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Author Topic:   PAL Ramp Follies
Orthon
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Posts: 110
From: Gilbert, Arizona 85296
Registered: May 2002

posted 06-16-2006 07:03 PM     Click Here to See the Profile for Orthon   Click Here to Email Orthon     Edit/Delete Message   Reply w/Quote
What a sad state of affairs this PAL Ramp controversy has become.
The dog chasing it's tail. This one problem has become a clear indication that NASA is not the agency it once was during the Von Braun era.
They have managed to create a vehicle that is so full of problems that they can't even engineer a fix on this.

[This message has been edited by Orthon (edited June 16, 2006).]

LT Scott Schneeweis
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posted 06-16-2006 07:43 PM           Edit/Delete Message   Reply w/Quote
Is there anticipated to be an additional launch delay resulting from the redesign efforts?

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Scott Schneeweis

URL http://www.SPACEAHOLIC.com/

Robert Pearlman
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posted 06-16-2006 10:07 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
Did I miss something while I was out to dinner? What PAL ramp controversy? Are you referring to the ice frost ramps?

In my mind this is exactly how von Braun would have tackled this problem. Make a change. Fly. See what happens. Make another change.

Which is exactly what is happening. We removed the PAL ramps after careful study. Here is a photograph of the wind tunnel model used to study the PAL ramps' removal, which I took yesterday at Glenn Research Center:

Now we fly. We record the results. Then attention turns to the ice frost ramps.

To answer Scott, unless Hale and his team have had a complete change of heart in the past few hours, there will be no design changes made to the ET for STS-121 or for STS-115.

[This message has been edited by Robert Pearlman (edited June 16, 2006).]

Orthon
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From: Gilbert, Arizona 85296
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posted 06-16-2006 10:17 PM     Click Here to See the Profile for Orthon   Click Here to Email Orthon     Edit/Delete Message   Reply w/Quote
Excuse me, I meant the frost ramps. And am I mistaken again, or was it Von Braun who was quoted as saying "this is an accident waiting to happen" when shown the design of the shuttle?

Robert Pearlman
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posted 06-16-2006 10:43 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
von Braun didn't think his Saturn V to be invulnerable either. If we had flown it 114 times, I doubt its perfect record would have stood the test of time, nor do I believe von Braun thought it would.

Flying when we knew that foam was falling off and doing nothing about it was anti-Braunian (if I can coin a term). Flying after we have worked the problem, tested it as best we can on the ground and not making matters worse by trying to change too many things at once is pure engineering.

Stephen Clemmons
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From: Wilmington, NC, New Hanover
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posted 06-18-2006 07:37 AM     Click Here to See the Profile for Stephen Clemmons   Click Here to Email Stephen Clemmons     Edit/Delete Message   Reply w/Quote
You're right, Robert. That's the only way we can find out if the fix works. Redesign and fly. That's how we did on the the early rockets and it worked.
But the main fix is yet to come.(If ever) that's the one that will take the crew out of harms way.
I think most of us that were around when the Shuttle was first proposed in 1968,including Dr. Von Braun, didn't think too much of the fact that the crew was doomed in case of a minor or major malfunction.
That was our biggest concern then and still is today.
I know, some of you will say it's sour grapes, that we have to take chances, called calculated risks in order to move ahead, but the fact remains, we still have a vehicle that is inherently a death trap with no chance of survival and if anything happens, we just add the victims names to the Astronaut memorial.
That's wrong, wrong, wrong.
Shortly before Columbia came back, I was at Kennedy and talked to several of my old friends, now managers that were working on Shuttle, about the foam problem.
I even saw the photo's of the foam hit. They couldn't understand why higher management within NASA did not consider it a real problem.
They were worried as well as I that the craft wouldn't make it back in one piece.
For the life of me, I couldn't understand why they had not considered tackling the foam problem earlier.
It was a known fact that every flight had recorded many hits resulting in tile damage dating back to the first flight, there were instruments and test equipment that would subject these tiles to the rigors of liftoff, yet they decided these tests were too costly and not really required.
One of the proposals that I saw back in 1968 was to build the cockpit and crew compartment so that it could be pulled away with a launch escape rocket in the first 200,000 feet,(38 miles). Four parachutes would drop it to the sea below.
Instruments would detect if the spacecraft was damaged or ruptured during launch and the crew would have a good chance of surviving.
It would have worked on both Challenger and Columbia. There were sensors on Columbia that had been deactivated that could have been installed on every shuttle just for that purpose.
I know I'm getting a little sideways on this post, but I don't feel that they have really considered everything. The ramp problems are just a part of the big picture.
They have probably considered everything that they can do something about and that's good.
Let's hope they have solved the foam problem anyway.
We need to say special prayers that day, July 1. I know I will.

Orthon
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From: Gilbert, Arizona 85296
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posted 06-18-2006 07:56 AM     Click Here to See the Profile for Orthon   Click Here to Email Orthon     Edit/Delete Message   Reply w/Quote
Thank you Stephen for the excellent post. Candy coating this programs many flaws will only lead to the loss of more lives.

[This message has been edited by Orthon (edited June 18, 2006).]

Robert Pearlman
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posted 06-18-2006 01:54 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
quote:
Originally posted by Stephen Clemmons:
Let's hope they have solved the foam problem anyway.
Based on recent comments by Hale and Griffin, NASA does not feel it has solved the foam problem, yet. However, what the agency has come to realize is that it cannot be solved without flying more missions and testing the changes made to date. Quoting Griffin this past week:
quote:
We are not in the situation we were with Columbia. We know we have a problem, we have elected to take the risk.
Hale said he believes the External Tank to be structurally sound to fly safely. However, the tank will be further modified even if STS-121 loses no foam when it launches next month.
quote:
Originally posted by Orthon:
Candy coating this programs many flaws will only lead to the loss of more lives.
I haven't seen anyone candy coating the problems. Instead, they are taking a measured approach learning how to fly the space shuttle as safely as is possible before it retires and is replaced by a vehicle designed using the lessons of the past 25- and next 4-years.

[This message has been edited by Robert Pearlman (edited June 18, 2006).]

GACspaceguy
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From: Guyton, GA
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posted 06-19-2006 11:14 AM     Click Here to See the Profile for GACspaceguy   Click Here to Email GACspaceguy     Edit/Delete Message   Reply w/Quote
All flying machines have issues that require some form of rectification. This is why the FAA issues airworthiness directives (AD). In some cases the situation is such that safety is compromised and the issues must have corrective action taken before further flight. In other cases (the vast majority) the issue is analyzed, documented and as such, the condition is allowed to remain in service for a time until the aircraft can be reworked at a convenient down time. For some cases, the inspection or action is taken so that more data can be obtained as a stepping stone to a final solution.

I see this as a similar situation for the Space Shuttle

LT Scott Schneeweis
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posted 06-22-2006 02:24 PM           Edit/Delete Message   Reply w/Quote
I dont share the enthusiasm of STS-121's impending launch....the shuttle has proven itself to be a death trap and remains so...every other airframe which operates at the edge of its respective peformance envelope offers an ability to punch out. The egress slide system is virtually worthless; the capsule ejection escape option should have been pursued even if it ment substantial redesign of the shuttle.

------------------
Scott Schneeweis

URL http://www.SPACEAHOLIC.com/

[This message has been edited by LT Scott Schneeweis (edited June 22, 2006).]

mjanovec
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posted 06-22-2006 05:23 PM     Click Here to See the Profile for mjanovec   Click Here to Email mjanovec     Edit/Delete Message   Reply w/Quote
I approach the coming launch with apprehension. The Shuttle is a flawed design and the problems it has are unlikely to be fully ironed out by the end of it's lifetime (2010). Having said that, however, I think NASA took the right approach by resuming the program, but with a very limited lifetime. Improvements can hopefully be made as flights proceed. That will allow certain goals to be met (hopefully) until the next generation of launch vehicals are ready.

I just hope there aren't other issues out there that have been ignored "because it hasn't gotten us" before. The O-Ring problems were well-documented before Challenger (see the Spacecraft Films DVD set for a full rundown of events). Foam shedding has been with us since STS-1, but was never thought to be a mission critical event up until STS-107 ended tragically. I wonder what other things are out there that can bite us.

Then again, one has to ask themselves how much riskier is the Shuttle than, say, an Apollo moon landing attempt? While the Shuttle is a flawed design, I have to wonder how many Apollo landing attempts would have resulted in accidents had we attempted 100+ landings.

Are we just more afraid to accept the risks these days? Or are the rewards of a lunar landing worth more risk than a low Earth orbit flight in the Shuttle? My gut tells me yes, but how will the public react when a moon landing mission results in an accident (and one WILL happen someday).

MCroft04
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posted 06-22-2006 10:25 PM     Click Here to See the Profile for MCroft04   Click Here to Email MCroft04     Edit/Delete Message   Reply w/Quote
I wonder if the shuttle were making at trip to the moon or mars if so many people would be against the launch. It just seems to me the people don't think going into low earth orbit is worth the risk. I disagree; I beleive that the next big discovery could very well be awaiting a shuttle astronaut's research on the shuttle. There is opportunity in low earth orbit; it just may take some time.

LT Scott Schneeweis
unregistered
posted 06-22-2006 11:42 PM           Edit/Delete Message   Reply w/Quote
quote:
Originally posted by MCroft04:
I wonder if the shuttle were making at trip to the moon or mars if so many people would be against the launch. It just seems to me the people don't think going into low earth orbit is worth the risk. I disagree; I beleive that the next big discovery could very well be awaiting a shuttle astronaut's research on the shuttle. There is opportunity in low earth orbit; it just may take some time.


From my perspective its not about the merits of low earth orbit - its about the payoff vs tangible risk and the choice of technology to get us there. There was greater investment in redundancy and safety in the Apollo program, even though that effort had fewer people placed in harms way on each mission and a more substantial payoff.

------------------
Scott Schneeweis

URL http://www.SPACEAHOLIC.com/

Stephen Clemmons
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posted 06-23-2006 06:17 AM     Click Here to See the Profile for Stephen Clemmons   Click Here to Email Stephen Clemmons     Edit/Delete Message   Reply w/Quote
Scott, you're so right. After Apollo I, Safety became the big isssue. The tools were there, just needed more details to work. The ground/flight crew could get off the tower in a short time if there was a problem down below.
The Astronauts could always punch out at any point after the white room was pulled away and if there was a problem during the early stages of launch, they had options of pulling out of harms way from the launch vehicle.
None of that exists today. If there's a problem, even a minor one,(Foam and Debris) it's a real death situation and that's wrong.
During Apollo, if there was any sign of a malfunction that would abort the mission, from ground launch to moon landing to earth landing, the astronauts had a sure way of getting back safely.
The only black mark was Apollo 13, which also proved that with the right support, even a disabled spacecraft could get home.
That doesn't exist on the Shuttle.
I asked my young grandson if he wanted to go to the Cape on July 1 to see the launch.
Even though he's a real space buff, he declined, saying he had no intention of watching the launchs again, after seeing pictures of Challenger and then watching television that morning when Columbia broke up on the way home.
I know that there are those brave astronauts that will volunteer to go, no matter what but I don't think it's good for our younger generation for NASA to continually and intentionally put our whole future space program in real jeapardy.
There's a good article from the NASA Safety Director about the present shuttle safety problems on SPACE.com. These comments were made shortly after the recent decision to fly . Interesting reading.
By the way, Scott, I wasn't able to get to the Cape to look for some of the artifacts at the Space Walk of Fame Museum that we talked about. Maybe later.

spaceuk
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posted 06-23-2006 06:28 AM     Click Here to See the Profile for spaceuk     Edit/Delete Message   Reply w/Quote
One element of von Braun's original 'paper' study of a multi-crewed shuttle vehicle was that it would have had escapable crew pods for each member.

The early NASA shuttle had ejection seats for the commander and pilot and I think they should have kept this design on each shuttle. So in this scenario of problem-fix-refly then only a commander/pilot would fly until NASA 'happy-ish' with results.

My long term concern with this current shuttle vehicle is that it is 'strapped' to the side of its ET/SRB tanks/motors.

Some of the earlier designs - before Rockwell design accepted - would have had the vehicle atop the ET/propellant motors .
Would have afforded a better chance of survival maybe?

The better solution is the Mercury/APollo/CEV design where an escape tower is fitted to eject capsule during the launch to orbit phases.


Phill
spaceuk

Robert Pearlman
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posted 06-23-2006 08:59 AM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
quote:
Originally posted by Stephen Clemmons:
The only black mark was Apollo 13, which also proved that with the right support, even a disabled spacecraft could get home.
Actually, all it proved was that NASA and the astronauts were incredibly lucky. Had the timeline of Apollo 13 been any different if the explosion had occurred after they had undocked from the LM in lunar orbit, or worse, after Aquarius had landed, there would have been no means of returning home.

Every U.S. space vehicle has had times in its flight profile where escape was impossible for the crew, were it during launch, orbit, or reentry. Even when there were means of escape, sometimes that route was considered more dangerous than the alternative. Stafford and Young, amongst others have commented on more than one occassion that given what they knew then and now, ejecting from Gemini was life-threatening (Young has said the same about the ejection system on STS-1).

Unlike Mercury, Gemini and Apollo, the shuttle has several abort options on its way to space. With the space station in orbit, it now has an additional "safe haven," which is why NASA's Chief Engineer and Safety Director did not oppose launching Discovery on July 1 despite their "no go" status. STS-121 will also be the first mission to launch with the ability to perform a completely autonomous landing so that in the situation that a reentry is deemed unsafe for the crew, NASA might still attempt a repair and possibly see Discovery return to Earth intact.

The shuttle is not a "deathtrap." Could it have additional safety features? Absolutely. But its naive to suggest that earlier vehicles were orders of magnitude safer during flight.

[This message has been edited by Robert Pearlman (edited June 23, 2006).]

KSCartist
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posted 06-23-2006 09:48 AM     Click Here to See the Profile for KSCartist   Click Here to Email KSCartist     Edit/Delete Message   Reply w/Quote
While I will be the first to admit that the Shuttle Program did not live up to its billing. It is because NASA and its contractors were forced by an unsupportive President, an unfriendly Congress and an apathetic public to over sell the shuttle.

Should the shuttle have been built with a break away crew compartment - absolutely. Vehicles should be designed and built to specifications of the mission not the budget.

But the shuttle program has been an incredible education. We have learned to repair satellites on orbit, overcome maintenance issues on the station and work with partners from around the world. The men and women who work in the program are just as dedicated to its success and those who took us to the Moon. They made fatal decisions based on pressures (that did not exist in the 1960's)because they are human.

Every person who has flown would say the same things, "Do not mourn for me because I was doing something that I loved." and "Lets fix the problem and go fly."

Should we wait until the Ice Frost Ramps are re-designed before STS-121 launches? I honestly don't know. They tested this current design that's on the pad now and it passed with stresses greater that the vehicle should experience. The rule in flight test has always been to make a design change test it in the wind tunnel and then fly it. That appears to be what they are doing. The redesign on the Ice Frost Ramps have not passed the tests in the wind tunnel.

I am praying that they got it right but I believe that Mike Griffin to Wayne Hale and all those who work for them are doing everything they can to fly as safely as possible. The only way to be safer is to not fly. I believe that the crew knows and accepts the risks.

While I am proud of our accomplishments with the Shuttle Program I will be releaved when it ends. The task before each and every one of us is to hold Congress' feet to the fire when they try and cut the budget for the CEV. So that vehicle is built as it is designed, even if costs go up.

Sorry to ramble but - my two cents.

Tim

Story Musgrave called the shuttle "a butterfly strapped to a bullet."

LT Scott Schneeweis
unregistered
posted 06-23-2006 12:03 PM           Edit/Delete Message   Reply w/Quote
quote:
Originally posted by Robert Pearlman:

Every U.S. space vehicle has had times in its flight profile where escape was impossible for the crew, were it during launch, orbit, or reentry.


Shuttle safety let economics vice efficacy serve as the determinate in the design...NASA was presented with range of choices offered to them, particuarly after STS-51L. A decision was made to not go with crew capsule ejection which, while not reducing to zero the possibility of crew loss, would have more significantly increased the range of options available throughout the shuttle's flight profile to get people home. The response to catastrophic failure of Apollo 1 was to mobilize a significant redesign of the Block II which did reduce to near zero the possibility of a cabin fire. Had there been subsequent crew loss during a flight, particularly one which involved a single of point of failure in the design, my guess is that NASA would have triggered an equally comprehensive fix for that problem as well before pressing on. I do not detect an analogous approach in the shuttle program.


None of the offered courses of action available for crew safety are paletable. Autonomous landing on STS-121? Possibly but it hasnt been demonstrated outside a simulated environment...if safety were a priority, NASA would either robotically or with a reduced crew fly a test mission and demonstrate real functionality. Its also only applicable during tiny windows of the flight profile and assumes that flight control surfaces remain available/undamaged to support vehicle steering.

ISS as a lifeboat? What then..we imperil another crew to launch in a second vehicle which has a demonstrated propensity to fail?


[This message has been edited by LT Scott Schneeweis (edited June 23, 2006).]

Robert Pearlman
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posted 06-23-2006 12:24 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
quote:
Originally posted by LT Scott Schneeweis:

Autonomous landing on STS-121? Possibly but it hasnt been demonstrated outside a simulated environment...


Sure it has: on the past 113 shuttle missions. Until now, the only aspect of landing that required the crew's interaction was deployment of the landing gear and drag chute. Every other step of the way, the ground/on-board computers could have taken control.

As for your other points, it is my understanding that the crew capsule ejection modifications would have come at a tremendous cost to payload capacity. The ISS and Hubble may have been impossible were it implemented, leaving the post-Challenger program without a purpose (given the ban on commercial rescue and repair activities).

I do not dispute that the shuttle could have been safer, but I disagree that its design is/was flawed. The losses of Challenger and Columbia were because of known problems that we either underestimated or chose to ignore. In both cases, there were opportunities where the crew could have been saved had engineers' warnings been heeded. The same could not be said for Apollo 13, were its outcome different.

As for "safe haven," if the shuttle is deemed too risky to launch again, then we have partners that we can work with to launch resupply and rescue vehicles. Its not a perfect situation, but its an option none the less.

[This message has been edited by Robert Pearlman (edited June 23, 2006).]

issman1
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posted 06-23-2006 12:41 PM     Click Here to See the Profile for issman1     Edit/Delete Message   Reply w/Quote
What I fail to understand is why Bryan O'Connor and his safety branch opposed the STS-121 launch at the FRR.
Then, a few days later, he does a complete U-turn and tells the world's press that launch is safe to proceed.
I believe that even if foam is shed, the Shuttle programme should continue without further delay until the final flight in '09. It's a calculated risk and one that is worth it.

Robert Pearlman
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posted 06-23-2006 01:04 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
quote:
Originally posted by issman1:
What I fail to understand is why Bryan O'Connor and his safety branch opposed the STS-121 launch at the FRR.
O'Connor's objection at the FRR was based solely on the safety of the vehicle, not the crew. Foam loss presents little to no risk during ascent and given the orbiter's new abilities for inspection and the "safe haven" option for the crew aboard the ISS, even if an entire ice frost ramp were to shake loose (which in of itself is a low risk), the crew's lives would not be directly threatened. O'Connor hasn't waived his concern about the ramps but has remained consistent that from a crew safety perpective, STS-121 is fit to fly.

Orthon
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From: Gilbert, Arizona 85296
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posted 06-23-2006 10:39 PM     Click Here to See the Profile for Orthon   Click Here to Email Orthon     Edit/Delete Message   Reply w/Quote
To sum up this discussion, it comes down to this: NASA has decided that if Discovery IS damaged by foam on ascent, the astronauts will be able to repair the damage or take refuge aboard the ISS until a return aboard Soyuz or Atlantis becomes available.
If Discovery can not be repaired, then this 2 - 3 billion dollar vehicle will be dumped into the ocean and the US will be out of the manned space arena for the next 7 - 10 years. Gee, thats great.

Robert Pearlman
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posted 06-23-2006 10:46 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
quote:
Originally posted by Orthon:
If Discovery can not be repaired, then this 2 - 3 billion dollar vehicle will be dumped into the ocean and the US will be out of the manned space arena for the next 7 - 10 years. Gee, thats great.
Actually, no. As Griffin has testified to Congress, CEV development could be accelerated if NASA were given more money. Without 18 shuttle missions to fund, its budget is (hopefully) repurposed to the CEV and we start flying test missions as early as perhaps 2009. The only reason we are still flying shuttle at least per Griffin's viewpoint is because the President's vision includes completing the ISS.

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