Author Topic: Could Ares 1 have Worked if things had been different?  (Read 195126 times)

Offline baldusi

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Re: Could Ares 1 have Worked if things had been different?
« Reply #120 on: 09/04/2011 08:14 pm »
The entire big throat solid Titan experience actually argues for solid motor reliability when compared to liquid rockets.  There were 123 flights of Titan 3C/D/E and 4 rockets, using 246 big throat solid motors.  Two of those solid motors suffered failures (a 99.19% success rate).  An additional 13 of these solid-boosted Titan-launched missions were thwarted by failures that affected the liquid stages or upper stages, lowering the overall mission success rate to 87.80 %. 
But that's the whole point! Using solids forces you to use bigger and more extreme second stages. You can't decide the reliability of the whole vehicle by using only a part that individually might have less failure occurrences, but that forces a higher complexity in the rest of the stack (namely, second stage and LAS).

Offline edkyle99

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Re: Could Ares 1 have Worked if things had been different?
« Reply #121 on: 09/04/2011 10:42 pm »
The entire big throat solid Titan experience actually argues for solid motor reliability when compared to liquid rockets.  There were 123 flights of Titan 3C/D/E and 4 rockets, using 246 big throat solid motors.  Two of those solid motors suffered failures (a 99.19% success rate).  An additional 13 of these solid-boosted Titan-launched missions were thwarted by failures that affected the liquid stages or upper stages, lowering the overall mission success rate to 87.80 %. 
But that's the whole point! Using solids forces you to use bigger and more extreme second stages. You can't decide the reliability of the whole vehicle by using only a part that individually might have less failure occurrences, but that forces a higher complexity in the rest of the stack (namely, second stage and LAS).

I don't follow.  The alternatives to Ares I were more, not less, complex than Ares I.  Atlas V Heavy, for example, would have used four liquid propulsion units using a total of four or five or more complex liquid rocket engines (including three staged-combustion engines).  Ares I would have used one solid motor and one gas generator engine powering two stages.  Show me a simpler rocket that can orbit as much mass.

 - Ed Kyle

Offline Lars_J

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Re: Could Ares 1 have Worked if things had been different?
« Reply #122 on: 09/04/2011 11:50 pm »
Slavish devotion to "simple" is exactly what led down the Ares I path. And the end result was a whole system which was NOT simple.

Offline alexw

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Re: Could Ares 1 have Worked if things had been different?
« Reply #123 on: 09/05/2011 01:39 am »
Ares I would have used one solid motor and one gas generator engine powering two stages.  Show me a simpler rocket that can orbit as much mass.
    An AV-Phase II variant using 1x RD-171 and 1x J-2S would probably have been fairly comparable, yes?

    The upper stage is much the same idea but somewhat smaller than AIUS (and could perhaps have been on 5m instead of 5.5m tooling), the J-2S was already developed and need not be pushed into the J-2X. Alternatively, build the core on the 5.5m tooling; indeed, building the core at Michoud as LockMart originally intended.
           -Alex

Offline Patchouli

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Re: Could Ares 1 have Worked if things had been different?
« Reply #124 on: 09/05/2011 03:39 am »
Slavish devotion to "simple" is exactly what led down the Ares I path. And the end result was a whole system which was NOT simple.

The pretty much sums it it up.

The people running the project would not change the design when it became obvious it was the wrong direction.

If the people doing Apollo had the same stubborn mindset we may have never landed on the moon and certianly would not have done so before the end of the decade.
Apollo originally was going to use a direct landing LOR was the underdog at first.

Kinda like Direct vs Ares.
« Last Edit: 09/05/2011 03:45 am by Patchouli »

Offline Downix

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Re: Could Ares 1 have Worked if things had been different?
« Reply #125 on: 09/05/2011 04:46 am »
Slavish devotion to "simple" is exactly what led down the Ares I path. And the end result was a whole system which was NOT simple.

The pretty much sums it it up.

The people running the project would not change the design when it became obvious it was the wrong direction.

If the people doing Apollo had the same stubborn mindset we may have never landed on the moon and certianly would not have done so before the end of the decade.
Apollo originally was going to use a direct landing LOR was the underdog at first.

Kinda like Direct vs Ares.
The 1961 vehicle was a cluster of Saturn C-3 first stages with super upper stages. 
chuck - Toilet paper has no real value? Try living with 5 other adults for 6 months in a can with no toilet paper. Man oh man. Toilet paper would be worth it's weight in gold!

Offline edkyle99

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Re: Could Ares 1 have Worked if things had been different?
« Reply #126 on: 09/05/2011 05:36 am »
Slavish devotion to "simple" is exactly what led down the Ares I path. And the end result was a whole system which was NOT simple.

The pretty much sums it it up.

The people running the project would not change the design when it became obvious it was the wrong direction.

If the people doing Apollo had the same stubborn mindset we may have never landed on the moon and certianly would not have done so before the end of the decade.
Apollo originally was going to use a direct landing LOR was the underdog at first.

Kinda like Direct vs Ares.

Nothing like "Direct vs. Ares".  If it were, NASA would be planning a lunar landing right now, using Direct.  It isn't.  Instead, the clamor for alternative ideas like "Direct" helped kill NASA's lunar landing program.

It wasn't about the rocket.  It was about the lack of funding from the outset.  There still isn't enough funding for a lunar landing even with Ares dead.

 - Ed Kyle

Offline edkyle99

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Re: Could Ares 1 have Worked if things had been different?
« Reply #127 on: 09/05/2011 05:38 am »
Slavish devotion to "simple" is exactly what led down the Ares I path. And the end result was a whole system which was NOT simple.

It was simpler than the alternatives.

 - Ed Kyle

Offline Lars_J

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Re: Could Ares 1 have Worked if things had been different?
« Reply #128 on: 09/05/2011 05:48 am »
Slavish devotion to "simple" is exactly what led down the Ares I path. And the end result was a whole system which was NOT simple.

It was simpler than the alternatives.

 - Ed Kyle

It seems like you still aren't getting my point - or you are playing devils advocate. If you stare yourself blind on "only two engines" and ignore all the other complexities arising from that decision, then you can't see the forest because of all the damn trees in the way.

There's a lot more to consider than the plain number of engines. You can have drastically different designs that both have two engines. In Ares 1's case the issue is compounded by a very poor first stage decision. (And looking at the number of small thrusters that have to fire during its ascent, and for its stage separation - one could actually argue that it has a LOT of engines that HAVE TO work)
« Last Edit: 09/05/2011 05:55 am by Lars_J »

Offline Patchouli

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Re: Could Ares 1 have Worked if things had been different?
« Reply #129 on: 09/05/2011 05:56 am »
Slavish devotion to "simple" is exactly what led down the Ares I path. And the end result was a whole system which was NOT simple.

The pretty much sums it it up.

The people running the project would not change the design when it became obvious it was the wrong direction.

If the people doing Apollo had the same stubborn mindset we may have never landed on the moon and certianly would not have done so before the end of the decade.
Apollo originally was going to use a direct landing LOR was the underdog at first.

Kinda like Direct vs Ares.

Nothing like "Direct vs. Ares".  If it were, NASA would be planning a lunar landing right now, using Direct.  It isn't.  Instead, the clamor for alternative ideas like "Direct" helped kill NASA's lunar landing program.

It wasn't about the rocket.  It was about the lack of funding from the outset.  There still isn't enough funding for a lunar landing even with Ares dead.

 - Ed Kyle

Both Ares I and V had serious design issues that made them unviable designs.
I knew Ares was doomed the moment they started gutting Orion to make it fly on Ares I and started talking about six engines on Ares V.
Even if they were finished NASA could not afford to fly two very different SDLVs.
Direct was an attempt to save Project Constellation.

What killed project constellation in the end was stubbornness on the part of people like  Mike Griffin and Scott Horowitz.

« Last Edit: 09/05/2011 06:01 am by Patchouli »

Offline Will

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Re: Could Ares 1 have Worked if things had been different?
« Reply #130 on: 09/05/2011 03:09 pm »
Slavish devotion to "simple" is exactly what led down the Ares I path. And the end result was a whole system which was NOT simple.

It was simpler than the alternatives.

 - Ed Kyle

Simplicity isn't the only figure of merit. Zenit 2 is simpler than Soyuz, but less reliable. Flight experience is also very important to build reliability. Ares I would have flown so rarely that it would have a low level of flight experience compared to other launchers.

Offline Will

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Re: Could Ares 1 have Worked if things had been different?
« Reply #131 on: 09/05/2011 04:34 pm »
Yes it is, considering how many SRB's failed after Challenger.  While they did not fail on the Shuttle, they still failed.
[like] this:


Titan 4 A-20 was not a solid motor failure.  It was an electrical (wiring harness short circuit) failure in the liquid core stages that caused loss of guidance/flight control.

The entire big throat solid Titan experience actually argues for solid motor reliability when compared to liquid rockets.  There were 123 flights of Titan 3C/D/E and 4 rockets, using 246 big throat solid motors.  Two of those solid motors suffered failures (a 99.19% success rate).  An additional 13 of these solid-boosted Titan-launched missions were thwarted by failures that affected the liquid stages or upper stages, lowering the overall mission success rate to 87.80 %. 

- Ed Kyle

However, the history also suggests that we can't expect the five segment solid to inherit the reliability of the four segment version. Titan 3C/D/E solids failed once in 84 flights, Titan 4 once in 39.

Offline Downix

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Re: Could Ares 1 have Worked if things had been different?
« Reply #132 on: 09/05/2011 05:24 pm »
Slavish devotion to "simple" is exactly what led down the Ares I path. And the end result was a whole system which was NOT simple.

The pretty much sums it it up.

The people running the project would not change the design when it became obvious it was the wrong direction.

If the people doing Apollo had the same stubborn mindset we may have never landed on the moon and certianly would not have done so before the end of the decade.
Apollo originally was going to use a direct landing LOR was the underdog at first.

Kinda like Direct vs Ares.

Nothing like "Direct vs. Ares".  If it were, NASA would be planning a lunar landing right now, using Direct.  It isn't.  Instead, the clamor for alternative ideas like "Direct" helped kill NASA's lunar landing program.

It wasn't about the rocket.  It was about the lack of funding from the outset.  There still isn't enough funding for a lunar landing even with Ares dead.

 - Ed Kyle
False Ed. The enemy always was those who wished to kill the lunar program. DIRECT was an attempt to save the moon mission from those forces. The egos of those in charge saw it as the enemy, which means they handed the weapons to their true enemy.
chuck - Toilet paper has no real value? Try living with 5 other adults for 6 months in a can with no toilet paper. Man oh man. Toilet paper would be worth it's weight in gold!

Offline baldusi

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Re: Could Ares 1 have Worked if things had been different?
« Reply #133 on: 09/05/2011 05:54 pm »
The entire big throat solid Titan experience actually argues for solid motor reliability when compared to liquid rockets.  There were 123 flights of Titan 3C/D/E and 4 rockets, using 246 big throat solid motors.  Two of those solid motors suffered failures (a 99.19% success rate).  An additional 13 of these solid-boosted Titan-launched missions were thwarted by failures that affected the liquid stages or upper stages, lowering the overall mission success rate to 87.80 %. 
But that's the whole point! Using solids forces you to use bigger and more extreme second stages. You can't decide the reliability of the whole vehicle by using only a part that individually might have less failure occurrences, but that forces a higher complexity in the rest of the stack (namely, second stage and LAS).

I don't follow.  The alternatives to Ares I were more, not less, complex than Ares I.  Atlas V Heavy, for example, would have used four liquid propulsion units using a total of four or five or more complex liquid rocket engines (including three staged-combustion engines).  Ares I would have used one solid motor and one gas generator engine powering two stages.  Show me a simpler rocket that can orbit as much mass.

 - Ed Kyle

So the complexity of the stack is only the "complexity" of the engines? The extra difficulty of the MECO is not an added complexity? The catastrophic failure modes of the solids is not a complexity? The LAS requirements of using solids is not a complexity? The post use inspection to keep the human rating on segmented solids is not a complexity? The limited flexibility of the solids design (up or down rate) is not a complexity? And you're wrong in that the only solution would have been an Atlas IV. You could have used an Atlas Phase II. And if you're worried about the amount of engines, then put an RD-171M. And the ACES with an J-2X. Traded one solid engine for one staged engine. But a very well characterized, tested and human rated engine. And let's recall that the Shuttle did had engine out on the pure SSME phase. And in fact it saved the STS-51L mission. So it's not clear that many engine with engine out capabilities are bad. You take every complexity as the same. And Tauffte was very clear in his Challenger failure findings that you have to add a degree of severity to each failure. Staged combustion is more complex? Yes, but that's why it gets so much testing before, is fired for acceptance, and is even tested while firing just before lift-off. And if correctly instrumented, it can be shut down gracefully most of the times. Yes, the solids are "simpler", but once on the pad, if it fails is a kaboom. I know, the "trade studies" said solids where still safer. I'm an econometrist and know perfectly well how you can put thumbs on the scale on those studies. Like saying taking the SSRM, changing the formula, the grain, the casing, the number of segments and nozzle and saying that it's the same engine. But then forgetting any sort of experience of actual liquid engines doing actual missions and getting actual reliabilities. It's like when they (allegedly) said that the bumble bee couldn't fly.
If Rusky engines were a no no (even made by AMROSS in the US), then do develop the TR-107, or PWR-1000. Meanwhile, use the RD-171M to test the rest of the stack. Aerojet would have developed eventually the AJ-500, too.

Offline edkyle99

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Re: Could Ares 1 have Worked if things had been different?
« Reply #134 on: 09/05/2011 06:50 pm »
There's a lot more to consider than the plain number of engines. You can have drastically different designs that both have two engines. In Ares 1's case the issue is compounded by a very poor first stage decision. (And looking at the number of small thrusters that have to fire during its ascent, and for its stage separation - one could actually argue that it has a LOT of engines that HAVE TO work)

Ares I uses a roll control thruster as I understand it, not a bunch of small thrusters, at least during first stage flight.  The second stage has thrusters, but so does Centaur (Centaur has 12 monopropellant thrusters for pitch, yaw, roll).

An Atlas V core fires eight stage separation motors.  Heavy would fire even more ordnance.

Atlas V Heavy would have more engines (high chamber pressure staged combustion engines on the cores), more separation events, more points of failure, and more complexity. 

 - Ed Kyle
« Last Edit: 09/05/2011 07:00 pm by edkyle99 »

Offline edkyle99

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Re: Could Ares 1 have Worked if things had been different?
« Reply #135 on: 09/05/2011 06:58 pm »
Both Ares I and V had serious design issues that made them unviable designs.

I don't see the Ares I design in particular as nonviable.  Augustine and others have said that Ares I would have worked. 

I see the "nonviable" claim as an excuse for lack of national will.  It is a way for decision makers to blame their own failure on someone's rocket design.  Ares I became the scapegoat because it was the first thing under development that, as all complex systems do, ran into design challenges.  It was surmounting those challenges. 

The issue was lack of funding for landing on the Moon - regardless of rocket.  If NASA could land on the Moon with less money, it would be happening. 

 - Ed Kyle
« Last Edit: 09/05/2011 06:58 pm by edkyle99 »

Offline Lee Jay

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Re: Could Ares 1 have Worked if things had been different?
« Reply #136 on: 09/05/2011 07:38 pm »
Both Ares I and V had serious design issues that made them unviable designs.

I don't see the Ares I design in particular as nonviable.

It was.  The premise behind Ares-I was to take two existing engines and use their extensive flight experience to make a simple, reliable rocket for Orion.  Then they discovered their choice for the second stage engine (SSME) wouldn't work and that they'd have to design a new second stage engine.  Then they discovered that the new engine wasn't going to give the performance of the original so they'd have to design a new first stage engine as well.  So the entire premise was falsified and the entire project should have been re-evaluated at that point.  Instead, they chose to push forward on a project that was in direct violation of its original design premise.  To me, that's non-viable unless there are very compelling cost and reliability reasons it isn't.  In this case, it was going to be very expensive and not necessarily reliable because of all the technical problems and their solutions, and the total lack of flight experience with either stage or either engine.

Offline edkyle99

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Re: Could Ares 1 have Worked if things had been different?
« Reply #137 on: 09/05/2011 11:51 pm »
Both Ares I and V had serious design issues that made them unviable designs.

I don't see the Ares I design in particular as nonviable.

It was.  The premise behind Ares-I was to take two existing engines and use their extensive flight experience to make a simple, reliable rocket for Orion.  Then they discovered their choice for the second stage engine (SSME) wouldn't work and that they'd have to design a new second stage engine.  Then they discovered that the new engine wasn't going to give the performance of the original so they'd have to design a new first stage engine as well. 
This is not correct. 

ESAS recommended the four-segment booster and SSME stage 2 design, but also described a five-segment booster and J-2 derived alternative.  The alternative was selected soon after ESAS.  It was selected not for any of the reasons you describe.  Instead, it was selected to speed up development of five-segment booster and J-2X for Ares V - a choice that was expected to save development costs for Ares V down the road.  In addition, the five-segment booster design actually outperformed the four-segment SSME design.  It's all right there in the ESAS report.

Quote
So the entire premise was falsified and the entire project should have been re-evaluated at that point. 

The falsification comes from your incorrect description of events!

 - Ed Kyle


Offline Lee Jay

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Re: Could Ares 1 have Worked if things had been different?
« Reply #138 on: 09/06/2011 12:14 am »
This is not correct. 

Sure it is.  Jan 14, 2004:

http://smartech.gatech.edu/jspui/bitstream/1853/8025/2/SSEC_SB4_doc.pdf

Quote
One logical, attractive approach to providing the launch capabilities necessary to support the overall exploration vision would be to leverage the existing Space Transportation System (STS) components and
infrastructure.

...

Since STS hardware has already been demonstrated in a human-rated environment, the cost associated with qualifying components for future human-rated applications would be significantly reduced.
Additionally, the proven aspect of that hardware would significantly reduce the risk and improve the safety of future missions involving human exploration and presence in space.

...

The baseline Inline CLV configuration, represented in Figure 1, is a 4 segment Reusable Solid Rocket Motor (RSRM) booster first stage and a LO2/LH2 Space Shuttle Main Engine (SSME) upper stage engine modified for air start capability with 385,000 lbm of propellant.

I'm pretty sure there's an even earlier paper with the same basic approach, but I can't find it right now.

Offline Downix

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Re: Could Ares 1 have Worked if things had been different?
« Reply #139 on: 09/06/2011 01:29 am »
Both Ares I and V had serious design issues that made them unviable designs.

I don't see the Ares I design in particular as nonviable.

It was.  The premise behind Ares-I was to take two existing engines and use their extensive flight experience to make a simple, reliable rocket for Orion.  Then they discovered their choice for the second stage engine (SSME) wouldn't work and that they'd have to design a new second stage engine.  Then they discovered that the new engine wasn't going to give the performance of the original so they'd have to design a new first stage engine as well. 
This is not correct. 

ESAS recommended the four-segment booster and SSME stage 2 design, but also described a five-segment booster and J-2 derived alternative.  The alternative was selected soon after ESAS.  It was selected not for any of the reasons you describe.  Instead, it was selected to speed up development of five-segment booster and J-2X for Ares V - a choice that was expected to save development costs for Ares V down the road.  In addition, the five-segment booster design actually outperformed the four-segment SSME design.  It's all right there in the ESAS report.

Yes, along with this gem about LC16, the 5-segment J-2 (and expander-cycle LR-85) derived solution (which scored behind both Atlas and Delta in the ESAS report):

"The J–2 or J–2S could not support the 2011 launch date requirement."
"...would be too expensive and exhibit an unacceptable development risk to meet the goal of the 2011 IOC for the CEV."
"However, the five-segment development added significant near-term cost and risk and the J–2S+/expander engine could not meet the 2011 schedule target."
"The J–2S option could not meet the 2011 target (whereas the SSME could) and had 6 percent less performance than the SSME-based option (LV 13.1)."

In short, ESAS did include LV16, the Ares I which was developed, and it came in *behind* the other CLV options, with a risk factor of 1.3, almost to the bottom, and the highest facilities cost out of any of the other options.  By the ESAS, the model to be designed should LV13.1 not be persued, was LV2, the Atlas V Heavy with a custom upper stage, with a risk of 1.03, second from the top.

So, just including it in the report does not mean that it was endorsed by the report.  Reading the report, it was the complete opposite, it was included and listed as a high risk of running over the budget, and missing the schedule, as well as listed as a severe risk of failing to meet performance predicted.
chuck - Toilet paper has no real value? Try living with 5 other adults for 6 months in a can with no toilet paper. Man oh man. Toilet paper would be worth it's weight in gold!

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