangled mass.

Mercifully unconscious?
But even if the crew cabin had survived intact, wouldn’t the violent pitching and yawing of the cabin as it descended toward the ocean created G-forces so strong as to render the astronauts unconscious?

That may have once been believed. But that was before the investigation turned up the key piece of evidence that led to the inescapable conclusion that they were alive: On the trip down, the commander and pilot’s reserved oxygen packs had been turned on by astronaut Judy Resnik, seated directly behind them. Furthermore, the pictures, which showed the cabin riding its own velocity in a ballistic arc, did not support an erratic, spinning motion. And even if there were G-forces, commander Dick Scobee was an experienced test pilot, habituated to them.

The evidence led experts to conclude the seven astronauts lived. They worked frantically to save themselves through the plummeting arc that would take them 2 minutes and 45 seconds to smash into the ocean.

That is when they died — after an eternity of descent.

Weighing the mystery
Some dispute this conclusion, and the truth is, there is no way of knowing absolutely at what moment the Challenger Seven lost their lives. But a common-sense, rational review of the evidence tell those with extensive backgrounds in flight that the seven astronauts lived all the way down.

In the face of such expert beliefs, NASA finally made this official admission: “The forces on the Orbiter (shuttle) at breakup were probably too low to cause death or serious injury to the crew but were sufficient to separate the crew compartment from the forward fuselage, cargo bay, nose cone, and forward reaction control compartment.”

The official report concluded, “The cause of death of the Challenger astronauts cannot be positively determined.”

“We’ll probably never know,” says a NASA spokesman.

But in the mind of one of the lead investigators, we do know. Three-time space shuttle commander Robert Overmyer, who died himself in a 1996 plane crash, was closest to Scobee. There no question the astronauts survived the explosion, he says.

“I not only flew with Dick Scobee, we owned a plane together, and I know Scob did everything he could to save his crew,” he said after the investigation.

At first, Overmyer admitted, he thought the blast had killed his friends instantly. But, he said sadly, “It didn’t.”

One could see how difficult it had been for him to search through his colleagues’ remains, how this soul-numbing duty had brought him the sleepless nights, the “death knell” for this tough Marine’s membership in the astronaut corps.

“Scob fought for any and every edge to survive. He flew that ship without wings all the way down.”

Standing in his oceanside condominium, Overmyer turned away to stare at where his friends had crashed with great speed into the sea. “They were alive,” he said softly. “They were alive.”

Next: Heroes from the sea

NBC News correspondent Jay Barbree has covered America’s space effort from Cape Canaveral for more than 40 years. This is an updated version of a series that was first published on MSNBC.com in January 1997.

© 2005 MSNBC Interactive

Offline nirvana

  • Platinum Member
  • ******
  • Posts: 5640
Article about Challenger
« Reply #1 on: March 01, 2005, 04:47:03 PM »
Wow, you'd like to think they died immediately imagining them falling 65,000 Feet, sheer terror perhaps they could pack parachutes like the ones that carried Apollo craft back down into the crew cabin.  Just my thought.
Who are you to wave your finger?

Offline mora

  • Gold Member
  • *****
  • Posts: 2351
Article about Challenger
« Reply #2 on: March 01, 2005, 04:50:17 PM »
Is there knowledge if the cabin was still pressurized? I'm sure the 5 astronauts who didn't deploy their emergency oxygen would have passed out if the pressurization failed. If you look at the video it's quite clear that the cabin didn't suffer very great forces.

AFAIK they installed an emergency exit and provided the astronauts with parachutes after the Challenger accident. Makes you wonder why they didn't have them in the first place. There could be plenty of scenarios where they could be handy, both in launch and landing phase.
« Last Edit: March 01, 2005, 04:55:18 PM by mora »

Offline SunTracker

  • Silver Member
  • ****
  • Posts: 1367
Article about Challenger
« Reply #3 on: March 01, 2005, 05:48:31 PM »
I think there were ejection seats installed on the Shuttle for about 15 flights.  It was removed.  Astronauts have parachutes now, but the bail out mechanism is about the same as bailing out of a B-17.

The crew compartment of the shuttle should be designed as a break away pod, with everything needed to survive a re-entry in case of emergency.  Shuttle flights arent cheap to start with, so whats a few more million?

Offline Kegger26

  • Nickel Member
  • ***
  • Posts: 553
Article about Challenger
« Reply #4 on: March 01, 2005, 07:24:20 PM »
Quote
Originally posted by SunTracker
Shuttle flights arent cheap to start with, so whats a few more million?

 About two years in congress.

Offline Charge

  • Gold Member
  • *****
  • Posts: 3414
Article about Challenger
« Reply #5 on: March 02, 2005, 06:43:17 AM »
After they lifted the bodies and the crew compartment I really don't think there was any question of how they died. It is just more mercifull for the big crowd to write it that way.

Given a proper ejection system some of them may have survived providing the speed of compartment plummeting towards the sea was low enough and it wasn't spinning at very high speed. But you can bail out at rather high speed can't you?? Also they may have experienced a bit more than 3Gs in that fireball rendering most of them unconscious.

:(

-C+
"When you wish upon a falling star, your dreams can come true. Unless it's really a giant meteor hurtling to the earth which will destroy all life. Then you're pretty much screwed no matter what you wish for. Unless of course, it's death by meteorite."

Offline SunTracker

  • Silver Member
  • ****
  • Posts: 1367
Article about Challenger
« Reply #6 on: March 02, 2005, 01:04:02 PM »
People can survive mach 1 bailouts easily.  Along with 9+ Gs.

Offline afool

  • Zinc Member
  • *
  • Posts: 71
Article about Challenger
« Reply #7 on: March 02, 2005, 01:18:02 PM »
Quote
Originally posted by mora
Is there knowledge if the cabin was still pressurized? I'm sure the 5 astronauts who didn't deploy their emergency oxygen would have passed out if the pressurization failed.


One can only hope.

afool

Offline Soda

  • Silver Member
  • ****
  • Posts: 1543
      • http://members.shaw.ca/soda_p/models.htm
Article about Challenger
« Reply #8 on: March 02, 2005, 02:19:48 PM »
Quote
Originally posted by SunTracker
People can survive mach 1 bailouts easily.  Along with 9+ Gs.


That's a pretty small part of the envelope of the shuttle though on either take-off or landing.

There was a TV show a decade or so ago that discussed some of the "options" that NASA may have introduced to allow the astronauts to survive.  It reviewed some of the original ideas/plans for the shuttle that included some forms of escape capsule or ejection seats.  The conclusion was that the limits on those technologies probably would not have helped under most of the "likely" scenarios NASA had evaluated (which I remember included major structural failures, explosion, missed-approachs, re-entry burn-up).  To include technologies to allow a high probabilty of survival under all these potential scenarios would have made the shuttle unflyable.

Can't believe they haven't followed up with a shuttle replacement though... it's the only launch vehicle they have and if something else should happen you have to think it would the the third strike for NASA manned programs.

-Soda

Offline Red Tail 444

  • Gold Member
  • *****
  • Posts: 2497
      • http://www.redtail.org
Article about Challenger
« Reply #9 on: March 02, 2005, 03:58:51 PM »
Edited, nevermind....it was already said in the full report....
« Last Edit: March 02, 2005, 04:04:28 PM by Red Tail 444 »

Offline SunTracker

  • Silver Member
  • ****
  • Posts: 1367
Article about Challenger
« Reply #10 on: March 02, 2005, 05:59:59 PM »
Now Nasa does have to make tradeoffs.  The Space Shuttle must be light enough to lift off.  But bailouts from several hundred thousand feet are survivable.

Quote
On August 16, 1960, he set three world records: the highest parachute jump (102,800 feet), the longest parachute free fall (4 minutes 36 seconds), and the first person to exceed the speed of sound without an aircraft or space vehicle (714 mph during free fall)."


Quote
On Aug. 16, 1960, Kittinger set the world's record (which remains unbroken) for the longest (19.5 miles) and fastest (4 minutes and 36 seconds) skydive. He reported his experience in National Geographic. His epic dive started from a helium balloon that he floated to an altitude of 102,800 feet (31,330 m). This high, the sky is black and the Sun intense."


http://hypertextbook.com/facts/2004/JerardKneifatiHayek.shtml

Offline hawker238

  • Silver Member
  • ****
  • Posts: 1563
Article about Challenger
« Reply #11 on: March 02, 2005, 08:26:24 PM »
I thought it was impossible to exceed the sound barrier in a free fall (for humans).  Did he have any aerodynamic shaping?

Offline OIO

  • Silver Member
  • ****
  • Posts: 1520
Article about Challenger
« Reply #12 on: March 02, 2005, 10:18:03 PM »
thin air up there hawker. when he hit denser air he slowed down, otherwise his chute wouldnt have opened hehe

Offline Soda

  • Silver Member
  • ****
  • Posts: 1543
      • http://members.shaw.ca/soda_p/models.htm
Article about Challenger
« Reply #13 on: March 03, 2005, 10:28:43 AM »
Quote
Originally posted by SunTracker
Now Nasa does have to make tradeoffs.  The Space Shuttle must be light enough to lift off.  But bailouts from several hundred thousand feet are survivable.


Not to downplay that record, but it's comparing apples and oranges.  That guy jumped from a pretty much stationary balloon basket and accelerated to something over 700mph.  The shuttle, after only 45 seconds, is already doing in excess of 1,000mph and by the time it hit a similar altitude would be well in excess of that (likely around 10,000mph as orbit velocity is slightly over 17,000mph).  Not like you can just eject at those kinds of speeds even with the atmopshere being very thin.

The article mentioned that ejection would really only have been possible in the first 30 seconds after launch or in the final landing phase.  Anything outside of those parameters probably wasn't survivable.

-Soda