So, who wants to win 1 million Euro?

[Echnaton]

Your self claimed motives and self reported IQ are not the issues.  Just answer the questions.  That is what discussions are about. 

[Glom]

So, to sum up:

Do you acknowledge that the LM did not use hydrazine as a fuel exlcusively?

Do you acknowledge that you have the LM fuel loads wrong?

Do you have a source besides that one schematic for your specifications for the SPS engine?

Do you have any eplanation for how you calculated the mass of fuel based on the volume in litres?

All figures/calculations I use are from or based on NASA reports/websites (or Wikipedia using same sources) quoted in my presentation. You do not really suggest I make up things? Why would I do that? I am interested in space travel safety. What is your interest?

Either your sources are wrong or you are misreading them because many of your facts and figures are wrong.

You got the fuel wrong.

You got the propellant load wrong.

You got the engine name wrong.

These are basic facts available widely and you got them wrong.  You need to acknowledge this before you can understand the safety of space travel.

[Jason Thompson]

IMHO it sounds crazy and only assholes could claim having done it.

You will STOP with the ad homs. I don't care what your opinion is, you are talking to people with relevant qualifications in the area, some of which are actually paid to apply that knowledge. Andromeda has more qualifications in physics than you do, I guarantee it.

Do you think it really happened? Could it be done 1969? I offer anybody €1 M to explain how! Isn't it generous?

No, it is not generous. Give up the pretense. We KNOW you don't have the money and that you have no intention of EVER giving it to anyone even if you did. Who do you think you are fooling?

[Heiwa]

The only thing we (not you) agree on is that your figures are wrong.

Pratt.

According George M Low (Willy) of NASA (actually more or less running the Apollo show) and his report 1969 the three persons/astronauts on Apollo 11 burnt 10 000 kg of rocket fuel in a 6 minutes braking while applying a 10 ton force on Apollo 11. The result was that the 43 000/34 000 kg space craft slowed down from 2400 to 1500 m/s, changed direction in space and started orbiting the Moon. IMHO it sounds crazy and only assholes could claim having done it.

Do you think it really happened? Could it be done 1969? I offer anybody €1 M to explain how! Isn't it generous?   

So where did you get this from? Are you afraid to quote your source......or maybe you 'can't remember'?

Georg M Low report - reference [1] of my presentation. Just read my presentation, copy/paste what you do not understand and we can discuss. Georg M Low was running the Apollo program 1969 or, IMHO, the Apollo hoax program. George died too early I am sad to add - 1986 or so. Some people called George Willy.

[Jason Thompson]

It is my satiric/ironic/irresponsible style when looking into hoaxes. Sounds funnier than assholes.

And marks you out as an immature individual. You want to be taken seriously, quit with that style.

[Heiwa]

Your self claimed motives and self reported IQ are not the issues.  Just answer the questions.  That is what discussions are about.

What was the questions?

[Jason Thompson]

All figures/calculations I use are from or based on NASA reports/websites (or Wikipedia using same sources) quoted in my presentation.

It's that 'based on' I want clarification of. Your website says you have 'assumed' the mass of propellant in the LM from the volume given in liters on that schematic. ALL your stuff seems to be based on that schematic rather than the actual reports.

You do not really suggest I make up things?

No, I think you incorrectly derive and incorrectly apply. I repeat my request for a further supporting statement about the specs of SPS engine, for example. The ONLY place that I can find that refers to it as a 'P 22K S' is that simplified schematic.

I am interested in space travel safety.

Rubbish. You are interested in trying to make yourself look like an expert, and trying to make yourself look more clever than people who have ACTUALLY achieved something amazing like sending men to the moon. How many qualified people agree with your calculations? Are you so deluded you really think you're the only person in over four decades to notice this complete impossibility you are talking about?

[Glom]

Your self claimed motives and self reported IQ are not the issues.  Just answer the questions.  That is what discussions are about.

What was the questions?

How about:

Do you acknowledge you got the fuel wrong?

Do you acknowledge you got the propellant load wrong?

Do you acknowledge you got the engine wrong?

We'll start with that.

[Jason Thompson]

copy/paste what you do not understand and we can discuss.

We have enough to discuss here thank you.

[Donnie B.]

Thanks Glom (edit: and Andromeda, posting while I typed )

Oops, I also forgot about the changing gravitational field. Is that a large or small effect on a launch?

Relatively small for a low earth orbit, but not negligible.  Much more significant for higher orbits including trans-lunar ones.  But still, the balance point between Earth and Lunar gravity is something like 85% of the way to the Moon.

I'm sure it's calculated in a launch, but due to air resistance and so forth, does the rocket get shut down at a certain speed or is it all precalculated and shut down after a certain time?

This is somewhat complicated and I'm probably not the best person to answer.  For one thing, it varies from one launch profile, type of launcher, and mission to another.  All rockets include on-board guidance, if for no other reason than to keep the engine pointing in the proper direction.  That guidance system is programmed to make the vehicle follow a particular pre-planned trajectory that takes it from the ground to some desired final state.  There are various things that can be controlled, depending on the design of the launcher, but the most common are the engine gimbaling (direction of thrust) and burn duration (for liquid fueled engines).  Some older designs (like the V-2) included vanes in the exhaust to vector the thrust rather than engine gimbaling.  Some engines also include throttling capability (as mentioned above) but most large engines do not.  Some thrust control is provided by having multiple engines that can be shut down independently, as previously mentioned.

Besides the on-board systems, space launches have ground controllers who monitor the path of the vehicle and telemetry from the on-board systems.  The controllers can't do much to correct major malfunctions but can destroy the vehicle if it deviates too much from its planned trajectory.  This is the responsibility of the "range safety officer".

So your simple question -- does a launcher shut down at a particular time or a specific speed? -- has no universal answer.  It shuts down when it has achieved its intended terminal state (the proper orbit, for example).  This can sometimes take a rather bizarre form if things don't go quite as planned.  The second launch of a full-up Saturn V experienced some engine failures and other problems, yet it still managed to enter the proper orbit... but it was thrusting backwards when it did!

[Andromeda]

Georg M Low report - reference [1] of my presentation. Just read my presentation, copy/paste what you do not understand and we can discuss.

Will you stop going on about your sodding "presentation"?!

FTR I understand more than you ever will.  Go spend 5 or 6 years studying physics and astrophysics, then we'll talk.

[Mag40]

Georg M Low report - reference [1] of my presentation. Just read my presentation, copy/paste what you do not understand and we can discuss. Georg M Low was running the Apollo program 1969 or, IMHO, the Apollo hoax program. George died too early I am sad to add - 1986 or so. Some people called George Willy.

Reference [1] is http://www.hq.nasa.gov/alsj/a11/a11MIssionReport_1971015566.pdf

Where in that report does it show your figure for the 8,777kg? Where did you get that from?

Your quote was here:

According Mr Low (Willy):

The 15 102 kg (or 33 294 lb) lunar module (LM), Eagle, fitted below the CSM at departure, carried 3 800 liters nitrogen tetroxide + 4 500 liters hydrazine (mass 8 777 kg) fuel for 1 descent engine with 46 700 N thrust and 1 ascent engine with 15 700 N thrust. …

[ka9q]

Since the mass of the rocket is changing, does the thrust also change to compensate and keep acceleration constant or does the acceleration increase?

As several others have pointed out, most rockets are fixed thrust, with some stages shutting down an engine early to limit peak acceleration, the Saturn V first stage being the classic example. At liftoff it has barely enough thrust to support its own weight, which is why it rose so slowly from the pad. But it burns propellant so furiously that the inboard engine has to be shut down to limit acceleration to 4 g. Then it rapidly builds back up to 4 g at outboard shutdown.

The Saturn V second stage has much less thrust than the first stage so it wasn't originally intended to have an early inboard shutdown. It was done after the first few flights to minimize a difficult 'pogo' problem.

One rocket did vary its thrust to compensate for its lightening propellant load, and that was the LM's descent stage. I don't know of any others. Designing a rocket that could be reliably throttled was a major challenge.

[ka9q]

Plus, remember it is easier to accelerate away as you climb further out of the Earth's gravity well.

This is certainly true for ion engines because they burn for such a long time, but chemical rockets burn so quickly that the change in gravitational acceleration during a burn is very small. Their burns can usually be modeled as instantaneous impulses with little error.

[ka9q]

Very well, perhaps i should have said high school physics is not enough on its own even if he did know it. You can't, for example, apply F=ma to a system where the mass is not constant, such as a rocket firing its engine.

Okay, then high school physics plus high school calculus to handle the changing mass. :-)