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interstellaryeller
2008-Dec-30, 05:00 PM
Columbia Disaster, New Report To Be Released. Today 2008, Dec 30. Nasa is expected to release the detailed report on the Columbia's demise. At approximaty 12:15 Pm eastern On CNN.:sad::sad::sad:

bunker9603
2008-Dec-30, 07:18 PM
The report paints a disturbing picture of what the astronauts went through and even says they didn't have some equipment and training that might have increased their chances of survival. The report found the astronauts knew for as long as 41 seconds that they did not have control of the space shuttle before they were likely knocked unconscious and killed as Columbia broke apart around them.

http://www.wftv.com/news/18381713/detail.html

Raw footage from inside the shuttle:

http://www.wftv.com/video/18381740/index.html

banquo's_bumble_puppy
2008-Dec-31, 11:57 AM
sorry to say but there was nothing that could have saved them....think about it MACH 19 @ 60 miles altitude......crew cabin comes apart...prevention was the only thing that would have saved them.

Buttercup
2008-Dec-31, 02:14 PM
...their seat belts failed
...spacesuits inadequate
...helmets inadequate
...shuttle apparently not fit to fly

Pathetic :mad:

RIP Columbia astronauts.

banquo's_bumble_puppy
2008-Dec-31, 02:50 PM
not to disrespect the above...what differnce would it have made if their suits worked/seat belts worked/etc?.....just shows that the shuttle was poorly designed....

BetaDust
2008-Dec-31, 04:00 PM
I agree with bbp. Coming in at Mach 19 and that altitude, there is no way they could have survived without the orbiter's heatshield.

djellison
2008-Dec-31, 05:58 PM
.what differnce would it have made if their suits worked/seat belts worked/etc?

None. Buttercup is reading a different report it seems. The crew were not in a survivable situation given the damage to the shuttle. The seat belts failed at a point beyond any survivable by a human anyway. One astronaut wasn't even in their seat.

Better seat belts would not have changed the outcome.

Again, full on crash helmets would not have changed the outcome

And even a full EVA suit for every astronaut would not have changed the outcome.

"The breakup of the crew module and the crew’s subsequent exposure to hypersonic entry conditions was not survivable by any currently existing capability"

That's the tragic truth. The Shuttle is a fragile and delicate launch and landing system. When it works - it's fine. But prang it, and you enter an unsurvivable regeime, no matter what you do.

Orion and Dragon are far more robust as a landing system.

Larry Jacks
2008-Dec-31, 06:03 PM
The part that always gets me from the video is the part where one of them says to the effect, "You really don't want to be outside right now." Not too long afterwards, that's where they found themselves as the Shuttle came apart.

KaiYeves
2009-Jan-01, 03:20 AM
The part that always gets me from the video is the part where one of them says to the effect, "You really don't want to be outside right now." Not too long afterwards, that's where they found themselves as the Shuttle came apart.
I, also. :sad:

aquitaine
2009-Jan-01, 05:47 AM
That's the tragic truth. The Shuttle is a fragile and delicate launch and landing system. When it works - it's fine. But prang it, and you enter an unsurvivable regeime, no matter what you do.

Maybe the spaceplane concept would have been a better choice, since the original designs AFIK didn't use delicate tiles and instead used some kind of molybdenum alloy.

cjameshuff
2009-Jan-01, 08:42 AM
Maybe the spaceplane concept would have been a better choice, since the original designs AFIK didn't use delicate tiles and instead used some kind of molybdenum alloy.

And hot frames, and massive (as in heavy) internal cooling systems that meant they would have trouble actually reaching orbit even with only a single occupant. And those alloys needed protective coatings as well...they might not have fared any better from ice impacts, and might very well have been worse at handling micrometeorite/debris impacts in orbit.

peteshimmon
2009-Jan-01, 06:44 PM
Something I have wondered about, the hole in
the wing should have made the aerodynamics
of the orbiter a bit assymetric and the main
engines would have gimballed a bit to
counteract. Until it reached some height.
I presume the telemetry shows this.

Larry Jacks
2009-Jan-01, 08:24 PM
I suspect the amount of additional drag from the damaged wing was very small compared to the thrust.

cjameshuff
2009-Jan-01, 09:13 PM
Something I have wondered about, the hole in
the wing should have made the aerodynamics
of the orbiter a bit assymetric and the main
engines would have gimballed a bit to
counteract. Until it reached some height.
I presume the telemetry shows this.


I suspect the amount of additional drag from the damaged wing was very small compared to the thrust.

The only thrusters in use at this time are the RCS maneuvering thrusters, and they are fixed. The Shuttle was in an aerodynamic glide, and would have been mainly using its control surfaces at this time in a normal landing. The telemetry did indicate that the autopilot was firing RCS thrusters in an attempt to control the craft shortly before loss of contact.

http://spaceflightnow.com/shuttle/sts107/030309autopilot/
http://www.spaceref.com/news/viewnews.html?id=733

Swift
2009-Jan-01, 10:06 PM
From the TV news story linked in the second post:

The agency hopes to help engineers design a new shuttle replacement capsule more capable of surviving an accident. An internal NASA team recommends 30 changes based on Columbia, many of them aimed at pressurization suits, helmets and seatbelts.

At first I thought this a strange comment - I took it that NASA was looking at design changes on the shuttles. That seemed strange, since they'll probably be retired before they could make any changes. Upon re-reading, I take it that they are incorporating these changes into the Ares design. I can see that for suits and helmets, but I not sure how much you could learn about design changes for Ares based on the shuttle - I would think there is just too much different about the behavior and mode of operating.

Larry Jacks
2009-Jan-01, 11:17 PM
The only thrusters in use at this time are the RCS maneuvering thrusters, and they are fixed. The Shuttle was in an aerodynamic glide, and would have been mainly using its control surfaces at this time in a normal landing. The telemetry did indicate that the autopilot was firing RCS thrusters in an attempt to control the craft shortly before loss of contact.

I'm not positive but when I read his question, I was under the impression that he's asking about drag changes during launch, not reentry. Here's his question again:

Something I have wondered about, the hole in
the wing should have made the aerodynamics
of the orbiter a bit assymetric and the main
engines would have gimballed a bit to
counteract. Until it reached some height.
I presume the telemetry shows this.

The main engines are only firing during launch. The part about "Until it reached some height" seems to refer to climbing, not descending.

Just before the Challenger exploded in 1986, telemetry indicated the engines were gimballing to counteract the SRB leak. Perhaps if the wing damage had been severe enough, some thrust gimballing would've been required but probably not too much. The extra drag on one wing while both SRBs were firing would've been only a tiny fraction of the thrust produced by the engines. As the vehicle climbed, it was accelerating but the atmosphere was also getting thinner. After Max Q, the drag would've been decreasing all of the way to orbit.

GeorgeLeRoyTirebiter
2009-Jan-01, 11:20 PM
At first I thought this a strange comment - I took it that NASA was looking at design changes on the shuttles. That seemed strange, since they'll probably be retired before they could make any changes. Upon re-reading, I take it that they are incorporating these changes into the Ares design. I can see that for suits and helmets, but I not sure how much you could learn about design changes for Ares based on the shuttle - I would think there is just too much different about the behavior and mode of operating.

I've only skimmed the report, but it looked like they were recommending that the Aries design take into account the possibility of a loss of control during re-entry, something that probably wasn't done for the shuttle. Also, the suits and related systems need to be better integrated into the vehicle, instead of being shoehorned into an existing design (as happened with the shuttle).

Some relevant recommendations from the summary:


Crew survival systems and procedures should be incorporated early into future spacecraft designs to ensure that they are compatible with nominal operations and that sufficient time exists to ensure all safety-critical equipment can be configured prior to entry interface.
Future spacecraft should be evaluated while still in the design phase for dynamics and entry thermal and aerodynamic loads during a vehicle LOC [loss of control] for adequate integration into development, design, and crew training.
Future crewed spacecraft vehicle design should account for vehicle LOC contingencies to maximize the probability of crew survival.
Future vehicle design should incorporate analysis for LOC/breakup to optimize for the most graceful degradation to vehicle systems and structure to enhance chances for crew survival. Operational procedures can then integrate the most likely scenarios into survival strategies.

matthewota
2009-Jan-02, 04:29 AM
I highly recommend that all of the participants in this thread read the report directly from the source and not to depend on what news reporters say. Inevitably they get the message wrong or out of context.
The official 400 page report in PDF format is here: (http://www.nasa.gov/pdf/298870main_SP-2008-565.pdf)


It is the most detail accident report I have ever read in my life. I
had access to Air Force accident reports while I was in the service,
and I read AW&ST accident reports on airline accidents. This report is
very very detailed.

The news media chooses to concentrate on the morbid parts of the story, in order to sensationalize and get ratings. Shame on them.

djellison
2009-Jan-02, 08:37 AM
The news media chooses to concentrate on the morbid parts of the story, in order to sensationalize and get ratings. Shame on them.

I've read it. All of it.

It's a report on exactly how and why 7 people died. When it's not actually describing the final moments of the crew and the mechanisms of death, it's describing the source of the data used to establish the details of the final moments of the crew and the mechanisms of death.

It's a document about how the crew died. That's what the media have reported. It's fundamentally a morbid document.

Doug

peteshimmon
2009-Jan-02, 06:57 PM
Thanks for the responce, I should have
indicated it was the launch I was thinking
about. I thought during the investigation
when the launch pictures showed the foam
coming off and hitting the orbiter, the
time would have been checked with the
main engines gimballing activity. They
are active all the time of course, while
the craft climbs through wind shears and
pressure variations but a distinctive
event may have been seen.

danscope
2009-Jan-03, 02:28 AM
Hi, It occurred to me that any spaceplane design, the Shuttle, etc. Have
some leading edge protection for launch purposes, which by design are either released in orbit, or are ablated on re-entry, but serve to protect the leading edge on launch, when they are most vulnerable. Perhaps there is a way....
Have any concepts been forwarded to anyone's knowledge?

Best regards, Dan

joema
2009-Jan-04, 03:41 PM
...launch pictures showed the foam
coming off and hitting the orbiter, the
time would have been checked with the
main engines gimballing activity. They
are active all the time of course, while
the craft climbs through wind shears and
pressure variations but a distinctive
event may have been seen.
The amount of increased drag from the left wing damage was so small, it just wasn't visible -- either during the flight or afterward during the accident investigation.

The wing damage was likely a 6 to 10 inch diameter hole in the leading edge of the inner wing (closer to the fuselage). 10 inches is about 0.54 square feet. The aerodynamic pressure at the moment of damage (T+82 sec) was about 480 pounds per square foot.

If the undamaged wing had zero drag, and if the damaged area had the drag coefficient of a flat plate, it might theoretically cause 0.54 * 480 = 259 pounds additional drag force. In actuality the wing has some drag, so the difference between undamaged and damaged state will be less than that.

If the wing damaged caused, say, 100 lbs additional drag force, this is microscopic relative to the other forces involved.

Both SRBs and SSMEs are constantly gimbaling to keep the vehicle on course, counteract propellant sloshing in the tanks, compensate for wind shear, etc. Together they produce about 6,000,000 pounds of thrust at T+80 sec.

During powered ascent, both SSMEs and SRBs are constantly gimbaling to keep the vehicle on course.

As the below graphs show, there's no obvious distinctive event in the gimbal data at T+82 sec.

The term "PE flights" in the SRB graph refers to "Performance Enhancements", a combination of flight software and trajectory design changes that were introduced in late 1997 for STS-85. These changes to the ascent flight profile allow the Shuttle to carry some 1,600 pounds of additional payload on International Space Station assembly missions. Although developed to meet the Space Station payload lift requirement, a modified PE profile has been used for all Shuttle missions since it was introduced. This was unrelated to the accident, but causes two distinct data groups when analyzing past flights.

peteshimmon
2009-Jan-04, 07:23 PM
Thanks joema, that is pretty comprehensive.
I was thinking perhaps shockwaves from the
shuttle structure forward of the wings was
limiting air entering the damaged leading
edge.

Fate is so nasty sometimes, the one mission
where the astronauts did not get out and see
their craft. But what could they have done!

mantiss
2009-Jan-09, 09:48 PM
Hi, It occurred to me that any spaceplane design, the Shuttle, etc. Have
some leading edge protection for launch purposes

That's why I always thought that the plan Europe had with Hermes (http://en.wikipedia.org/wiki/Hermes_%28shuttle%29) was a better idea, sit the shuttle atop the rocket stacks and nothing drops on you.

Nicolas
2009-Jan-12, 01:23 PM
The problem with Hermes was that this on-top position introduces an instability and gives a lot of aerodynamic loads on the connection with the Ariane5.

danscope
2009-Jan-12, 05:33 PM
Yes, it does encourage instability. I believe that the leading edges can be armoured. They just never bothered, or figured that the shuttle will be retired.
The other alternative would be foam insulation that properly adheres, and
removes the problem of ice ablating on ascent. Just my 2 cents in.
I welcome other opinions.
Best regards, Dan

cjameshuff
2009-Jan-12, 07:22 PM
Or you could...build an orbital vehicle without wings.

They're a nuisance on the way up, they're dead weight on orbit, they're a liability on the way down, and they're not the only way to land. If you insist on a runway landing, parafoils seem like a much better solution...you could actually design the airfoil for operation at the speeds where it's most useful.

danscope
2009-Jan-12, 10:31 PM
You have to consider the amount of weight you have to decelerate from orbital velocity to managable atmospheric velocity....ie > 275kts.
And we need to slow 110 tons of space shuttle from 18,000 MPH to
something managable for atmospheric purposes. That's a lot to ask of parachutes.
By employing the wing/body of sts , we have a lot more area to employ aerobraking. It works well if your tiles are intact.
Even then, you want to softland with a chute with 110 tons of delicate
space shuttle? I don't know Tim.

Dan

cjameshuff
2009-Jan-12, 11:46 PM
You have to consider the amount of weight you have to decelerate from orbital velocity to managable atmospheric velocity....ie > 275kts.

I did not suggest parachuting from orbital velocity. You don't need wings to aerobrake. You don't particularly want wings while aerobraking, they generally require active control to make reentry survivable. Capsules can be designed to reenter ballistically as a fallback, a safety feature that has been unintentionally tested a couple times on the Soyuz.



Even then, you want to softland with a chute with 110 tons of delicate space shuttle? I don't know Tim.

I also did not suggest landing the Shuttle by parafoil. Taking large wing areas through reentry requires building them to withstand enormous stresses, and shaping them in ways that are inefficient at low speeds. A capsule or lifting body design would be lighter and less delicate, lacking wings backed by enough structure to withstand hypersonic flight and shielding to keep them intact during reentry.

Parachutes and parafoils have been demonstrated to work for vehicles the size of the Orion capsule, and the technology has plenty of room to develop further.

Also, my name's not Tim.

joema
2009-Jan-13, 12:23 AM
Parachutes and parafoils have been demonstrated to work for vehicles the size of the Orion capsule, and the technology has plenty of room to develop further...
And that assumes you need that capability. Even the Apollo capsule had a lift/drag ratio of about 0.4 and probably had a few hundred miles of cross-range steering. This was achieved by just rolling the capsule left/right.

With today's computerized GPS guidance, a precision deorbit burn coupled with steering a capsule's L/D ratio, landing within a few hundred meters of a target is probably achievable.

A winged vehicle has greater L/D ratio and cross range. However it MUST have this, as it can only land at special sites. By contrast a capsule can land almost anywhere.

cjameshuff
2009-Jan-13, 12:37 AM
A winged vehicle has greater L/D ratio and cross range. However it MUST have this, as it can only land at special sites. By contrast a capsule can land almost anywhere.

Indeed. Every corn field and cow pasture can be an emergency landing site, while the Shuttle can't even land at your average airfield. Parafoils might allow landing heavier payloads, though, by allowing the vehicle to "pull up" just before touching down, dropping both forward and downward velocity below what could be achieved with a parachute of the same area.

A horizontal landing might be useful for getting particularly shock-sensitive experiments back down to the ground, but there are other ways to reduce the landing shock. A small solid rocket burning just before landing, a spring winch to haul the capsule toward the chutes at the last moment, collapsable payload mounts, etc.