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STS Shuttle discussion thread


GoSlash27

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Just now, Jaff said:

Satisfy a question if you would guys, 

 

challenger - if they knew the booster was goosed 20 seconds before it went bang, why not separate them and abort the mission? 

Because they couldn't.

The Orbiter and External Tank at liftoff massed on the order of 850 tonnes. The SSMEs provided about 5250 kN of thrust at launch. That is a TWR of less than 1.0.

The first abort they could possibly begin was an RTLS, that begins at SRB separation. There was no abort plan for SRB malfunction because the Shuttle simply couldn't safely abort until after they had burned to depletion.

4 minutes ago, PB666 said:

Sometimes it is and you have to suck it up

And in this case it isn't. Between "overly expensive and dangerous" vs. "much cheaper and safe", you're choosing the "overly expensive and dangerous" option.

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4 minutes ago, Jaff said:

challenger - if they knew the booster was goosed 20 seconds before it went bang, why not separate them and abort the mission? 

 Jaff,

 Good question. I'm not sure that it was an option. The mounting points would be under tremendous load and there's the problem of how the shuttle/ stack would behave. Maybe they thought it was a better gamble to hope it held together?

Best,
-Slashy

1 minute ago, PB666 said:

And that philosophy is why NASA is now underperforming.

And your philosophy is why you're not in charge at NASA :wink:

 

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4 minutes ago, Starman4308 said:

Because they couldn't.

The Orbiter and External Tank at liftoff massed on the order of 850 tonnes. The SSMEs provided about 5250 kN of thrust at launch. That is a TWR of less than 1.0.

The first abort they could possibly begin was an RTLS, that begins at SRB separation. There was no abort plan for SRB malfunction because the Shuttle simply couldn't safely abort until after they had burned to depletion.

And in this case it isn't. Between "overly expensive and dangerous" vs. "much cheaper and safe", you're choosing the "overly expensive and dangerous" option.

Im choosing that NASA should perform an extension of function over time over abdication of function for more than a decade.

Edited by PB666
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1 minute ago, PB666 said:

Im choosing that the should perform an extension of function over time over abdication of function for more than a decade.

Well, they can't. That option is no longer on the table. Cooler heads prevailed, and the majority here agrees with that decision.

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Just now, GoSlash27 said:

Well, they can't. That option is no longer on the table. Cooler heads prevailed, and the majority here agrees with that decision.

Not to worry, while they are dropping the ball on manned space flight, SpaceX will pick it up soon enough.

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6 minutes ago, Starman4308 said:

Because they couldn't.

The Orbiter and External Tank at liftoff massed on the order of 850 tonnes. The SSMEs provided about 5250 kN of thrust at launch. That is a TWR of less than 1.0.

The first abort they could possibly begin was an RTLS, that begins at SRB separation. There was no abort plan for SRB malfunction because the Shuttle simply couldn't safely abort until after they had burned to depletion.

And in this case it isn't. Between "overly expensive and dangerous" vs. "much cheaper and safe", you're choosing the "overly expensive and dangerous" option.

Ok realistically at some point during design they must have thought “what if one of these not turney offey things doesn’t behave” so why wasn’t there an option to get shot of them with adequate warning of something being not right? 

 

Granted if it went 100ft in the air there wouldn’t be much that could be done but challenger was a Fair way down range before things went wrong. I’d imagine light enough to blow the boosters away and maintain some sort of flight back to the floor 

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Just now, PB666 said:

Not to worry, while they are dropping the ball on manned space flight, SpaceX will pick it up soon enough.

I'm looking forward to it. In the meantime, NASA has successfully accomplished everything it might've otherwise used the shuttle to do, spent less money, and nobody got killed in the process. I call that a win.

Your mileage may (and clearly does) vary.

Best,
-Slashy

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1 minute ago, GoSlash27 said:

I'm looking forward to it. In the meantime, NASA has successfully accomplished everything it might've otherwise used the shuttle to do, spent less money, and nobody got killed in the process. I call that a win.

Your mileage may (and clearly does) vary.

I never said they had to keep the shuttle, but one has to what there motives were for abruptly ceasing certain functions. They clearly have dropped the ball, and Orion is unlikely to be a suitable replacement. It will be cancelled at some point because of time delays and cost overruns.

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Just now, PB666 said:

I never said they had to keep the shuttle, but one has to what there motives were for abruptly ceasing certain functions. They clearly have dropped the ball, and Orion is unlikely to be a suitable replacement. It will be cancelled at some point because of time delays and cost overruns.

They made it abundantly clear what their motive was: They were convinced that the Shuttle was going to get somebody killed if they continued flying it. As for Orion, it's not intended to be a replacement for the Shuttle.

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6 minutes ago, Jaff said:

Ok realistically at some point during design they must have thought “what if one of these not turney offey things doesn’t behave” so why wasn’t there an option to get shot of them with adequate warning of something being not right? 

 

Granted if it went 100ft in the air there wouldn’t be much that could be done but challenger was a Fair way down range before things went wrong. I’d imagine light enough to blow the boosters away and maintain some sort of flight back to the floor 

They probably thought about it. I believe NASA wanted liquid fueled boosters, but was overridden. The Shuttle program was a train wreck from start to finish. Nothing was the way the Shuttle was originally intended to be, a compromise solution for many different groups with mutually contradictory goals.

In terms of safety, you had jawdroppers like insisting the SRBs had gimbal for the minute possibility of issues with SSME gimbal, and no plan for SRB failure.

Could have. Should have. Didn't, and astronauts paid the price for it.

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Yeah, Aerojet was gonna do liquid side boosters, but a Senator from Utah...

My son had a talk at school last week from a guy at the lab who lost his sister on Columbia (she was the doc aboard). We heard Columbia reenter over Albuquerque (our living room picture window sounded like a hawk flew into it from the sonic boom), and his family was out watching as it did the overflight.

That said, I’ve met many shuttle astronauts (10 or so), and they all liked their experiences—though they lived to tell me about them, lol, so some bias there I suppose.

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1 hour ago, GoSlash27 said:

I'm looking forward to it. In the meantime, NASA has successfully accomplished everything it might've otherwise used the shuttle to do, spent less money, and nobody got killed in the process. I call that a win.

I'm not sure you can really say that. I think your statement is nearly unfalsifiable (and therefore not terribly meaningful). Could you (or anybody) list the things that were NOT done because there was no shuttle? Speculating on negative evidence is very unreliable.

The shuttle was never just a Falcon 9 or Atlas 5 -- it was a small space station that was launched each time it was used and then recovered (most of the time....). One might argue that the shuttle was used to build its own replacement, because the ISS now serves to do all the "people in space" stuff that the shuttle did (except the specific task of servicing the Hubble telescope).

That being said, if we were to deorbit the ISS tomorrow, would we be able to build a replacement? What would take the place of the shuttle for that? It's kind of like the Saturn system in a way -- the shuttle represents a capability we once had but intentionally gave up because it was very expensive and we thought we were done with it.

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mikegarrison,

 I think you've just answered your own question here.

 In the very narrow scope of my comment, the question is "between July 21st 2011 and today, did NASA have any planned or desired missions that had to be scrapped because the shuttle was no longer flying at the time"? I'd say the answer to that is no, but if I'm mistaken I'm sure that somebody will correct me. In the last 6 1/2 years, NASA has done what it intended to do without the services of the shuttle. Therefore it was not necessary in the interim.

 In the case of past missions which required the unique abilities of the shuttle, I'm glad we had those abilities and I'm thankful for what it has provided. In the hypothetical future missions where a shuttle *might* prove helpful, I'm sure that the retired STS program would not have been considered a viable option anyway. We'd either find another way to get it done or simply not do it before considering using a mothballed highly sketchy vehicle with a billion dollar price tag per launch and heavy risk to human lives. If worst comes to worst, we'd build a new fleet of markedly improved shuttles.

 I see the comparison to Apollo as highly appropriate in that sense. It did what we needed it to do, and we didn't need it for the jobs we did afterwards.

Best,
-Slashy

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6 minutes ago, GoSlash27 said:

mikegarrison,

 I think you've just answered your own question here.

 In the very narrow scope of my comment, the question is "between July 21st 2011 and today, did NASA have any planned or desired missions that had to be scrapped because the shuttle was no longer flying at the time"? I'd say the answer to that is no, but if I'm mistaken I'm sure that somebody will correct me. In the last 6 1/2 years, NASA has done what it intended to do without the services of the shuttle. Therefore it was not necessary in the interim.

The logic is kind of corrupt. You cannot plan a material test if you have no means to bring it back to Earth. There are a variety of new materials develope since the last material test was concluded that will never be tested in space because of the extreme difficulty in bring them back without a shuttle. You could do them outside the space station, that would require 2 space walks and the size of the test would be limited to what an astronaut can safely take and mount in space. The shuttle conducted several of these during its tenure.

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Replace ISS? What's a Bigelow cost? A billion? For the price of 2-3 empty Shuttle launches (plus the fixed cost of the program that would enable them), you could buy more volume in Bigelow stations than ISS is. Add a fraction of that in launch cost. Done, ISS replaced.

4 minutes ago, PB666 said:

The logic is kind of corrupt. You cannot plan a material test if you have no means to bring it back to Earth. There are a variety of new materials develope since the last material test was concluded that will never be tested in space because of the extreme difficulty in bring them back without a shuttle. You could do them outside the space station, that would require 2 space walks and the size of the test would be limited to what an astronaut can safely take and mount in space. The shuttle conducted several of these during its tenure.

You're saying that we could not figure out a low g reentry vehicle for materials tests if we gave someone a few billion dollars to come up with one? 3 billion is ~2 shuttle launches.

Oh, wait, we have 2 vehicles that could do this, one in service (X-37), and one soon to be in service (Dream Chaser).

Edited by tater
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3 minutes ago, PB666 said:

The logic is kind of corrupt. You cannot plan a material test if you have no means to bring it back to Earth. There are a variety of new materials develope since the last material test was concluded that will never be tested in space because of the extreme difficulty in bring them back without a shuttle. You could do them outside the space station, that would require 2 space walks and the size of the test would be limited to what an astronaut can safely take and mount in space. The shuttle conducted several of these during its tenure.

^ Tenuous at best. There were no material tests I'm aware of that NASA wanted to do but couldn't. Certainly none that they would've risked a whole crew for, spent a billion dollars, and definitely couldn't do at the ISS.

 

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13 minutes ago, GoSlash27 said:

In the very narrow scope of my comment, the question is "between July 21st 2011 and today, did NASA have any planned or desired missions that had to be scrapped because the shuttle was no longer flying at the time"? I'd say the answer to that is no, but if I'm mistaken I'm sure that somebody will correct me. In the last 6 1/2 years, NASA has done what it intended to do without the services of the shuttle. Therefore it was not necessary in the interim.

I'm just saying, of course nobody planned out missions that they knew couldn't be done. That's not the same as saying nobody dreamed up any missions they would like to have done and then realized that without the Shuttle they were impossible.

Anyway, don't get me wrong here. I am content that the shuttle was retired. Clipper ships were great in their day, but nobody ships tea to England in them anymore.

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1 minute ago, mikegarrison said:

I'm just saying, of course nobody planned out missions that they knew couldn't be done. That's not the same as saying nobody dreamed up any missions they would like to have done and then realized that without the Shuttle they were impossible.

Right, but conversely nobody ever said "well, we were *gonna* do this, but the shuttle's gone and now we can't". So... not really missed. I mean... there was never a backlash in the scientific community saying they need a shuttle, even when it was being shut down. So in the last 6 1/2 years, how critical was it really? I don't think it was critical at all.

Best,
-Slashy

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With regards to building a new space station, while the Space Shuttle did help somewhat in bringing up a sophisticated manned platform for the initial construction, I don't really see any reason why we couldn't send up modules on an expendable heavy lift platform, much like how the Russians sent up their modules on Proton and Soyuz rockets. The Space Shuttle was convenient for the ISS courtesy of having an at-the-time unmatched payload capacity and crew delivery capabilities.

While none of the upcoming systems save perhaps the SLS have the same combination of crew capacity, heavy payload, and auxiliary equipment like the Canadarm, that is merely convenient, not necessary for building a space station. The Falcon 9 in expendable mode comes close in payload mass, and the Falcon Heavy exceeds it, although its fairing volume leaves something to be desired. The Delta IV Heavy, so far as I can tell, is pretty close to the capacities of the Space Shuttle, and the New Glenn should just blow the Space Shuttle away (which is part of why I'm so excited for New Glenn).

All the equipment that made the Shuttle unique can be duplicated; a robotic arm could be included with the first space station module, etc. I see no reason why, with a little bit of creativity, conventional launch vehicles could not be used to replace the ISS... and it's got to be better than paying out the nose for the overly expensive Shuttle launches.

For other missions such as returning payloads from LEO... just put a heatshield and a small maneuvering unit on the payload. Ask the Air Force to put it on the X-37. Sierra Nevada would probably love to put it on the Dream Chaser. The Space Shuttle had numerous capabilities, yes, but a lot of them were wasted on all the flights where it just acted as an outrageously expensive HLV, and the rare missions where the unique capabilities of the Space Shuttle really shined... probably could have been done more economically by sending up a custom mission module on a separate unmanned vehicle, and sending up any necessary crew on something smaller and less deadly.

EDIT: To further clarify a point, the New Glenn's gigantic 7 meter fairing is filled with my hopes and dreams for an ISS replacement. It's a pretty large fairing.

Edited by Starman4308
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18 minutes ago, Starman4308 said:

The Space Shuttle had numerous capabilities, yes, but a lot of them were wasted on all the flights where it just acted as an outrageously expensive HLV

^ This, and a lot of the other missions were merely sending crews up to the ISS on an outrageously- dangerous and expensive platform because it was the only one we had at the time.

Edited by GoSlash27
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21 minutes ago, GoSlash27 said:

^ This, and a lot of the other missions were merely sending crews up to the ISS on an outrageously- dangerous and expensive platform because it was the only one we had at the time.

Let’s not forget all those early flights that just launched commsats... <_<

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4 minutes ago, CatastrophicFailure said:

Let’s not forget all those early flights that just launched commsats... <_<

I would argue that almost none of the shuttle flights only did one thing. Sure, maybe they launched a commsat. But they were up there for a weeks and also did whatever the hell it is that people do in space stations. "Science", I guess they call it. How many shuttle missions didn't have experiments packed into the closets?

Of course if all you were doing was launching a commsat then the shuttle was really expensive overkill. But that was never all they were doing. That's why I say it seems to have been the ISS that really finished obsoleting the shuttle. Now we had a space station to do all the space stationy stuff and didn't need the shuttle for that.

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3 hours ago, Jaff said:

Ok realistically at some point during design they must have thought “what if one of these not turney offey things doesn’t behave” so why wasn’t there an option to get shot of them with adequate warning of something being not right? 

 

Granted if it went 100ft in the air there wouldn’t be much that could be done but challenger was a Fair way down range before things went wrong. I’d imagine light enough to blow the boosters away and maintain some sort of flight back to the floor 

To address your question in a bit more depth, this is all very hard to do. They couldn’t separate the boosters or the orbiter from the tank early, there was simply no procedure (“button”) to do so, the entire launch was controlled by the computer. There was no procedure, because the assembly couldn’t survive it. Like someone else said, everything was under an incredible amount of stress while the engines were running. Ever forget to check yo staging and have your running boosters come back and hit your core?

The orbiter too was extremely fragile, which seems like an odd thing to say, but most of the shuttle’s abort modes, such as they were, were limited by not overstressing the airframe. The RTLS (return to launch site) abort in particular was like something right out of Kerbal. If the shuttle lost one or more engines while the boosters were lit, it would have to continue downrange until the boosters were dropped, then continue downrange some more, then turn around, flying backwards, and burn towards Florida. This was catefully planned so that when the orbiter finally separated from the ET, the tank was down to 2% fuel. Any more and a successful separation was unlikely. If the shuttle lost all three engines while the boosters were running, it might be able to continue on until separation, but would be Lost anyway as the airframe couldn’t take reentry from that.

Now, in theory, they could have made a big, ejecting crew module, but this is really, really hard when there’s so much structure surrounding the cabin. There was a proposal to put the crew in basically a big space capsule in the cargo bay, or some such, but would have been so heavy and complicated it was deemed “not worth it.”

As it turns out, aborting from the side of a rocket in General is really really hard. 

4 minutes ago, mikegarrison said:

I would argue that almost none of the shuttle flights only did one thing. Sure, maybe they launched a commsat. But they were up there for a weeks and also did whatever the hell it is that people do in space stations. "Science", I guess they call it. How many shuttle missions didn't have experiments packed into the closets?

Of course if all you were doing was launching a commsat then the shuttle was really expensive overkill. But that was never all they were doing. That's why I say it seems to have been the ISS that really finished obsoleting the shuttle. Now we had a space station to do all the space stationy stuff and didn't need the shuttle for that.

Here’s part of the problem. Having that great big commsat in the cargo bay severely limits what station science you can do. It’s a huge compromise, either for the sat or the science. Now if we’d just have launched that second Skylab...

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