Author Topic: 5.5 Segment Ares I  (Read 44370 times)

Offline guru

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5.5 Segment Ares I
« on: 06/17/2008 04:04 PM »
So, NASA is considering switching the CaLV booster to use a 5.5 segment motor.  Does this mean that they have to go back and redesign Ares I, since most of the justification for it is to create components for the CaLV (Ares VI)?

Offline hyper_snyper

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Re: 5.5 Segment Ares I
« Reply #1 on: 06/17/2008 04:16 PM »
How long will the gap be with a 5.5seg? 

Offline guru

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Re: 5.5 Segment Ares I
« Reply #2 on: 06/17/2008 04:29 PM »
How long will the gap be with a 5.5seg? 

Forever and ever, worlds without end. j/k I think.

My guess is that the gap will be longer by at least a year and a half, since they've already built and test fired a couple of those, and thus already have the tooling and grain design in place.  If they think flight oscillation is bad with five segments, though, wait until you fly with six.

(By the way, what is it with all of the "and a half" s.  e.g. one and a half launch architecture, five and a half segments.)

Offline guru

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Re: 5.5 Segment Ares I
« Reply #3 on: 06/17/2008 04:30 PM »
By "a couple of those" I mean "a couple of the five segment boosters".
« Last Edit: 06/17/2008 04:31 PM by guru »

Offline Thorny

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Re: 5.5 Segment Ares I
« Reply #4 on: 06/17/2008 04:45 PM »
If memory serves, a "segment" is made up of two "drums" loaded with propellant and connected at the factory (a "factory joint"). Then the segments are connected "in the field" at the launch site (the "field joint").

The Five Segment SRB previously planned had one more segment (two drums) than the Shuttle SRBs.

The new lengthened SRB gains one more drum, not two, so it is only gaining half a segment, i.e., 5 1/2 segments.

Offline Patchouli

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Re: 5.5 Segment Ares I
« Reply #5 on: 06/17/2008 04:49 PM »
Wouldn't it be easier to just switch the the Jupiter 120 then mess with a 5.5 segment srb since even the five segment srb is trouble?
Other options why not use some small strap on srbs to get extra performance like JAXA does on the H2A?
If they added four GEM60s they might even be able to get away with just a four segment RSRM.
Yes I know this makes five srb start events vs one but if you ask me it's probably a lot safer then working the bugs out on what turns out to be a completely new SRB design with new nozzles,a new fuel grain,and new recovery systems etc.
Other solutions maybe use four of the H2A boosters on Ares V plus the two RSRMs.

But the best solution would is that provided by the direct launcher group as both vehicles only have two SRB start events and RSRM remains unchanged from the shuttle.
The J-120 CLV also has no air start events so I think it would be safer then Ares I.

Offline marsavian

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Re: 5.5 Segment Ares I
« Reply #6 on: 06/17/2008 05:12 PM »
The J-120 would be easier but it's not safer. 2 SRBs, a big fuel tank and 2 RS-68s all in parallel is not a safer configuration than a J2-X on top of a SRB both intuitively and by the calculated numbers.

Offline Tim S

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Re: 5.5 Segment Ares I
« Reply #7 on: 06/17/2008 06:27 PM »
So, NASA is considering switching the CaLV booster to use a 5.5 segment motor.  Does this mean that they have to go back and redesign Ares I, since most of the justification for it is to create components for the CaLV (Ares VI)?

Ares I remains a five segment first stage solid. The 5.5 is for Ares V, and may be six segments, but Ares I remains unchanged. There's a long way o go until anything happens with Ares V, so Ares I will continue unhindered.

This is the correct move as additional changes to Ares I's first stage at this time may delay us past the 2016 first flight to the ISS, which is not desirable.

Offline TrueBlueWitt

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Re: 5.5 Segment Ares I
« Reply #8 on: 06/17/2008 06:49 PM »
So, NASA is considering switching the CaLV booster to use a 5.5 segment motor.  Does this mean that they have to go back and redesign Ares I, since most of the justification for it is to create components for the CaLV (Ares VI)?

Ares I remains a five segment first stage solid. The 5.5 is for Ares V, and may be six segments, but Ares I remains unchanged. There's a long way o go until anything happens with Ares V, so Ares I will continue unhindered.

This is the correct move as additional changes to Ares I's first stage at this time may delay us past the 2016 first flight to the ISS, which is not desirable.

Why have a program where you have to wait till 2016 in the first place?  How strict are the weather launch limits going to be on Ares-I with "sail" effect? Won't this increase potential LOM when trying to launch to meet up with a short shelf life EDS launched on the Ares V monstrosity?

Doesn't the new height of AresV now almost preclude ever man rating it as there won't be clearance for the LAS?

How does building two brand new non-shuttle derived rockets make economic sense?

If you are starting from "Scratch" at least come up with an "optimized" solution(Direct or otherwise), not putting band-aids on top of band-aids, that still don't give you a system that meets your exploration requirements.

Offline gladiator1332

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Re: 5.5 Segment Ares I
« Reply #9 on: 06/17/2008 07:15 PM »
So, NASA is considering switching the CaLV booster to use a 5.5 segment motor.  Does this mean that they have to go back and redesign Ares I, since most of the justification for it is to create components for the CaLV (Ares VI)?

Ares I remains a five segment first stage solid. The 5.5 is for Ares V, and may be six segments, but Ares I remains unchanged. There's a long way o go until anything happens with Ares V, so Ares I will continue unhindered.

This is the correct move as additional changes to Ares I's first stage at this time may delay us past the 2016 first flight to the ISS, which is not desirable.

Taking a "we'll worry about it when we get there" policy with Ares V is just setting this thing up for failure. We are now building two completely new and different vehicles that have little in common.

One of the strongest arguments Griffin has made for Ares I is that the 5 seg is needed for Ares V...now this commonality is out the window. That argument has been blown out of the water by changing to the 5.5 seg for Ares V.

Offline Jim

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Re: 5.5 Segment Ares I
« Reply #10 on: 06/17/2008 07:27 PM »

This is the correct move as additional changes to Ares I's first stage at this time may delay us past the 2016 first flight to the ISS, which is not desirable.

It will do that on its own without any help

Offline Antares

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Re: 5.5 Segment Ares I
« Reply #11 on: 06/17/2008 11:18 PM »
"Worry about it when we get there": that's the story of ESAS funding, ladies and gents.
If I like something on NSF, it's probably because I know it to be accurate.  Every once in a while, it's just something I agree with.  Facts generally receive the former.

Offline madscientist197

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Re: 5.5 Segment Ares I
« Reply #12 on: 06/18/2008 02:26 AM »
This is pretty much the worst possible outcome possible from the VSE. If China actually has lunar ambitions, they must be laughing.

Why is it that NASA can't budget properly? This is my biggest concern - why have they systematically underestimated costs/mass requirements?

IMHO they need to start cutting back on features to save the lunar program. I would start by giving up on anytime return, I also suspect a methane/oxygen ascent stage would be somewhat cheaper than the 5.5 segment/core stretch/extra engine changes (not that I know the precise tradeoffs).
« Last Edit: 06/18/2008 02:41 AM by madscientist197 »
John

Offline Danny Dot

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Re: 5.5 Segment Ares I
« Reply #13 on: 06/18/2008 02:38 AM »
This is pretty much the worst possible outcome possible from the VSE. If China actually has lunar ambitions, they must be laughing.

Why is it that NASA can't budget properly? This is my biggest concern - why have they systematically underestimated costs/mass requirements?

I think "Vanilla" summed it up well in a different thread.  The conceptual design of NASA vehicles is not being done by conceptual design teams.  It is being done by politically motivated managers.
Danny Deger

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Re: 5.5 Segment Ares I
« Reply #14 on: 06/18/2008 02:43 AM »
This is pretty much the worst possible outcome possible from the VSE. If China actually has lunar ambitions, they must be laughing.

Why is it that NASA can't budget properly? This is my biggest concern - why have they systematically underestimated costs/mass requirements?

IMHO they need to start cutting back on features to save the lunar program. I would start by giving up on anytime return.

This is a little unfair.  What we have here is not underestimating costs, but major engineering issues that are driving changes and the cost way beyond the original estimate or orginal architecture proposal.  Essentially we are now in apples and organges mode when it comes to the the ESAS pick and what is in development. 

It is very hard to estimate cost when you are willing to do anything to have your pet architecture fly, regardless of the effect on other elements or to schedule and budget.
Enjoying viewing the forum a little better now by filtering certain users.

Offline madscientist197

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Re: 5.5 Segment Ares I
« Reply #15 on: 06/18/2008 02:48 AM »
This is a little unfair.  What we have here is not underestimating costs, but major engineering issues that are driving changes and the cost way beyond the original estimate or orginal architecture proposal.  Essentially we are now in apples and organges mode when it comes to the the ESAS pick and what is in development. 

You're right, the same thing happens in software engineering. Tons of projects go overbudget/late and it's impossible to see what all the problems will be down the line that may affect cost/schedule etc. It doesn't make me feel any better though, and for-better-or-worse it is very easy to blame NASA.

If I was in their position, I probably wouldn't have done any better - but it is frustrating.
« Last Edit: 06/18/2008 02:50 AM by madscientist197 »
John

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Re: 5.5 Segment Ares I
« Reply #16 on: 06/18/2008 02:51 AM »
So, NASA is considering switching the CaLV booster to use a 5.5 segment motor.  Does this mean that they have to go back and redesign Ares I, since most of the justification for it is to create components for the CaLV (Ares VI)?

Ares I remains a five segment first stage solid. The 5.5 is for Ares V, and may be six segments, but Ares I remains unchanged. There's a long way o go until anything happens with Ares V, so Ares I will continue unhindered.

This is the correct move as additional changes to Ares I's first stage at this time may delay us past the 2016 first flight to the ISS, which is not desirable.

I agree this is exactly what will happen and have said this in the Ares V hot topic thread.

I'm curious as someone who works at MSFC, what your opinion is on this.  I have no idea who you are but do you personally think this is the best use of our limited budget given the new development costs that will be added to Ares V and then the increased sustaining/operating costs that will each project will have to absorb if Ares I does not change? 

Do you belive that it is worth the cost to develop/qual Ares I to a 5.5 segment later after all that will have been spent on this version?
Enjoying viewing the forum a little better now by filtering certain users.

Offline Patchouli

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Re: 5.5 Segment Ares I
« Reply #17 on: 06/18/2008 04:05 AM »
The J-120 would be easier but it's not safer. 2 SRBs, a big fuel tank and 2 RS-68s all in parallel is not a safer configuration than a J2-X on top of a SRB both intuitively and by the calculated numbers.

Actually the J-120 would be much safer as it has better mass margins and the four segment RSRM is well understood.
Also having better payload margins means the Orion can keep it's redundant systems.
I seen too many instances where a redundant system saved a shuttle mission and a failure was just an annoyance vs a life threating situation.
A good example of this is when one of the pumps in the shuttle's coolant loop system failed and they still had a second backup with the flash evaporator.
Lastly the abort options are a lot better with the J120 and a lot less likely to be used since the RS-68s are ground started the vehicle doesn't leave the pad until it's known the main engines are healthy.

Most rocket engine failures happen in the first few seconds of operation hard starts,FOD or turbo pump failures etc.

Ares I if the second stage fails to start guess where you come down in the middle of the Atlantic not a desirable option.

If you ask me Ares I has turned out to be a death trap it needs active damping just to not kill anyone riding it that doesn't sound very safe to me.

I question those who calculate the safety on concepts and their ability or at the very least honesty.
 I also wonder where they get their numbers but I think we can safely say those numbers are not worth the paper they are printed on.

It seems they don't know of things that have been developed since 1967 such as vehicle health monitoring and Kevlar shields which would allow one to escape the stack long before it's in the process of exploding.

BTW on the reliability of vehicle health monitoring and computer controls if you ever fly on an airliner or ride a train your life is depending on the reliability of such systems.
« Last Edit: 06/18/2008 04:15 AM by Patchouli »

Offline Jim

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Re: 5.5 Segment Ares I
« Reply #18 on: 06/18/2008 04:31 AM »

Ares I if the second stage fails to start guess where you come down in the middle of the Atlantic not a desirable option.


No, just 150 mi or so offshore just like the SRB's

Offline MrTim

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Re: 5.5 Segment Ares I
« Reply #19 on: 06/18/2008 01:45 PM »
Actually the J-120 would be much safer as it has better mass margins and the four segment RSRM is well understood.
Also having better payload margins means the Orion can keep it's redundant systems.
I seen too many instances where a redundant system saved a shuttle mission and a failure was just an annoyance vs a life threating situation.
A good example of this is when one of the pumps in the shuttle's coolant loop system failed and they still had a second backup with the flash evaporator.
Lastly the abort options are a lot better with the J120 and a lot less likely to be used since the RS-68s are ground started the vehicle doesn't leave the pad until it's known the main engines are healthy.(snip)
Yet another thread gets swallowed-up by Direct advocacy (sigh)
1. Mass margins are not everything, and if Ares I/Orion (which is what we are getting) ends-up with low margins, they'll simply cut down on what they crew can take with them rather than leaving the redundant safety options on the pad. NOBODY will say "Here, Guenter, hold this backup computer, I'm taking a cake, a buzz lightyear toy and another change of clothes instead!" as he climbs aboard a capsule. Obviously, those decisions will happen well-before launch day, but some people seem to not understand that all flying vehicles experience trade-offs early in their designs; they rarely make it to first flight with all the options and capabilities initially proposed...and there's nothing wrong with that.
2. Just what are the abort options when one of your precious J-120 SRBs ignites and the other one does not? (I know, no SRB has ever failed to start, but it is possible and has always been a danger with STS. No SRB had ever burned-through on STS before Challenger. "Never happened before" is not proof it will never happen, or proof it will not happen on the very next launch attempt.)
3. Air-starting the second stage is indeed a LOM risk, but that is a risk the US program has accepted in Gemini and Apollo. With Ares I, the basic rocket is so cheap that if the upper stage is lost (and assuming they keep the 1st stage and the capsule re-usable) you may really only lose the consumables, abort system, and the upper stage; you do not even lose the cargo, since it's either in the capsule with the crew or on another rocket. You could even have a second Ares I stacked in the VAB and a backup crew ready to go so an overall "mission" to the moon or Mars would not be lost. ( It makes more sense to me to not launch one Ares I until the next one is stacked and ready. After the 1st pair are stacked, you stack the same number per year, but you gain options for things like a rescue mission. After each launch, the backup become the next primary, and you start stacking the next backup. )

If you ask me Ares I has turned out to be a death trap it needs active damping just to not kill anyone riding it that doesn't sound very safe to me.
"death trap" is way too far. You've been reading (or perhaps imagining and writing) too many anti-Ares I rants. No rocket will ever be as safe as your car; there is simply too much energy being contained in a structure that must be light enough to fly. Ares I and Orion will be safer than Mercury, Gemini, and Apollo were. I do not care for Ares or Orion, but even I can see and accept that.

I question those who calculate the safety on concepts and their ability or at the very least honesty. I also wonder where they get their numbers but I think we can safely say those numbers are not worth the paper they are printed on.
The "numbers" are of little value other than in arguing for or against any particular person's preferred architecture (just ask the crews of Challenger and Columbia). I doubt that any vehicle has ever exactly met the LOC/LOM "numbers" that were "calculated" before the 1st use of the design. I may question the notion of LOC/LOM "numbers", but that does not mean that the underlying concepts used to determine that one rocket design may be safer than another are invalid. With 1 engine per stage, Ares will have a certain basic simplicity.

It seems they don't know of things that have been developed since 1967 such as vehicle health monitoring and Kevlar shields which would allow one to escape the stack long before it's in the process of exploding.

BTW on the reliability of vehicle health monitoring and computer controls if you ever fly on an airliner or ride a train your life is depending on the reliability of such systems.
I think you go too far here. There certainly is a tendency in safety-critical operations to cling to older (proven) tech, but Kevlar and better computers may not gain as much as you think. The first sign of trouble may simply not be detectable any sooner, so your better computer may not be able to do anything earlier. Rockets contain a lot of energy and when they perform an involuntary conversion into scrap, that energy goes somewhere and throws the bits and pieces with a good deal of force; a little Kevlar may offer very little protection against a sharp-edged, meter-long, chunk of tank wall moving at Mach 1 (accompanied by a large fireball). An abort system using the technologies you hold in low regard is probably capable of getting the crew clear faster than needed and is likely being limited in this design to keep the abort G-loads on the crew survivable.

Offline Jim

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Re: 5.5 Segment Ares I
« Reply #20 on: 06/18/2008 02:15 PM »

1.  With Ares I, the basic rocket is so cheap that if the upper stage is lost (and assuming they keep the 1st stage and the capsule re-usable) you may really only lose the consumables, abort system, and the upper stage;

 Ares I and Orion will be safer than Mercury, Gemini, and Apollo were. I do not care for Ares or Orion, but even I can see and accept that.


1.  It isn't cheap.  Most of the money is in the second stage.  What is reused on the first stage is insignifican

2.  That can't be said at the moment.

Offline Star-Drive

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Re: 5.5 Segment Ares I
« Reply #21 on: 06/19/2008 04:56 AM »
To Mr. Tim:

Considering how many dual and even single fault tolerant primary subsystems in the Orion have been left on the parking lot due to the inadequate payload capacity of the current Ares-I rocket, inlcuding the little known fact that if Orion is in transiit to/from or orbiting the Moon and loses one of its solar power photovoltaic arrays due to just one of several credible faliure modes that the crew will die before they can get back to Earth due to a total power failure after xx-hours, tells me that the current Constellation program, along with its Ares and Orion projects are broken in a very fundamental way.  They make continuing flying the Space Shuttle look better and better every day this evollving fiasco continues...
Star-Drive

Offline MrTim

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Re: 5.5 Segment Ares I
« Reply #22 on: 06/19/2008 01:40 PM »
1.  With Ares I, the basic rocket is so cheap that if the upper stage is lost (and assuming they keep the 1st stage and the capsule re-usable) you may really only lose the consumables, abort system, and the upper stage;

 Ares I and Orion will be safer than Mercury, Gemini, and Apollo were. I do not care for Ares or Orion, but even I can see and accept that.

1.  It isn't cheap.  Most of the money is in the second stage.  What is reused on the first stage is insignifican

What's cheaper, Jim, tossing an Ares I upper stage (which we plan to do on every mission anyway) or tossing a Delta IV Heavy? I was making the point that an Ares I abort (assuming everything is nominal on the abort and the abort is due to 2nd stage engine not firing after staging (which was the issue raised)) only tosses the second stage... and that's cheap (not to a typical home owner or small business person, but within the field of rockets)


2.  That can't be said at the moment.
OK, Jim, I'll give you this one, sort of... we have not flown them yet, so we do not yet know with certainty how safe they will turn-out to be ( I should have stayed with my usual cautions ). The design, however, is in may ways superior and will be built and filled with superior tech and benefit from lessons learned (as long as they don't really screw-up) so Orion should be safer.

Offline Jim

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Re: 5.5 Segment Ares I
« Reply #23 on: 06/19/2008 01:54 PM »
1.  D-IV Heavy would be cheaper.

2.  Since the Ares I doesn't not use the legacy SRM, it won't be as safe as a liquid stage.

Offline MrTim

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Re: 5.5 Segment Ares I
« Reply #24 on: 06/19/2008 01:57 PM »
To Mr. Tim:

Considering how many dual and even single fault tolerant primary subsystems in the Orion have been left on the parking lot due to the inadequate payload capacity of the current Ares-I rocket,
You miss my earlier point. No Orion capsule has yet been built (the mock-up recently flown to Dryden does not count...it's not a real flight article which will carry men into space). As such, NOTHING HAS BEEN LEFT IN THE PARKING LOT. Not a single redundant system has yet been left out of a manned, flying Orion. All the design trade-offs being considered are still not implemented in a single capsule. It is WAY too early for anybody to be screeching that the sky is falling, the crews are all doomed, etc. Things like power systems and Avionics are getting lighter, smaller, and more efficient with every passing month, so it is quite possible that systems currently slated to be left out will be added back-in two years from now as other systems end-up being lighter. Indeed, it is likely that over the years of operation succeeding Orions will take advantage of shifting technology and the vehicle will become safer and more capable.

inlcuding the little known fact that if Orion is in transiit to/from or orbiting the Moon and loses one of its solar power photovoltaic arrays due to just one of several credible faliure modes that the crew will die before they can get back to Earth due to a total power failure after xx-hours, tells me that the current Constellation program, along with its Ares and Orion projects are broken in a very fundamental way.  They make continuing flying the Space Shuttle look better and better every day this evollving fiasco continues...
There are a number of scenarios where a crew could die in transit to/from the moon. The question is: HOW CREDIBLE are the modes you are worried about and will systems added to deal with them add more failure modes and thereby not end-up adding more safety? Where are the details that accompany this FACT you are so concerned about? Is there a manned Orion currently on the way to the moon and currently in danger of this failure, or are you just concerned that a possible failure mode is not addressed by a current concept? Is this failure mode you are worried about more likely than a massive solar flare that fries the crew? If not, are you upset that the vehicle lacks tons of lead shielding to deal with this failure mode?

Offline MrTim

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Re: 5.5 Segment Ares I
« Reply #25 on: 06/19/2008 02:11 PM »
1.  D-IV Heavy would be cheaper.
An entire 3-core Delta 4 Heavy will be cheaper (unit cost, not all the R&D) than a single Ares I upper-stage? I'd love to see the accounting on that.
2.  Since the Ares I doesn't not use the legacy SRM, it won't be as safe as a liquid stage.
Look, Jim, I have always hated the idea of people riding solid rockets and was disgusted with the way NASA went from "no men on solids" to "solids are great for manned flight" during the development of STS (letting budgets drive a change in safety positions). But the entire safety rationale for the first stage of Ares I being a solid rocket is based upon the number of safe shuttle flights. THEREFORE, with each safe Orion flight, its 5 (or 5.5 or 6...) segment SRB will gain flight experience that will count toward the same rationale being used to declare it "safe" (shazam! Insert magic here!)  As I said, I don't like that, but what's good for the pot is good for the kettle. Ares I #1 will be safer than STS-1 (half as many completely untried 1st stage SRB's) and Ares I #2 will be safer than STS-2 was, etc. NASA set a precedent here that cannot be unwritten.

edit: Sorry meant to also say: Jim, I agree with your sentiments in that I would have preferred an all-liquid "stick" if we were going with this capsule on small rocket and optional mission package on big rocket model for manned spaceflight.
« Last Edit: 06/19/2008 02:16 PM by MrTim »

Offline gladiator1332

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Re: 5.5 Segment Ares I
« Reply #26 on: 06/20/2008 03:45 AM »
1.  D-IV Heavy would be cheaper.
An entire 3-core Delta 4 Heavy will be cheaper (unit cost, not all the R&D) than a single Ares I upper-stage? I'd love to see the accounting on that.


I would like to see some numbers on the D4 claim. However, you do have to remember, while the first stage of Ares I is recovered, it isn't free. There is refurbishment costs to take into account.

Offline wannamoonbase

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Re: 5.5 Segment Ares I
« Reply #27 on: 06/20/2008 12:19 PM »
You can bet that with NASA and ATK involved that the cost of an Ares 1 launch will be hundreds of millions of dollars and involve 1000's of people for months between launches. 

One of the factors that will drive up costs will be 2 launches per year.  As those 1000's of people will still need to come to work 5 days a week.
SpaceX, just a few things planned for 2018: FH, Starlink Prototypes, Block 5, Dragon 2, Increased launch rate.

Offline khallow

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Re: 5.5 Segment Ares I
« Reply #28 on: 06/20/2008 03:08 PM »
1.  D-IV Heavy would be cheaper.
An entire 3-core Delta 4 Heavy will be cheaper (unit cost, not all the R&D) than a single Ares I upper-stage? I'd love to see the accounting on that.


I would like to see some numbers on the D4 claim. However, you do have to remember, while the first stage of Ares I is recovered, it isn't free. There is refurbishment costs to take into account.

Another thing to consider here is whether either vehicle can accomplish the desired missions.  Delta IV has the edge since it can be expanded beyond the capabilities of the Ares 1, which is limited by the SRM first stage.

Personally, I'm in favor of developing the EELVs further because those rockets can be used for other things than NASA missions. So a modestly more expensive Delta IV Heavy and more expensive Atlas V Heavy would in my humble opinion be justified on those grounds alone. It'd also be an opportunity to unmake the ULA and introduce some competition into the 20-25 ton range again.

Having said that, I don't see what's going to make the Ares 1 cheaper than the Delta IV Heavy. Recycling SRMs at a rate of under six launches a year isn't economic. It could very well end up that Delta IV Heavy is cheaper than recycling SRMs. A lot depends on whether the heavy versions of EELVs will ever service markets other than NASA and DOD.
Karl Hallowell

Offline gospacex

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Re: 5.5 Segment Ares I
« Reply #29 on: 06/21/2008 05:21 AM »
Another thing to consider here is whether either vehicle can accomplish the desired missions.  Delta IV has the edge since it can be expanded beyond the capabilities of the Ares 1, which is limited by the SRM first stage.

Personally, I'm in favor of developing the EELVs further because those rockets can be used for other things than NASA missions. So a modestly more expensive Delta IV Heavy and more expensive Atlas V Heavy would in my humble opinion be justified on those grounds alone. It'd also be an opportunity to unmake the ULA and introduce some competition into the 20-25 ton range again.

Not to mention that aesthetically Delta IV Heavy is a beauty while Ares I is an ugly duckling. Flying (and shaking) hammer.

Any chance they can upgrade avionics on Delta IV?

Offline BogoMIPS

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Re: 5.5 Segment Ares I
« Reply #30 on: 06/22/2008 10:31 PM »
OK... completely showing my armchair rocket-builder ineptitude here, but I'll pose my question regardless.

The SSME was the original engine for Ares-1, but it was dropped due to the difficulty discovered in modifying it for air-start.

STS never needed it for air-start, since it lights them on the ground.

Could an Ares-I "stick" do the same thing?   i.e. mount the SSME, or some other engine(s), on the upperstage in such a way that you could start it on the ground?

I'm not suggesting putting the crew back alongside the SRB, which I know would never happen again... I'm thinking of the upperstage still being atop the SRB, but the SSME nozzle "sticking out the side" of the stage, or having two such engines on either side of the top of th eSRB.

I can imagine a various-and-sundry grab-bag of problems with this arrangement... even bigger sail-problems, increased drag, asymmetrical thrust, less performance, looks insane, etc.

An inline SSME with some sort of an ablative thrust deflector atop the SRB with an "open interstage" might be an interesting thought experiment too, but I suspect that's even goofier.

I'm suppose I'm way outside the box, but if we're married to a single-SRB crew launch solution for Orion, information seems to suggest the outside-of-the-box is in play.

Offline kraisee

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Re: 5.5 Segment Ares I
« Reply #31 on: 06/23/2008 01:56 AM »
An engine that far up the structure will 'burn' anything lower down on the vehicle.   As the vehicle lifts the atmospheric pressure decreases and the plume widens a lot compared to around Sea Level.

It wouldn't be good to expose the sides of the SRB casings and joints to the heat and forces produced by any engines for any length of time.

A ground-lit main engine will have to be down somewhere near the bottom of the rocket.

Ross.
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Offline libs0n

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Re: 5.5 Segment Ares I
« Reply #32 on: 06/23/2008 02:10 AM »
In the related thread, there's talk of an Ares V with three, four segment solid rocket boosters.  With that in mind, I wonder if there are ways to get back to an Ares 1 that utilized the current SRB without the extra segments thus proposed. 

One idea I have is a three stage vehicle; an SRB first stage, and two liquid stages atop it, with whatever engines that may be applicable in that situation.  My thinking is that since the SRB doesn't bring much impulse and the second stage does most of the work necessary to achieve orbit, a staging sequence there would be beneficial in terms of performance.  It does bring the added staging event as a risk, but it would presumably bring back the safety of the standard SRB, and I consider the escape tower of such benefit that any vehicle with it included to be "safe enough", most of the time.  As an added idea, perhaps the third stage of this proposal could be refuelable, in an "orbital fuel depot" type architecture, and function as the EDS for the CEV itself, for an L2 or other location type rendezvous.

Another option might be accepting the reduced payload of a 4 segment, j-2x second stage, and radically altering the structure of the CEV, perhaps with the TEI functions offloaded to a component launched with the other cargo components on the Ares V.  That is assuming that such a vehicle layout offers any useful payload at all.
« Last Edit: 06/23/2008 02:16 AM by libs0n »

Offline edkyle99

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Re: 5.5 Segment Ares I
« Reply #33 on: 06/23/2008 03:07 AM »
I'm suppose I'm way outside the box, but if we're married to a single-SRB crew launch solution for Orion, information seems to suggest the outside-of-the-box is in play.

What information?  NASA's says Ares I is meeting its design goals.  Why would the Agency need to consider an alternative to a design that is meeting its goals?

 - Ed Kyle

Offline renclod

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Re: 5.5 Segment Ares I
« Reply #34 on: 06/23/2008 08:36 AM »
OK... completely showing my armchair rocket-builder ineptitude here, but I'll pose my question regardless.

The SSME was the original engine for Ares-1, but it was dropped due to the difficulty discovered in modifying it for air-start.

STS never needed it for air-start, since it lights them on the ground.

Could an Ares-I "stick" do the same thing?   i.e. mount the SSME, or some other engine(s), on the upperstage in such a way that you could start it on the ground?


My own armchair rocket-builder ineptitude produced this :

http://forum.nasaspaceflight.com/index.php?topic=7011.0

the one-and-a-half-shuttle-derived-crew-launch-vehicle !

It was fun and I learned a lot while pushing it on this forum. Was shut down by the large majority of responders. But the basic ideea keeps surfacing now and then. What attracted me to this asymmetrical concept was how easy it was to play with SRB and H2 tank lenghts.

« Last Edit: 06/24/2008 08:48 AM by renclod »

Offline BogoMIPS

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Re: 5.5 Segment Ares I
« Reply #35 on: 06/23/2008 03:21 PM »
I'm suppose I'm way outside the box, but if we're married to a single-SRB crew launch solution for Orion, information seems to suggest the outside-of-the-box is in play.

What information?  NASA's says Ares I is meeting its design goals.  Why would the Agency need to consider an alternative to a design that is meeting its goals?

 - Ed Kyle

Ares-I performance was #4 on the project top risks matrix in May.  The data is on L2.  4x4 risk.

There is obviously still significant concern about Ares-I performance.  I'm not saying that aren't solvable.  Of the two current Ares rockets, Ares-1 seems like it will probably fly operationally at some point, as long as the political situation doesn't change.

The political situation changing, however, seems like a 5x5 risk to me for the system right now.


Offline edkyle99

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Re: 5.5 Segment Ares I
« Reply #36 on: 06/23/2008 04:11 PM »
I'm suppose I'm way outside the box, but if we're married to a single-SRB crew launch solution for Orion, information seems to suggest the outside-of-the-box is in play.

What information?  NASA's says Ares I is meeting its design goals.  Why would the Agency need to consider an alternative to a design that is meeting its goals?

 - Ed Kyle

Ares-I performance was #4 on the project top risks matrix in May.  The data is on L2.  4x4 risk.

This matrix business!  The matrix allows managers to rank areas that need their attention in the program.  There is always risk in development.  It does not mean that Ares I won't meet its targets.  Indeed, Ares I *has* to meet its targets!  NASA is not going to develop a launch vehicle that doesn't do what the program needs it to do.

 - Ed Kyle

Offline Norm Hartnett

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Re: 5.5 Segment Ares I
« Reply #37 on: 06/23/2008 07:51 PM »
Ed,

I'm curious, at what point does NASA reach a decision that the Constellation Program is not going to work, if in fact it will not?

Is there some guideline that says if there are x number of problems crop up or x amount of development dollars is spent or x number of delays occur this program must be canceled?

Can NASA cancel a program like this? Have they ever canceled a program like this or have they always been forced to cancel by exterior forces?

At what point do they say "this plow don’t scourer" and move on?
« Last Edit: 06/23/2008 08:08 PM by Norm Hartnett »
“You can’t take a traditional approach and expect anything but the traditional results, which has been broken budgets and not fielding any flight hardware.” Mike Gold - Apollo, STS, CxP; those that don't learn from history are condemned to repeat it: SLS.

Offline kraisee

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Re: 5.5 Segment Ares I
« Reply #38 on: 06/23/2008 07:55 PM »
NASA won't cancel the program.   NASA almost never cancels programs.

It is usually Congress who would pull the plug when they reach a point where they believe NASA is just wasting money chasing a pipedream.

Ross.
« Last Edit: 06/23/2008 07:57 PM by kraisee »
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Offline guru

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Re: 5.5 Segment Ares I
« Reply #39 on: 06/23/2008 09:19 PM »
NASA won't cancel the program.   NASA almost never cancels programs.


Sure they do.  X-33, X-34, and X-38 all come to mind.  Two of those were almost ready to fly modified, and the third had flown a full scale glider version.  Half a billion dollars more for an ACRV and we wouldn't need to build an all new Orion capsule now.

A lot of programs do morph, though -  like the space shuttle.  It started out being fully reusable with all liquid propulsion.  Now it's neither.  Or Ares I/V.  It started out being almost entirely shuttle derived, now it's entirely not shuttle derived.  Of course, just one more morph and you could have the Ares-II/III, and so save the program from cancellation. 


Offline Antares

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Re: 5.5 Segment Ares I
« Reply #40 on: 06/23/2008 10:51 PM »
Is NASA subject to Nunn-McCurdy?

Source: http://en.wikipedia.org/wiki/Nunn-McCurdy_Amendment
The Nunn–McCurdy Amendment or Nunn–McCurdy Provision, introduced in the United States 1982 Defense Authorization Act and made permanent in 1983, is designed to curtail cost growth in American weapons procurement programs.

It requires cost growth of more than 15% to be notified to the United States Congress, and calls for the termination of programs whose total cost grew by more than 25% over the original estimate, unless the Secretary of Defense submits a detailed explanation certifying that the program is essential to the national security, that no suitable alternative of lesser cost is available, that new estimates of total program costs are reasonable, and that the management structure is (or has been made) adequate to control costs.

Very rarely is a program actually cancelled under this provision—Congress normally regards the explanations from the Secretary of Defense as acceptable—but it has led to many changes to project management. SBIRS has been affected by the provision in 2002 and again in 2005, and the NPOESS meteorology satellites have been redesigned with lesser capabilities after being affected by the provision.

In 2006 the House of Representatives proposed amending the provision to require a detailed explanation, including information about possible alternatives, at the 15%-cost-growth mark.
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Offline yinzer

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Re: 5.5 Segment Ares I
« Reply #41 on: 06/24/2008 02:14 AM »
This matrix business!  The matrix allows managers to rank areas that need their attention in the program.  There is always risk in development.  It does not mean that Ares I won't meet its targets.  Indeed, Ares I *has* to meet its targets!  NASA is not going to develop a launch vehicle that doesn't do what the program needs it to do.

 - Ed Kyle

The Shuttle *had* to meet its performance targets too.  But it didn't.  Life went on, the space station slipped twenty years, CRAF got cancelled, a bunch of research didn't happen.  There's nothing stopping the same thing from happening this time around.  Ares I looks like it should be able to get the Orion to ISS without too much difficulty.  It's easy to imagine a call to "revamp the Constellation Architecture to save life-cycle costs and reduce the chances of mission failure" happening at about the same time big checks have to start getting written for Ares V.
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Offline edkyle99

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Re: 5.5 Segment Ares I
« Reply #42 on: 06/24/2008 02:51 AM »
NASA won't cancel the program.   NASA almost never cancels programs.

Sure they do.  X-33, X-34, and X-38 all come to mind. 

Research efforts, all of them.  NASA's real human space system development efforts have a much different record.  Ares/Orion isn't like X-33.  It is like Mercury, Gemini, Apollo, and Shuttle.  It will fly because it has to fly.

 - Ed Kyle

manlymissileman

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Re: 5.5 Segment Ares I
« Reply #43 on: 06/24/2008 03:54 AM »
Is Ares I meeting its targets?  (safe, simple, soon)

manlymissileman

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Re: 5.5 Segment Ares I
« Reply #44 on: 06/24/2008 04:10 AM »
NASA won't cancel the program.   NASA almost never cancels programs.

Sure they do.  X-33, X-34, and X-38 all come to mind. 

... It will fly because it has to fly.
...

On the other hand, one can hammer a square peg into a round hole given enough time and budget, surely.  (perhaps that's what is called for?) However, sometimes cutting one's losses and going back to the drawing board is a better solution.  I don't know what the current status of this project is, though.

Offline MrTim

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Re: 5.5 Segment Ares I
« Reply #45 on: 06/24/2008 09:08 PM »
Is Ares I meeting its targets?  (safe, simple, soon)
"Safe Simple Soon" is a slogan... not Ares I "targets".

Offline Scotty

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Re: 5.5 Segment Ares I
« Reply #46 on: 06/24/2008 09:41 PM »
As to Ares I, it is more like:
Not quite as safe as first thought, no where as simple as first thought, and no where as soon as first thought.

Offline ckiki lwai

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Re: 5.5 Segment Ares I
« Reply #47 on: 06/25/2008 07:40 AM »
Going back on topic, Scotty wrote this in the "more SRB's"  thread:
One point that is not well known outside the KSC engineering and operations world, there is a sixteen (16) segment limit to the number of segments that can be with in the VAB at any one time.
That limit has to do with the Quanity - Distance / Explosive Equivalancy limitation placed upon the VAB.
In my opinion the number is totally arbitrary and is based on just a judgment call, but it is on the books and has been so for 30 plus years.
To change the segment limit would require a high level NASA manager to "stick his neck out", and I do not see that happening.

And, how many segments do we have at the moment:
2x5.5 + 5 = 16
Thus Ares I can't go 5.5 segments!
Unless, like Scotty said, a high level NASA manager to sticks his neck out.
Don't ever become a pessimist... a pessimist is correct oftener than an optimist, but an optimist has more fun, and neither can stop the march of events. - Robert Heinlein

Offline kevin-rf

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Re: 5.5 Segment Ares I
« Reply #48 on: 06/25/2008 12:42 PM »
Going back on topic, Scotty wrote this in the "more SRB's"  thread:
One point that is not well known outside the KSC engineering and operations world, there is a sixteen (16) segment limit to the number of segments that can be with in the VAB at any one time.
That limit has to do with the Quanity - Distance / Explosive Equivalancy limitation placed upon the VAB.
In my opinion the number is totally arbitrary and is based on just a judgment call, but it is on the books and has been so for 30 plus years.
To change the segment limit would require a high level NASA manager to "stick his neck out", and I do not see that happening.

And, how many segments do we have at the moment:
2x5.5 + 5 = 16
Thus Ares I can't go 5.5 segments!
Unless, like Scotty said, a high level NASA manager to sticks his neck out.

That doesn't work, that means only one shuttle can be stacked at a time. I am sure there have been more than one stacked shuttle in the VAB during the program history.
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Offline psloss

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Re: 5.5 Segment Ares I
« Reply #49 on: 06/25/2008 01:00 PM »
That doesn't work, that means only one shuttle can be stacked at a time. I am sure there have been more than one stacked shuttle in the VAB during the program history.
Each shuttle has two four-segment boosters, so 16 allows for two shuttles.

Edit: when they did this there weren't 16 segments in the VAB, but there were 24 in the near vicinity:
http://forum.nasaspaceflight.com/index.php?topic=1823.msg24609#msg24609
« Last Edit: 06/25/2008 01:09 PM by psloss »

Offline kkattula

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Re: 5.5 Segment Ares I
« Reply #50 on: 06/25/2008 03:41 PM »

...

It will fly because it has to fly.

 - Ed Kyle

Why does it have to?  Will the world end if it doesn't?  Will the commissars have everyone shot? Are NASA infallible like the Pope?  Why can't they just say "this one isn't coming together, let's try again" ?

The goal is important, not the means.

NASA seem to be mesmerized by their own legend: "Failure is not an option."

But when failure is not an option, success can be very, very expensive.

Offline A_M_Swallow

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Re: 5.5 Segment Ares I
« Reply #51 on: 06/25/2008 06:30 PM »

And, how many segments do we have at the moment:
2x5.5 + 5 = 16
Thus Ares I can't go 5.5 segments!
Unless, like Scotty said, a high level NASA manager to sticks his neck out.

Do not forget the LON Ares I, it may not fly but it has to be waiting in an assembled form.

2*5.5 + 5 + 5 = 21

DIRECT will need a LON J-120/J-232.

The VAB may need modifying to take the extra segments.

Offline jimvela

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Re: 5.5 Segment Ares I
« Reply #52 on: 06/25/2008 06:46 PM »
Do not forget the LON Ares I, it may not fly but it has to be waiting in an assembled form.

Where are there requirements that a LON capability must exist for the VSE or ARES-ISS launches? 

These are not orbiters and do not share the fragile TPS that drives this need on present launches.

Offline A_M_Swallow

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Re: 5.5 Segment Ares I
« Reply #53 on: 06/25/2008 07:02 PM »
Do not forget the LON Ares I, it may not fly but it has to be waiting in an assembled form.

Where are there requirements that a LON capability must exist for the VSE or ARES-ISS launches? 

These are not orbiters and do not share the fragile TPS that drives this need on present launches.

The same one that says the sister ships of the Titanic need a complete set of lifeboats.

In this matter the TPS being fragile is nearly irrelevant.

Offline Antares

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Re: 5.5 Segment Ares I
« Reply #54 on: 06/25/2008 07:05 PM »
I'm sorry.  We're not amateurs here.  We use requirements documents.  As jimvela says, there is no requirement for LON rescue for Ares I.  The current STS LON is driven by the delicate, exposed RCC and tile on the orbiter.  The Orion TPS design has it protected in the spacecraft adapter outside the airstream.
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Offline kraisee

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Re: 5.5 Segment Ares I
« Reply #55 on: 06/25/2008 07:28 PM »
LON for an inline design could be a pre-stacked and pre-checked-out EDS/PLF/SCA/Spacecraft sitting in the corner of a HighBay.

Whatever is the next vehicle on the flow could have its original payload offloaded and replaced in an emergency.   And if we have all the vehicle umbilicals mated in the VAB prior to rollout (requires an umbilical tower), then at-the-Pad processing can be greatly expedited.

Of course that's another argument for having a high flight rate - you would always have a vehicle near to being 'ready' if you have a dozen of them flying every year.   It's quite a lot less likely to have something near-ready if you have a system which you can only afford to fly four times a year though.

And to mount a rescue for a crew trapped in Lunar orbit would require both Ares-I and Ares-VI.   A single J-232 could do that rescue though.

Ross.
« Last Edit: 06/25/2008 07:31 PM by kraisee »
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Offline A_M_Swallow

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Re: 5.5 Segment Ares I
« Reply #56 on: 06/25/2008 07:45 PM »
I'm sorry.  We're not amateurs here.  We use requirements documents.  As jimvela says, there is no requirement for LON rescue for Ares I.  The current STS LON is driven by the delicate, exposed RCC and tile on the orbiter.  The Orion TPS design has it protected in the spacecraft adapter outside the airstream.

True the correct word is cowboys.

This is an obvious safety matter.  One to which ever schoolboy in the world knows the answer.  They and the press will say so following the first Orion accident.  The accident could be in the SM or oxygen system or avionics or...  Not having a planned LON (or alternative) has a too obvious financial motive.

NASA can only claim to be obeying orders if some else wrote the orders.

Offline jimvela

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Re: 5.5 Segment Ares I
« Reply #57 on: 06/25/2008 09:13 PM »

True the correct word is cowboys.

This is an obvious safety matter.  One to which ever schoolboy in the world knows the answer. 
No offense, but that is garbage.  The lesson learned is that you shouldn't put a fragile mission-critical subsystem alongside a launch vehicle and out in the airstream.  Further, you should NEVER put humans (or even cargo you care about) beside the lower stages.

Quick question:  Do you make your morning commute with an ambulance, police car, and tanker in escort?  That's an equally obvious safety issue, and every schoolboy who's never actually driven anything anywhere might pontificate about...  Those whom practice in the real world see it for a ridiculous proposition, just like LON for a capsule launcher.

Quote
They and the press will say so following the first Orion accident.  The accident could be in the SM or oxygen system or avionics or...  Not having a planned LON (or alternative) has a too obvious financial motive.
Again, rubbish.  All of those things, are either properly designed or they are not.  I trust that the design review process will find the obvious flaws.  Flight heritage and murphy's law will find the rest.

The Russians have this part right:  Fly it, fix it, fly it some more, then repeat.

There simply isn't any guarantee that you have the right capability to rescue when there isn't a fragile TPS that is  overwhelmingly the highest risk.  In your example, assume a life support failure that causes lack of oxygen.  Crew's dead, the 2nd launch is then a recovery and investigation mission.  The only way to even hope to rescue would be to have the 2nd LV sitting at the pad and ready to launch immediately behind the 1st LV.  Even then, no guarantee of rescue.


Rocket flight, just by the physics of it, is harsh and dangerous.  Some risk will have to be assumed. 


Offline BeanEstimator

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Re: 5.5 Segment Ares I
« Reply #58 on: 06/25/2008 09:18 PM »
It is very hard to estimate cost when you are willing to do anything to have your pet architecture fly, regardless of the effect on other elements or to schedule and budget.

This reminds me of a joke I heard at a cost estimating event.  Came from a "grey beard":

Q:  Why is great to be a cost estimator? 
A:  Because you're never wrong, it's guaranteed that what will be built is not what is being estimated.

 8)
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Offline ckiki lwai

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Re: 5.5 Segment Ares I
« Reply #59 on: 06/25/2008 10:26 PM »
Each shuttle has two four-segment boosters, so 16 allows for two shuttles.

Edit: when they did this there weren't 16 segments in the VAB, but there were 24 in the near vicinity:
http://forum.nasaspaceflight.com/index.php?topic=1823.msg24609#msg24609

I followed the link, but there wasn't any info about 24 segments, only pictures of 2 shuttle stacks (which looked very cool btw).
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Offline psloss

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Re: 5.5 Segment Ares I
« Reply #60 on: 06/25/2008 10:33 PM »
I followed the link, but there wasn't any info about 24 segments, only pictures of 2 shuttle stacks (which looked very cool btw).
Just using the picture to note the occurrence.  The context is documented in a roundabout way; I'll bump one of those threads instead of carrying on the tangent in this one.

Offline psloss

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Re: 5.5 Segment Ares I
« Reply #61 on: 06/25/2008 10:37 PM »
Quick question:  Do you make your morning commute with an ambulance, police car, and tanker in escort?  That's an equally obvious safety issue, and every schoolboy who's never actually driven anything anywhere might pontificate about...  Those whom practice in the real world see it for a ridiculous proposition, just like LON for a capsule launcher.
Just curious, how would you change this analogy for the shuttle?

Offline MrTim

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Re: 5.5 Segment Ares I
« Reply #62 on: 06/25/2008 11:49 PM »
Do not forget the LON Ares I, it may not fly but it has to be waiting in an assembled form.
Where are there requirements that a LON capability must exist for the VSE or ARES-ISS launches? 

These are not orbiters and do not share the fragile TPS that drives this need on present launches.
There may not be any such written requirements now, but NASA has already effectively created them by the way they have reacted to Columbia. With STS, NASA told the public we were no longer in the test pilot stage of spaceflight (where losses are expected because you are pushing the edge of what's possible). With the destruction of the two orbiters, NASA has added bail-out capability and LON etc again signaling that we will not just leave the option of certain death when we have a reasonable alternative. In abandoning STS, NASA has told the taxpayers that even a very safe system WITH LON is still not safe enough; the agency has sold Ares/Orion as much safer than STS. If we lose a crew in Orion that could have been saved by a LON mission (but NASA has not planned for and provided the LON mission capability) I predict the end of NASA (something I am not normally inclined to do).
Consider the possible public reactions/conclusions:
1. they will  feel deceived over the replacement of orbiters with capsules
2. they may feel the whole "capsule is safer" thing was a lie and either:
    (a)  there is no good way to fly in space or
    (b) the current generation of NASA people are incompetent in being unable to reproduce the successes of 40 years ago.
3. they may finally reach a point of anger with NASA for taking such boldly stupid risks when nearly free options were available (like simply not launching an Ares I until the next one is ready to fly, it's common-sense and anybody who sees the VAB "knows" there are 4 high bays) )

I'm still curious about whether NASA will have the guts to do the WWI thing and not give the crew individual chutes (so they have an option of the mains fail). It may have flown as a concept in the 60's but I'm not so sure it'll go over well with the public of today (particularly since all orbiter crews have their own chutes and they're not expected to just trust that the vehicle's primary landing mode will work) Again, they may not have intended to box themselves in here, but NASA's reactions to the the orbiter losses have set some real precedents in the minds of the public.

Offline Jim

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Re: 5.5 Segment Ares I
« Reply #63 on: 06/25/2008 11:57 PM »

And, how many segments do we have at the moment:
2x5.5 + 5 = 16
Thus Ares I can't go 5.5 segments!
Unless, like Scotty said, a high level NASA manager to sticks his neck out.

Do not forget the LON Ares I, it may not fly but it has to be waiting in an assembled form.

2*5.5 + 5 + 5 = 21

DIRECT will need a LON J-120/J-232.

The VAB may need modifying to take the extra segments.

No LON requirement for Orion.
« Last Edit: 06/26/2008 03:33 PM by James Lowe1 »

Offline kevin-rf

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Re: 5.5 Segment Ares I
« Reply #64 on: 06/26/2008 12:09 AM »

Lets not forget, LON by another name was implemented for SkyLab.

Wasn't the docking adapter on Orion supposed to be uni-sex so it could dock with another Orion. I vaguely remember a blurb somewhere about the uni-sex part of it weighing to much, thus eliminating any LON capability outside of docking with the ISS first.

LON is nice, just like having a sub rescue sub is nice. This is despite the fact that outside of coastal area's, almost all the ocean is to deep for a damaged sub to survive on the ocean floor. Outside of Orion docking with ISS, the chances of a damaged Orion surviving until help arrives are most likely the same.
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Offline Zpoxy

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Re: 5.5 Segment Ares I
« Reply #65 on: 06/26/2008 12:14 AM »
3. they may finally reach a point of anger with NASA for taking such boldly stupid risks when nearly free options were available (like simply not launching an Ares I until the next one is ready to fly, it's common-sense and anybody who sees the VAB "knows" there are 4 high bays

There will be only one mobile launcher for Ares 1

Offline MrTim

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Re: 5.5 Segment Ares I
« Reply #66 on: 06/26/2008 01:22 AM »
3. they may finally reach a point of anger with NASA for taking such boldly stupid risks when nearly free options were available (like simply not launching an Ares I until the next one is ready to fly, it's common-sense and anybody who sees the VAB "knows" there are 4 high bays

There will be only one mobile launcher for Ares 1
That may be the current plan, and I do not personally have a problem with the notion of missions with black zones, I was just cautioning that NASA has set the public up to have VERY different expectations and they had better be thinking about that! Even Apollo, with its moon-in-a-decade-or-bust approach had multiple launchers... 40 years ago. Indeed, if future Mars missions would use more than one Orion to get the crew to the orbiting mission package, you'd need a second mobile launcher. Failure to have a second means limiting the mars mission to an unsustainable boots-and-flags gig with a crew of 6 or less.

Jim is correct in his blunt assessments of some of this (things like LON may have less utility with Orion lunar missions and may be less likely to be needed because of the architecture) but the raw, blunt engineering assessments of what is needed/justified/likely (the sort of assessments I usually favor) do not address the expectations of the public who is paying for all this (and I think that's what the original post referencing LON with Orion was getting at). When you set the customer up with certain expectations, you cannot then profess to be surprised later when he has those expectations. Ares/Orion is, unfortunately, not a purely engineering endeavor; It's supposed to be a sustainable program to support ISS, a permanently manned moon facility and Mars; it cannot be those things if it is not also wrapped in layers of good PR and unlikely to needlessly kill a crew (thus grounding it and possibly getting the whole thing canceled)

BTW: I think some of the safety requirements on Cx are actually a bit over-emphasized; Once we have a facility on the moon that can support a crew for 6 months, we gain a whole new set of mission abort and safety options we never before had (so things like return to Earth from anywhere on the moon within x hours become less important). The public may well accept some black zones for particular specific reasons if those reasons are explained and seem necessary, but I do not think it wise for NASA to have any black zones for a typical mission if there is a reasonable option (the public, and the accident investigation boards, not NASA, will get to decide what reasonable is)

Offline A_M_Swallow

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Re: 5.5 Segment Ares I
« Reply #67 on: 06/26/2008 01:34 AM »

True the correct word is cowboys.

This is an obvious safety matter.  One to which ever schoolboy in the world knows the answer. 
No offense, but that is garbage.  The lesson learned is that you shouldn't put a fragile mission-critical subsystem alongside a launch vehicle and out in the airstream.  Further, you should NEVER put humans (or even cargo you care about) beside the lower stages.

Quick question:  Do you make your morning commute with an ambulance, police car, and tanker in escort?  That's an equally obvious safety issue, and every schoolboy who's never actually driven anything anywhere might pontificate about...  Those whom practice in the real world see it for a ridiculous proposition, just like LON for a capsule launcher.

{snip}
Quick answer.  Ambulance, police and fire vehicles exist and can be dispatched within 20 minutes during the morning commute.  The RNLI lifeboat can be launched to help ships in distress by calling the same emergency phone number.

Offline Richard Ellis

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Re: 5.5 Segment Ares I
« Reply #68 on: 06/26/2008 01:49 AM »
the only thing irrelevant are your posts

It is refreshing to see even the most level headed contributor here can get fed up reading endless circular posts.

If I may, I would like to hijack this thread to: Re: 5.5 Segment Ares I

There is a study option to develop a 5.5 segment SRB for Ares V which some have suggested is the new baseline plan.  Subsequent to this, Constellation manager Jeff Hanley stated 'Key elements of Ares I are also down payments on Ares V - the first stage solid motors and J-2X engine will be used on the big rocket as well as Ares I, with very little if any modification.'

If both of these are true, should we expect an announcement Ares I will use a 5.5 segment SRB?  If so, how will this affect the vehicle?  Will it reduce or eliminate the payload to orbit concerns?  Will it cause more vibration issues, or less.  Will LOC, LOM estimates go up or down?

In short, what are the pros and cons likely to be with a design change to a 5.5 segment SRB?  Would it be a good idea or not?  I thank you all, in advance for your replies.



Offline jimvela

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Re: 5.5 Segment Ares I
« Reply #69 on: 06/26/2008 02:15 AM »
Quick answer.  Ambulance, police and fire vehicles exist and can be dispatched within 20 minutes during the morning commute. 
True.

Quote
The RNLI lifeboat can be launched to help ships in distress by calling the same emergency phone number.

Non sequitur, and FALSE.  First, the obvious one that you wouldn't call 911 for a LON/rescue mission, it would be initiated by mission control and agency management for the first mission and/or a diplomatic channel if it were a foreign mission giving/needing support.

Second, you don't just launch a rescue mission anytime.  Orbital mechanics and launch logistical operations get in the way.  Even with a fully prepared and fueled vehicle sitting on another pad, there are only limited times when you could launch and still easily rendezvous with a crippled vehicle.

Remember the key constraint about LON, which is to go to an orbiter with TPS damage and retrieve the crew.  This vehicle system won't have that problem.

The far, far better option is safe haven.  Go to ISS and park.  Wait there for supplies and a ride home.  Not going to ISS, then have an intermediate destination where supplies and lifeboat can be prepositioned rather than hoping for an improbably reactionary mission.

Offline edkyle99

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Re: 5.5 Segment Ares I
« Reply #70 on: 06/26/2008 02:15 AM »

It will fly because it has to fly.

 - Ed Kyle

Why does it have to?  Will the world end if it doesn't? 


If Ares/Orion turned into a massive program failure, a costly nightmarish public relations disaster, NASA would be out of the human spaceflight business for nearly a decade at minimum. 

So yes, it has to fly.

 - Ed Kyle
« Last Edit: 06/26/2008 02:17 AM by edkyle99 »

Offline jimvela

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Re: 5.5 Segment Ares I
« Reply #71 on: 06/26/2008 03:37 AM »

Quote
The RNLI lifeboat can be launched to help ships in distress by calling the same emergency phone number.

Non sequitur, and FALSE.  First, the obvious one that you wouldn't call 911 for a LON/rescue mission, it would be initiated by mission control and agency management for the first mission and/or a diplomatic channel if it were a foreign mission giving/needing support.

OK, I'm wrong about the RNLI lifeboat, as it turns out it's a UK charity, and they do launch rescue vessels at sea.  That still turns out to have bupkis in common with a rescue mission in space, and all of the other points in my reply are valid.

Sorry about my ignorance of UK facilities, some day I'd love to spend some time touring your country.


Offline MrTim

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Re: 5.5 Segment Ares I
« Reply #72 on: 06/26/2008 03:57 AM »
There is a study option to develop a 5.5 segment SRB for Ares V which some have suggested is the new baseline plan. (snip) If so, how will this affect the vehicle?  Will it reduce or eliminate the payload to orbit concerns?  Will it cause more vibration issues, or less.  Will LOC, LOM estimates go up or down?

In short, what are the pros and cons likely to be with a design change to a 5.5 segment SRB?  Would it be a good idea or not?  I thank you all, in advance for your replies.
Should not change the LOC/LOM "numbers". Oh, I'm sure somebody will do some "calculations" to arrive at new "numbers" (justified by, for example, a change in the number of joints) but in general you will be replacing one SRB that has no flight history with another one that has no flight history, and IMHO this big issue dwarfs the impact of lesser details. Put another way: I am sufficiently skeptical of precision in LOC/LOM "numbers" that the difference would be a small portion of last bit of wand-waving by any wizard offering such numbers. Marginally more risk from the motor itself, perhaps marginally more issues with overall vehicle dynamics, possible inter-stage structural issues as vehicle becomes even longer, but possibly minor added safety from better mass margins? It will not eliminate TO issues (all solids have them) but will likely change them enough to alter the mitigation plans (not necessarily the method of mitigation, but the details). If Ares V is going to 5.5, then it's probably a good idea to look at them for Ares I, but they had better decide soon; the Ares I-X test shot is less than a year away and the primary justification for that shot is that it is essentially a 1-up wind tunnel run on the OML of the Ares I. If the Ares I OML will grow with a 5.5seg SRB, they'd better squeeze that extra .5 into the I-X not just for good data but also for credibility.



Offline MrTim

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Re: 5.5 Segment Ares I
« Reply #73 on: 06/26/2008 04:22 AM »
Second, you don't just launch a rescue mission anytime.  Orbital mechanics and launch logistical operations get in the way.  Even with a fully prepared and fueled vehicle sitting on another pad, there are only limited times when you could launch and still easily rendezvous with a crippled vehicle.
True, but NASA does not refuse to plan an STS LON because there are some situations where it would not work. The unforgivable sin in the eyes of the public is to not plan one for the times when one would work. If NASA kills a crew it could have saved, it had better prepare for a public outcry for prosecutions. This would be a very different thing from Columbia or Challenger where the public accepted that the disaster was unexpected/unanticipated and there was no way at the time of the disaster to save the crew.

Remember the key constraint about LON, which is to go to an orbiter with TPS damage and retrieve the crew.  This vehicle system won't have that problem.
But because it is made by man, and man is imperfect, it will have problems of its own which none of us here and now know about. As a capsule with a service module, I am sure it will be just as ferpect as Apollo-13 was.  ;)

The far, far better option is safe haven.  Go to ISS and park.  Wait there for supplies and a ride home.  Not going to ISS, then have an intermediate destination where supplies and lifeboat can be prepositioned rather than hoping for an improbably reactionary mission. 

I think you're getting a bit too picky about the definition of LON (Launch On Need). For all but Hubble, the current LON plans assume the 1st vehicle would go to (or stay at) ISS and the LON vehicle would go there... so in that regard an ISS-bound-Orion LON would be no different than an ISS-bound-STS LON but might just be for different reasons (like some catastrophic service module failure). Keep in mind that the whole point of such missions is to deal with unplanned emergencies, so by definition we do not today know what might cause an Orion LON mission, just as folks in the 70's did not plan for the current LON mission scheme in response to wing leading edge failures. It's not going to work to go hat-in-hand to the voters after the 1st Orion kills a crew and say "sure we might have saved them, but we decided not to and, well, at least they died in a capsule and not in one of those winged space-plane thingies"

Also, a LON mission might not even be safety-related; If we get a full Mars mission package assembled in LEO and ready to go, but the crew aborts with a 2nd stage engine failure, having another Orion with a backup crew ready to go could save a pile of cash and taxpayer patience.

Some plans should be made precisely because you do not know what will happen.

Offline Lampyridae

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Re: 5.5 Segment Ares I
« Reply #74 on: 06/26/2008 07:05 AM »
There's an alternative to LON which is called reliability engineering. Increase the fault tolerance of your systems, reduce the number of potential failure modes. Ares I has minimal stage separations but Orion has been stripped of safety features. Not to mention how the oscillation environment affects the rest of the stack. Increasing mass for extra safety features on the Orion IMHO is safer than having a minimal stage sep. Yes, it can blow up on the pad but that's what escape towers are for. What you do not want is an electrical fire 300 000km from Earth.
SKYLON... The League of Extraordinary Gentlemen's preferred surface-to-orbit conveyance.

Offline jeff.findley

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Re: 5.5 Segment Ares I
« Reply #75 on: 06/27/2008 07:25 PM »

Where's the LON for Soyuz? Where was it for Mercury, Gemini or Apollo? LON exists for one reason only - the fragility of the shuttle TPS. Carrying that requirement on into other programs that don't suffer the same weakness is a waste of resources and effort.

Safety can be taken too far.

How do you count the plans for a rescue Apollo CSM flight to Skylab in case the CSM docked to Skylab developed a serious problem?  The hardware "kit" for that mission was built and ready for use, should the need arise.  In that case, Skylab had enough supplies to keep the crew alive until the rescue mission could be flown.

Jeff


Offline MrTim

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Re: 5.5 Segment Ares I
« Reply #76 on: 06/28/2008 10:04 AM »
Where's the LON for Soyuz? Where was it for Mercury, Gemini or Apollo? LON exists for one reason only - the fragility of the shuttle TPS.  (snip)
How do you count the plans for a rescue Apollo CSM flight to Skylab in case the CSM docked to Skylab developed a serious problem?  The hardware "kit" for that mission was built and ready for use, should the need arise. (snip)
The point is that LON was not a program requirement. It wasn't until Skylab that the possibility of LON even emerged, and it still wasn't a program requirement.
The congress, and NASA have become far more risk-averse now and would probably not tolerate those earlier architectures today. LON does not exist now because thermal tiles are fragile (they were always fragile and this has always been known, indeed the glue that held them on was even an issue in the early flights) The real reason for LON now is not some hardware detail, it is a change in tolerance for stupid, avoidable LOC risks. The shuttle has always had some big bold black zones (which the public accepts because we all know there is no possible rescue method) and Ares/Orion lunar flights will have some too, but any failure mode where a recovery would be reasonably possible but which NASA does not prepare for is simply no longer acceptable. Flying shuttles is far safer today than it was at the beginning of the program but the increasing safety has not been able to stay ahead of the increase in risk-aversion. This is a large part of why STS is being retired (safer than it ever was, but now considered too unsafe).

Just imagine what the public outcry would have been if the following been true:
1. The hole in Columbia's wing detected on flight day 1
2. NASA had been aware of the possibility from before Enterprise was built
3. A method to save the crew in that circumstance had always been known and would have been relatively simple
4. Each orbiter was effectively capable of such a rescue by virtue of having the proper docking hardware designed and built-in from the beginning of the program (so a rescue would not even require a single spacewalk)
5. The crew rescue would have only required a second mobile launcher (which was also needed by other future aspects of the program) and change in program management which would stack each system in time to be a LON vehicle instead of just in time to fly its own mission. (no more stackings per year, just a schedule change in stacking dates and launch dates)
6. (and finally) The agency announced that it could have saved the crew but had decided not to bother and to just count on redundant systems (which had failed), the crew were a bunch of risk-taking silk-scarfed test pilots anyway, so the crew was simply going to be allowed to die in a few days.

BZZZZT! Wrong answer. Congressional inquiries and court cases to follow.

We are not in the 60's anymore. Rescue in the early missions with their primitive technology was generally accepted by the public  as impossible (everybody knew that NASA was pushing the edges of what was humanly possible at that time), but that's not the case today and NASA has made that very point by having LON missions available for STS; this is called "setting a precedent"

Offline MrTim

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Re: 5.5 Segment Ares I
« Reply #77 on: 06/28/2008 10:13 AM »
There's an alternative to LON which is called reliability engineering. Increase the fault tolerance of your systems, reduce the number of potential failure modes. (snip)
Yup, worked really well for Challenger and Columbia. Works so well that NASA will not bother with LON plans for the Hubble mission.... errr.... no, wait.... scratch that  ;)
There is a big difference between, on the one hand, doing everything you can to make your systems as safe as possible and, on the other hand, planning a way to rescue people when your "safe" system fails. These two things are not mutually exclusive, and only a complete idiot does the first and not the second in today's society. The public can forgive you for not trying the second when it's not possible, but they are unlikely to forgive you if it is both possible and not even particularly expensive or inconvenient but you choose not to even try.

Offline Jim

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Re: 5.5 Segment Ares I
« Reply #78 on: 06/28/2008 01:34 PM »
this is called "setting a precedent"

BZZZZT! Wrong !!!!
Which not applicable to the CEV and future missions. 

The CEV will be able to stay attached the ISS for 6 months.  No need to scramble for an LON. 

LON is not applicable to lunar missions. 

Offline A_M_Swallow

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Re: 5.5 Segment Ares I
« Reply #79 on: 06/28/2008 04:22 PM »
Since LON is off topic for the thread title and there has been more than 3 replies I have created a new topic in the General Discussions section called "Space Rescue Missions and Vehicles".
http://forum.nasaspaceflight.com/index.php?topic=13604.0

Offline A_M_Swallow

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Re: 5.5 Segment Ares I
« Reply #80 on: 06/28/2008 05:00 PM »

Please save all your rhetoric and simply point me to the Constellation Program requirement for LON.

Try the high level requirement to minimise the Loss of Crew.

A rescue mission prevents a LOM event becoming a LOC event.
See for some risk definitions.
http://en.wikipedia.org/wiki/Hazard_analysis

Offline MrTim

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Re: 5.5 Segment Ares I
« Reply #81 on: 06/28/2008 08:05 PM »
this is called "setting a precedent"
BZZZZT! Wrong !!!!
Which not applicable to the CEV and future missions. 
The CEV will be able to stay attached the ISS for 6 months.  No need to scramble for an LON. 
LON is not applicable to lunar missions. 
Sorry Jim, forgot you were here. Of course you are correct that Orion and Ares are perfect, there will never be a failure... and if there is, the vehicle will safely make it to ISS (but no rescue mission would even be mounted then because that would be a LON mission which you indicate would never be needed). I am also sure you are correct that if we launch an Ares I to LEO at the start of a lunar mission and there is some critical failure NASA will simply allow the crew to die rather than trying a rescue and you are probably correct that the public will not care. The LON requirement might not be written down in the formal program specs, but for those parts of a mission where it could save a crew, it is part of the basic requirements of the Cx program.... which has as its premise: Thou shalt not kill a crew Some things (like "remember to breathe several times per minute") do not need to be written down; reasonably smart persons are expected to figure them out.

NASA has proven your roll-the-dice-on-crew-survival model wrong already by planning a Skylab rescue mission and by planning STS rescue missions. They seem to appreciate more than you do that some things are simply unacceptable to the public who are after-all the ones providing the funding. Your love of disposable rockets seems to have morphed into an acceptance of disposable crews.

Offline MrTim

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Re: 5.5 Segment Ares I
« Reply #82 on: 06/28/2008 08:10 PM »
Since LON is off topic for the thread title and there has been more than 3 replies I have created a new topic in the General Discussions section called "Space Rescue Missions and Vehicles".
http://forum.nasaspaceflight.com/index.php?topic=13604.0
A good idea, except that replies to messages belong in the same threads as the original messages (and those messages are here). Any way to selectively move the earlier messages and replies over there? Maybe Chris has a way?

Offline Jorge

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Re: 5.5 Segment Ares I
« Reply #83 on: 06/28/2008 09:41 PM »
this is called "setting a precedent"
BZZZZT! Wrong !!!!
Which not applicable to the CEV and future missions. 
The CEV will be able to stay attached the ISS for 6 months.  No need to scramble for an LON. 
LON is not applicable to lunar missions. 
Sorry Jim, forgot you were here. Of course you are correct that Orion and Ares are perfect, there will never be a failure... and if there is, the vehicle will safely make it to ISS (but no rescue mission would even be mounted then because that would be a LON mission which you indicate would never be needed). I am also sure you are correct that if we launch an Ares I to LEO at the start of a lunar mission and there is some critical failure NASA will simply allow the crew to die rather than trying a rescue and you are probably correct that the public will not care. The LON requirement might not be written down in the formal program specs, but for those parts of a mission where it could save a crew, it is part of the basic requirements of the Cx program.... which has as its premise: Thou shalt not kill a crew Some things (like "remember to breathe several times per minute") do not need to be written down; reasonably smart persons are expected to figure them out.

If the United States really has become that risk-averse, then there are two and only two possible outcomes:

1) If LON becomes a program requirement, Constellation will become too expensive and will be cancelled sooner or later.

2) If LON is not implemented and a crew is killed, the program gets cancelled.

Either way the conclusion is inescapable: If we've really become that risk-averse, then the program has zero chance of survival in the long term and the United States does not deserve to have a space program. Period, full stop, end of story. In that case, we should cancel the whole farce now before we waste a lot of money on it, and let those who are willing to shoulder the risk reap the reward.

Quote
NASA has proven your roll-the-dice-on-crew-survival model wrong already by planning a Skylab rescue mission and by planning STS rescue missions. They seem to appreciate more than you do that some things are simply unacceptable to the public who are after-all the ones providing the funding. Your love of disposable rockets seems to have morphed into an acceptance of disposable crews.

As has your love of over-the-top and over-the-line rhetoric.
JRF

Offline Jim

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Re: 5.5 Segment Ares I
« Reply #84 on: 06/28/2008 09:44 PM »

1. Sorry Jim, forgot you were here. Of course you are correct that Orion and Ares are perfect,

2,  I am also sure you are correct that if we launch an Ares I to LEO at the start of a lunar mission and there is some critical failure NASA will simply allow the crew to die rather than trying a rescue 

3. The LON requirement might not be written down in the formal program specs, but for those parts of a mission where it could save a crew, it is part of the basic requirements of the Cx program....

4.  NASA has proven your roll-the-dice-on-crew-survival model wrong already by planning a Skylab rescue mission and by planning STS rescue missions.

Still wrong

1.  Never said they were.

2.  The architecture doesn't support an LON for lunar mission.  Both pads will be launching vehicles for the mission.  One VAB cell is only going to support Ares I. 

3.  It has to be in the basic requirements or it doesn't exist.  No work will be authorized without the requirement.  No changes to hardware, software, ground systems, etc will be done.

4.  Shuttle LON's exist because the vehicle is not safe.  Skylab used rescue missions and not an "LON" mission. Big difference.  The next vehicle in line was to be used for as a rescue vehicle.  Just as I stated for ISS, they just wait for the next Orion launch or use the Soyuz.  If the Orion is not at the ISS and can't reach it, it will be SOL

LON is define as having hardware  in some sort of readiness state.

Offline kfsorensen

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Re: 5.5 Segment Ares I
« Reply #85 on: 06/28/2008 10:44 PM »
Either way the conclusion is inescapable: If we've really become that risk-averse, then the program has zero chance of survival in the long term and the United States does not deserve to have a space program. Period, full stop, end of story. In that case, we should cancel the whole farce now before we waste a lot of money on it, and let those who are willing to shoulder the risk reap the reward.

Thank you Jorge, I had wanted to say similar things but had been reticent in this very pro-human-spaceflight forum.  Plus you said them much better than I would have.

Anyone seen "WALL-E", the latest Pixar movie?  If you have, you'll know what I'm thinking of when I imagine (fearfully) what future manned spaceflight systems will look like if this corrosive approach to risk management continues to carry the day...

Offline jimvela

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Re: 5.5 Segment Ares I
« Reply #86 on: 06/28/2008 11:04 PM »
Either way the conclusion is inescapable: If we've really become that risk-averse, then the program has zero chance of survival in the long term and the United States does not deserve to have a space program. Period, full stop, end of story. In that case, we should cancel the whole farce now before we waste a lot of money on it, and let those who are willing to shoulder the risk reap the reward.

..
Thank you Jorge, I had wanted to say similar things but had been reticent in this very pro-human-spaceflight forum.  Plus you said them much better than I would have.

Agreed, very well said, and true, Jorge!!!


Offline bholt

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Re: 5.5 Segment Ares I
« Reply #87 on: 06/28/2008 11:58 PM »
Risk is part of the game here. We all take risks every day. Over 40,000 people a year die in the U.S. because of car accidents. You cannot eliminate risk.
All NASA can do is reduce the risk as much as possible. I remember on Sep. 29, 1988 (STS-26R) the now late CNN reporter John Holliman saying "But NASA says people can and will make mistakes and some day in the future there will be another shuttle accident. Their job is to make sure that the next accident is as far in the future as they can make it." (Not an exact quote)
87 flights later Columbia was lost.
Like the shuttle, Orion will be far from perfect and will be subject to cost cutting and engineering shortcuts. If it flies long enough, a catastrophic failure will occur. That's just the way it is.
Many who strongly criticize NASA for the Challenger and Columbia accidents would have made the same decisions as NASA did that led to those accidents. (Remember the term "group think?) Humans are far from perfect and the things we build can't be either.

Brent
"We choose to go to the Moon! We choose to go to the Moon in this decade, and do the other things, not because they are easy, but because they are hard."
-JFK, September 1962

Offline Avron

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Re: 5.5 Segment Ares I
« Reply #88 on: 06/28/2008 11:59 PM »
Ga...


wow.. ok.. so what does this say.. its game over already? Or could it change back to the right stuff in time to save US manned spaceflight?

or is it just the case of analysis paralysis,, with study after study, for a price? If that is true is a 5.5 Seg LV just that, a study costing a fortune , providing nothing of value.. and not meeting the needs of the customer, Joe public? 

Offline gladiator1332

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Re: 5.5 Segment Ares I
« Reply #89 on: 07/05/2008 02:27 AM »
Here is a quick render of the 5.5 seg Ares I.

One the left is the current Ares I, on the right is the 5.5 monster

Offline Eerie

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Re: 5.5 Segment Ares I
« Reply #90 on: 07/05/2008 10:07 AM »
Here is a quick render of the 5.5 seg Ares I.

One the left is the current Ares I, on the right is the 5.5 monster

Why is it a monster compared to 5 segments?

Offline Eerie

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Re: 5.5 Segment Ares I
« Reply #91 on: 07/05/2008 10:08 AM »
wow.. ok.. so what does this say.. its game over already?

There was some game going on?

Offline gladiator1332

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Re: 5.5 Segment Ares I
« Reply #92 on: 07/05/2008 02:50 PM »
Here is a quick render of the 5.5 seg Ares I.

One the left is the current Ares I, on the right is the 5.5 monster

Why is it a monster compared to 5 segments?

Just spicing things up a bit  ;)

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Re: 5.5 Segment Ares I
« Reply #93 on: 07/06/2008 03:33 AM »
Is Ares I meeting its targets?  (safe, simple, soon)
"Safe Simple Soon" is a slogan... not Ares I "targets".


You are not suggesting the prime contractor ATK lied, are you?

Offline martian1

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Re: 5.5 Segment Ares I
« Reply #94 on: 07/07/2008 08:22 PM »
Not a rocket engineer but,
on Ares 1 why not use 2 smaller side mounted SRBs, make the upper stage larger and light it on the ground.
Then use 4 of these smaller SRBs on Ares 5.
I know they won't be 'shuttle derived' anymore but who cares.

Offline nacnud

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Re: 5.5 Segment Ares I
« Reply #95 on: 07/07/2008 08:42 PM »
See the 'stumpy' thread and article.

http://www.nasaspaceflight.com/content/?cid=4670

Offline martian1

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Re: 5.5 Segment Ares I
« Reply #96 on: 07/07/2008 08:55 PM »
Interesting article.
I was thinking of something a little sleeker, but NASA has thought of everything just in case by the looks of it!

Offline arachnitect

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Re: 5.5 Segment Ares I
« Reply #97 on: 07/09/2008 12:42 AM »
Here is a quick render of the 5.5 seg Ares I.

One the left is the current Ares I, on the right is the 5.5 monster

Nice work, thanks for posting.

I think that it actually looks better than the 5 seg. version... "better proportioned."

Speaking aesthetics... I don't really mind how Ares 1 looks (which is not to say I have no concerns about how it performs). I think Ares 1 has a very contemporary post-modernist / industrial appearance. Flashy "space age looks" are seriously out of style these days. All Ares 1 needs is some open lattice structure to complete the look.

I'm going to get a lot of flak for that. Oh well.

 

Offline Avron

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Re: 5.5 Segment Ares I
« Reply #98 on: 07/09/2008 01:45 AM »
wow.. ok.. so what does this say.. its game over already?

There was some game going on?

You'r joking .. right?

Offline gladiator1332

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Re: 5.5 Segment Ares I
« Reply #99 on: 07/09/2008 02:53 AM »
Here is a quick render of the 5.5 seg Ares I.

One the left is the current Ares I, on the right is the 5.5 monster

Nice work, thanks for posting.

I think that it actually looks better than the 5 seg. version... "better proportioned."

Speaking aesthetics... I don't really mind how Ares 1 looks (which is not to say I have no concerns about how it performs). I think Ares 1 has a very contemporary post-modernist / industrial appearance. Flashy "space age looks" are seriously out of style these days. All Ares 1 needs is some open lattice structure to complete the look.

I'm going to get a lot of flak for that. Oh well.

 

At one time it did have some open lattice structure:
http://forum.nasaspaceflight.com/index.php?topic=9205.0

That was shortly after ESAS.

All in all, I have to agree, the 5.5 seg does not look ridiculous and does not add too much height to the overall stack. With performance being an issue, it isn't too crazy to think that a 5.5 seg Ares I could be possible, especially with the added bonus of Ares V commonality.


Offline rcaron

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Re: 5.5 Segment Ares I
« Reply #100 on: 07/24/2008 02:35 PM »
I was at the Joint Propulsion Conference yesterday where there was a whole track of presentations related to Ares. I asked the Ares V presenter about the 5.5 steel (now baselined) and the composite w/ PBAN and whether either of those would be retrofitted onto Ares I as a later upgrade. My thoughts were akin to the lunar nozzles.

Both the presenter and the Ares I presenter had a very enthusiastic NO. The trouble primarily stems from how the Ares I booster already has a reentry profile ~50% 'hotter' than current shuttle (120kft shuttle apogee, 190kft ares I, Mach 4 vs Mach 6 respectively). TPS would start becoming a real concern if you increased the booster performance any further. The parachute system is also struggling to keep the velocity at impact the same as shuttle, since any higher would increase damage and impact reusability.

Offline kraisee

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Re: 5.5 Segment Ares I
« Reply #101 on: 07/24/2008 02:46 PM »
So it looks like it will be divergent SRB's after all.   Interesting.

If they end up with steel 5.0-seg for Ares-I and composite 5.5- or 6.0-seg disposables for Ares-5/6/7 I'm thinking the board at ATK won't be very upset at all.

Ross.
"The meek shall inherit the Earth -- the rest of us will go to the stars"
-Robert A. Heinlein

Offline rcaron

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Re: 5.5 Segment Ares I
« Reply #102 on: 07/24/2008 05:17 PM »
So it looks like it will be divergent SRB's after all.   Interesting.

And I mentioned that this architecture was sold to us not only on shuttle commonality but also between the Ares vehicles. He said that while they would technically be divergent they would share substantial commonality with respect to manufacturing and ground handling and the like. Of course, this is only true if they stick with the steel 5.5s and not the composite PBANs.

He mentioned that there is a directive from somewhere up above to keep the composite PBANs in the tradespace for the foreseeable future. According to the charts, they do offer quite a deal more lunar payload capability, on the order of 3mT over the  5.5s if i remember correctly. Wish I took more notes, but those charts were packed!

Offline renclod

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Re: 5.5 Segment Ares I
« Reply #103 on: 07/24/2008 09:12 PM »
So it looks like it will be divergent SRB's after all.   Interesting.

If they end up with steel 5.0-seg for Ares-I and composite 5.5- or 6.0-seg disposables for Ares-5/6/7 I'm thinking the board at ATK won't be very upset at all.

Ross.

I'm thinking that, if the composite overwrapped case/HTPB booster gets selected for Ares V, the "board at ATK" has a surprise coming their way in the form of "competitive acquisition environment for booster"

As opposed to "single source".

http://www.lpi.usra.edu/pss/presentations/200806/12neal.pdf


Offline Herb Schaltegger

Re: 5.5 Segment Ares I
« Reply #104 on: 07/24/2008 11:32 PM »
Take a look at the makeup of the ATK Board . . .

http://www.atk.com/CorporateGovernance/corpgov_boardofdirect.asp

And then realize that most of these folks sit on more than one (many Directors sit on three or more corporate booards).
Ad astra per aspirin ...

Offline Antares

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Re: 5.5 Segment Ares I
« Reply #105 on: 07/25/2008 04:14 AM »
rcaron, who were the presenters for Ares at JPC this year?  Poor MSFC tech writers do all the work and the civil servants put their names on the papers.
If I like something on NSF, it's probably because I know it to be accurate.  Every once in a while, it's just something I agree with.  Facts generally receive the former.

Offline gospacex

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Re: 5.5 Segment Ares I
« Reply #106 on: 07/25/2008 11:06 AM »
Nice work, thanks for posting.
I think that it actually looks better than the 5 seg. version... "better proportioned."

Well, the best shape for tanks to have highest possible mass ratio is a sphere, but it is difficult to build. Next best is a "fat" cylinder, which is much easier to build, but it has too big a cross section and creates lots of drag when flown as a rocket. So you need to stretch it, trading worsening mass fraction for improving aerodynamics.

I don't know what proportions are deemed optimal in this regard. I do know, however, that most LVs, as they evolve, chose to stretch the tanks instead of widening them, as this is somewhat easier on infrastructure. Thus most existing LV's are evolved to be "too tall and thin".

I think Atlas Phase 2 is one which is closest to optimal width/height. Look at the attached picture - it is quite stubby. Got to have good mass fractions on both stages and does not stand excessively tall on launch pad.

In this regard, Ares I looked awful from the start. Long, thin (=> bad mass fraction) 1st stage with ugly (IMHO) "hammerhead" second stage. 5 seg only made it worse.

Offline rcaron

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Re: 5.5 Segment Ares I
« Reply #107 on: 07/25/2008 04:46 PM »
rcaron, who were the presenters for Ares at JPC this year?  Poor MSFC tech writers do all the work and the civil servants put their names on the papers.

Steve Creech did the Ares V refinements presentation (AIAA 2008-4981)
Tomas Byrd did the J-2X ( -4980)
Charles Nola did Ares I avionics ( -4898)
Teresa Vanhooser did the Ares I booster ( -4895)

unfortunately I don't recall who did the Ares I upper stage.  Sorry to hear all these people use ghost writers...

Offline rcaron

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Re: 5.5 Segment Ares I
« Reply #108 on: 07/25/2008 05:00 PM »
whoops. just noticed i err'd wrt to the composites. they (clearly) use the new HTPB where the steels use the legacy PBAN. Hope I didn't confuse anybody!

Some other notes:
Current baseline is 51.0.48 (5.5 steel PBAN, 6 engine core)
composite variant 51.0.47 (5.0 composite HTPB, 6 engine core) to be decided upon at Constellation Lunar SRR in 2010

the presentation renclod linked above from LPI appears virtually identical to what was presentated at JPC

Offline kook59

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Re: 5.5 Segment Ares I
« Reply #109 on: 07/18/2009 02:08 PM »
   Shuttle SRB sep occurs at 150k ft. Why not solve the 5.5 seg reentry problem by not recovering the SRBs. Somewhere I read it was questionable if it saved any money anyway. How much payload would be gained with a 5.5 seg booster and no parachutes? How would 5.5 seg affect the T.O. problem?

Offline Jim

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Re: 5.5 Segment Ares I
« Reply #110 on: 07/18/2009 02:23 PM »
   Shuttle SRB sep occurs at 150k ft. Why not solve the 5.5 seg reentry problem by not recovering the SRBs. Somewhere I read it was questionable if it saved any money anyway. How much payload would be gained with a 5.5 seg booster and no parachutes? How would 5.5 seg affect the T.O. problem?

Because the company line that SRB's are "safer" hinges on recovery and post flight inspection.

Offline TrueBlueWitt

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Re: 5.5 Segment Ares I
« Reply #111 on: 07/18/2009 03:08 PM »
Some interesting stuff here

from last slide..

1:37000 LOC for Ares V.. 

Considering it doesn't carry a crew.. how exactly did they calculate that?

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