So, who wants to win 1 million Euro?

[Jason Thompson]

They do not add up when you do it because you are doing it WRONG. How many more times and ways do we need to say this before you get it? You CANNOT disregard the mass and energy of the spent fuel.

The fact that you ask 'why use it' in relation to the Tsiolkovsky equation says it all really.

[Inanimate Carbon Rod]

IMO

Your opinion as a worthless as it uninformed. A fact repeatedly noticed and commented upon.

the Apollo 11 command module, when velocity was say 6 000 m/s  will rotate the module and kill the people inside. The module was not stable ... like a Ford Edsel.

That is incorrect - the following document, Aerodynamic Stability Characteristics of the Apollo Command Module, explains in why detail

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19680021973_1968021973.pdf

Please don't lie about having read it.

But I fear the module will burn up already at 7 000 m/s speed in the atmosphere.

Ablative heatshields. This has been explained to you already.

[Glom]

Heiwa:

Can you tell us why you are so wedded to your attempt to draw conclusions from the kinetic energy of a spacecraft?  The Tsiolkovsky rocket equation, which is derived from the linear momentum of a rocket when acted upon by outside forces, will give you an answer that accounts for the energy changes.

I am only interested in the kinetic energy of the space ship itself before/after burning fuel. Masses/velocities are known. The difference is the kinetic energy of the fuel burnt that produce the force that change the velocity of the space ship. The Tsiolkovsky formula is not required for that - why use it? And it seems that too little fuel was available to produce the velocity changes of Apollo 11 and that the numbers produced by NASA do not add up as shown in my simple presentation.

Why are you interested in the kinetic energy?  If you are trying to work out whether the mechnics are correct, the Tsiolkovsky equation will do just fine and is the generally accepted way of doing it.  The delta-v required is known, the specific impulse of the spacecraft is known, the initial and final masses are known.  Do it that way.

Have you even redone your incorrect calculations using the correction energy density for Aerozine 50 and nitrogen tetroxide that we gave you?  What energy density are you using?

[ka9q]

I am only interested in the kinetic energy of the space ship itself before/after burning fuel.

Your interests are too narrow. Consider broadening them.

Masses/velocities are known.

Indeed they are. So why did you say they weren't?

The difference is the kinetic energy of the fuel burnt that produce the force that change the velocity of the space ship.

Wrong, as we've been telling you, and as any textbook on the subject will confirm.

The Tsiolkovsky formula is not required for that - why use it?

It most definitely is required, as you'd know if you weren't so incredibly ignorant and unable to learn.

And it seems that too little fuel was available to produce the velocity changes of Apollo 11 and that the numbers produced by NASA do not add up as shown in my simple presentation.

And it seems you're simply wrong.

[ka9q]

IMO the drag and lift forces acting on, e.g. the Apollo 11 command module, when velocity was say 6 000 m/s  will rotate the module and kill the people inside. The module was not stable ... like a Ford Edsel.

Your opinion is worthless because it is not informed by any facts.

The Apollo command modules (not just the Columbia of Apollo 11) were actually quite stable. But just in case, they carried a reaction control system to keep them pointed in the right direction. They even used that system to direct a lift vector that steered the trajectory to the desired recovery zone. Guess you didn't know that, huh?

But I fear the module will burn up already at 7 000 m/s speed in the atmosphere.

You're a little out of date. Fear not, it landed safely over 43 years ago. You can even see it in the Air & Space Museum in Washington DC. You can inspect for yourself the remnants of the ablative heat shield that kept it from burning up.

[Mag40]

There is a very often used expression.....made when something is supposed to be easy to understand.

"It isn't rocket science."

Well guess what.....this is! Repeating your mistakes over and over again, whilst being shown how totally wrong you are.....by people who do this for a living.....that is either crass stupidity or trolling......or both.

http://en.wikipedia.org/wiki/Variable-mass_system

Now read it.....go and educate yourself.

[Heiwa]

Let me after about 785 posts remind you about topic, i.e. my Challenge about safety of space travel and associated fuel consumption. You have to demonstrate how to travel to the Moon and back to win the prize (€1M). It is not easy.

Say that your space ship has mass 32 676 kg excluding fuel and that you must slow down from 2 400 to 1 500 m/s velocity to insert into Moon orbit. Your space ship has a P-22 KS rocket engine with 97 400 N thrust (at full blast). How much fuel do you require to carry out the braking maneuver?

If you suggest, e.g. 10 898 kg, you must support your answer with proper calculations to win the prize (€1M). I have a feeling you need >80 000 kg.

Say that your space ship has mass 12 153 kg excluding fuel and that you must speed up from 1 500 to 2 400 m/s velocity to get out of Moon orbit to carry out a so called trans-Earth injection. Your space ship still has a P-22 KS rocket engine with 97 400 N thrust (at full blast). How much fuel do you require to carry out the acceleration maneuver?

If you suggest, e.g. 4 676 kg, you must support your answer with proper calculations to win the prize (€1M). I have a feeling you need > 20 000 kg.

In order to proceed with the discussion, I suggest you try to clarify above basic questions of fuel consumption.
 
Pls do not suggest that I do not know anything about space travel, astrophysics, that I am broke, a criminal that cannot carry out my work, etc, etc, because it is clear from link in post #1 what I am doing for a living. My biz is safety at sea. And I am quite good.

[Daggerstab]

But I fear the module will burn up already at 7 000 m/s speed in the atmosphere.

Ablative heatshields. This has been explained to you already.

His problem is not that much the heatshield, but what exactly happens during re-entry. He thinks that all the re-entry heat gets dumped into the spacecraft.

What actually happens is that the re-entering body pushes a cushion/shockwave of air, which heats due to compression, turning into ionized gas/plasma. The majority of the energy of re-entry is spent heating atmospheric air. The purpose of the heat shield is to prevent this superheated envelope from destroying the spacecraft.

[Jason Thompson]

IMO the drag and lift forces acting on, e.g. the Apollo 11 command module, when velocity was say 6 000 m/s  will rotate the module and kill the people inside. The module was not stable ... like a Ford Edsel.

That's your opinion. Fine. What engineering principle is it based on? What knowledge do you have of the construction of the command module to allow you to decide if it is stable or not?

But I fear the module will burn up already at 7 000 m/s speed in the atmosphere.

That's because you don't understand how the heat shield actually worked.

[Heiwa]

What actually happens is that the re-entering body pushes a cushion/shockwave of air, which heats due to compression, turning into ionized gas/plasma. The majority of the energy of re-entry is spent heating atmospheric air. The purpose of the heat shield is to prevent this superheated envelope from destroying the spacecraft.

Did Apollo 11 push a cushion or shockwave of air in front of it while trying to keep the trim angle right while flying up/down in the atmosphere? And only this cushion of air heats up and turns into ionized gas/plasma.
Have this strange phenomenom been tested in a laboratory or air tunnel test installation? Pls provide some evidence. I have a feeling you are just making it up SF style.

[ka9q]

Or, if you don't believe NASA (or any other damn Yankees) try reading Ways To Spaceflight by the German Hermann Oberth. He wrote it in 1929, about 30 years before NASA even came into being:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19720008133_1972008133.pdf

See page 200 for a discussion of what has come to be known as the Oberth Effect. Oberth himself first thought he had broken the conservation of energy, only to realize that he was simply looking at the problem incorrectly. He had to account for all of the energy in the system, including that in the propellant both before and after it is burned and ejected from the rocket engine.

[sts60]

Strike one, Heiwa.

Do you deny the existence of aerodynamic drag? 

No, evidently not, pls refer to my presentation - link in post #1. IMO

There are a number of professional engineers in this thread, some of whom actually work in aerospace.  Please explain why any of us should pay any attention to your opinion, when you have repeatedly demonstrated ignorance of even the most basic aspects of space flight and an inability to grasp even the most fundamental principles involved.

the drag and lift forces acting on, e.g. the Apollo 11 command module, when velocity was say 6 000 m/s  will rotate the module and kill the people inside. The module was not stable ...

Wrong.  Inanimate Carbon Rod has already provided a detailed reference - the existence of which you were ignorant - refuting this silly claim:
NASA TN-D-4688, Aerodynamic stability characteristics of the Apollo command module.  But you are also ignorant of other work, such as
NASA TN-D-3890, Stability characteristics of the Apollo command module, and
Simulation of the Apollo command module aerodynamics at high altitudes, and
Simulation of the Apollo Command Module aerodynamics at re-entry altitudes, and
NASA-TM-X-1395, Longitudinal aerodynamic characteristics of the Apollo command module at a Mach number of 20 and data comparisons over a wide Mach number-Reynolds number range, and on and on.

There is an enormous amount of documentation about the design and test of the Command Module and its stability and steering.   I worked (long after Apollo) for the guys who designed it.  You simply don't know what you're talking about, and you aren't even dimly aware of the work that went into it.  You aren't even remotely qualified to render an opinion about it; you're just as spectacularly wrong about this as you have been about everything else to do with Apollo in particular and space flight in general.

like a Ford Edsel.

The Edsel, whatever its faults, was stable.  Once again, you have no idea what you are talking about - to the point that you provided an example that contradicts your own claim!

But I fear the module will burn up already at 7 000 m/s speed in the atmosphere.

You are wrong, and you don't get any less wrong by repeating your ignorant opinion, and I and others have already explained how ablative shielding works - and that it has been standard engineering practice for more than half a century.   

You still need to address another claim you made:

Only Apollo 11 is SF.

Is this an admission that you accept the reality of the other Apollo missions (and Mercury and Gemini and Soyuz and Shenzhou and Skylab and Salyut and Mir and ISS and Cygnus and Genesis and etc.)?  Or that you were simply unaware of the other missions' existence?  Or that you are simply unable to keep track of your claims?  Or that you are simply trolling?

Now, as I have said several times before:  Kindly stop dodging the serious problems with your claims I brought to your attention in reply #558:

1. You are offering money you don't have, for a challenge you have defined poorly - and redefined - and has no proper adjudication.  Your challenge is fraudulent.

2. Your primary calculation is completely wrong because you don't understand energy balances.  Your errors have been explained to you in excruciating detail, yet you refuse to acknowledge them.  You simply keep repeating your error - even after the simplest possible case provides an obviously wrong answer using your method.

3. You have no idea what you are talking about, and no apparent interest or ability in relieving your own ignorance.  Yet you continue to offer you ignorant opinion without even acknowledging the corrections and voluminous references provided to you.

Again, strike one.

[Peter B]

From Heiwa's Moontravel page:

In order to do a correct braking - reducing speed - in universe of a space ship by retrograde firing of a rocket engine close to the Moon, the rocket engine outlet must evidently be positioned in the direction of flight during the 700 000 to 900 000 m curved braking trajectory. It means that the three space pilots flew backwards, when suddenly braking to insert into Moon orbit. The trajectory was evidently not straight as you curved into Moon orbit.

(bolds are my emphasis)

Why the emphasis on the trajectory being curved? The first reference comes straight after the statement that "...the rocket engine outlet must evidently be positioned in the direction of flight..." I therefore suspect that Heiwa believes the spacecraft had to gradually change attitude during the burn to keep the engine pointed in the direction of travel.

Well, it didn't. The spacecraft was aimed in a particular direction for the burn, and remained pointed in that direction for the duration of the burn.

Heiwa might need to add "stellar inertial" to the list of concepts he needs to learn about. (For example, go to http://history.nasa.gov/ap08fj/02earth_orbit_tli.htm and scroll down a little way to see the difference in spacecraft attitude between a stellar inertial orbit and an orb rate orbit.)

[ChrLz]

While all this is quite fun, and I will miss it when it's over...  Heiwa, I think it's time we discovered who's right and who's wrong...

So, would you be kind enough to do the following?

First, identify the nearest (to you) 'centre of excellence' in regard to the topic of 'rocket science' or a related discipline like aeronautical engineering.  Then, identify the best qualified person there, who could adjudicate.  I would note that given you claim expertise in these matters, surely you must already know who that might be (as an analogy, I am very interested in the marine sciences so as soon as I moved to a new state I immediately looked up the knowledgeable locals for a bit of networking...)

Anyway, you can then name that person and their credentials, work history, peer-reviewed papers, etc - if you are a bit shy about all this, PM me and I'll take it from there.

As it's your alleged money, it's only fair that you pick the location from which the suitably credentialed/ experienced person comes, so ... have at it..



If you are not willing to do that, could you elaborate on why?

[grmcdorman]

OK, looking up the LaTex, I can do Heiwa's equations in a more readable form. This gives another way of looking at the problem.

So, given:

mi	Initial mass
vi	Initial velocity
mf	Final mass
vf	Final velocity
e	Energy (J) available from fuel combustion

[jstex]\frac{1}{2}m_i v_i^2 - \frac{1}{2}m_f v_f^2 = e[/jstex]

Equ. 1

So, solving for v_f:

[jstex]\frac{1}{2}m_f v_f^2 = \frac{1}{2}m_i v_i^2 - e[/jstex]
[jstex]v_f^2 = \frac{2 ( 1/2 m_i v_i^2 - e ) }{m_f}[/jstex]
[jstex]v_f = \sqrt{ \frac{m_i v_i^2 - 2e}{m_f} }[/jstex]	Equ.2

Heiwa, do you:

• Agree that this is correct?
• Agree that using Equ. 2, we can calculate the spacecraft's final velocity, given the initial velocity and mass, the final mass, and the energy from the burned fuel?