Updates Ares Updates and Discussion

If you want to carpool, let me know. I have cleared my schedule so I can go September 1st if that is indeed the date. I am just north of you, so I could meet you anywhere from Layton north.
 
I apologize if this has been posted before, but somebody posted this link on a discussion on NSF:

http://www.nasa.gov/ppt/382364main_46 - 20090802.6.CSO inline concerns.ppt#306,3,Objective

(It is a MS Powerpoint)

It is a 2005 report by the Crew Safety Office on using an inline SRB for crewed launches. At the risk of over simplifying their conclusions, the gist of it is that they were deeply skeptical of the safety claims that ATK/SAIC were making, especially when compared to findings based on actual data gathered from historical solid motor firings. Furthermore they thought that the crew survivability would be inferior to a system using a liquid stage.
 
I have to spare just a weary smile on those whole safety issue discussions and reports regarding SRB usage as a single first stage for manned launch vehicles. Wernher von Braun and other people back in the 60's already did not like the idea of SRB's for manned launch vehicles on the whole. But the STS has proved that SRB's are usable and reliable.

The Ares1 first stage of course is in a totally different configuration as the STS SRB's, although certain people tend to argue that the Ares1-X flight is useless because the Shuttle already demonstrates those SRB's for decades. That's how people twist and confuse facts so that it fits into the Ares/NASA criticism. The Ares1 is not comparable to the Shuttle stack. It's something new. And once SRB's burn, they burn. That's not different to the Shuttle SRB's.

If we talk about vibrations: the SaturnV had produced massive vibrations causing damage to equipment. The crew was almost incapable to read certain gauges and reach certain switches during early ascent. They took away their hands from the abort handle to not accidentally activate it because of those vibrations. We have to keep in mind that the SaturnV's five F1 engines produced 7.5 millions pounds of thrust at lift off. Compared to that, the Ares1 SRB just is a toy. And I don't think it will be comparable to a SaturnV launch at all.

The SaturnV had been flown manned after only two unmanned test flights, while the latest one did look like anything, but not promising. And today we are afraid of something like the Ares1, actually the little grandchild of the SaturnV. People complain almost like little unsatisfied and defiant kids. I can only imagine discussions and blubbering in case the Shuttle development would take place these days, with a planned first flight manned. Today we live in a world that cries for safety and certainty at every turn. I can only spare a weary smile. Nothing is certain.

Not to build Ares because people think and conclude it might shake its crews "to death" (LOL) is an invalid argument. Development always is accompanied by challenges, just like manned space flight always is and will be challenging.
 
Moonwalker said:
I have to spare just a weary smile on those whole safety issue discussions and reports regarding SRB usage as a single first stage for manned launch vehicles. Wernher von Braun and other people back in the 60's already did not like the idea of SRB's for manned launch vehicles on the whole. But the STS has proved that SRB's are usable and reliable.

The Ares1 first stage of course is in a totally different configuration as the STS SRB's, although certain people tend to argue that the Ares1-X flight is useless because the Shuttle already demonstrates those SRB's for decades. That's how people twist and confuse facts so that it fits into the Ares/NASA criticism. The Ares1 is not comparable to the Shuttle stack. It's something new. And once SRB's burn, they burn. That's not different to the Shuttle SRB's.

If we talk about vibrations: the SaturnV had produced massive vibrations causing damage to equipment. The crew was almost incapable to read certain gauges and reach certain switches during early ascent. They took away their hands from the abort handle to not accidentally activate it because of those vibrations. We have to keep in mind that the SaturnV's five F1 engines produced 7.5 millions pounds of thrust at lift off. Compared to that, the Ares1 SRB just is a toy. And I don't think it will be comparable to a SaturnV launch at all.

The SaturnV had been flown manned after only two unmanned test flights, while the latest one did look like anything, but not promising. And today we are afraid of something like the Ares1, actually the little grandchild of the SaturnV. People complain almost like little unsatisfied and defiant kids. I can only imagine discussions and blubbering in case the Shuttle development would take place these days, with a planned first flight manned. Today we live in a world that cries for safety and certainty at every turn. I can only spare a weary smile. Nothing is certain.

Not to build Ares because people think and conclude it might shake its crews "to death" (LOL) is an invalid argument. Development always is accompanied by challenges, just like manned space flight always is and will be challenging.
Click to expand...

Your condescending tone combined with your obvious lack of engineering sense is astounding.
 
^ what he said
From your words here, you clearly don't understand the intricacies involved in building a booster. I don't either. But I do know that these vibrations aren't the standard flow-instabilities encountered in a liquid booster. It's called POGO named for pogo sticks. Saturn V had a problem with it in the second stage and as a result, Apollo 6 nearly got shaken apart, and Apollo 13's center S-II engine shut down.

As to "something new" yes Ares I is, no Ares 1X isn't. The only new thing is where the mass is and the fact that it doesn't have a twin across an external fuel tank from it. Ares1X uses the same 4-segment design STS uses. Unless you can convince me and everyone else that 4 != 4 Ares 1-X != Ares 1.

Yes, SaturnV flew manned after only two unmanned test flights, but it was built around proven technology and systems. Is there a precedent for launching people on top of a single solid rocket? No. Have they ever used solid rockets this big before? No.
Liquid engines had been being tested since...well probably Robert Goddard flew the first one. Solids in smaller sizes have been used quite a bit, but none as big as Ares1 will use.
 
Anything had to be used for the first time at the beginning. Not to do something because it had not been done before is no valid reasoning. With that kind of reasoning no Apollo Spacecraft would have ever gone beyond low earth orbit. Sheppart and Gagarin would be nothing more than unknown names. SRB's being used for decades, especially the Shuttle SRB's which are the biggest ones and are going to become even bigger for Ares1. When the Shuttle was in development nobody had ever used such SRB's for such purposes before. That wasn't and isn't a logical reason not to try it.

The fact that Ares1-X uses a Shuttle SRB does not take away the fact that Ares1-X is a completely new and untested vehicle. The 4-segment SRB is comparable to the Shuttle SRB's, but the configuration of Ares1-X is not comparable with the STS stack at all.

If comparing Ares1-X with the Shuttle stack is not lack of engineering sense, then I'm happy to experience that my lack of engineering sense is astounding.
 
Zatnikitelman said:
As to "something new" yes Ares I is, no Ares 1X isn't. The only new thing is where the mass is and the fact that it doesn't have a twin across an external fuel tank from it. Ares1X uses the same 4-segment design STS uses. Unless you can convince me and everyone else that 4 != 4 Ares 1-X != Ares 1.
Click to expand...

You're summarizing the entire reason for the Ares 1X flight test - it's "old" technology (SRB booster segments and 2nd stage cryogenic) arranged in a "new" configuration. The engineering reasoning for this test is sound - it is to provide flight data of the vibrational behavior of a system similar to the production Ares 1 to validate computational design models.

If they can successfully validate their models against data from the Ares 1X flight, then they can feel better about going ahead in final design of the full Ares 1 stack. It is a bootstrap design approach - get something to the 90% design level, test it, refine based on test.
 
[rant]

Man-rate an existing EELV and be done with this Ares I nonsense.

[/rant]
 
I realize that not everybody has powerpoint and cannot view the link I posted. What follows is my digest, for what it is worth, of the observations made by the Crew Safety Office in that presentation:

  • In 44 years of human space flight no flight crew has been lost during ascent as the result of a totally liquid based launch vehicle
  • However, in 24 years of flight on SRB based systems one flight crew has been lost as the result of an SRB failure during ascent
Click to expand...
Of the seven SRB failures in the previous table:


  • Four resulted in vehicle destruction with little or no warning
    • STS 51L
      [*]      Titan 34D-9

      [*]      Titan 403A K-11 (45F-9)
    • Delta 2 7925-10

    [*]    The three TVC failures were caused by loss of hydraulic fluid
Click to expand...
  • SAIC, p. 11: “The proposed design offers significant, as much as an order of magnitude, improvement in crew survival during ascent as compared to the current shuttle system.”

    [*]    CSO: Since the shuttle has no ascent crew survival capability during a first stage SRB failure this statement means “something is better than nothing.”
Click to expand...
  • SAIC, p. 25: 11. There is sufficient warning time, and signals for 80% of the loss of control (thrust augmentation) failures.

    [*]    CSO: There is no analysis that supports the 80% claim.
Click to expand...

  • SAIC, p. 25: 12. An escape system can be designed for the CEV that will provide escape capability after loss of control.
  • CSO: The Titan IV-A LOC (8/12/98) suggests that this may be difficult. 1.7 seconds elapsed between the full pitch command and vehicle breakup at an alpha of ~13 degrees. The time between a reasonable launch abort redline (5 degrees) and breakup was much smaller.
Click to expand...
  • SAIC, p. 8: “Simple Inherently Safe Design – A single human-rated SRB first stage matured through years of experience with over 176 flights of the current design for launching crew”
  • CSO: This statement, while true of the current shuttle RSRB, is not necessarily applicable to the proposed new 5 segment RSRB or RSRB inline configuration. Also, is the shuttle RSRB human rated because it truly meets human rating requirements or because there were no viable alternatives to it for the shuttle system? Is it truly human rated or human rated because humans ride on it?
Click to expand...

I'm certainly no engineer. That's why I tend to listen to those that are on engineering matters.
 
However, in 24 years of flight on SRB based systems one flight crew has been lost as the result of an SRB failure during ascen
Click to expand...



This argument is kinda stupid. They fail to take into account the countless warnings engineers made to the management. The management was well aware of the problems launching in cold temperatures will cause, but because STS-51 was postponed several times before, the go-ahead was given.

Blaming the Challenger disaster on the SRB is like blaming a car crash on the wheels slipping and neglecting the fact that the driver was drunk and driving on ice.
 
RisingFury said:
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This argument is kinda stupid. They fail to take into account the countless warnings engineers made to the management. The management was well aware of the problems launching in cold temperatures will cause, but because STS-51 was postponed several times before, the go-ahead was given.

Blaming the Challenger disaster on the SRB is like blaming a car crash on the wheels slipping and neglecting the fact that the driver was drunk and driving on ice.
Click to expand...

Much as I'm not a fan of Ares, this is a valid statement. The SRB failure on Challenger was a result of a known weakness of the SRB joints in cold weather that was ignored by management. You could call it an engineering weakness in the SRB design, but it's one that was easily mitigated by just following the launch condition rules.
 
Blaming the Challenger disaster on the SRB is like blaming a car crash on the wheels slipping and neglecting the fact that the driver was drunk and driving on ice.
Click to expand...

Indeed. Challenger is an example of a failiure caused by ignorance/pushing the hardware beyond safe parameters, and Columbia is an example of a failiure caused by a real design flaw in the system.
 
The Challenger disaster is the extreme end of SRB failures, compounded by poor risk management decisions made leading up to the launch. The report lists 31 occasions where SRB anomalies were discovered, 16 of them since Challenger. My take on it was that the CSO doesn't expect SRBs to be perfect, but the level of reliabilty claimed by the figures supplied by ATK/SAIC don't reflect historical fact and that the nature of SRB failures in the past don't lend themselves to having a survivable abort scenario for the crew.
 
I would also agree that Challenger was caused by people ignoring problems which were easy to mitigate, and which were later engineered out of existence. SRBs would appear to be fairly safe and reliable for producing thrust without blowing up; even Challenger's faulty SRB did not explode nor even lose thrust, continuing to function even after the vehicle broke up.

The real problem with Ares' solid rocket is that it is essentially a bran new SRB with predicted heavy vibrations and no flight history.

The CSO asks about the meaning of "man-rated", but that's kind of subjective. You do the analysis, figure out how likely a rocket is to fail catastrophically, and then decide if the risk level is below your comfort zone. 1 in a million chance? How about 1 in a 1000? 1 in a 100? Whatever you're comfortable with.

I will give NASA this much: Ares 1 will be test flown unmanned a few times before anybody tries to ride this thing.

That's a whole lot more than you could say about STS. I don't know whether I would call Young and Crippen brave or crazy.
 
The STS-51L example indeed is invalid. Thoes SRB's are absolutely reliable for now. They boost the Shuttle during early ascent for nearly 30 years. The STS-51L disaster was caused by carelessness.

One could also try to argue that a mixed solid and liquid based launch vehicle like the Shuttle stack is unsafe, because the Shuttle SRB has caused the external tank to dramatically fail.
 
Yea, sure it was the management failure that ultimately contributed to the destruction of STS-51L, but if the system had been liquid fueled, the management failure might not have happened.
Posted before seeing the new posts EDIT:
Another thing that sets liquid fuels apart from SRBs is that Liquid engines have one area of combustion instead of being a combustion up the entire length of the vehicle. In STS the crew cabin actually sits below part of the combusting part of the engine.
 
Andy44 said:
That's a whole lot more than you could say about STS. I don't know whether I would call Young and Crippen brave or crazy.
Click to expand...

I'd call them both, but with a positive meaning. They show that people don't have to be afraid too much to do something risky to gain human progress as a result.

The STS SRB also was brand new and had no flight history. That's one reason why I just have to spare a weary smile on those safety discussions. And it shows the capabilities of the minds who work for NASA, their country and in a way for humankind I think.
 
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