So, who wants to win 1 million Euro?

[Jason Thompson]

You are thus right that multiplying with 71 kg I get 0 J, 68.5 J, 1753.1 kJ and 1775.0 kJ difference of the two last one being 22 kJ, which is the difference in kinetic energy of the walking 71 kg person on the plane.

As the mass remains 71 kg everywhere the load on the person's legs remains the same.

Yes, I know that. So tell me why the person doesn't need legs 320 times as powerful to move his mass at 805 km/h on the plane compared to 5 km/h on the ground. That is, after all, exactly what you propose is the issue with the Apollo spacecraft when taken purely in terms of kinetic energy.

If the person's mass and therefore the load on his legs is the same whatever speed he is moving at or wherever he is, and therefore he only needs to apply enough energy to change his speed by 5 km/h wherever he may be, why does that principle not apply to Apollo 11 in your example? Why are you insistent on using the speeds in that example when you claim they are not relevant here?

Are you upset that you don not qualify to win 1 million Euro (topic)?

Give up. You don't have a million Euros. No-one here believes you have it or that you have any intention of ever parting with it if you do. I am not remotely upset about not qualifying to receive a prize I never believed you ever had any intention of providing. I am rather enjoying your total inability to grasp basic facts, however.

[Heiwa]

... you are referring to Apollo 13, yes?
It never entered lunar orbit. Rather, after the explosion, the LM descent stage made a burn to put the CSM/LM stack *back* into the free return trajectory, looping around the moon, that would return it back to Earth, a pretty minor change in velocity. The figures are easily available.

Hm, ... free return trajectory, looping around the moon, minor change in velocity ... no fuel consumed ? ... figures easily available. It does not sound convincing. Suggest you explain how Apollo 13 managed to change direction in space and get back to Earth and fuel consumed for the maneuver.

You admit things can *get* into Earth orbit, yes? You've claimed shuttle sightings were just a fake satellite sent up to fool people, yes? But once they are in orbit, not spending any fuel, *they're flight is *constantly* looping, loops that loop back on themselves, constantly changing direction relative to the body being orbited. Heck, the same could be said of the moon around the Earth and the Earth around the Sun.
The answer is gravity.
And, yes, the figures are easily available. Such as right here on page 28 of the PDF.
Apollo 13 did have to spend some fuel to get back into a free return trajectory, but, once it was done, to quote the film based on the events in question, they "put Sir Isaac Newton in the driver's seat" though they did later burns to speed up and get home faster.
Oh, and are you still going to try to claim the figures and information on the ablative thermal shielding for Apollo are some kind of secret?
It's Not a Secret!

Of course I have been told that Apollo 13 (service module out of order) with pure luck managed to steer close to the Moon (requiring fuel) using the LM engine/fuel/steering aids, so it could swing around the Moon using its gravity and then, at the right moment managed to change direction towards Earth (requiring more fuel), etc, etc, blah, blah, to land safely on Earth.
All nonsense of course! The NASA SF writers produced a little drama ... assisted by Hollywood. I assume you are sorry you cannot win 1 million Euro?

[Jason Thompson]

I am getting sea sick. The landlubber thinks there is no up or down deviation at sea. 

Do you have to take special classes to be that obtuse? I know that there is up and down motion during sea travel. I suffer from horrendous seasickness. But it cancels out over the course of the journey, and you always arrive at your destination in the same level you set off at: sea level. How many ships arrive 100 feet up in the air and have to descend to get into port, for heaven's sake? How many ships have engines or rudders designed to make them move up and down?

That is absolutely NOT the case in space travel. Devaitions in any dimension are not self-correcting and therefore must be considered in navigation and propulsion systems. I don't know why you have such trouble grasping that concept.

[Jason Thompson]

it could swing around the Moon using its gravity and then, at the right moment managed to change direction towards Earth (requiring more fuel),

Again the concept of a free-return trajectory eludes you, I see.

[Heiwa]

That is, after all, exactly what you propose is the issue with the Apollo spacecraft when taken purely in terms of kinetic energy.

I think you have misunderstood what I write. 

[Andromeda]

That is, after all, exactly what you propose is the issue with the Apollo spacecraft when taken purely in terms of kinetic energy.

I think you have misunderstood what I write. 

No, you misunderstand what you write.

[Andromeda]

Just for fun, a summary of the more amusing gaffes made by Heiwa to show how little research he actually has under his belt:

...

He considers sea travel to be similar to space travel, despite the obvious lack of an up or down deviation in course on any sea voyage.

...

I am getting sea sick. The landlubber thinks there is no up or down deviation at sea. 

He said deviation in course.  There are many things you can get away with, but do not insult Jason.

[Heiwa]

Do you have to take special classes to be that obtuse? I know that there is up and down motion during sea travel. I suffer from horrendous seasickness. But it cancels out over the course of the journey, and you always arrive at your destination in the same level you set off at: sea level.

No, I am always nice and gentle with people I know. On forums like this maybe not. I am sorry that you suffer from seasickness. It explains a lot.
Re sea level - which one do you refer to? High tide? Low tide?

[Jason Thompson]

Very well then, please enlighten me as to where I went wrong.

You claim that to calculate the energy requirement to change speed on Apollo 11 you need to work out the difference between the kinetic energy before and after the burn using KE = 1/2 mv^2. So you need the starting speed and the final speed, from which you calculate the difference in kinetic energy between those two speeds for a spacecraft of given mass. That determines the energy change you need to affect with the engine to achieve the end result. Yes?

So why is in invalid for me and others to point out that if you do that for a man standing on Earth and a man travelling at 800 km/h on a plane, the one on the plane needs to change his kinetic energy by about 320 times more than the one on the ground, and yet his legs work fine in both cases to affect the change in speed he needs to be able to walk forwards?

[Jason Thompson]

It explains a lot.

It is irrelevant except to indicate that I am familiar with up and down motions at sea, since they often result in the upward motion of my last meal.

Re sea level - which one do you refer to? High tide? Low tide?

Now you're just clutching at straws. Anything to avoid admitting your ridiculous mistakes. High tide or low tide doesn't matter. Again, this is something that the ship does not have to compensate for. Wherever it goes, wherever it sets out from, wherever it ends up and whatever conditions it meets on the journey, barring disaster it will always end up in port floating on top of the water, just like when it left.

[Heiwa]

That is, after all, exactly what you propose is the issue with the Apollo spacecraft when taken purely in terms of kinetic energy.

I think you have misunderstood what I write. 

No, you misunderstand what you write.

No, what I write is correct and easy to understand. I understand you are upset not having won my 1 million Euro, though. You are not alone.

[Andromeda]

That is, after all, exactly what you propose is the issue with the Apollo spacecraft when taken purely in terms of kinetic energy.

I think you have misunderstood what I write. 

No, you misunderstand what you write.

No, what I write is correct and easy to understand. I understand you are upset not having won my 1 million Euro, though. You are not alone.

Oh get over it.  We all know you haven't got the money, and I'm not the least bit bothered that I won't get fake money.  I've got plenty of Monopoly money already!

[Jason Thompson]

No-one is upset, Heiwa, since no-one ever believed you had the million euros to start with. Quite sniping and deal with the substance of the arguments being presented or else clear off and pollute some other forum with your ridiculous ignorance.

[cjameshuff]

Re sea level - which one do you refer to? High tide? Low tide?

How much difference in altitude is there between the two? How much difference in potential energy is there between the two, and what difference does it make to the fuel requirements or speed of travel? Somewhat less than that involved in space travel, now, isn't it?

[Andromeda]

No-one is upset, Heiwa, since no-one ever believed you had the million euros to start with. Quite sniping and deal with the substance of the arguments being presented or else clear off and pollute some other forum with your ridiculous ignorance.

He already has.  He got his arse handed to him on UniverseToday.