-
Rebuilding legacy hardware
by
Bernie Roehl
on 26 Jan, 2010 22:44
-
I've been reading a bit about the AIO-50 project to rebuild the Gemini spacecraft from the original blueprints, using updated materials and avionics.
That leads me to wonder what's actually involved in a project like that. How much of the construction detail is included in the plans, and how much was in the heads of the engineers and technicians who actually built it? Is such a project even possible?
-
#1
by
JayP
on 27 Jan, 2010 01:40
-
I've been reading a bit about the AIO-50 project to rebuild the Gemini spacecraft from the original blueprints, using updated materials and avionics.
That leads me to wonder what's actually involved in a project like that. How much of the construction detail is included in the plans, and how much was in the heads of the engineers and technicians who actually built it? Is such a project even possible?
It depends. There are two things to consider here.
First, how much information is in the drawings and documentation. That depends on the culture of the company did them and the regulations in place at the time. Ideally, you would think that the drawings are maintained and completed as design changes are made, but in reality, that can be hit and miss and can depend alot on wether or not the person who pays the bills wants to do it. Also, the drawings may be lost to time after the project was completed. I don't know about Gemini, but I have heard stories about boxes of the drawings of the LM being thrown out to make space. Durring the Columbia accident investigation, the board was very disapointed that they were not able to get ahold of design drawings because no one knew where they were stored.
Second, what exactly do they mean by "using updated materials and avionics"? Even if they have all of the original documentation, if they are making changes that would affect material strengths, CG or manufacturing methods, they will have to do a complete reanalysis at the very least and probably have to create all new production drawings.
-
#2
by
Robotbeat
on 27 Jan, 2010 01:46
-
BTW, if you wanted to reuse a capsule after a water landing, and that'd be your primary mode of recovery, it'd make sense to make it with alloys that simply don't corrode on contact with seawater.
-
#3
by
Bernie Roehl
on 27 Jan, 2010 01:49
-
First, how much information is in the drawings and documentation. That depends on the culture of the company did them and the regulations in place at the time.
That's surprising... I would have thought the companies would be required to maintain those sorts of things.
Also, the drawings may be lost to time after the project was completed. I don't know about Gemini, but I have heard stories about boxes of the drawings of the LM being thrown out to make space.
I imagine maintaining all the data is a lot easier to do these days, since everything is digital.
That's a shame about the LM drawings being lost. It occurs to me that a (relatively) inexpensive lunar lander could be built based on that design, and the total mass would be a lot less than Altair would have been.
Second, what exactly do they mean by "using updated materials and avionics"? Even if they have all of the original documentation, if they are making changes that would affect material strengths, CG or manufacturing methods, they will have to do a complete reanalysis at the very least and probably have to create all new production drawings.
I'm not a mechanical engineer, but I was assuming they'd have to create new production drawings based on the old ones in any case, and that a certain amount of analysis would have to be done since it wouldn't be a 100% perfect copy. I certainly can't imagine them rebuilding 1960's discrete circuits, so the avionics would certainly be different (and therefore the flight control software as well).
-
#4
by
robertross
on 27 Jan, 2010 02:02
-
BTW, if you wanted to reuse a capsule after a water landing, and that'd be your primary mode of recovery, it'd make sense to make it with alloys that simply don't corrode on contact with seawater.
I'm not sure how LiAl reacts with saltwater, but if you had to use a metal that will not corrode (or be less corroded), then it will undoubtably be heavier.
-
#5
by
JayP
on 27 Jan, 2010 02:15
-
I did work as a mechanical engineer for years. I worked on a lot of projects that were "just updates" of existing ones and they always ended up being redesigned from scratch. I wouldn't be surprised that in the end the only thing this project will have in common with the gemini capsule will be its general size and shape.
-
#6
by
Robotbeat
on 27 Jan, 2010 02:55
-
BTW, if you wanted to reuse a capsule after a water landing, and that'd be your primary mode of recovery, it'd make sense to make it with alloys that simply don't corrode on contact with seawater.
I'm not sure how LiAl reacts with saltwater, but if you had to use a metal that will not corrode (or be less corroded), then it will undoubtably be heavier.
No doubt this is quite likely and should be involved in any trade study.
HOWEVER, quick googling points in the opposite direction. I uncovered a patent that uses LiAl alloy particles to actually inhibit corrosion:
http://www.patentstorm.us/patents/6069197/description.html
-
#7
by
A_M_Swallow
on 27 Jan, 2010 04:53
-
First, how much information is in the drawings and documentation. That depends on the culture of the company did them and the regulations in place at the time.
That's surprising... I would have thought the companies would be required to maintain those sorts of things.
Only for a limited number of years. Once the project librarian/registrar is fired to save money the unread paperwork soon disappears.
Also, the drawings may be lost to time after the project was completed. I don't know about Gemini, but I have heard stories about boxes of the drawings of the LM being thrown out to make space.
I imagine maintaining all the data is a lot easier to do these days, since everything is digital.
{snip}
Things are much easier these days, computers come with delete keys.
Depending on the media used computer files have to be copied to a new disk or magnetic tape every few months. Many organisations only keep back up copies for 6 months.
-
#8
by
Bernie Roehl
on 27 Jan, 2010 09:26
-
Depending on the media used computer files have to be copied to a new disk or magnetic tape every few months.
Magnetic tape? I would have thought they'd back everything up on DVDs these days.
A related question... who "owns" the designs for a spacecraft like Gemini? Or for that matter, Orion?
I would have thought that since the development was paid for by tax dollars, everything would belong to the US government. Could they not "open source" all the design and manufacturing information if they chose to, and make it available to the public? That would at least ensure its long-term survival.
-
#9
by
Downix
on 27 Jan, 2010 11:57
-
Depending on the media used computer files have to be copied to a new disk or magnetic tape every few months.
Magnetic tape? I would have thought they'd back everything up on DVDs these days.
A related question... who "owns" the designs for a spacecraft like Gemini? Or for that matter, Orion?
I would have thought that since the development was paid for by tax dollars, everything would belong to the US government. Could they not "open source" all the design and manufacturing information if they chose to, and make it available to the public? That would at least ensure its long-term survival.
And if they are open, makes me wonder about other bits. I'd love to see the plans for the S-IC sometime, for example.
-
#10
by
Jim
on 27 Jan, 2010 13:21
-
Could they not "open source" all the design and manufacturing information if they chose to, and make it available to the public? That would at least ensure its long-term survival.
There are company specific processes that are involved that may be hard to duplicate or find.
-
#11
by
Downix
on 27 Jan, 2010 16:50
-
Could they not "open source" all the design and manufacturing information if they chose to, and make it available to the public? That would at least ensure its long-term survival.
There are company specific processes that are involved that may be hard to duplicate or find.
Not fully relevent. While it would prevent duplication of the design, the knowledge would not be lost.
Example, I have a full design for the old Atari Jaguar console, including the custom chips. It was developed with an internal Atari design tool, long lost to history. However, even with the original design being useless for directly manufacturing without this tool (and who'd want to build a Jaguar anyways?) the design can be studied for future work, to learn what worked, and did not work.
-
#12
by
Jim
on 27 Jan, 2010 17:04
-
Not fully relevent. While it would prevent duplication of the design, the knowledge would not be lost.
Not so, it is very relevant. "Processes" are more than design tools. They include things like bonding surface prep, tube bending, etc
-
#13
by
beb
on 27 Jan, 2010 17:15
-
FYI: the project can b found at:
http://www.aio50.org/UAHproject.phpFrom the link student are exploring the feasibility of the Rogallo wing for land landings and are currently building a 1/3 size model to test handling characteristics of the wing. If these tests are promising they will go forwards with a full size model but there does not appear to be an plans to have it actually launched into space.
-
#14
by
Bernie Roehl
on 27 Jan, 2010 17:30
-
FYI: the project can b found at:
http://www.aio50.org/UAHproject.php
[...]
there does not appear to be an plans to have it actually launched into space.
That's what I got from reading it too, but the site also says they're planning to launch the Gemini-IR into orbit on a Falcon 9 on Feb 20, 2012 (just over two years from now).
Are they just blowing smoke, or is it credible that they will be able to pull this off?
-
#15
by
tankmodeler
on 27 Jan, 2010 17:46
-
As has been said, it is impossible that every single mechanical or electronic component from Gemini is avialable today. It is extremely unlikely that _any_ component from 1963 is avilable today. That said, the cost to reproduce a Gemini would be then be significantly higher than the original (even allowing for inflation) because testing & validation regimes are significantly more stringent today than they were in 1963-64 when the Gemini was developed. I'd bet none of the mechanical drawings are available, so every part would have to be designed from scratch. Add to that the need to convert old materials & processes to new ones plus the unbelievably complex & costly need to design the avionics and then test them and you have a recipe for a very costly system. I would bet that it wouldn't cost a whole lot less than Orion, when all was said and done. Most of the cost of something like a Gemini or Orion is in the development of the design, and is pretty much unrelated to the size of the spacecraft involved. The costs are much more related to the functionality of such a capsule as opposed to the basic size or mass.
All that aside, though, I'd love to see full scale deployment testing done on a Gemini/Rogallo wing recovery system. The concept holds some promise for the less costly land landing and reuse of capsule type spacecraft. I've always thought it could provide lifting body capabilities in a capsule shaped re-entry body. Of course, the Rogallos are pretty intolerant of deployment failures...
Paul
-
#16
by
Robotbeat
on 27 Jan, 2010 17:56
-
As has been said, it is impossible that every single mechanical or electronic component from Gemini is avialable today. It is extremely unlikely that _any_ component from 1963 is avilable today. That said, the cost to reproduce a Gemini would be then be significantly higher than the original (even allowing for inflation) because testing & validation regimes are significantly more stringent today than they were in 1963-64 when the Gemini was developed. I'd bet none of the mechanical drawings are available, so every part would have to be designed from scratch. Add to that the need to convert old materials & processes to new ones plus the unbelievably complex & costly need to design the avionics and then test them and you have a recipe for a very costly system. I would bet that it wouldn't cost a whole lot less than Orion, when all was said and done. Most of the cost of something like a Gemini or Orion is in the development of the design, and is pretty much unrelated to the size of the spacecraft involved. The costs are much more related to the functionality of such a capsule as opposed to the basic size or mass.
All that aside, though, I'd love to see full scale deployment testing done on a Gemini/Rogallo wing recovery system. The concept holds some promise for the less costly land landing and reuse of capsule type spacecraft. I've always thought it could provide lifting body capabilities in a capsule shaped re-entry body. Of course, the Rogallos are pretty intolerant of deployment failures...
Paul
Testing and validation expense is almost free using the unlimited "free energy" of grads and undergrads. They won't put men in it, but they could still fly and test it.
I still don't understand how we can say that it's ridiculously expensive to test and validate something today versus 50 years ago, but almost in the same breath say that test-flights are completely unnecessary with modern techniques. What? It sounds to me like if you were doing something like this (which doesn't have a customer in mind, just needs to provide motivating and interesting and marketable experience for students), you could quite easily avoid paralysis by analysis and, after being careful to catch the big mistakes, just fly the thing and see if you've done a good enough job. If it fails, it'd be a very good chance to teach the students how to do an accident investigation and see what you did wrong.
Something is seriously wrong if testing/validation is so much more expensive today than forty or fifty years ago. I don't know how to fix it, but it still seems like a problem to me.
-
#17
by
bad_astra
on 27 Jan, 2010 18:14
-
As I understood it, the AIO50 version would differentiate from the historical Gemini most noticably in the adaptor module.
There are some items, like the Guidance Computer which should be pretty well understood and are in fact already emulated (I know emulators are slower typically than the descrete components they replace, but in this case that's hard to imagine).
Materials wise, not so certain why AIO50 would be in a rish to change too much to the hardware's composition. True it can't be rebuilt entirely the same way, or from the same components, but due to the reason for the program, and the fact that they are on a shoestring budget, it would seem best to stick as close to the original as possible.
As for rogallos: I hope they avoid it. Rogallo's have been superceded. If they somehow got in a luff with one, that would be horrible.
-
#18
by
Takalok
on 27 Jan, 2010 18:53
-
That leads me to wonder what's actually involved in a project like that. How much of the construction detail is included in the plans, and how much was in the heads of the engineers and technicians who actually built it? Is such a project even possible?
Pretty impressive. They've paid for a launch from Space-X and have a launch date (Feb 20,2012).
http://www.aio50.org/index.phpIt looks like they're going to drop test a 1/3 scale model and make several other "in atmosphere" tests at Redstone Aresenal before moving onto full scale development.
Also of note on the page, is a mention of converting "NASA blueprints" to CAD. So evidently, some significant documentation remains.
http://www.aio50.org/UAHproject.phpIt sounds like an exciting, serious project.
-
#19
by
tankmodeler
on 28 Jan, 2010 18:20
-
Testing and validation expense is almost free using the unlimited "free energy" of grads and undergrads. They won't put men in it, but they could still fly and test it.
I still don't understand how we can say that it's ridiculously expensive to test and validate something today versus 50 years ago, but almost in the same breath say that test-flights are completely unnecessary with modern techniques. What? It sounds to me like if you were doing something like this (which doesn't have a customer in mind, just needs to provide motivating and interesting and marketable experience for students), you could quite easily avoid paralysis by analysis and, after being careful to catch the big mistakes, just fly the thing and see if you've done a good enough job. If it fails, it'd be a very good chance to teach the students how to do an accident investigation and see what you did wrong.
Something is seriously wrong if testing/validation is so much more expensive today than forty or fifty years ago. I don't know how to fix it, but it still seems like a problem to me.
OK, let’s get things straightened out here…
My comments were based on posters about a “project to rebuild the Gemini spacecraft from the original blueprints, using updated materials and avionics”. My interpretation was that this would be flown and my comments are only relating to men flying to space in the resulting vehicle. Once I found out that no-one was going to space in it, all my comments became moot.
If it’s a university program, nothing _has_ to be tested, no specs _have_ to be met and no rigour _has_ to be achieved. It’s whatever you need to do to educate the students (which is, BTW a very good idea).
If we get to the meat of your comments, though, i.e. “how we can say that it's ridiculously expensive to test and validate something today versus 50 years ago”, I can tell you that, in fact, it is much more expensive to test today than “yesterday”. This is because a) we can and do test much more thoroughly than before, earlier tests simply are not considered adequate today because we look for more information now than then, and b) individual test costs are significantly higher than they were that long ago, even allowing for inflation due to increased data returns and increased analysis time of the increased data.
As to the concept of “testing/validation is so much more expensive today than forty or fifty years ago” being wrong, I don’t think so. Certainly we are more risk adverse now and testing is all about reducing risk. But we also know significantly more about how to optimise designs to specific environments and, once you get to the pointed end of an optimised design, you really have to test it a lot and from a lot of different angles to ensure that you can handle all the environments you are designing for and that you haven’t exceeded the requirements of those environments, because that tends to mean that you could have optimised more. In the “old days” we couldn’t design right to the “bleeding edge” of the capabilities of our materials & processes so there were higher margins on things which also meant that you could get away with less testing and still meet acceptable risk levels. Today we can design right up to the edge of failure, our margins are paper thin and we need to be absolutely sure that it never fails. Therefore we test an awful lot.
Paul
