Author Topic: Commercial Crew Program (CCP-CTS-CCT) Requirements  (Read 139748 times)

Offline DaveH62

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Re: Commercial Crew Program (CCP-CTS-CCT) Requirements
« Reply #100 on: 08/25/2011 04:16 pm »
Jorge


I don't know what you mean by "flight system updates".

I thought electronic avionics were added around 2000, and they switched to all digital displays for piloting the Shuttle. Perhaps not for docking though.

Offline Jorge

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Re: Commercial Crew Program (CCP-CTS-CCT) Requirements
« Reply #101 on: 08/25/2011 04:32 pm »
I don't know what you mean by "flight system updates".
I thought electronic avionics were added around 2000, and they switched to all digital displays for piloting the Shuttle. Perhaps not for docking though.

The digital displays replaced the CRTs and steam gauges, not the windows.
« Last Edit: 08/25/2011 04:32 pm by Jorge »
JRF

Offline simonbp

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Re: Commercial Crew Program (CCP-CTS-CCT) Requirements
« Reply #102 on: 08/25/2011 07:44 pm »
This thread just further validates my opinion that the sooner we get CST-100 and Biglow going NASA will still be worrying about window placement, fiber optics, and "piloting".

Indeed; what a silly requirement.

In the entire history of ISS (and Shuttle-Mir), did an orbiter ever dock solely by eye? Indeed, has any US vehicle performed such a maneuver since ASTP?

Modern cameras are so cheap and light that it's lighter (and safer!) to just put on a bunch of redundant cameras on the vehicle...
« Last Edit: 08/25/2011 07:47 pm by simonbp »

Offline DaveH62

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Re: Commercial Crew Program (CCP-CTS-CCT) Requirements
« Reply #103 on: 08/25/2011 08:07 pm »
This thread just further validates my opinion that the sooner we get CST-100 and Biglow going NASA will still be worrying about window placement, fiber optics, and "piloting".

Indeed; what a silly requirement.

In the entire history of ISS (and Shuttle-Mir), did an orbiter ever dock solely by eye? Indeed, has any US vehicle performed such a maneuver since ASTP?

Modern cameras are so cheap and light that it's lighter (and safer!) to just put on a bunch of redundant cameras on the vehicle...
I think the larger issue is not camera versus window. Obviously you can see better with a camera properly located on the docking ports in the front of the capsule. An HD camera will provide a much better view of the docking process than any window, unless the hatch is translucent.
The issue is that procurement and design polices that are driven by legacy development systems and do not allow for building on new tools and systems, you will always favor incumbents, slow development cycles and costly and late products.
If anyone has an exception to this rule I would be fascinated to know more.

Offline corrodedNut

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Re: Commercial Crew Program (CCP-CTS-CCT) Requirements
« Reply #104 on: 08/26/2011 02:52 am »
I don't have problem with requiring windows, cameras can break, this is space flight after all, "$hit happens".

The problem I have is with the exclusion of hatch windows.  What about being in a hatch makes a window unsuitable for piloting tasks?  The Soyuz "forward porthole" looks hardly bigger than a hatch window, and I suspect that if it wasn't for the nature of the probe-and-drogue mechanism there would be a centerline hatch window instead, and it would be used for "piloting tasks'' in a similar fashion.

Maybe I'm all wrong, and someone can explain why hatch windows are only good for seeing the close-out crew give you the "thumbs up".
« Last Edit: 08/26/2011 02:53 am by corrodedNut »

Offline Jim

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Re: Commercial Crew Program (CCP-CTS-CCT) Requirements
« Reply #105 on: 08/26/2011 03:00 am »

Maybe I'm all wrong, and someone can explain why hatch windows are only good for seeing the close-out crew give you the "thumbs up".

They aren't forward facing

Offline HMXHMX

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Re: Commercial Crew Program (CCP-CTS-CCT) Requirements
« Reply #106 on: 08/26/2011 03:02 am »

Maybe I'm all wrong, and someone can explain why hatch windows are only good for seeing the close-out crew give you the "thumbs up".

They aren't forward facing

The hatch window in the iLIDS would be. 

Offline corrodedNut

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Re: Commercial Crew Program (CCP-CTS-CCT) Requirements
« Reply #107 on: 08/26/2011 03:10 am »

Maybe I'm all wrong, and someone can explain why hatch windows are only good for seeing the close-out crew give you the "thumbs up".

They aren't forward facing

Yeah, I was getting a little cute with that line. Ditto what HMXHMX said, cause "3.10.14.7 The CTS shall provide a window on all sealable hatches..."

Offline Ronsmytheiii

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Re: Commercial Crew Program (CCP-CTS-CCT) Requirements
« Reply #108 on: 08/26/2011 03:25 am »

Indeed; what a silly requirement.

In the entire history of ISS (and Shuttle-Mir), did an orbiter ever dock solely by eye? Indeed, has any US vehicle performed such a maneuver since ASTP?

Yes, just like the lack of a LAS use on Apollo showed that including it as a requirement on shuttle as silly.....

Just because a safety system was not needed previously does not mean it is silly or frivolous at all.

Offline Robotbeat

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Re: Commercial Crew Program (CCP-CTS-CCT) Requirements
« Reply #109 on: 08/26/2011 04:39 am »

Indeed; what a silly requirement.

In the entire history of ISS (and Shuttle-Mir), did an orbiter ever dock solely by eye? Indeed, has any US vehicle performed such a maneuver since ASTP?

Yes, just like the lack of a LAS use on Apollo showed that including it as a requirement on shuttle as silly.....

Just because a safety system was not needed previously does not mean it is silly or frivolous at all.
Just because the word "safety" is used doesn't mean it's actually essential for safety. NASA can make it so that every single bolt must have a stack of pages written about it a foot thick. In the name of safety. If they choose.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline manboy

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Re: Commercial Crew Program (CCP-CTS-CCT) Requirements
« Reply #110 on: 08/26/2011 08:28 am »

Indeed; what a silly requirement.

In the entire history of ISS (and Shuttle-Mir), did an orbiter ever dock solely by eye? Indeed, has any US vehicle performed such a maneuver since ASTP?

Yes, just like the lack of a LAS use on Apollo showed that including it as a requirement on shuttle as silly.....

Just because a safety system was not needed previously does not mean it is silly or frivolous at all.
Just because the word "safety" is used doesn't mean it's actually essential for safety. NASA can make it so that every single bolt must have a stack of pages written about it a foot thick. In the name of safety. If they choose.
Or a poorly thought out safety requirement could doom the crew, as with Apollo 1.
"Cheese has been sent into space before. But the same cheese has never been sent into space twice." - StephenB

Offline Ronsmytheiii

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Re: Commercial Crew Program (CCP-CTS-CCT) Requirements
« Reply #111 on: 08/26/2011 01:16 pm »
Just because the word "safety" is used doesn't mean it's actually essential for safety. NASA can make it so that every single bolt must have a stack of pages written about it a foot thick. In the name of safety. If they choose.

As has already been stated before, there were real concrete reasons for needing a window in the docking process in the first place.

Just because the almighty SpaceX does not have a window does not mean it is not needed.

Offline Robotbeat

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Re: Commercial Crew Program (CCP-CTS-CCT) Requirements
« Reply #112 on: 08/26/2011 02:08 pm »
...
Just because the almighty SpaceX does not have a window does not mean it is not needed.
Of course not. And just because NASA has "always done it that way" does not mean it's necessarily the only way it can be done or even the safest.

As Jorge said, a periscope (or something like it) would probably meet the intent of the requirement, if not the word. That's what I'm concerned about: the way the safety "requirement" is worded becoming more important than the actual safeness inferred by such a feature. The possibility that equivalently-safe ways of doing the same thing will be excluded because of red-tape instead of sound systems engineering reasons. There has to be flexibility on the exact way of accomplishing equivalent levels of safety or commercial crew will not be affordable or on schedule.

It'd be ironic if a Soyuz-type approach (i.e. periscope) not being allowed for commercial crew leads to delays causing NASA to continue to be reliant on Soyuz. Ironic, not surprising.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Ronsmytheiii

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Re: Commercial Crew Program (CCP-CTS-CCT) Requirements
« Reply #113 on: 08/26/2011 02:27 pm »
Of course not. And just because NASA has "always done it that way" does not mean it's necessarily the only way it can be done or even the safest.

As Jorge said, a periscope (or something like it) would probably meet the intent of the requirement, if not the word. That's what I'm concerned about: the way the safety "requirement" is worded becoming more important than the actual safeness inferred by such a feature. The possibility that equivalently-safe ways of doing the same thing will be excluded because of red-tape instead of sound systems engineering reasons. There has to be flexibility on the exact way of accomplishing equivalent levels of safety or commercial crew will not be affordable or on schedule.

It'd be ironic if a Soyuz-type approach (i.e. periscope) not being allowed for commercial crew leads to delays causing NASA to continue to be reliant on Soyuz. Ironic, not surprising.

I agree with you on the periscope, but still disagree on the intent.  When one is near a large, delicate, and expensive spacecraft like ISS passive ability to back out will be needed, whether it is a periscope or window.  I am sure NASA will include a periscope if asked, but I reject the notion that the requirement is frivolous, again NASA has much more experience with docking than commercial.

Offline apace

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Re: Commercial Crew Program (CCP-CTS-CCT) Requirements
« Reply #114 on: 08/26/2011 02:44 pm »
I agree with you on the periscope, but still disagree on the intent.  When one is near a large, delicate, and expensive spacecraft like ISS passive ability to back out will be needed, whether it is a periscope or window.  I am sure NASA will include a periscope if asked, but I reject the notion that the requirement is frivolous, again NASA has much more experience with docking than commercial.

I think the problem is not if this is a security requirement or not, but more an example as you can write the rules. You can write it like "for docking, there need two or more redundant system to check the approach", or you can write as it's done and to specify every detail.

I clicked a little bit trough the documents and I had the impression, that NASA allows not a lot of different engineering ideas but rule what they want to have and how they want to have it.

Offline Robotbeat

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Re: Commercial Crew Program (CCP-CTS-CCT) Requirements
« Reply #115 on: 08/26/2011 03:57 pm »
Of course not. And just because NASA has "always done it that way" does not mean it's necessarily the only way it can be done or even the safest.

As Jorge said, a periscope (or something like it) would probably meet the intent of the requirement, if not the word. That's what I'm concerned about: the way the safety "requirement" is worded becoming more important than the actual safeness inferred by such a feature. The possibility that equivalently-safe ways of doing the same thing will be excluded because of red-tape instead of sound systems engineering reasons. There has to be flexibility on the exact way of accomplishing equivalent levels of safety or commercial crew will not be affordable or on schedule.

It'd be ironic if a Soyuz-type approach (i.e. periscope) not being allowed for commercial crew leads to delays causing NASA to continue to be reliant on Soyuz. Ironic, not surprising.

I agree with you on the periscope, but still disagree on the intent.  When one is near a large, delicate, and expensive spacecraft like ISS passive ability to back out will be needed, whether it is a periscope or window.
...
I'm not sure if passive is really needed. An equivalently reliable backup of any type (as long as it's equivalently reliable) should be allowed. After all, you can hardly use the thrusters if all power is lost!

But I certainly agree that there should be a reliable backup to the primary, whether it's video or not. If it were me doing the designing, I'd probably include a way to get "Mark 0 eyeballs" on it (i.e. I'd use "passive" as you mention it). But that's the point: I should be open to, even encouraging, the idea that the commercial crew providers will think of better ways to do something than I would. That's almost the whole point of commercial crew, from a certain perspective.

If alternatives can be shown to be just as good, that should be allowed, and not just as a waiver (IMHO).
« Last Edit: 08/26/2011 04:24 pm by Robotbeat »
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Offline simonbp

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Re: Commercial Crew Program (CCP-CTS-CCT) Requirements
« Reply #116 on: 08/26/2011 04:03 pm »
As has already been stated before, there were real concrete reasons for needing a window in the docking process in the first place.

Except there isn't. As I said, cameras are small and cheap, so you can put four fully redundant cameras, each with its own separate string to the control panel, and it would still have less than 1/10 the mass impact on the vehicle as forward-looking window. And frankly, if they loose any major sensors during flight, docking will be aborted anyways, regardless of any windows.

This not a real engineering requirement driven by an actual failure mode. This is a luddite requirement imposed by a pilot-astronaut who thinks he know how to do engineering better than professionals. And I'm sorry, but NASA isn't who I trust when it comes to real safety requirements. They have sadly (and fatally) proved that several times in the past.

Offline erioladastra

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Re: Commercial Crew Program (CCP-CTS-CCT) Requirements
« Reply #117 on: 08/26/2011 05:29 pm »
As has already been stated before, there were real concrete reasons for needing a window in the docking process in the first place.

Except there isn't. As I said, cameras are small and cheap, so you can put four fully redundant cameras, each with its own separate string to the control panel, and it would still have less than 1/10 the mass impact on the vehicle as forward-looking window. And frankly, if they loose any major sensors during flight, docking will be aborted anyways, regardless of any windows.


Cameras are not neccessarily better.  Yes, cameras *may* have less mass, but you trade that against power and data transfer for the camera plus an extra crew display.  So you might not be less mess and you are trading against critical items like power and increasing the complexity of the system (which means cost, risk) etc.

Offline Robotbeat

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Re: Commercial Crew Program (CCP-CTS-CCT) Requirements
« Reply #118 on: 08/26/2011 05:39 pm »
As has already been stated before, there were real concrete reasons for needing a window in the docking process in the first place.

Except there isn't. As I said, cameras are small and cheap, so you can put four fully redundant cameras, each with its own separate string to the control panel, and it would still have less than 1/10 the mass impact on the vehicle as forward-looking window. And frankly, if they loose any major sensors during flight, docking will be aborted anyways, regardless of any windows.


Cameras are not neccessarily better.  Yes, cameras *may* have less mass, but you trade that against power and data transfer for the camera plus an extra crew display.  So you might not be less mess and you are trading against critical items like power and increasing the complexity of the system (which means cost, risk) etc.
Yeah, the trade could go different ways. But don't you think it should be up to the commercial crew provider to find the most cost-and-performance-optimal solution that meets the required level of safety?
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline simonbp

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Re: Commercial Crew Program (CCP-CTS-CCT) Requirements
« Reply #119 on: 08/26/2011 07:37 pm »
Yeah, the trade could go different ways. But don't you think it should be up to the commercial crew provider to find the most cost-and-performance-optimal solution that meets the required level of safety?

Precisely. The requirements should be about defining safety, not the particular implementation. Wanye Hale hit the nail on the head.
« Last Edit: 08/26/2011 07:38 pm by simonbp »

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