35+ years after the fact this technology is still under research and development and it still cant be done.Hogwash. The rocket stabilization problem was solved in the 1930s. Every rocket requires active stabilization.
As I said Jay you would have no link and no documentation of the LEM of 1969 being successfully tested.Changing horses.
You asked for evidence of
successful LLRV flights, wrongly believing that they were intended as the LM test flights. You specifically asked for it in hyperlink form, for whatever reason. I told you I was not aware of any links. But I did refer you to Spacecraft Films, which includes films of LLRV flights in their DVD. I referred you to the Dryden test center, where the flights took place. The curator there will be pleased to answer your questions and arrange for you to inspect the records of the flights.
If you're asking for evidence of the
LM test program, that's a different story. Start with Tom Kelly's
Moon Lander, then I suggest you read
Chariots for Apollo, which I believe is online at NASA. I have the print version, so I don't know the link. I'm sure one of my friends here has it in a bookmark.
Those are seconary sources. They will give you an overview of the development and test programs. When you have read those books I will be pleased to answer any questions you might have and to give you additional, more technical material.
Did either you someone else mentioned it was tested in space? That is not helpful to NASA's problem since there was nothing to land on...Apollo 11 tested the LM by landing it on the moon. All the other functions had been tested in previous missons or in ground qualification programs. And it is not correct that flight dynamics can only be tested faithfully in the presence of gravity. See below.
There is nothing to learn unless its done on a gravitional body.What is your training in classical Newtonian dynamics? What is your personal experience in engineering test methodology? What is your personal experience in flight test methodology? I'm not prepared to accept this statement without an argument to support it.
This is because the continually changing center of gravity...All rocket-powered vehicles have changing centers of gravity in all flight modes. The rocketry of the 1930s solved this problem.
...for such a smallSmaller vehicles are easier to control because they have lower moments of inertia.
...and relatively top heavy craft like the LEM...Top-heavy compared to what? Please show me your studies by which you arrived at the conclusion that the LM was top-heavy.
The technology needed would have had to have included some form of reliable mechanical weight distribution compensation...Straw man. Why do you think the solution to changing center of mass is redistributing the mass? That is
by far the most complicated way I can think of to address the problem.
Off-axis thrust (i.e., thrust whos vector does not pass through the center of mass) creates a moment. The moment creates a rotation rate. You already have a means of detecting rotation and a means of intentionally causing rotation on your spacecraft. Why not simply correct the effect with your existing equipment instead of trying to correct the cause?
Yet the dificulty with stabilization was plainly evident!Yes. Stabilizing a Harrier is a much more difficult job because you have an atmosphere and aerodynamic surfaces to catch it. If the air moves, the Harrier moves. The engine is also ten times more powerful than the LM's, leading to much greater off-axis moments.
Plus the real LEM-. which you will never see being tested because all attempts failedWhoa! Before you told us there was no evidence the LM was successfully tested. Now you're telling us you have evidence that the LM was tested, but that it failed the tests. I'd like to see that evidence, please.
had to be continuously interacting with a fairly complex onboard computer...Describe, in specific numerical terms, the degree of complexity that a computer would need in order to assist in landing the LM. "Fairly complex" could be anything. I want numbers.
...which it didnt have.The LM had a computer. A very nice one.
The computers of 1969 had about 37k enough to change from wash to spin cycle on a washing machine.Handwaving. I have a degree in computer science and have designed embedded systems myself. You don't know what you're talking about. Judging a computer's suitability to a task based on memory size alone is a common layman's error, but it won't wash here.
Please specify, using actual numbers, the operational requirements you believe would have been necessary for a LM computer, and please show the computations or justifications you used to arrive at each requirement.
Lets not even get into the wattage that would have been needed that it didnt have.No, let's do. There are electrical engineers here who can check your claim. Or is this just more handwaving?
If you look closely it looks alot more like the real LEMSubjective and irrelevant. The LLRV was not designed to resemble the LM or to test the LM design.
I think NASA tried to stay close to the real specs here...Hogwash. The LLRV specification and design were completely separate from the LM's. The LLRV was built by a completely different company. I'm not interested in what you think; I want to know what you can show evidence for.
Think about it...I have. It's my job.
...properly modulating jet flight control is still relatively complex, a massive assortment of computerized sensors are integrated and must be employed in order to safely control the likes of a Stealth fighter.Apples and oranges. A modern high-performance jet fighter is intentially designed to be aerodynamically unstable. The instability aids in manueverability, but comes at the cost of the effort needed to maintain straight and level flight. The F-117 is even more egregious because the shape is dictated by stealth factors, making it even more unstable beyond that required for manueverability.
The desirable instability in these cases comes from the vehicle's interaction with the atmosphere as the vehicle pushes through it, not from the vehicle's inherent mass-dictated dynamics. It is indeed true that these aircraft require complex flight control systems in order to maintain controlled flight. But the proper way to think about it is that the
availability of such control systems enables us to build inherently aerodynamically unstable aircraft that can be manuevered more sharply.
Previously we had to build aircraft that interacted with the air more amicably, and those aircraft did not require complex active controls. In fact, airplanes designed for stability can be "trimmed" to maintain straight and level flight with
no control input.
The LM had no atmospheric effects to deal with. And it was not designed to be inherently dynamically unstable. It was designed to be dynamically
stable. Hence the overall stability problem did not require an extensive computer solution.
However, this issue is simplistic compared to that of modulating rocket engines and multiple thrusters.Hogwash.
LM stability is a
much easier problem to solve than stabilizing a high-performance aerodynamic vehicle. In fact, you can break it down to the same problem repeated in each of the three cardinal axes. The only source of unwanted moments is off-axis thrust. For gross effects, the LM engine could be steered. For fine effects, the RCS was used.
The V-2 rocket had an active stabilization platform using analog controls. That was in the 1940s and resulted in highly accurate trajectories.
Unfortunatley the real LEM had neither a mass gyro...Yes it did.
...nor such multiple modulated thrusters.Yes it did.
The LEM successful documentation films have never been shown by NASA because they dont exist.Grumman filmed a great deal of the LM design and development process. I've seen many of them. I don't have links to them and I don't know if they're online.
LM flight test footage is ubiquitous. I believe Apolloarchive.com might have some online.
...it would serve no purpose in addressing the problems that needed to be solved that were by and large gravity related?No.
It is a common misconception that a rocket stability solution must incorporate the gravity vector. It does not. This misconception is known as the Pendulum Theory, and rocket engineers are forever having to explain why that's not right.
A flying rocket is a fully-consistent, self-contained rotational reference frame, regardless of whether it's flying in deep space or near a planet with gravity. Rockets do not "fall off" their thrust if they tilt too far to one side.
Robert Goddard discovered this the hard way. He originally thought the Pendulum Theory was correct, so his original rocket design put the thrust chamber above the center of mass. His rocket spun out of control. It did not self-correct, as Goddard had assumed it would. He went back to his physics books and did some more study, then slapped his forehead and realized that the relative position of the thrust and the center of mass, with respect to gravity (if any), is utterly irrelevant.
When Apollo planning was underway in 1960, NASA was looking for a simulator to profile the descent to the moon's surface.From
www.nasa.gov/centers/dryden/news/FactSheets/FS-026-DFRC.htmlSo you see there is no mention of any "space testing" as the history of the program...Straw man.
You went to Dryden's web site on the LLRV. And you complain that the LLRV page doesn't describe flight testing of the LM, or
any testing of the LM. And then you conclude that NASA must somehow be hiding the documentation of LM testing, because it wasn't given on a page devoted to a completely different subject. That makes sense only if you presupposed the LLRV was intended to be the LM test bed.
The LLRV was not designed to test the LM
Again, any proof of the LEM being tested sucessfully is in fact non-existent and bears witness to the fact that the entire project failed to solve the stabilization problems due to gravitational constraints placed upon such a top heavy vechicle.No, it only proves that you -- or whoever you're copying your ideas from -- don't really know much about rocket stability. You're falling into the classic layman's errors.
Now 35+ years later we are still waiting for a simple demonstration...You're only waiting because you ignore the existing examples.
In rocketry vertical takeoff is the easy part. The difficult and so far impossible part is the descent landing.I don't recognize you as an expert on rocketry.
Landing is indeed more difficult, but for reasons that have little to do with rotational stability. Ascent allows you to fire the rocket at full thrust. Landing requires a variable-thrust engine. We have those, but they are more finicky than simpler engines.
During the first five or so minutes of ascent, the air is thick enough to let you use aerodynamics to help correct any rotational instability that arises, much like an arrow. After that, the rocket ascent problem is rotationally identical to the rocket descent problem.
Landing a rocket on Earth adds the difficulty of correcting rotations induced by atmosphere. A gust of wind poses a problem that must be addressed. Not so for vehicles that fly in space. Only off-axis thrust is a problem -- as it is for any rocket.
I do believe that this problem will eventually be solved using bottom heavy crafts...Nope. Goddard proved decades ago that rearranging the mass won't solve any problems.
What is needed is some kind of anti-gravity system...No, just a correct understanding of physics.
As always I welcome any film documentation or links to such that would dispute my contention that the LEM was indeed a LEMON.Your contention is best disputed by noting that your expectations of what rocketry is or should be are based largely on ignorance. Thankfully that can be corrected. I suggest some elementary texts on spacecraft dynamics.
I want to believe!I don't see any indication that you do.
If you wanted to believe, and if you respected me as the authority on Apollo that you presumed I was, then I should just have to say, "Yes, I've seen the film and read the journals and technical reports." And that would be sufficient. It shouldn't matter if they were difficult to find, or difficult to understand. That's partly why we have experts to summarize and characterize what they've learned through their diligence.
But your approach is becoming clearer.
You don't "want to believe," and in fact it's pretty obvious that you want to
disbelieve. You identified me as an authority on Apollo only so that your straw man tactics would seem more credible. You propose that I provide something, and if I -- the authority on Apollo -- can't provide it, that must mean it doesn't exist. And if it doesnt' exist, but you think it should, then there's something fishy.
Unfortunately you're looking in all the wrong places. You maintain, without justification, that evidence of the LM's viability should be found in LLRV sources. You maintain, without justification, that the only acceptable information is that found on the web. You maintain, based on ignorance, that valid LM testing would be impossibly problematic. In short, you place all sorts of unjustified limits on the question to ensure it won't be answered. Then you can try to read motive and intent into the lack of an answer.
You're only about the dozenth person who has run this play.
"I really want to believe, but I have this one problem. If you could just clear it up, I'd be happy." Then we discover the "problem" is a simple misconception. Instead of the relief we'd expect from discovering that one's sticky wicket was only imaginary, we get a very entrenched and largely ignorant defense of the misconception. People who are unhappily skeptical are generally very pleased to learn that it was all just a misunderstanding.
But until this subject is changed from being a question of faith to a question of fact...Yes. Once you stop having faith in conspiracy theory web sites and in those authors' (in)ability to teach you correct principles, and start paying attention to the facts of rocket propulsion and guidance, you'll be much better off.