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Gemini
2009-Aug-14, 07:14 PM
I love it when a rocket comes together.
http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=15284.0;attach=160 140

from Nasaspaceflight

novaderrik
2009-Aug-14, 07:41 PM
now they just gotta launch that thing.

NEOWatcher
2009-Aug-14, 07:43 PM
I love it when a rocket comes together.
http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=15284.0;attach=160 140

from Nasaspaceflight
What's the cage on top for?

AtomicDog
2009-Aug-14, 09:44 PM
What's the cage on top for?

It looks like the rig used to lift the crew module/escape tower into place.

Glom
2009-Aug-15, 06:24 AM
Looks quite Russian.

novaderrik
2009-Aug-15, 09:33 AM
Looks quite Russian.
in Russia, rocket builds you..

Dave J
2009-Aug-15, 02:18 PM
Haven't seen anything that tall in the VAB in a long, long time.

Amber Robot
2009-Aug-15, 02:20 PM
It looks like the rig used to lift the crew module/escape tower into place.

That's correct.

http://img.photobucket.com/albums/v256/hd37903/Space%20Shuttle/STA_6254Panorama.jpg

http://img.photobucket.com/albums/v256/hd37903/Space%20Shuttle/IMG_6265.jpg

Glom
2009-Aug-15, 03:07 PM
Those pictures looked computer generated at first, because I couldn't imagine yellow lifting equipment not being caked in grease.

Antice
2009-Aug-15, 06:39 PM
caked in grease. now that would be against safety regulations in most EU nations at the least.. dunno about US safety-regs, but around here you'd get fined for not keeping lifting rigs clean enough for daily inspections.

KaiYeves
2009-Aug-15, 06:52 PM
It is BIG.


in Russia, rocket builds you..
In Soviet Russia, dog shoot you into space.

Glom
2009-Aug-15, 08:03 PM
caked in grease. now that would be against safety regulations in most EU nations at the least.. dunno about US safety-regs, but around here you'd get fined for not keeping lifting rigs clean enough for daily inspections.

I hyperbolise. But they're certainly not glowing yellow like in the photo. Of course, that could just be related to the photography.

Antice
2009-Aug-15, 08:15 PM
the one used in the photo was probably spank'n new tho. so new the wet paint sign only got taken off like yesterday.

Glom
2009-Aug-15, 08:23 PM
the one used in the photo was probably spank'n new tho. so new the wet paint sign only got taken off like yesterday.

That's still no excuse. When I visited the Hoover Dam in the Spring, I was impressed by how clean the turbine hall was and that's a place that's 80 years old. This 25 year old place is brand new by comparison.

Maybe it's the flags. A giant hanging national flag just magics the filth away with the power of high grade patriotism.

Antice
2009-Aug-15, 08:38 PM
Didnt ya know. all flags above wall to wall size comes with it's own spit'n polish crew to make everything sparkle fitfully

mike alexander
2009-Aug-16, 04:39 AM
It just wanted to see the rocket's red glare.

JonClarke
2009-Aug-16, 11:28 AM
in Russia, rocket builds you..

Meaning?

ugordan
2009-Aug-16, 11:36 AM
Meaning?
http://en.wikipedia.org/wiki/Yakov_Smirnoff#Russian_reversal

matthewota
2009-Aug-16, 07:33 PM
The yellow lifting fixture is called "The Birdcage".

Larry Jacks
2009-Aug-16, 09:45 PM
So, I maybe the Potemkin Rocket (http://www.transterrestrial.com/archives/2008/07/potemkin_rocket_1.html) may fly after all, perhaps just in time for Ares I to get canned. Reportedly, this test is costing over $300 million and none of it is actual Ares flight hardware.

ugordan
2009-Aug-16, 10:03 PM
this test is costing over $300 million and none of it is actual Ares flight hardware.
Yes, hence the irony of calling this a test...

matthewota
2009-Aug-16, 10:37 PM
So, I maybe the Potemkin Rocket (http://www.transterrestrial.com/archives/2008/07/potemkin_rocket_1.html) may fly after all, perhaps just in time for Ares I to get canned. Reportedly, this test is costing over $300 million and none of it is actual Ares flight hardware.

I would not place much credence on a private citizen's blog posting.

Blogs are very opinionated and are frequently in error. I rarely see blogs with references at the end of the postings.

Some of the systems on Ares 1-X are flight hardware, the SRB separation rockets, for example.

Larry Jacks
2009-Aug-16, 11:01 PM
$300 million to test the SRB separation rockets seems a bit steep to me but what do I know, I'm just a taxpayer.

The SRB is has 4 active segements with a dummy 5th segment - not flight hardware. It won't have the same vibration characterists (or any other characteristics) with an operational 5 segment SRB.

The upper stage is a dummy. So is the Orion capsule and the LES.

The guidance system isn't flight hardware, either.

If the SRB separation rockets are flight hardware, then fine. But that still is a pretty poor return on a $300+ million investment.

matthewota
2009-Aug-16, 11:50 PM
You fail to mention that the upper stage and the fifth segment are ballasted to match the mass of the flight vehicle. If you would study the engineering of the vehicle you would understand the objectives of the test better.

Sure, it would be nice to do "all up" testing like they did with the Saturn V, but remember NASA had a bigger chunk of change to do it.

AtomicDog
2009-Aug-17, 12:10 AM
For the first Saturn I test flight, the upper stages were dummies filled with water.

Nicolas
2009-Aug-17, 07:16 AM
The upper stage of Ares IX is filled with loads and loads of equipment, returning lots of data on the ascent.

It is no real Ares1. But apparently it comes close enough for the people behind it to believe it will generate lots of relevant data.

ugordan
2009-Aug-17, 08:29 AM
For the first Saturn I test flight, the upper stages were dummies filled with water.
With the Saturn I program they were effectively learning rocket science because it was still in its infancy, the concepts of clustering multiple engines and tanks to produce one stage were unproven. They also effectively designed rockets with slide rules back then, 50 years ago.

The upper stage on Ares I-X is a mass simulator filled with ballast. In fact the entire stack above the 4 segment SRB (including the 5th, dummy SRB segment) is an inert mockup with no functionality. What real payoff does this "test" achieve for over $300 million it costs?

Nicolas
2009-Aug-17, 11:25 AM
With the Ares IX program they are effectively learning rocket science because it is still in its infancy, the concepts of having a single solid rocket engine to produce a stage are unproven.

Also, no matter how many computer simulations, it still doesn't hurt to actually launch a vehicle to learn about its behaviour.

ugordan
2009-Aug-17, 12:23 PM
With the Ares IX program they are effectively learning rocket science because it is still in its infancy, the concepts of having a single solid rocket engine to produce a stage are unproven.

Rocket science is far from its infancy and solid rocket stages were very much proven already. Minuteman, Taurus, Minotaur, Peacekepper to name a few.

You're saying NASA is learning rocket science again because it doesn't know how to do what the industry already knows? What a great way to spend taxpayer dollars and reduce the gap.

Lorrac
2009-Aug-17, 01:15 PM
Well, it should generate some PR for NASA and Ares, god knows they need it...

Once they get Ares hardware off the ground maybe all the in-fighting and lobbying will stop and the agency as a whole might focus on the goal rather on trying to get pet projects aproved.

Gotta say, I'm no engineer but from the outside NASA and the space program right now looks like a bunch of monkeys flinging poo and seeing who's projectile gets to stick higher in the wall of budget money.

Nicolas
2009-Aug-17, 05:25 PM
Rocket science is far from its infancy and solid rocket stages were very much proven already. Minuteman, Taurus, Minotaur, Peacekepper to name a few.

You're saying NASA is learning rocket science again because it doesn't know how to do what the industry already knows? What a great way to spend taxpayer dollars and reduce the gap.

One can imagine that you'd want to test for instance just how much shaking actually occurs with this single SRB, since it is a major hurdle to take in the design.

I sometimes get the feeling that NASA simply can't do right with Ares for some people. If they don't test, it's a paper rocket. If they do test, it's money thrown away. If they don't test, the vibrations of this unique and unproven single SRB design may kill the crew. If they do test, there's no reason for it as it's all known already. If a test is postponed, it's bad. If a test uses boiler plate material to make it happen earlier in the development, it's bad.

It sounds reasonable to me that the people actually involved with Ares have good reasons for the 1X test flight. It's not like that's a decision you just come up with during a coffee break. The experiments and requirements thereof will have been thoroughly thought through.

As I don't know all details about the decisions made during Ares 1 design, I can't say whether this test is good or bad. I don't know whether it uses too much or too little boiler plate material. I don't know whether it will perform the right or wrong measurements. I don't know. I'll just wait and see what the people actually involved have to say about it.

ugordan
2009-Aug-17, 06:05 PM
One can imagine that you'd want to test for instance just how much shaking actually occurs with this single SRB, since it is a major hurdle to take in the design.

If this actually was a test of the final SRB configuration I would agree that there is merit to the test. This test, however, does no such thing. It flies the basic Shuttle 4 segment SRB topped with a dummy 5th segment. The final Ares I SRB would have completely different propellant grain and geometry. They say this test is to validate their models of thrust oscillation, not provide concrete data pertinent to the real Ares I. Validate models with a dummy segment which, for all we know, could radically change the way the stack responds to the thrust oscillation forcing function. Not to mention the lack of damping liquids in the upper stage, but having a rigid "tuna can" stack instead. And thrust oscillation magnifies exponentially with SRB length. It will quantify nothing about the real Ares I first stage. In the end they still only have a model and need to test the real deal anyway. That was to be the Ares I-Y test, one that actually made engineering sense. But what, then, is the purpose of this?

This "test" doesn't even use avionics designed for Ares I, it uses modified Atlas V avionics! It's a poor excuse for a test not worth the $300 million it costs. A cost of a Discovery class mission burned in 2 minutes on something that's not actually a test of the real product. But perhaps I'm just crazy in not seeing the underlying logic to it.

novaderrik
2009-Aug-17, 06:39 PM
the $300 million spent on this test will likely offset some of the costs of future tests, and possibly make the whole project go faster and come in cheaper.
if nothing else, building and launching this big rocket gives people practice in building and launching big rockets again, and that alone justifies some of the costs.

samkent
2009-Aug-17, 07:01 PM
The final Ares I SRB would have completely different propellant grain and geometry.

The geometry and grain may be different but the test will show if their software models are on the right track.

The lack of liquid dampers may be to see if the magnitude of thrust oscillation is as bad as the models suggest. Who knows it might be less of a problem and the weight of the dampers could be lightened.


It will quantify nothing about the real Ares I first stage.

Wrong it will check the accuracy of their computer models. If the results of the test don’t jive with the what the computer says it should be using shuttle SRB’s, then the computer model is wrong.


This "test" doesn't even use avionics designed for Ares I

Who cares if a monkey with a joy stick hanging from a parachute does the guidance, as long as it flies the flight profile. If the avionics works then it works. Your spare tire doesn’t match but it gets you to the tire shop.


Face it, you don’t have to paint the entire room to know if you like the color.

Antice
2009-Aug-17, 07:05 PM
one of the things being tested on the Ares 1x is the aerodynamics of the integrated stack. there are some modelling accuracy risks that has to be tested out prior to going ahead. It's better to spend 300 million now and find out if there is something critically wrong in the design rather than continuing further and spend another 600 mill on dev then have to trace back and pay those 600 again because your model is flawed.

Nicolas
2009-Aug-18, 09:11 AM
If this actually was a test of the final SRB configuration I would agree that there is merit to the test. This test, however, does no such thing. It flies the basic Shuttle 4 segment SRB topped with a dummy 5th segment. The final Ares I SRB would have completely different propellant grain and geometry. They say this test is to validate their models of thrust oscillation, not provide concrete data pertinent to the real Ares I. Validate models with a dummy segment which, for all we know, could radically change the way the stack responds to the thrust oscillation forcing function. Not to mention the lack of damping liquids in the upper stage, but having a rigid "tuna can" stack instead. And thrust oscillation magnifies exponentially with SRB length. It will quantify nothing about the real Ares I first stage. In the end they still only have a model and need to test the real deal anyway. That was to be the Ares I-Y test, one that actually made engineering sense. But what, then, is the purpose of this?

This "test" doesn't even use avionics designed for Ares I, it uses modified Atlas V avionics! It's a poor excuse for a test not worth the $300 million it costs. A cost of a Discovery class mission burned in 2 minutes on something that's not actually a test of the real product. But perhaps I'm just crazy in not seeing the underlying logic to it.


In this post, 1 SRB segment is an uncertainty so large it makes the test useless. Yet in your previous post, the undustry had loads and loads of experience with single solid stage designs, making a test unnecessary. Which one is it?

As I said, the people who decided upon IX will have there reasons for it. Checking their models is a reason they gave. It seems logical to me to do a model check as early as possible. Sure that's a tradeoff with boiler plate parts, but apparently IX turned out useful according to their criteria.

It's not uncommon to validate a model with a test other than one of the final product.

When we were validating calculation models for engines, we tested an inlet design and a single combustion chamber section. That way, we had confidence early on that the model would predict our final design correctly as well.

ugordan
2009-Aug-18, 12:27 PM
In this post, 1 SRB segment is an uncertainty so large it makes the test useless. Yet in your previous post, the undustry had loads and loads of experience with single solid stage designs, making a test unnecessary. Which one is it?

(emphasis mine)
Who said tests were unneeded with solid stages? Did I not concede above that the Ares I-Y test would make engineering sense?



As I said, the people who decided upon IX will have there reasons for it. Checking their models is a reason they gave. It seems logical to me to do a model check as early as possible. Sure that's a tradeoff with boiler plate parts, but apparently IX turned out useful according to their criteria.

It's not uncommon to validate a model with a test other than one of the final product.

When we were validating calculation models for engines, we tested an inlet design and a single combustion chamber section. That way, we had confidence early on that the model would predict our final design correctly as well.
In the end, a model is only a model. It's got its error bars and uncertainties. They already flew shuttle SRBs on one flight with detailed instrumentation recently for this very purpose and IIRC got somewhat unexpected results, i.e. that thrust oscillation was masked by interactions with the stack. What's to say the same won't happen with Ares I-X configuration which, from an engineering standpoint is very far from the real deal. If you think it's "just one more segment" then you're obviously downplaying the complexity of developing large SRB boosters. As I said, thrust oscillations dont' scale linearly with booster length, they scale exponentially. 5 segments does not produce simply 25% more T.O. than 4 segments and the magnitude by how it affects the vehicle (because it's effectively a resonance), depends on the rest of the vehicle.

What happens if/when their model doesn't agree with Ares I-X results or model uncertainties end up too large for it to be useful?

A model should be tested ideally by something as close to the final product as possible. Ares I-Y is that. Ares I-X isn't.

Nicolas
2009-Aug-18, 01:11 PM
What happens if/when their model doesn't agree with Ares I-X results or model uncertainties end up too large for it to be useful?

You've got two options: first, you can change the laws of physics. Since that turns out to be a bit cumbersome ;) , the model is changed and optionally subsequent tests are performed to validate the modified model.


A model should be tested ideally by something as close to the final product as possible.

Should it? Remember that you're validating the calculation model, not the product. Using a simplified product or even something completely else to validate a model may be a good choice (for example to save time or money or labour).

ugordan
2009-Aug-18, 01:15 PM
Should it? Remember that you're validating the calculation model, not the product. Using a simplified product or even something completely else to validate a model may be a good choice (for example to save time or money or labour).
Yes, because a simplified test or one that significantly departures from the final system you're trying to model ends up increasingly more uncertain. You have more and more assumptions input into the model the more you move from your target system that the confidence in the model behavior also drops. Worst case scenario: do a different enough test and you can't tell with any confidence how your end system would perform. Which means you need to test the end system anyway. There is a point of diminishing returns when you depart significantly from your end system. The shuttle SRB tests ended up providing much fine data, but not really proving the model or increasing the confidence of its makers. It goes with the territory.

Nicolas
2009-Aug-18, 01:38 PM
How then do you explain that model validation tests using (totally) different products than the thing you're actually designing are common practice?

Also, the IX test will not be meant to have data on each and every aspect of Ares 1. The IY test has a purpose too.

The IX test is meant to validate certain aspects of the model early in the design. And you don't necessarily need the final product for this. If you simulate the IX stack in your software and the IX test flight behaves the same as in your computer model, you have seriously increased your confidence that the Ares 1 behaviour in the same computer model will resemble its real behaviour.

It's common engineering practice. You need to take care when deciding upon the boundary conditions of your test, but when you do this these model validation tests can be very useful.

I see no reason to doubt the ability of NASA engineers to set up a proper model validation test.

And in this case the model validation test uses a configuration that resembles the final product in certain aspects. Strictly speaking, you don't need to do this for model validation. But as you also said, it can help in removing some uncertainties and extrapolations.

CJSF
2009-Aug-18, 01:55 PM
This sounds like something JayUtah could weigh-in on, too. Perhaps I'll invite him to the discussion?

CJSF

slang
2009-Aug-18, 02:24 PM
A model should be tested ideally by something as close to the final product as possible.

Without getting into which flight is good for what, but the above depends on what kind of model needs to be tested, and which part of the model needs to be studied, no? For a windtunnel test of car aerodynamics one hardly needs the finished product, up to the latest version of the car stereo installed. A mockup of the exterior will do, proper weight distribution might be needed in some cases.

JayUtah
2009-Aug-18, 02:58 PM
Mathematical models for things such as structural resonance are valid for more than one individual design; they're just parameterized differently in each case. It is not improper to test fly a full-scale a prototype that has been designed with the model even if it is not the final configuration, in order to validate the model.

The model will predict certain behavior in the prototype. The prototype will be instrumented to collect data to compare to the model predictions parameterized for that design. This tests the core algorithms of the model and may also reveal any numerical instability. Yes, the fidelity of the prototype affects the validity of the test. But there is no need, for example, to install the final control computer in order for the test to remain valid.