Space Shuttle Lost Over Texas

[billvon 3,076]

>Sorry folks, even a nerf bat travelling at mach 3 can take your head off..

Correct, but the foam came from the ET which was also moving at mach 3. Getting hit by a person traveling at 120 MPH can also kill you, but if you get hit by the front floater right after exit, he is going about the same speed as you are so there's less energy in the impact.

Note that nearly every spacecraft launch sheds something - ice that forms on the exterior of the cryogen fuel tanks, debris from ejection motors and pyrotechnics, escape mechanisms, even actual stages and interstages. Some kinds of impacts (like ice impacting the Saturn V first state) were quite routine.

[billvon 3,076]

>i guess they were hoping for the best because there was nothing they could have done about it anyway.

Yep; about all they could have done was stayed in orbit and waited for rescue. Not sure about the details of their orbit, but generally orbiter missions don't carry enough OMS fuel to change their orbit significantly, so resupply/rescue from the ISS would have been unlikely.

[wmw999 2,545]

Leroy: I'm a lead programmer for the shuttle's general purpose computers; I work on the software that runs when it's on orbit. My software doesn't run when it's on ascent or coming in for a landing.

As far as the insulation hitting, here's what I heard at the news conference, and it jibes completely with what I know about how things are done.

The insulation broke free and hit about 80 seconds after launch. I don't know how long the RTLS window is, but it's not very long. There are trans-Atlantic abort scenarios also.

80 seconds out, the shuttle is really far away, frankly. That's about how far away the Challenger was when it blew up -- remember the pictures from the ground?. The only reason they knew the piece of insulation hit was because they were analyzing launch films that are always taken. If it's a normal-looking launch (and this was), it's done after the shuttle is on orbit.

Wendy W.

There is nothing more dangerous than breaking a basic safety rule and getting away with it. It removes fear of the consequences and builds false confidence. (tbrown)

[cameramonkey 0]

Quote

Correct, but the foam came from the ET which was also moving at mach 3. Getting hit by a person traveling at 120 MPH can also kill you, but if you get hit by the front floater right after exit, he is going about the same speed as you are so there's less energy in the impact.

sorry didnt mean it literally. I just meant that anything, no matter how squishy or tiny, given the right amount of energy behind it can do ALOT of damage. I intended to mean that just because it seems light and insignificant, doesnt mean you can automatically write it off as a non issue.

[flyingferret 0]

Wendy,

I wanted to pass along good vibes to you and everyone you work with. Thanks for all the effort. To me your job seems awesome, although the grass is always greener... Anyway, I grew up wanting to be an astronaut, and I remember Challenger. THANK YOU to you, your team, your whole complex, and the 7 that paid the ultimate price to chase a dream.

BSBD

--
All the flaming and trolls of wreck dot with a pretty GUI.

[sinker 0]

May perpetual light shine upon them
and may they through the mercy of God
rest in peace.

Man, there's a lot of love in you dz.commers.
If only the world had more of y'all in it...

-the artist formerly known as sinker

[billvon 3,076]

>I don't know how long the RTLS window is, but it's not very long. There
> are trans-Atlantic abort scenarios also.

Yeah, but in this case, an ATO, AOA (or even maybe a TAL) might put you in exactly the same position i.e. with a lot of energy to lose during reentry, which is problematic if there are heatshield problems. Not that it makes much difference in this case; aborts are primarily designed around SSME failures, and they had no way of knowing there was any problem on ascent.

BTW (I'm sure you know this) the first orbiter abort happened around 1985; I forget which mission. They lost an SSME (main engine) and initiated the AOA (abort to orbit) plan, which put them in a much lower but salvageable orbit.

[IronMike 0]

To all the finger pointers and second guessers:

I Quote Theodore Roosevelt

"It is not the critic who counts: not the man who points out how the strong man stumbles or where the doer of deeds could have done better. The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood, who strives valiantly, who errs and comes up short again and again, because there is no effort without error or shortcoming, but who knows the great enthusiasms, the great devotions, who spends himself for a worthy cause; who, at the best, knows, in the end, the triumph of high achievement, and who, at the worst, if he fails, at least he fails while daring greatly, so that his place shall never be with those cold and timid souls who knew neither victory nor defeat.

"Speech at the Sorbonne, Paris, April 23, 1910

[Gawain 0]

Wendy, I did get to watch part of a NASA press conference today, and Mr. Dittamore (sp?) seemed on the ball, as you mentioned.

I have a question. There was a video shot of what looked like a close up of Columbia. It appeared as though the orbiter was going sideways. Have you seen this and is that normal (i.e. shedding speed or heat) or within the realm of your knowledge or experience?

So I try and I scream and I beg and I sigh
Just to prove I'm alive, and it's alright
'Cause tonight there's a way I'll make light of my treacherous life
Make light!

[Craig 0]

Quote

Wendy, I did get to watch part of a NASA press conference today, and Mr. Dittamore (sp?) seemed on the ball, as you mentioned.

I have a question. There was a video shot of what looked like a close up of Columbia. It appeared as though the orbiter was going sideways. Have you seen this and is that normal (i.e. shedding speed or heat) or within the realm of your knowledge or experience?

Wendy may be able to add or clairify but:
The shuttle will "roll" to the side to decrease the amount of lift being produced and provides a higher sink rate. It is used to help with the "range" of the orbiter, or the distance it will travel. They are performed to the left and right and are known as "S-turns" or "Roll Reversals". They will increase the amount of heat the orbiter sees but is signifigantly less that if pitch changes (nose up or down) were used for the same purpose. It is a routine menouver used at the time Columbia was lost.

[fudd 0]

This is pure speculation that strikes me as a possible cause. Could one of the flaps they use for steering the decent have jammed causing the shuttle to flip around. I can imagine that if the shuttle flips it will get torn apart at those speeds.

Just a thought.

There are only 10 types of people in the world. Those who understand binary, and those who don't.

[falxori 0]

Quote

Could one of the flaps they use for steering the decent have jammed causing the shuttle to flip around

i'm pretty sure the flaps can be tested before re-entry.
unlike the tiles, which are either there or not in a place you can't see, the hydraulic systems can be tested like in a normal aircraft.

O

"Carpe diem, quam minimum credula postero."

[TB99 0]

This is going to be another one of those moments where in the future someone will ask, "Where were you when the Columbia broke up on re-entry?" I hate those moments because a lot (not all) of them are bad times. I was at the DZ, watching this all in horror (when the sonic boom never came, we knew something was up). I can't imagine being a family member, my thoughts and heart goes out to all of them. None of us really know what happened yet, so I'm not going to speculate anything and am going to just wait for some results. Hopefully they went fast and didn't have to feel anything. The good thing is at least they had the best 16 days of their lives and gave their life to something they loved. To me, that's the best way to go (rather than being killed by a drunk driver or something).
I salute all the members on board ... BSBD.

Trailer 11/12 was the best. Thanks for the memories ... you guys rocked!

[rhino 0]

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The most immediate abort option they had at that time was RTLS, in which the shuttle continues out of the atmosphere, separates the SRB's, does a 180, thrusts back against its direction of flights, separates from the ET in a nose-down position, then pulls up and starts a landing pattern for the runway at Canaveral. That's never been tested; you'd have to have a really catastrophic failure for it to be attempted (like a loss of cabin integrity, making even a short stay on orbit too dangerous to attempt.)

You mean to tell me they can't abort a takeoff once those rockets start? Can't they separate them at 100,000 feet or something? Dump the tank? The whole purpose being to avoid the re-entry stress on the aircraft and the heat shingles.

Rhino

[falxori 0]

here is a great link with all you wanted to know and had no one to ask about a lot of things.

this specific article is about space shuttles and the recent disaster.

http://science.howstuffworks.com/space-shuttle.htm

Ori

"Carpe diem, quam minimum credula postero."

[kallend 2,107]

Quote

This is pure speculation that strikes me as a possible cause. Could one of the flaps they use for steering the decent have jammed causing the shuttle to flip around. I can imagine that if the shuttle flips it will get torn apart at those speeds.

Just a thought.

The forces aren't all that high because at 200,000ft the air is less than 1% of the density at sea level. The dynamic pressure at M18 and 200,000 ft is around 1/2 psi, or the same as around 200mph at sea level. In other words, the forces aren't much different than those seen by a head down skydiver.

The big difference is that because the flow is hypersonic the forces will be very non-uniformly distributed, and the energy dissipation rate is enormous, like 15kW per square inch!

...

The only sure way to survive a canopy collision is not to have one.

[billvon 3,076]

>You mean to tell me they can't abort a takeoff once those rockets
> start?

Unfortunately no. The SRB's cannot be throttled back or stopped once ignited. The only thing you could do is to separate them early, and if you think getting hit by a piece of foam is bad, imagine getting hit by a 500,000+ lb SRB or even getting hit by its exhaust (each one generates about 3 million pounds of thrust.)

>Can't they separate them at 100,000 feet or something?

They separate at about 50km.

>Dump the tank?

That's actually easier to do, since the main engines (the SSME's) are throttleable and can be shut down. In one abort option (the TAL) the ET is dumped early and the orbiter continues on to a landing in Spain or Senegal. As you mentioned below, though, you still get thermal stress from reentry, although it is a little less than normal since the orbiter isn't quite at orbital speeds.


Here is a good overview of the various abort modes. Unfortunately there is a limited number of failures (mainly the failure of one main engine) that they are useful for.

[billvon 3,076]

>This is pure speculation that strikes me as a possible cause. Could
> one of the flaps they use for steering the decent have jammed
> causing the shuttle to flip around.

Possible but unlikely for two reasons. One, the crew has a surface position indicator that would indicate one of the control surfaces (there are seven) in a bad position. Their communications while the event was unfolding did not indicate that they saw any problem with the surfaces, nor did the preliminary analysis of the telemetry data seem to indicate that the surfaces were not in their commanded position.

Two, there are indications that the control system (which uses both the control surfaces and RCS rockets to maintain attitude) was actively correcting for an increase in drag on the left wing. In other words, the flaps/RCS were doing their job trying to compensate for another problem.

[VivaHeadDown 0]

In case anyone isn't on NASA's info email list, and still would want to view:

The President and Mrs. George W. Bush will join NASA Administrator Sean O'Keefe Tuesday afternoon, Feb. 4, in paying tribute to the brave heroes of the Space Shuttle Columbia crew during a special memorial service at the NASA Johnson Space Center in Houston.

The ceremony to honor NASA astronauts Rick Husband, William McCool, Michael Anderson, Kalpana Chawla, David Brown, Laurel Clark, and Israeli astronaut Ilan Ramon is scheduled to begin at 1 p.m. EST in the Central Mall area behind Building One. Gates are scheduled to open at 10 a.m. EST.

This is a private ceremony for family members, friends, and invited guests, along with NASA employees and contractors. The service will be carried live on NASA Television and available
on the Internet at: www.nasa.gov.

[rhino 0]

Still seems like the main shuttle should theoretically be able to separate from the Fuel tank and the boosters, pulling back on the stick lightly gaining plenty of safety from the fuel tank and boosters?

[PhreeZone 20]

Disconecting from the EFT means its out of gas and turns into a glider then and there. The SRB's are some mean power right there. Just doing a seperation with them still buring is a bad thing since they have no directional control and will propel until they are out of propellant. This means they can point back at FL and burn until they impact in Orlando for the worst case. Safest thing is just to take them until they are low on propellant and then discard them. The fuel tank is like a loaded bomb just waiting to go off if it impacts on something. Seperate too late and it will have enough fuel and energy it could be lobbed onto the Europian mainland. Even the seperation sequence is computer controled and has to be timed right in its seperation to avoid having the SRB's point at the fuel tank or have the thrust point at the tank and make it explode then. SRB's are short lived, about 2 minutes and the rest of the energy comes from the EFT. Thats a lot of fuel you have to deal with, its almost another 6-7 minutes of burn time from SRB cutoff to EFT jettison.


TAS is the most likely situation if abort is called, but then things have to be timed very well or its more dangerous to the general population then it is to have the shuttle continue on.

Yesterday is history
And tomorrow is a mystery

Parachutemanuals.com

[billvon 3,076]

>Still seems like the main shuttle should theoretically be able to
> separate from the Fuel tank and the boosters, pulling back on the
> stick lightly gaining plenty of safety from the fuel tank and
> boosters?

You mean as a unit? That's worse in a way. Even if the separation mechanism allowed for those sort of loads (which I don't think they were designed for) here's what would have to happen:

1. SSME's (main engines) are shut off. The thrust centerline is now way off the CG, and the whole assembly starts to pitch towards the ground.

2. LOX/LH (i.e. fuel from the external tank) feedline valves are closed.

3. Orbiter separates.

4. RCS pitches the shuttle a little away from the (now accelerating) ET/SRB assembly. Not too much happens since there's not much air to work with at that altitude.

Think about the position that puts you in. You are now beneath the SRB's exhaust, off to one side a bit. The stack is accelerating like crazy now that the mass of the orbiter has been removed, and you are essentially unpowered. On your belly are two fuel line hatches which are just starting to close which contain spilled liquid oxygen and hydrogen, and part of the SRB exhaust (six million pounds all told) is hitting the nose and belly of the orbiter.

NASA has always gone into pretty great detail analyzing abort options - most of the early manned flights had escape towers on the top that would pull the capsule free of a failed booster, and even this orbiter originally had ejection seats for the commander and pilot. (They were removed after the first flight.) Some abort scenarios put the crew at more risk than just continuing with the flight, so not all possible scenarios are 'allowed' or even planned for.

[kallend 2,107]

video of 'foam' hitting left wing.

Looks to me like more than one piece.

How do they know it's foam and not ice or something else?

...

The only sure way to survive a canopy collision is not to have one.

[billvon 3,076]

>>and was travelling at about mach 6.

--------------------------------------------------------------------------------

>Try Mach 18.+

I just came across this (see attachement.) Ah, the media.

[kallend 2,107]

Quote

>>and was travelling at about mach 6.

--------------------------------------------------------------------------------

>Try Mach 18.+

I just came across this (see attachement.) Ah, the media.

Authorities too! Sheriff Maddox is the sheriff of Sabine Co, LA. From CNN's web site:

"Maddox warned search crews as well as
the public that the debris contained three
hazardous materials that should be
"avoided at all cost." He said the fuels and
oxidizers would give off a strong odor of
fish, ammonia or bleach."

Given that the toxic dose of monomethyl hydrazine is lower than the amount you can detect by smell, encouraging people to smell the debris seems a bit dumb! If you smell it, it will be the last thing you ever smell.

...

The only sure way to survive a canopy collision is not to have one.