Ares I (CLV) - status

GCNRevenger · 2008-03-13 11:52:45

the "vibrations" issue is an official NASA claim, the same was the problem of flight stability (from press release) the doubt about the Ares-1 come from (good or bad) evaluations from several places, the Orion overweight was admitted (despite they say that have/will solve it)
at this point, that myths NEED a REAL flight to be debunked

No, the myth is that Ares-I's vibration issue is impractical to solve, not that there is no issue. And this is categorically false, and should be easily remedied as Dan Golden has said.

And the myth that Ares-I is underpowered was "admitted" by NASA? How is that? NASA officially and explicitly contradicts that statement, so where did the rumor of performance problems come from? And if the official NASA statement says its not true, why should we believe a rumor?

gaetanomarano · 2008-03-13 12:46:21

And if the official NASA statement says its not true, why should we believe a rumor?

there is difference between a problem SOLVED and a problem they HOPE (or are SURE) to solve in the next months/years... just need to wait to see the Ares-1 to fly... if fly...

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GCNRevenger · 2008-03-13 12:48:50

And if the official NASA statement says its not true, why should we believe a rumor?
there is difference between a problem SOLVED and a problem they HOPE (or are SURE) to solve in the next months/years... just need to wait to see the Ares-1 to fly... if fly...

You are dodging the issue, if NASA says there is no weight problem, then where did the rumor come from? And why should we believe the rumor?

gaetanomarano · 2008-03-13 15:23:44

And why should we believe the rumor?

personally, I believe that rumors are true since they match with my evaluations about the Ares-1 (but this is a personal opinion, of course)

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GCNRevenger · 2008-03-13 15:27:00

So what you are saying is that your opinion is founded on baseless, uninformed arrogance instead of what the well informed professional engineers say.

gaetanomarano · 2008-03-13 16:32:23

founded on baseless

I explain my opinions with data and evaluations, not only words

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cIclops · 2008-03-14 05:05:46

ATK progresses Ares I first-stage development - 7 Mar 2008

By Rob Coppinger
Alliant Techsystem's development work on the first stage of NASA's Ares I crew launch vehicle is progressing, with segments for the ground vibration test article already fabricated.
Preparations are under way to ship hardware for the analog test flight Ares I-X to NASA's Kennedy Space Center by July.
Ares I's first stage is a five-segment solid rocket boster (SRB). For ground vibration testing, ATK is to supply two five-segment stacks: one empty of the solid fuel, the other an inert version of a fuelled stack.
These will be tested at NASA's Marshall Spaceflight Center in 2010. ATK has produced three of the inert stack's five segments, using them as manufacturing process pathfinders.
The Ares I-X test flight, which uses a four-segment SRB first stage with a dummy fifth segment, upper stage and Orion crew exploration vehicle payload, is scheduled for 15 April 2009. ATK expects the last of its hardware for that launch to be at Kennedy by October.
But almost two weeks before that analog flight will be the 2 April 2009 test-firing of the first five-segment development motor, DM-1. This will take place at the company's T-97 test stand, used for Shuttle SRB testing and to be modified for the five-segment booster's extra power.
DM-1 will be followed by three more tests, DM-2, -3 and -4, taking place in September 2009, August 2010 and February 2011, respectively. The segment casings for DM-1 have already flown "six or seven" times on Space Shuttle missions, says ATK Ares I programme manager Fred Brassfield.
A five-segment SRB has been fired previously - in 2003, under development work for the Shuttle programme, when the fleet was still expected to last until 2020. But beyond having five segments, the stack was no different to the Shuttle booster.
During Ares' first-stage development, ATK will be qualifying a number of changes, including: new insulation, work on which began under the Shuttle programme an altered solid fuel with reduced oxidiser levels placing of all the separation motors on the aft skirt, with one or two perpendicular to it, to kick the stage into a tumbling re-entry mode and larger parachutes for the faster descent speeds from its higher separation. Also, says Brassfield: "We need to build a larger bearing for gimballing the larger nozzle."
ATK space launch systems vice-president Michael Kahn says that, as the requirement for Ares I nozzle gimballing is "slightly less" than on the Shuttle, the thrust vector control (TVC) system does not have to be changed.
But a TVC system that uses helium to drive the actuator hydraulics, instead of hydrazine, is being examined as a potential life-cycle cost-reduction effort because it removes the expensive controls and precautions required when dealing with a hazardous chemical such as hydrazine.
One element of the first-stage design that will not change is the segment's metal casings, says Kahn. The loading on them from the combined mass of the upper stage and CEV will be no higher than that experienced during Shuttle launches, he adds.

cIclops · 2008-03-15 00:47:55

From Mr. Steve Bouley presentation Pratt & Whitney (PDF 2MB) - J-2X Engine - 26 Feb 2008

J-2X is on the critical path for Ares I development, first flight test will be Orion 1 Q2 2013.

gaetanomarano · 2008-03-22 10:40:46

cIclops · 2008-03-22 12:34:54

No comment.

RedStreak · 2008-03-22 12:51:28

No comment except I'd choose:

e) Something not from Ghost NASA

...and that is why there is no e) in Gaeto's JPEG

gaetanomarano · 2008-03-22 14:37:10

Something not from Ghost NASA

why not?

add a second J-2X is not a new idea (others have already suggested that to add power to the 2nd stage) only the position change in my concept ...go back to the 4-segments SRB has several advantages (already listed several times) and the upperstages' mass match the "asparagus" figures... about the small Shuttle atop the SRB, there is no reason the same motor can't lift the same mass to the same altitude with the same acceleration (over 85% of the power that lifts the Shuttle come from its two SRBs)

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RedStreak · 2008-03-22 14:51:53

add a second J-2X is not a new idea (others have already suggested that to add power to the 2nd stage) only the position change in my concept

They had considered two engines for the EDS on Ares-V and since have reduced it to one now, and the Ares-V is going to be an even more powerful vehicle - that itself tells me two engines on an Ares-I would be a waste as well.

gaetanomarano · 2008-03-22 15:36:48

They had considered two engines for the EDS on Ares-V and since have reduced it to one now, and the Ares-V is going to be an even more powerful vehicle - that itself tells me two engines on an Ares-I would be a waste as well.

in the "Ares V Ascent Profile" table (published in the NASA .pdf document posted by cIclops in Ares V thread) you can read that the EDS' J-2X ignition happen at 122 km. of altitude (just 100 km. under the 120 nmi orbital insertion altitude) while, the Ares-1 J-2X starts burn around 60 km. of altitude (and the Shuttle SRBs are jettisoned at 45 km. of altitude) also, since NASA admits that the Ares-5 is underpowered (just read the AvWeek article linked in my blog) it's very likely they'll come back to the twin J-2X design for the final EDS

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GCNRevenger · 2008-03-22 16:54:42

Oh brother... I don't even know where to begin.

I vote for E) as well

gaetanomarano · 2008-03-23 03:53:31

I don't even know where to begin.

can I help you ?

maybe, you can start with the 4-segments SRB used in this "short Ares-1"

- it's powerful enough to lift a "right sized" Orion

- it's READY AVAILABLE NOW... I repeat... it's READY AVAILABLE NOW... I repeat... it's READY AVAILABLE NOW... I repeat... it's READY AVAILABLE NOW ...NOT in 2011 or 2012 or 201x... but NOW

- it cost $0.oo of R&D compared with the $3 billion of the 5-segments SRB

- each reusable SRB costs $40M compared with an unknown (but surely higher) SRB-5 price

- it's ALREADY man-rated... I repeat... it's ALREADY man-rated

- it will have NO "vibrations" problems (assuming the SRB-5 problems can be solved... someday) when used on the Ares-1 since it has had NO vibrations problems on the Shuttle

- it has been ALREADY TESTED in 240+ (successfull) MANNED flights (counting two per Shuttle flight) with just ONE "human" failure 20 years ago ...that compared with the ZERO manned (and, so far, also "unmanned") flights' tests of the SRB-5

do you need further help ?

or, do you want to talk about my (BETTER) rockets' concepts on my NewMars' "gaetanomarano' ghetto thread" ?

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cIclops · 2008-03-23 06:47:10

- it's powerful enough to lift a "right sized" Orion
- it's READY AVAILABLE NOW... I repeat... it's READY AVAILABLE NOW... I repeat... it's READY AVAILABLE NOW... I repeat... it's READY AVAILABLE NOW ...NOT in 2011 or 2012 or 201x... but NOW
- it cost $0.oo of R&D compared with the $3 billion of the 5-segments SRB
- each reusable SRB costs $40M compared with an unknown (but surely higher) SRB-5 price
- it will have NO "vibrations" problems (assuming the SRB-5 problems can be solved... someday) when used on the Ares-1 since it has had NO vibrations problems on the Shuttle

Orion has been sized for lunar, ISS lifeboat and Mars missions and to be the primary crew spacecraft for the future US exploration program. A smaller Orion is not the right choice for long duration deep space missions.

The STS 4 segment RSRB is not available for Ares I now. It would need extensive modifications to be used with Ares I such as : gimbaled engine, roll control system, interstage adapter etc etc. The cost of this is not zero and these modifications will take some years.

The 5 segment SRB contract with ATK is $1.8 billion not $3 billion

All solid boosters have vibration issues. The Shuttle 4 segment boosters are not different. On Shuttle they are in a totally different dynamic configuration with the massive tank and Orbiter, this damps the thrust oscillation behavior.

The 5 segment SRB is not on the critical path for Ares I, it's the J-2X engine. Changing back to a 4 segment SRB will not help to bring Ares I online sooner.

gaetanomarano · 2008-03-23 08:22:54

Orion has been sized...

the weight saved cutting the interstage and adopting the underside-LAS allows the Orion to remain as it is now

...4 segment RSRB is not available for Ares I now...cost of this is not zero...

that's true, it need some (small and low cost) changes... that, surely, don't need 4+ years and three billion$$$ ...also, all attitude controls are in the 2nd stage

...contract with ATK is $1.8 billion not $3 billion...

this is the first "slice" of the SRB-5 R&D costs... NASA has already paid money in the past and will pay in future... NASA officials NOW admit that Ares-1 will cost $10 billion only for R&D (but GAO claims it will cost $14.4 billion)

The Shuttle 4 segment boosters are not different.

the problem is simple... if only the SRB-5 has too much oscillations, it must be changed with the 4 segments version, while, if ALL kind of SRB has the same problem, then, BOTH must be changed with something different

Changing back to a 4 segment SRB will not help to bring Ares I online sooner.

that's true, but they can save very much money and, maybe, use part of these funds to develop the J-2X faster (if possible)

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GCNRevenger · 2008-03-23 08:23:04

Gaetano, chanting things in upper case, particularly things that aren't true, is very bad form. The kind of thing spammers and children do.

I agree with everything Ciclops says:

-The present Orion is the right size (seats 4 for a week, or 6 for a few days). Its perfect for what NASA needs it to do.
-The four-segment booster cannot be used on Ares-I without much of the same modifications that the five-segment booster will need. Adding a segment to a booster is really not very hard, and most of the expense for the five-segment booster involves other things like improved thrust vectoring that Shuttle doesn't need. It is just a simple, plain, and obvious lie to say that the booster is "readily available now."
-Remember that the vibration issue is a fluctuation in acceleration not thrust, it isn't a problem for Shuttle since it is much heavier the acceleration is lower. The same percentage changes to the lower acceleration yield less vibration on the heavier Shuttle. For that matter, since your designs are generally lighter, the vibration problem will be a problem for you too. Gee, I hope it might be possible to fix it, heh.

Got any more caps-lock lies to pollute our board with, gaetano?

gaetanomarano · 2008-03-23 08:31:35

...vibration issue is a fluctuation in acceleration not thrust, it isn't a problem for Shuttle since it is much heavier the acceleration is lower. The same percentage changes to the lower acceleration yield less vibration on the heavier Shuttle. For that matter, since your designs are generally lighter, the vibration problem will be a problem for you too...

again, the problem come from the choice of the SRB-5 ... the Shuttles fly at 3G and their SRBs are jettisoned at 45 km. while, the (same burning time) SRB-5 will be jettisoned around 58 km. ... going back to the 4-segments SRB + a more powerful (or two) 2nd stage engine, may allow a shuttle-like flight profile, a similar acceleration and NO dangerous vibrations

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GCNRevenger · 2008-03-23 10:33:33

It will not. No proposed version of the Ares-I upper stage will be radically heavier than the current one, and even with a modest decrease in thrust of the four-segment booster, you will still have vibration problems to contend with. The Shuttle external tank, fueled, weighs almost eight hundred tonnes, and add the Shuttle orbiter with a full payload to that, and the boosters push almost a thousand tonnes. Ares-I's upper stage doesn't weigh anywhere near that.

gaetanomarano · 2008-03-23 12:05:34

It will not. No proposed version of the Ares-I upper stage will be radically heavier than the current one, and even with a modest decrease in thrust of the four-segment booster, you will still have vibration problems to contend with. The Shuttle external tank, fueled, weighs almost eight hundred tonnes, and add the Shuttle orbiter with a full payload to that, and the boosters push almost a thousand tonnes. Ares-I's upper stage doesn't weigh anywhere near that.

assuming you're right on this claim... that means the Ares-1 must be entirely SCRAPPED from the plan (no matter its design) ...but, to do what? ..."Direct"... ? ...ok, DIRECT !!! (but just call it "FAST-SLV"... )

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RedStreak · 2008-03-23 13:18:52

It will not. No proposed version of the Ares-I upper stage will be radically heavier than the current one, and even with a modest decrease in thrust of the four-segment booster, you will still have vibration problems to contend with. The Shuttle external tank, fueled, weighs almost eight hundred tonnes, and add the Shuttle orbiter with a full payload to that, and the boosters push almost a thousand tonnes. Ares-I's upper stage doesn't weigh anywhere near that.
assuming you're right on this claim... that means the Ares-1 must be entirely SCRAPPED from the plan (no matter its design) ...but, to do what? ..."Direct"... ? ...ok, DIRECT !!! (but just call it "FAST-SLV"... )

If anything ought to be scrapped it's your website.

GCN is trying to break it down to you. A four segment SRB is already designed to lift a massive vehicle into orbit as will its five part successor - if anything the fact it was made to work in pairs means the transition will be easier when adapting it to Ares-V. The Orion is going to be a vehicle specialized for crew transport first and foremost versus the shuttle which was a huge vehicle built on compromises...in short a smaller vehicle with less trouble to worry about. Coupled with the second stage I have no doubt it will launch.

So kiss it gaeto

gaetanomarano · 2008-03-23 14:24:07

A four segment SRB is already designed to lift a massive vehicle into orbit as will its five part successor - if anything the fact it was made to work in pairs means the transition will be easier when adapting it to Ares-V. The Orion is going to be a vehicle specialized for crew transport first and foremost versus the shuttle which was a huge vehicle built on compromises...in short a smaller vehicle with less trouble to worry about. Coupled with the second stage I have no doubt it will launch.

it seems you must (first of all) find an agreement between you on this point... ...can the (4 or 5) segments SRB work alone? ...or not? ...while I'm writing my articles and posts, I assume it CAN (or could...) fly (mainly, since adopted by NASA) ...despite I fear it can't

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GCNRevenger · 2008-03-23 18:11:18

The point of contention is that NASA's five-segment first stage with small upper stage somehow has a vibration issue but the four-segment first stage/large upper stage will not because Shuttle doesn't have the problem.

This is not true, because the problem in Ares-I in either configuration is due to the much larger thrust from the SRB paired with the much lower weight of the upper stage versus Shuttle. So, simply because the four-segment booster does not have a problem with Shuttle does not mean Ares-I with the booster will not.

The problem in either version of the Ares-I should be pretty easily fixed.

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#501 2008-03-13 11:52:45

Re: Ares I (CLV) - status

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Re: Ares I (CLV) - status

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