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TarDevil

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Mods, I hope this is acceptable. I figured since we thoroughly thrashed Boeing's woes this might be worthy of discussion.

From my perspective it's simple: NASA is using off-the-shelf hardware to build the SLS, yet it's years behind schedule and billions over budget.

Why? Engines and boosters are flight proven. I know space ain't easy, but this rocket should've been easier than all new hardware.
 

Wanttaja

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Haven't paid any attention to SLS, but I'm betting the off-the-shelf hardware they're using is not man-rated. IIRC, the required margin of safety for non-man-rated space hardware is 10%, but it's 25% if humans are going to be using it. WHOLE lot bigger problem.

Then there's the whole integration thing. Maybe your engines are man-rated, maybe the structure is man-rated, but the integrated whole needs to be proven as well.

As I mention on a discussion with a friend years ago, the word "Just" cannot be used in space systems design. You can't "just" bolt Part A to Part B and assume all will be well.

Ron Wanttaja
 

narfi

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but if you do it repeatedly with cheap components and record the data you might get quicker or cheaper results
I don't know.... just repeating what someone said somewhere on the internet
Also: 'Government'.......
 

Wanttaja

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but if you do it repeatedly with cheap components and record the data you might get quicker or cheaper results
I don't know.... just repeating what someone said somewhere on the internet
Also: 'Government'.......
It's true, Musk can trash any number of rockets as long as the data helps him finalize the design. If NASA crashes one, there's likely to be a Congressional investigation.....

Ron Wanttaja
 

Dana

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NASA did a great job on Mercury through Apollo. That's the proper job of government, to build roads. But then came the Shuttle, with design flaws that were obvious even to an undergraduate engineering student. It's not the proper job of government to run the buses on the road, but they had to feed their standing army of engineers and technicians.

NASA succumbed to the Iron Law of Bureaucracy.

Pournelle's Iron Law of Bureaucracy states that in any bureaucratic organization there will be two kinds of people:

First, there will be those who are devoted to the goals of the organization. Examples are dedicated classroom teachers in an educational bureaucracy, many of the engineers and launch technicians and scientists at NASA, even some agricultural scientists and advisors in the former Soviet Union collective farming administration.

Secondly, there will be those dedicated to the organization itself. Examples are many of the administrators in the education system, many professors of education, many teachers union officials, much of the NASA headquarters staff, etc.

The Iron Law states that in every case the second group will gain and keep control of the organization. It will write the rules, and control promotions within the organization.
 

Topaz

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Mods, I hope this is acceptable. I figured since we thoroughly thrashed Boeing's woes this might be worthy of discussion.

From my perspective it's simple: NASA is using off-the-shelf hardware to build the SLS, yet it's years behind schedule and billions over budget.

Why? Engines and boosters are flight proven. I know space ain't easy, but this rocket should've been easier than all new hardware.
Because repurposing one design - or worse, parts from one design - to build a completely different design for different specifications of any significant degree has always been more expensive and time-consuming than simply designing something new to the new specification. Every single time this has been tried - from adapting Bf-109 parts to make a high-altitude fighter by Blohm und Voss in WWII, to various attempts to cobble new and different ship together from parts of old ones, to the SLS's use of Shuttle engines and the "sort-of-kind-of" main fuel tank - has always been a disaster. If the parts were properly designed for their original use, they'll need to be modified to accommodate the new loads and environment for their new use, and if you constrain the designers by the very act of using someone else's earlier, unrelated design, you make their work harder and more time-consuming. The Shuttle's tank was never designed to hold the weight of a second stage on top. The idea was to just "reuse" the main tank "with some modifications." The SLS core is almost, but not quite, completely redesigned, but the design was constrained by the dimensions, materials, and many of the processes used in its ancestor Shuttle tank. It would've been cheaper and quicker if they could've just designed a new rocket from scratch, even if it used RS-25's for engines.

If NASA wanted to build a new heavy-lift launch vehicle out of the Shuttle, the answer was Shuttle-C. That just removed parts from the orbiter (cabin, heat shield, wings, vertical tail) and that weight removed turned into additional payload weight. SLS is trying to use parts designed for the Shuttle in a totally different rocket. It's gone bad and will always be bad, and by that I mean "a sub-optimal, poorly-performing solution."

The rest of the problem is political, and outside the scope of HBA's topic and rules.
 

mcrae0104

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NASA did a great job on Mercury through Apollo. That's the proper job of government, to build roads. But then came the Shuttle, with design flaws that were obvious even to an undergraduate engineering student. It's not the proper job of government to run the buses on the road, but they had to feed their standing army of engineers and technicians.

NASA succumbed to the Iron Law of Bureaucracy.
1) When have you driven the "Apollo road" to the moon for the purpose of interstate commerce? (I agree it was legitimate spending, but your reasoning is a stretch on the basis offered.)

2) Please state the design flaws of the Shuttle program that are obvious to an engineering student. Perhaps because I am not an engineering student, they are not obvious to me.

3) It's a bit of a sweeping accusation to ascribe the Shuttle program to "feed[ing] their standing army of engineers and technicians." Placing defense assets in space seems to be a legitimate government function (as opposed to the supposed "road to the moon," which I, and most other folks, have yet to traverse).
 
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Voidhawk9

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SLS was never about being cheap or simple, it is about continuing to employ persons in legacy rocket parts production and operation, despite those parts, processes, etc. being decades out of date. The design was literally defined by politicians, who made laws forcing NASA to use parts and companies that built and maintained the Shuttle.
10 or 15 years ago, SLS may have had a place. Today, it is quickly being overshadowed by commercial enterprise - indeed, SLS may be completely obsolete by the time it flies next year. NASA and its backers are at high risk of being something of a laughingstock. You could literally buy dozens of commercial medium / heavy-lift launches for the price of a single SLS launch.
 

Kiwi303

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Remember the C17 saga? Air force didn't want more, didn't ned more, congressmen with parts suppliers in the districts ganged together and pork barrelled though a budget supplimentary to buy more which then sat on an airfield somewhere for some years before being FMS'ed off somewhere below cost to another allied air force that really wanted A400's but took what was larger and costlier to run cause it was cheaper and brought favor points with US pollies.

Same idea, protect jobs and extend production line running times at the taxpayers dime.
 

BJC

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Here is the “homebuilt” version:

Previously discussed here:


BJC
 

Aesquire

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On my bookshelf is the Congressional Report on the Shuttle Program. Includes Skylab and the next generation heavy lifters.

Shuttle design flaws? The short form is for every design submitted the Politicians applied Political Math.
A design that cost ( numbers here are for illustration only, the real numbers are much higher ) 3 billion dollars a year for 3 years, was in nearly every case rejected for a design that cost 2 billion a year for 10 years,to save money in each fiscal year. Each iteration of that process increased cost per ton, payrolls in multiple Congressional districts, and reduced capabilities in reusable components.

My 2 favorite rejected designs are the Chrysler First stage that used F1 Saturn 5 engines with the exact same return to Canaveral with vertical landing for reuse as the Space X flight profile. And the Lockheed first stage that was a winged horizontal take off and land system using 8 P&W J58 "Blackbird" engines. I'd want a ride on either over a solid fuel strapon.
 

Dana

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1) When have you driven the "Apollo road" to the moon for the purpose of interstate commerce? (I agree it was legitimate spending, but your reasoning is a stretch on the basis offered.)
Regardless of whether anyone has personally traveled that "road", I think it's safe to say that the entire world has benefited from space technology (comsats, GIS and weather satellites, GPS, etc.) derived from earlier NASA work. But afterward, NASA's monopoly on that "road" made it impossible for private companies to get into the space trucking business. (Come on, come on, come on, Let's go space truckin'... sorry, couldn't resist.)

2) Please state the design flaws of the Shuttle program that are obvious to an engineering student. Perhaps because I am not an engineering student, they are not obvious to me.
Well, the thousands of tiles, every one different, was the first thing that jumped out at me. I remember discussing it with one of my AE professors, he just said, "I know, I know, but it's the only game in town" with a sad smile. (Some years later I was at Sikorsky, working on ways to limit damage to those same tiles during launch.) Solid rocket boosters in sections so they'd fit on highway trucks, because they had to be made in Utah for political reasons instead of somewhere they could be shipped by sea in one piece. Then put them together with rubber O-rings, though nobody back then knew what a mess that would become.

The Shuttle was designed to launch really big cargo, like the then proposed Mars mission. We didn't go to Mars, of course, so we had to find something else to use it for, even though most of what the Shuttle took to orbit would have been better handled by smaller launch vehicles.

3) It's a bit of a sweeping accusation to ascribe the Shuttle program to "feed[ing] their standing army of engineers and technicians." Placing defense assets in space seems to be a legitimate government function (as opposed to the supposed "road to the moon," which I, and most other folks, have yet to traverse).
There are (and were) a lot of good people at NASA. There are also a lot of bureaucrats and political apointees. It's paper pushers overruling the real engineers that led to the Challenger disaster.

But I agree, this has little to do with HBA, except that airplane people are naturally interested in space travel, too. Homebuilt spacecraft! Rocket Ship Galileo, anyone?
 

Wanttaja

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But I agree, this has little to do with HBA, except that airplane people are naturally interested in space travel, too. Homebuilt spacecraft! Rocket Ship Galileo, anyone?
For a REAL homebuilt spacecraft story, try John Varley's Red Thunder. One "suspension of disbelief" technological breakthrough, and everything else in the spacecraft is made from off-the-shelf components.

Ron Wanttaja
 

DaveK

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If you look into these things it’s not NASA’s fault, it’s Congress. Same happened with the space station, Galileo, and a bunch of other projects that got drawn out, reconfigured repeatedly, a turned into excuses to spend money by Congress. Same thing happens at the DOD, C130 bought by the dozens that aren’t needed against the wishes of the Airforce. Planes selected because they have suppliers in every state instead of the one that works the best. Insisting on this ridiculous notion of “multi role”. F35 anyone? Allowing merger after merger so we now have only one carrier manufacturer, one sub manufacturer, basically one bomber manufacturer, etc. No competition leads to high costs and poor products. If Congress would just give Nasa a steady budget and stop changing the mission every couple years things could get done. They really can do amazing things if they are allowed to do it. Congress is going to remain a mess until money is removed from politics.
 

bmcj

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One "suspension of disbelief" technological breakthrough, and everything else in the spacecraft is made from off-the-shelf components.
That’s one of the things I like about SyFy’s (now Amazon’s) “The Expanse”. The suspension of belief item is a revolutionary propulsion system, but most everything else man made is within reasonable range of being possible in the near future with minor advances in technology.
 
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