So, who wants to win 1 million Euro?

[Inanimate Carbon Rod]

I don't think he's trolling. 

I think he is, as he's deliberately ignoring corrections, evidence etc from every posting who ain't a hoaxer.

[cjameshuff]

I think he is, as he's deliberately ignoring corrections, evidence etc from every posting who ain't a hoaxer.

You're assuming he's rational. People do sometimes simply ignore information they don't like, preferring their delusions to reality. It's not a terribly common or desirable trait in engineers...

(Nor is the inability to think in terms of systems, accurately identify the parts of a task that are actually difficult, refusal to consider cross-checks using different mathematical approaches such as doing a problem both in terms of energy and momentum, preference of a demonstrated-inaccurate source of data, etc...)

[Echnaton]

In order to win you have to understand basic space travel physics....

Since you believe everyone here is not qualified to make valid criticisms of your work, please provide us with a short list of qualified engineers or physicist that agree with your method of making calculations.  A simple and polite response is likely to get posted through the moderation. 

[sts60]

Hello, Heiwa.  I have just caught up on reading this thread, but I am afraid I see several major problems with your claims:

1. Your fundamental premise is that you will give a million Euros to anyone who can show Apollo could go to the Moon.  This means you are essentially soliciting a contract (money for (intellectual) work), but there is no evidence whatsoever that you intend to fulfill the terms of the contract.  First, no one - myself included - believes that you have a million Euros to offer to anybody.  You said you "evidently" do, but that would require evidence, and you have offered none.  Second, the terms are vague and the adjudication fatally flawed - your opinion only.  Technically speaking, I believe this constitutes a fraudulent offer, but since no competent person takes your offer seriously, I do not believe you are in any particular danger of prosecution (although I am not a lawyer).

2. One of your main claims - that the Apollo spacecraft could not carry enough fuel to, say, enter lunar orbit - is based on a complete misunderstanding of how such quantities are calculated.  Your attempt at an energy balance is fundamentally broken because you simply neglect a major component of the system in its final configuration - the expelled reaction mass.  I am only the latest in a series of actual practicing engineers to point out this very basic error to you.  You cannot draw a control boundary around a system and ignore mass and heat flow across that boundary.  It's that simple.  Why you would do so deliberately, and continue to do so after having this egregious error pointed out to you, is baffling, especially from someone who claims to be an engineer.

3. Many of the claims and questions you have put forth in this thread indicate wide-ranging ignorance of the principles of space flight in general and the Apollo record in particular, unhappily coupled to an apparent inability to find even the simplest facts about the subject in question.

 For example, you talk about using the "Sun gravity" as a tool to maneuver spacecraft to various planetary bodies, which is patent nonsense, while ignoring actual gravity assist maneuvers such as that used to rescue AsiaSat-3.  You claimed that the CM's thermal protection system was "secret", that the Shuttle had "no heat shield", and that it re-entered "backward" - all egregiously silly claims which no one who knew anything about spaceflight would make, and any of which could have been remedied by a half-minute of searching.  For example,

I have asked NASA how the Apollo 1969 heat shield was designed, what material it used, how it was tested, lab reports, etc. SECRET!

The very first result returned by Google is NASA TN-D-7564, Apollo Experience Report - Thermal Protection Subsystem, which dutifully reports,

The ablative material selected for the TPS is designated Avco 5026-39G and consists of an epoxy-novalac resin reinforced with quartz fibers and phenolic microballoons.  The density of this material is 31 lb/ft³...

That is only one of dozens of references into the development, design, and testing of the Apollo TPS freely available online - and that is before looking up physical copies or buying publicly-available papers from AIAA and the like. 

To put it bluntly, you have no idea what you're talking about.  Sorry, but there is no way to put it gently. 

Such egregious examples, I am afraid, call into question your seriousness in creating your Web "challenge" and participating in this thread.  I am not a "NASA PhD", but I am a practicing space systems engineer with over two decades in this line of work, and I will be happy to assist you in learning about space flight as best I can - but can only do so if you actually want to learn something.  Do you?

[Chew]

Hey, Heiwa, do rocket engines work in vacuum?

Rocket engines work in this case in space ships like Apollo 11. Try to be on topic and avoid stupid questions.

"like Apollo 11"?

Why add an unnecessary phrase like that unless you have some reservations about some other rockets? I smell some weaseling coming on.

[Noldi400]

Heiwa

You are extremely aggressive and abusive towards NASA in particular and I am curious as to why.  Did NASA run over your dog or something?

My personal theory is that they dropped a house on his mother.

[Zakalwe]

I'm watching this thread with interest. The maths and knowledge is way over my head, but the sight of the professionals dealing with errors in Heiwa's "calculations" is a testament to how engineering and science gets things done.

My personal theory is that they dropped a house on his mother.

You footnote is as good a way to wrap up the seemingly massive blindspot in Heiwa's vision...you know the one that allows him to see parts of some of the replies but not the ones that clearly demonstrate the errors in his workings-out....

"Ignorance more frequently begets confidence than does knowledge" - Charles Darwin

Personally, I am now calculating how long it will be until Heiwa implodes and stomps off in a massive flounce,


or, alternatively, until the banning hammer is wielded by Lunar Orbit.

[Bob B.]

Okay, here you go. Remember, this is for a stoichiometric mixture of Aerozine 50 with N₂O₄, so my numbers will be higher than yours.

Assuming the reaction products are gaseous N₂, liquid H₂O and gaseous CO₂ at STP, 1 kg of Aerozine 50 requires 2.249 kg of N₂O₄, for a sum of 3.249 kg of propellants, and the enthalpy change is 8.124 MJ/kg. This looks quite reasonable, don't you think?

That's definitely higher than I'm getting with my method.  As I wrote before, I got about 5.16 MJ/kg using the following:

Propellant mixture ratio:  1.6
Temperature of reactants:  298 K
Combustion chamber pressure:  6.8 atm (100 psi)
Combustion chamber temperature:  3,056 K
Nozzle expansion ratio:  62.5
Nozzle exit pressure:  0.00703 atm
Nozzle exit temperature:  925 K
Enthalpy of reactants:  0.33026 MJ/kg
Enthalpy of products at exit:  -4.8299 MJ/kg
Change in enthalpy:  5.1602 MJ/kg

[JayUtah]

That's definitely higher than I'm getting with my method.  As I wrote before, I got about 5.16 MJ/kg...

I think he's trying to set an upper bound, in order to forestall weaseling over parameters.  "Cannot possibly exceed X" is valuable for recalcitrant posters who insist a value must "somehow" be higher.  You're approaching more real-world conditions.

[dwight]

Just curious, did any of us here actually say we _wanted_ the alleged million??

[Bob B.]

I think he's trying to set an upper bound, in order to forestall weaseling over parameters.  "Cannot possibly exceed X" is valuable for recalcitrant posters who insist a value must "somehow" be higher.

That certainly makes sense.  When I apply the same method that I think ka9q is using, I get 7.90 MJ/kg with liquid H2O and 7.03 MJ/kg with gaseous H2O.  My 7.90 is pretty close to his 8.12, but I'm not sure why we should differ that much, unless our sources for heat of formation are that far apart.  I've found that it's not uncommon for different sources to publish different values.  I'm using http://webbook.nist.gov/chemistry/.  Here's how I got my number:

Heat of Formation of Reactants
N2O4         2.9375 mol x  -19.56 kJ/mol =  -57.46 kJ
C2H8N2            1 mol x   50.63 kJ/mol =   50.63 kJ
N2H4          1.875 mol x   48.3  kJ/mol =   90.56 kJ
Total                                        83.74 kJ

Heat of Formation of Products
CO2               2 mol x -393.52 kJ/mol =  -787.04 kJ
H2O (liq)      7.75 mol x -285.83 kJ/mol = -2215.18 kJ
N2           5.8125 mol x    0.00 kJ/mol =     0.00 kJ
Total                                      -3002.22 kJ

Mass of Products
CO2               2 mol x   44.010 g/mol =    88.02 g
H2O (liq)      7.75 mol x   18.016 g/mol =   139.62 g
N2           5.8125 mol x   28.013 g/mol =   162.83 g
Total                                        390.47 g

Thus, the change in specific enthalpy is

delta-h = (83.74 - (-3002.22)) / 390.47 = 7.903 kJ/g (or MJ/kg)

For gaseous H2O, substitute -241.83 kJ/mol.

Ka9q, how does the above compare with your calculations?  Where are we different?

You're approaching more re-world conditions.

Well, I'm certainly trying.

[Bob B.]

Just curious, did any of us here actually say we _wanted_ the alleged million??

Not that I recall.

[Echnaton]

Just curious, did any of us here actually say we _wanted_ the alleged million??

I took Daggerstab's question as being tongue in cheek, as apparently did the other regulars here.  No one besides Heiwa seems to believe the money is really there to be won.  But he isn't very strong on empirical verification of his claims. 

[ka9q]

My personal theory is that they dropped a house on his mother.

That is one of the funniest comebacks I have ever read. Is it original with you? I want to give proper credit.

[ka9q]

N2O4         2.9375 mol x  -19.56 kJ/mol =  -57.46 kJ

I used +9.16 kJ/mol, which I got from the Wikipedia page. Whether it's liquid or vapor is not specified, but the temperature is given as 298K. That's just above its nominal boiling point at standard pressure, so I assume it's for the gas, not the liquid, and that could account for the difference. I also wonder how  meaningful it is since N₂O₄ has a habit of largely dissociating into NO₂ at these temperatures so the actual enthalpy of the real material would be different.

I did my calculations with a spreadsheet so it's easy to change parameters and recalculate. Lessee... sure enough, when I plug in -19.56 MJ/kg for the enthalpy of formation of N₂O₄ I get 7.9 MJ/kg just as you did. That gives me good confidence that we both did it right.

Your number is the right one because the propellants do start as liquids. I should also have used the enthalpy for water as a gas, but I used the value for water as a liquid because that gave a greater result and I was trying, as Jay said, to establish a theoretical upper bound that cannot be exceeded. It also produces an interesting result for the efficiency of the engine at turning chemical energy into kinetic energy. Rocket engines aren't as bad as we think. It's the requirement to carry reaction mass that's the real bitch in space travel.