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#260
by
ulm_atms
on 28 May, 2022 23:03
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....and no other manned spacecraft has ever designed it to be detachable.....
Soyuz and Shenzhou both drop the heatshield before landing.
Please correct me if I am wrong, but my understanding is that those two dropping the heat shield was required due to the last second retro rockets that cushion the landing. Water landings can use water so heat shield can stay. Starliner uses airbags....so heat shield has to go.
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#261
by
Dalhousie
on 28 May, 2022 23:07
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....and no other manned spacecraft has ever designed it to be detachable.....
Soyuz and Shenzhou both drop the heatshield before landing.
And Mercury's heatshield separated just before landing, although remained attached to the main body at the end of the landing bag or skirt.
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#262
by
SoftwareDude
on 28 May, 2022 23:16
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I’m sure this has been hashed and rehashed, but this picture vividly illustrates why I would never fly on this spacecraft. Yes, all space vehicles have a number of deployments that must go perfectly for any crew to survive. But the engineering design decision to return to land, necessitating the requirement to make the heat shield completely detachable, is I believe, a bridge too far. Especially when you consider a very heavy service module also must be jettisoned minutes before that heat shield is needed to protect the occupants from a now-unavoidable fiery plunge into the exponentially dense lower atmosphere. I’m reminded of the worry over Friendship 7’s heat shield before John Glenn rode it in on America’s first manned reentry, and now the fuss over a recent Dragon heat shield failing a pre-qualification test. The heat shield is such a critical part, and no other manned spacecraft has ever designed it to be detachable; this Boeing design just does not inspire confidence, IMHO.
Yes, Starliner has a lot of things that have to go right, but all these capsule transportation systems have white knuckle moments. Watching Dragon has its share of, it has to work or else, moments. Can the capsule design ever be considered a truly reliable crew transportation system? Perhaps Starship is a step forward in that regard. I do agree that Starliner design seems at least to have some unnecessary risks that could be designed out.
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#263
by
Jim
on 29 May, 2022 13:12
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I do agree that Starliner design seems at least to have some unnecessary risks that could be designed out.
What makes you think they are? And what qualifies you to have such an opinion?
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#264
by
Jim
on 29 May, 2022 13:13
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. Can the capsule design ever be considered a truly reliable crew transportation system?
Yes, it is.
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#265
by
Jim
on 29 May, 2022 13:14
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I’m sure this has been hashed and rehashed, but this picture vividly illustrates why I would never fly on this spacecraft. Yes, all space vehicles have a number of deployments that must go perfectly for any crew to survive. But the engineering design decision to return to land, necessitating the requirement to make the heat shield completely detachable, is I believe, a bridge too far. Especially when you consider a very heavy service module also must be jettisoned minutes before that heat shield is needed to protect the occupants from a now-unavoidable fiery plunge into the exponentially dense lower atmosphere. I’m reminded of the worry over Friendship 7’s heat shield before John Glenn rode it in on America’s first manned reentry, and now the fuss over a recent Dragon heat shield failing a pre-qualification test. The heat shield is such a critical part, and no other manned spacecraft has ever designed it to be detachable; this Boeing design just does not inspire confidence, IMHO.
Non problem and wrong opinion.
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#266
by
edkyle99
on 29 May, 2022 13:59
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Can the capsule design ever be considered a truly reliable crew transportation system? Perhaps Starship is a step forward in that regard. I do agree that Starliner design seems at least to have some unnecessary risks that could be designed out.
If you worry about the capsule heat shields, wait until you start to understand the risks of the much larger, more complicated Starship heat shield. They've had tiles popping off while the thing is standing on the pad. As for the capsules, just look at the history of Mercury, Gemini, Apollo, Vostok, Voskhod, Soyuz, Shenzhou, Dragons 1 and 2, and now Starliner. The reentry loss took place on Shuttle, with a Starship-type head shield.
- Ed Kyle
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#267
by
Lee Jay
on 29 May, 2022 14:17
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Can the capsule design ever be considered a truly reliable crew transportation system? Perhaps Starship is a step forward in that regard. I do agree that Starliner design seems at least to have some unnecessary risks that could be designed out.
If you worry about the capsule heat shields, wait until you start to understand the risks of the much larger, more complicated Starship heat shield. They've had tiles popping off while the thing is standing on the pad. As for the capsules, just look at the history of Mercury, Gemini, Apollo, Vostok, Voskhod, Soyuz, Shenzhou, Dragons 1 and 2, and now Starliner. The reentry loss took place on Shuttle, with a Starship-type head shield.
- Ed Kyle
No, the entry loss was caused by foam hitting hollow RCC on ascent, not by the loss of tiles fastened to substructure. That's not Starship like at all.
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#268
by
ppb
on 29 May, 2022 15:35
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Can the capsule design ever be considered a truly reliable crew transportation system? Perhaps Starship is a step forward in that regard. I do agree that Starliner design seems at least to have some unnecessary risks that could be designed out.
If you worry about the capsule heat shields, wait until you start to understand the risks of the much larger, more complicated Starship heat shield. They've had tiles popping off while the thing is standing on the pad. As for the capsules, just look at the history of Mercury, Gemini, Apollo, Vostok, Voskhod, Soyuz, Shenzhou, Dragons 1 and 2, and now Starliner. The reentry loss took place on Shuttle, with a Starship-type head shield.
- Ed Kyle
No, the entry loss was caused by foam hitting hollow RCC on ascent, not by the loss of tiles fastened to substructure. That's not Starship like at all.
That was the proximate cause—the root cause was the engineering design decision to place a giant cryogenic tank right next to the orbiter and its fragile heat shield. Murphy will always find a way, no matter how much of a “non-problem” mitigation efforts appear to render it.
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#269
by
mandrewa
on 29 May, 2022 17:30
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Can the capsule design ever be considered a truly reliable crew transportation system? Perhaps Starship is a step forward in that regard. I do agree that Starliner design seems at least to have some unnecessary risks that could be designed out.
If you worry about the capsule heat shields, wait until you start to understand the risks of the much larger, more complicated Starship heat shield. They've had tiles popping off while the thing is standing on the pad. As for the capsules, just look at the history of Mercury, Gemini, Apollo, Vostok, Voskhod, Soyuz, Shenzhou, Dragons 1 and 2, and now Starliner. The reentry loss took place on Shuttle, with a Starship-type head shield.
- Ed Kyle
It's my hope that before a human being is launched on Starship that there will have already been a lot of flights of the Starship. My hope and expectation is that they will do enough uncrewed flights to identify and then solve many of the likely issues that the Starship may have before they put people on it.
If SpaceX does this then that will put Starship in a different category than Mercury, Gemini, Apollo, Vostok, Voskhod, Soyuz, Shenzhou, Starliner, and Orion, all of which were launched or will launch with crews for the first time from a very limited basis of experience.
Now that doesn't mean the Starship will be
safe. Even if the Starship has been launched successfully 100 times in a row then the 95% interval will still pretty broad
(What is it called? Not the Lewis Point Estimate but the other? And where is your website? I just went to look for it and it is not there.) But this will be a huge improvement over what has been the normal standard before now.
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#270
by
arachnitect
on 29 May, 2022 18:23
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Can the capsule design ever be considered a truly reliable crew transportation system? Perhaps Starship is a step forward in that regard. I do agree that Starliner design seems at least to have some unnecessary risks that could be designed out.
If you worry about the capsule heat shields, wait until you start to understand the risks of the much larger, more complicated Starship heat shield. They've had tiles popping off while the thing is standing on the pad. As for the capsules, just look at the history of Mercury, Gemini, Apollo, Vostok, Voskhod, Soyuz, Shenzhou, Dragons 1 and 2, and now Starliner. The reentry loss took place on Shuttle, with a Starship-type head shield.
- Ed Kyle
It's my hope that before a human being is launched on Starship that there will have already been a lot of flights of the Starship. My hope and expectation is that they will do enough uncrewed flights to identify and then solve many of the likely issues that the Starship may have before they put people on it.
If SpaceX does this then that will put Starship in a different category than Mercury, Gemini, Apollo, Vostok, Voskhod, Soyuz, Shenzhou, Starliner, and Orion, all of which were launched or will launch with crews for the first time from a very limited basis of experience.
Now that doesn't mean the Starship will be safe. Even if the Starship has been launched successfully 100 times in a row then the 95% interval will still pretty broad (What is it called? Not the Lewis Point Estimate but the other? And where is your website? I just went to look for it and it is not there.) But this will be a huge improvement over what has been the normal standard before now.
FYI:
https://forum.nasaspaceflight.com/index.php?topic=56087.0
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#271
by
kevinof
on 29 May, 2022 18:53
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I’m sure this has been hashed and rehashed, but this picture vividly illustrates why I would never fly on this spacecraft. Yes, all space vehicles have a number of deployments that must go perfectly for any crew to survive. But the engineering design decision to return to land, necessitating the requirement to make the heat shield completely detachable, is I believe, a bridge too far. Especially when you consider a very heavy service module also must be jettisoned minutes before that heat shield is needed to protect the occupants from a now-unavoidable fiery plunge into the exponentially dense lower atmosphere. I’m reminded of the worry over Friendship 7’s heat shield before John Glenn rode it in on America’s first manned reentry, and now the fuss over a recent Dragon heat shield failing a pre-qualification test. The heat shield is such a critical part, and no other manned spacecraft has ever designed it to be detachable; this Boeing design just does not inspire confidence, IMHO.
Non problem and wrong opinion.
Opinions can't be wrong Jim. They are his/her opinions and while you might not agree , he/she is allowed to have them and they don't always have to match yours.
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#272
by
Lee Jay
on 29 May, 2022 20:10
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Opinions can't be wrong Jim. They are his/her opinions and while you might not agree , he/she is allowed to have them and they don't always have to match yours.
A too-often held wrong statement. Opinions can be wrong if they are about objective reality. Lots of people have wrong "opinions" - flat Earth, creationism, COVID vaccines have microchips in them, etc.
You're only entitled to have opinions about subjective subjects, not objective ones.
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#273
by
kevinof
on 29 May, 2022 20:25
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Opinions can't be wrong Jim. They are his/her opinions and while you might not agree , he/she is allowed to have them and they don't always have to match yours.
A too-often held wrong statement. Opinions can be wrong if they are about objective reality. Lots of people have wrong "opinions" - flat Earth, creationism, COVID vaccines have microchips in them, etc.
You're only entitled to have opinions about subjective subjects, not objective ones.
Nonsense and a rubbish argument. The earth will never be flat, it's an impossibility so it's just wrong to claim it is, but in years to come we could see an issue with the starliner system ( I think it's a fine engineering solution btw) which renders the engineering questionable. So yes his opinion is valid and can't be dismissed out of hand.
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#274
by
SoftwareDude
on 30 May, 2022 00:24
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There was a comic strip by a man named Rube Goldberg where he drew cartoons about ridiculously complicated machines; if you've played the children's game "Mousetrap" then you know what I'm talking about. A "Rube Goldberg Machine" is an entertaining contraption composed entirely of lots of single points of failure. Rube Goldberg machines are a "bad smell" when it comes down to design.
How bad does Starliner smell? It is a matter of opinion.
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#275
by
Roy_H
on 30 May, 2022 01:13
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I'm not regular here, and I thank those who answered my previous question from nasaspaceflight article. Now I have another from the latest Starliner article:
"The spacecraft experienced a temporary loss of signal and communication with the ground during the re-entry phase as an envelope of ionized air forms around the spacecraft due to the extreme heat as temperatures can rise to 1,930° C (3,500° F). Approximately four minutes before touchdown, Starliner’s heat shield was jettisoned, followed by the deployment of the drogue parachutes.
These help to slow the spacecraft down, with the drogues making way for the three main parachutes about one minute and 10 seconds later. Just two minutes and 49 seconds before touchdown, rotation handles deployed which aligned the Starliner to land perpendicularly on the land. Shortly after, its base heat shield was separated, followed by the inflation of airbags which cushioned the spacecraft as it landed at the White Sands Space Harbor in New Mexico."
So there are two heatshield ejections? Is the second a frame for the heatshield or is it a second layer of heat shielding? Please explain because it does not make sense to me. One jettison (I would think after parachute deployment best) only to be required.
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#276
by
dccraven
on 30 May, 2022 01:55
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There is an forward heat shield and a base heat shield, therefore two heat shields are ejected after the craft passes through reentry.
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#277
by
woods170
on 30 May, 2022 08:17
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<snipped the embedded image, which is not allowed at NSF>
I’m sure this has been hashed and rehashed, but this picture vividly illustrates why I would never fly on this spacecraft. Yes, all space vehicles have a number of deployments that must go perfectly for any crew to survive. But the engineering design decision to return to land, necessitating the requirement to make the heat shield completely detachable, is I believe, a bridge too far. Especially when you consider a very heavy service module also must be jettisoned minutes before that heat shield is needed to protect the occupants from a now-unavoidable fiery plunge into the exponentially dense lower atmosphere.
I will casually point out that Soyuz has been doing this very thing (dropping the heat shield shortly before touchdown on land) successfully since the 1960s. Shenzou has been doing the same thing since the early 2000s.
It is nothing new, it is fully understood and most definitely NOT an engineering bridge too far. Neither is jettisoning a service module btw, which has been done by Gemini, Apollo, Soyuz and Shenzou. And both cargo Dragon and Crew Dragon do something very similar: they jettison their trunks to expose their heat shields.
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#278
by
rpapo
on 30 May, 2022 09:11
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<snipped the embedded image, which is not allowed at NSF>
I’m sure this has been hashed and rehashed, but this picture vividly illustrates why I would never fly on this spacecraft. Yes, all space vehicles have a number of deployments that must go perfectly for any crew to survive. But the engineering design decision to return to land, necessitating the requirement to make the heat shield completely detachable, is I believe, a bridge too far. Especially when you consider a very heavy service module also must be jettisoned minutes before that heat shield is needed to protect the occupants from a now-unavoidable fiery plunge into the exponentially dense lower atmosphere.
I will casually point out that Soyuz has been doing this very thing (dropping the heat shield shortly before touchdown on land) successfully since the 1960s. Shenzou has been doing the same thing since the early 2000s.
It is nothing new, it is fully understood and most definitely NOT an engineering bridge too far. Neither is jettisoning a service module btw, which has been done by Gemini, Apollo, Soyuz and Shenzou. And both cargo Dragon and Crew Dragon do something very similar: they jettison their trunks to expose their heat shields.
And, from all that has been said here, NASA would be extremely nervous if the Dragon or Starliner heat shields had not been covered by their respective trunk and service module until just before reentry. The chance of damage to the heat shield due to micro-meteoroids or orbital debris is too great, in their opinion. They would rather see the heat shield entirely covered by something until the last moment.
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#279
by
clongton
on 30 May, 2022 12:08
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I do agree that Starliner design seems at least to have some unnecessary risks that could be designed out.
<snip> </snip> And what qualifies you to have such an opinion?
No one needs to be qualified to have an opinion Jim. You may not agree with his opinion and that's ok, but he has a right to have one.
I value your opinions very highly and I rarely disagree. When I do it is never because you stated your opinion. That's your right, as it is his.