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#1100
by
edkyle99
on 05 Sep, 2015 23:49
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I'm convinced that, five years from now, we will all see clearly that Boeing has developed the best manned LEO spacecraft that has yet flown. Spend some time really studying the details of its design and you'll see what I mean.
- Ed Kyle
Well of course. It will be better than Vostok, Voskhod, Soyuz, Mercury and Gemini, and will be safer than Shuttle. All those were LEO-only spacecraft. Boeing's new spacecraft will be better than all of them for a variety of reasons. Apollo and Dragon OTOH were both designed as BOE spacecraft, not LEO-limited spacecraft.
It'll be better than Dragon too, IMO.
- Ed Kyle
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#1101
by
adrianwyard
on 06 Sep, 2015 00:30
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I'm convinced that, five years from now, we will all see clearly that Boeing has developed the best manned LEO spacecraft that has yet flown. Spend some time really studying the details of its design and you'll see what I mean.
- Ed Kyle
Well of course. It will be better than Vostok, Voskhod, Soyuz, Mercury and Gemini, and will be safer than Shuttle. All those were LEO-only spacecraft. Boeing's new spacecraft will be better than all of them for a variety of reasons. Apollo and Dragon OTOH were both designed as BOE spacecraft, not LEO-limited spacecraft.
It'll be better than Dragon too, IMO.
- Ed Kyle
Care to put together a list of capabilities, comparing Starliner with Dragon 2?
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#1102
by
obi-wan
on 06 Sep, 2015 02:52
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I'm convinced that, five years from now, we will all see clearly that Boeing has developed the best manned LEO spacecraft that has yet flown. Spend some time really studying the details of its design and you'll see what I mean.
- Ed Kyle
Well of course. It will be better than Vostok, Voskhod, Soyuz, Mercury and Gemini, and will be safer than Shuttle. All those were LEO-only spacecraft. Boeing's new spacecraft will be better than all of them for a variety of reasons. Apollo and Dragon OTOH were both designed as BOE spacecraft, not LEO-limited spacecraft.
It'll be better than Dragon too, IMO.
- Ed Kyle
You know, I really hate this kind of discussion, turning the whole thing into "my NFL team is better than your NFL team" level of discourse. Both vehicles are still in detailed design, fabrication is at its early stages, and neither contractor has been free enough with details to permit more than educated guesses as to what the final systems will be like. I wish both contractors full funding and the best of luck, and when they're both flying we can all get into "Mac vs. PCs" religious arguments... :-)
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#1103
by
arachnitect
on 06 Sep, 2015 04:36
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Does anyone know how they're sealing the seam between the upper and lower halves of the CM clam shell? Seems to be a failure mode looking for a time to happen.
How is that any different than joining these to modules or attaching the bulkhead? Or joining the Spacelab support module to the experiment module and after installing the experiment racks, attaching the endcone?
They didn't/don't have to survive re-entry, or potentially keep water out after doing so - especially if the chutes take you for a ride in rough seas. Potential leak prevention is why mariners try to minimize the number and size of hull penetrations. This appears larger than the rest of Starliner's other penetrations combined, and then some. Excrement happens.
The windows and hatches would fail long before the circumferential seam, it's got more bolts in it than all of Bristol.
Yes, it could fail, but so could lots of other things.
BTW, if a Starliner ever ends up in the ocean, I bet they'll write it off.
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#1104
by
edkyle99
on 06 Sep, 2015 04:42
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Care to put together a list of capabilities, comparing Starliner with Dragon 2?
In my mind, it isn't about capabilities, since both are being designed to meet the same requirements. It is about the overriding concepts behind the designs. It is about reliability. It is about ease of use. Etc.
CST-100 will ride on a more reliable, more proven launch vehicle. That is my first point of comparison.
CST-100 puts the big abort/retro motors behind the crew in the service module rather than hang them around the crew on the outside of the capsule. The Boeing design is conventional, and based on previously flown spacecraft design. The SpaceX design is unconventional and its concept is unproven (especially during reentry). That's No. 2.
CST-100 will be recovered on land and its design allows for easier dis-assembly for refurbishment than Dragon. Dragon is dropping into water. If SpaceX does develop a land-recovery variant, it will use thrusters to land - another unproven method with crews. That's No. 3.
Since it doesn't bring back the service module, CST-100 capsule should weigh less than Dragon 2 for reentry and landing. I see that as a plus. It means less heating, smaller parachutes, or less stress on them, etc.
I don't doubt that SpaceX can successfully develop a crewed spacecraft. I just believe that its design has more chances for development trouble than the more conservative CST-100.
- Ed Kyle
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#1105
by
Comga
on 06 Sep, 2015 05:10
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I'm convinced that, five years from now, we will all see clearly that Boeing has developed the best manned LEO spacecraft that has yet flown. Spend some time really studying the details of its design and you'll see what I mean.
- Ed Kyle
Well of course. It will be better than Vostok, Voskhod, Soyuz, Mercury and Gemini, and will be safer than Shuttle. All those were LEO-only spacecraft. Boeing's new spacecraft will be better than all of them for a variety of reasons. Apollo and Dragon OTOH were both designed as BOE spacecraft, not LEO-limited spacecraft.
It'll be better than Dragon too, IMO.
- Ed Kyle
You know, I really hate this kind of discussion, turning the whole thing into "my NFL team is better than your NFL team" level of discourse. Both vehicles are still in detailed design, fabrication is at its early stages, and neither contractor has been free enough with details to permit more than educated guesses as to what the final systems will be like. I wish both contractors full funding and the best of luck, and when they're both flying we can all get into "Mac vs. PCs" religious arguments... :-)
I agree
None of these posts have anything to do with the CST-100 announcement. They just pollute the thread.
I am sure Boeing can build a reliable system to the customer's requirements given a hefty budget.
I am sure Boeing could have found a zippier name that Starliner, but it really doesn't matter.
No one can be sure if either Dragon or CST-100 will fly more than a handful of times. That will be the ultimate arbiter of "better" IMHO. That's not only a technical issue, although everyone if free to prefer one to another for reasons technical and non-technical.
But for now we have some nice CGI of the CST-100 being assembled, snappy videos, photos of some cool hardware, and big graphics on a building with significant heritage.
Can we go with that?
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#1106
by
kch
on 06 Sep, 2015 05:59
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... if a Starliner ever ends up in the ocean, I bet they'll write it off.
Not sure why -- would it not then be an Oceanliner?
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#1107
by
baldusi
on 06 Sep, 2015 12:33
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Care to put together a list of capabilities, comparing Starliner with Dragon 2?
In my mind, it isn't about capabilities, since both are being designed to meet the same requirements. It is about the overriding concepts behind the designs. It is about reliability. It is about ease of use. Etc.
CST-100 will ride on a more reliable, more proven launch vehicle. That is my first point of comparison.
CST-100 puts the big abort/retro motors behind the crew in the service module rather than hang them around the crew on the outside of the capsule. The Boeing design is conventional, and based on previously flown spacecraft design. The SpaceX design is unconventional and its concept is unproven (especially during reentry). That's No. 2.
CST-100 will be recovered on land and its design allows for easier dis-assembly for refurbishment than Dragon. Dragon is dropping into water. If SpaceX does develop a land-recovery variant, it will use thrusters to land - another unproven method with crews. That's No. 3.
Since it doesn't bring back the service module, CST-100 capsule should weigh less than Dragon 2 for reentry and landing. I see that as a plus. It means less heating, smaller parachutes, or less stress on them, etc.
I don't doubt that SpaceX can successfully develop a crewed spacecraft. I just believe that its design has more chances for development trouble than the more conservative CST-100.
- Ed Kyle
Ed, I believe you are mixing up "risky" vs "worse" concepts.
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#1108
by
Jim
on 06 Sep, 2015 12:58
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They didn't/don't have to survive re-entry, or potentially keep water out after doing so - especially if the chutes take you for a ride in rough seas. Potential leak prevention is why mariners try to minimize the number and size of hull penetrations. This appears larger than the rest of Starliner's other penetrations combined, and then some. Excrement happens.
What does "survive re-entry" have to do with it? TPS takes care of the entry environment and not the joint. As far as loads, entry is benign, launch is worse. Keeping water out is not a problem, holding air in is harder. Air pressure will be the source of the largest loads on the CST-100 joint. CST-100 has a nice circular joint and the loads are in tension. Anyways for Spacehab, using a flat bulkhead is going see more loads from the pressure inside and the module center joint is going to see nosewheel slap down loads. The modules never leaked air.
This is a non-issue and excrement does not apply here.
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#1109
by
edkyle99
on 06 Sep, 2015 15:09
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Ed, I believe you are mixing up "risky" vs "worse" concepts.
As far as I'm concerned, when it comes to human space flight, less risk = better, more risk = worse.
- Ed Kyle
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#1110
by
woods170
on 06 Sep, 2015 16:09
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Ed, I believe you are mixing up "risky" vs "worse" concepts.
As far as I'm concerned, when it comes to human space flight, less risk = better, more risk = worse.
- Ed Kyle
Agreed. But you equal new technology to higher risk. And that is just plain silly. With such an attitude mankind never would have progressed beyond the stone-age.
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#1111
by
adrianwyard
on 06 Sep, 2015 16:48
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It's certainly true that to ignore the risk-tolerance of the current culture/customer would be foolhardy. Boeing evidently gauged NASA (CCP)'s risk-tolerance vs price-sensitivity correctly in this regard. And it sounds like Ed thinks they're making smart judgements. Imagine the fall-out if NASA had picked two whizz-bang unproven designs that both failed and/or killed people.
But that risk-sensitivity and willingness to try new technologies can change. It was surely different during the space race and Apollo program. Back then Gerst would not have had the option of preferring "a spacecraft design that is fairly mature in design" as everything was new. I think some here - me included - long for the return of that Apollo era gung-ho attitude to spaceflight. The right path forward is probably somewhere between the two extremes.
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#1112
by
rcoppola
on 06 Sep, 2015 17:18
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Both Starliner and Dragon will be highly complex and capable vehicles. There's no question that with Boeing's heritage and vast resources and expertise, they will provide a best-in-class space transportation vehicle. It is a well-understood design in the hands of some of the most talented and experienced designers and project managers on the planet. I have little doubt it will be successful and importantly, IMO, allows more risk to be present in the program because...
Dragon is another beast all together and needs to be allowed to fly its' freak flag freely. Which is such a joy to watch.
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#1113
by
adrianwyard
on 06 Sep, 2015 18:16
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Setting Boeing's more conservative, lower-risk design aside the for moment, Gerst did also say:
CST-100 was “the strongest of all three proposals in both mission suitability and past performance." and "Boeing’s system offers the most useful inherent capabilities for operational flexibility in trading cargo and crew for individual missions.
So compared to Dragon 2, Starliner is:
1] More suitable to the mission.
2] More useful/capable due to its ability to trade cargo for crew.
Can anyone familiar with the Starliner design add to that list or flesh these out?
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#1114
by
Endeavour_01
on 06 Sep, 2015 18:41
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I agree with rcoppola. Both Dragon and Starliner will be amazing spacecraft. I have no doubt that the fine engineers, computer programmers, and other employees at Boeing and SpaceX will deliver quality products that we will watch launch into space for many years to come.
It will be fun to see a friendly competition between the two.
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#1115
by
jak Kennedy
on 06 Sep, 2015 19:05
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Care to put together a list of capabilities, comparing Starliner with Dragon 2?
In my mind, it isn't about capabilities, since both are being designed to meet the same requirements. It is about the overriding concepts behind the designs. It is about reliability. It is about ease of use. Etc.
CST-100 will ride on a more reliable, more proven launch vehicle. That is my first point of comparison.
CST-100 puts the big abort/retro motors behind the crew in the service module rather than hang them around the crew on the outside of the capsule. The Boeing design is conventional, and based on previously flown spacecraft design. The SpaceX design is unconventional and its concept is unproven (especially during reentry). That's No. 2.
CST-100 will be recovered on land and its design allows for easier dis-assembly for refurbishment than Dragon. Dragon is dropping into water. If SpaceX does develop a land-recovery variant, it will use thrusters to land - another unproven method with crews. That's No. 3.
Since it doesn't bring back the service module, CST-100 capsule should weigh less than Dragon 2 for reentry and landing. I see that as a plus. It means less heating, smaller parachutes, or less stress on them, etc.
I don't doubt that SpaceX can successfully develop a crewed spacecraft. I just believe that its design has more chances for development trouble than the more conservative CST-100.
- Ed Kyle
I must be missing something and yes probably I am but isn't the Atlas V going away? I thought it was going to be updated?
Point 2, I thought abort motors were typically on a tower above the crew.
Point 3, if they use thrusters to land then it will be a proven method, ha!
Point 4, The Dragon returns the service module?
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#1116
by
billh
on 06 Sep, 2015 20:56
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I must be missing something and yes probably I am but isn't the Atlas V going away? I thought it was going to be updated?
Point 2, I thought abort motors were typically on a tower above the crew.
Point 3, if they use thrusters to land then it will be a proven method, ha!
Point 4, The Dragon returns the service module?
The restriction on RD-180 is for military and national security launches, I believe. ULA could continue to fly them for NASA. I haven't heard anyone say definitively, but I assume it will be around long enough to complete the commercial crew contract. Has anyone heard how Boeing intends to address that?
Point 2: Past capsule designs have done so, but both CST-100 and Dragon propose a pusher escape system.
Point 3:
Point 4: For Dragon, the "service module" is integral with the capsule. The trunk section provides only solar cells and radiators. CST-100 has a jettisonable service module that also includes the abort motors.
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#1117
by
Ike17055
on 06 Sep, 2015 22:01
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I'm convinced that, five years from now, we will all see clearly that Boeing has developed the best manned LEO spacecraft that has yet flown. Spend some time really studying the details of its design and you'll see what I mean.
- Ed Kyle
Well of course. It will be better than Vostok, Voskhod, Soyuz, Mercury and Gemini, and will be safer than Shuttle. All those were LEO-only spacecraft. Boeing's new spacecraft will be better than all of them for a variety of reasons. Apollo and Dragon OTOH were both designed as BOE spacecraft, not LEO-limited spacecraft.
It'll be better than Dragon too, IMO.
- Ed Kyle
You know, I really hate this kind of discussion, turning the whole thing into "my NFL team is better than your NFL team" level of discourse. Both vehicles are still in detailed design, fabrication is at its early stages, and neither contractor has been free enough with details to permit more than educated guesses as to what the final systems will be like. I wish both contractors full funding and the best of luck, and when they're both flying we can all get into "Mac vs. PCs" religious arguments... :-)
Well, the forums are full of SpaceX enthusiasts lecturing everyone about how their craft is so much better, and their company is so much better...but as soon as someone On this thread expresses their preference for Boeing's conservative approach, the griping starts. And there will likely be more. Many of us wish both contractors success, but there are good reasons Boeing and its project enjoy great confidence among NASA decision makers. And It should be ok to say so.
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#1118
by
Ike17055
on 06 Sep, 2015 22:11
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It's certainly true that to ignore the risk-tolerance of the current culture/customer would be foolhardy.
I think some here - me included - long for the return of that Apollo era gung-ho attitude to spaceflight. The right path forward is probably somewhere between the two extremes.
Apollo was far from "gung-ho." Except perhaps in the rush to lauch an inadequately prepared and incompletely tested "Apollo 1." That failure to adhere to the strictest standards, to give in to schedule pressure, not risk-averseness, is what nearly derailed the program for good.
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#1119
by
jak Kennedy
on 06 Sep, 2015 22:14
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I must be missing something and yes probably I am but isn't the Atlas V going away? I thought it was going to be updated?
Point 2, I thought abort motors were typically on a tower above the crew.
Point 3, if they use thrusters to land then it will be a proven method, ha!
Point 4, The Dragon returns the service module?
The restriction on RD-180 is for military and national security launches, I believe. ULA could continue to fly them for NASA. I haven't heard anyone say definitively, but I assume it will be around long enough to complete the commercial crew contract. Has anyone heard how Boeing intends to address that?
Point 2: Past capsule designs have done so, but both CST-100 and Dragon propose a pusher escape system.
Point 3:
Point 4: For Dragon, the "service module" is integral with the capsule. The trunk section provides only solar cells and radiators. CST-100 has a jettisonable service module that also includes the abort motors.
I was thinking more about ULA's new Vulcan rocket. And yes I don't recall ULA etc stating when a changeover for commercial crew could occur but would they really fly two different rockets for long.
Point 2 exactly my point.
Point 4 edkyle99 perhaps could explain why smaller chutes are better. Doesn't Soyuz use just one main chute?
