What If I Told You Rockets Just Don't Work In Space?

Incorrect, thrusters work in zero gravity hard vacuum.

Whenever you throw something in one direction you (the thrower) ALWAYS receives an impulse in the opposite direction.

You are correct that kinetic energy does not retard perceivably in open space, due to no air friction.

Opie, you're dumber than a gaggle of NASA fanboys and you make the truth movement look retarded. please shut up.

Here's a simple proof you're full of shit. Why does it take 2 firemen to hold a three and a half inch hose when it's turned on? you think it's pushing against the air?

The recoil of a gun begins to occur the instant the bullet starts moving in the barrel, it's ebcause of Newtons third law. The energy of the bullet is equal to the energy of the recoil. Rockets work because the gasses are expelled at extreme velocity, the energy imparted is equal to 1/2 the mass of the gasses time the velocity of the gasses exiting the rocket nozzle squared Ke=1/2 Mass (velocity X velocity)

If you have a rocket with a thousand pounds of fuel and oxidizer and burn it, the expansion of the gasses in the combustion chamber reaches extreme pressure, which expels the gasses from the rocket engine's nozzle at very high velocities.

let us use a hypothetical velocity of 10,000 ft per second in the formula

E = 1/2 1000lbs (10,000ft/sec X 10,000ft/sec)
E=500 X 100,000,000 = 50,000,000,000 ft/pds. Thats 50 billion ft pounds of energy, and this is why rockets can accelerate to extremely high velocities.

Hey genius, "nice" example. Do the hoses weight into space as well?

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Last Edited by IWASTHERE on 08/09/2014 10:48 AM

satellites and space station dont either

Hey Ducky you really are the dumbest poster on GLP. What amazes me most is that you are not ashamed of your dumbness. You really should get out of your mom's basement evrey now and then. There is a whole world out there ya know. Hell, who knows, you may even learn a thing or two.

OP,

did you even read what I took the time to write to you?

whay start a thread when you can't even be bothered to read the posts.

dumbass!

I see, how many walking deads are there?

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Another Q that comes in mind just right now is:

WHY they did choose a 0 altitude location at the sea level as a launching point?

For example, at 13.000 feet, they would make it so much less expensive about fuel AND stuff.



Last Edited by IWASTHERE on 08/09/2014 11:45 AM

I'm going to say false, unless you meant to say the derivative of the kinetic energy with respect to velocity is conserved. The kinetic energy is increasing all the time, it's a scalar value and even if it wasn't the difference between the total sum of exhaust KE and the Rocket KE is increasing too.

Just sayin

From wikipedia [link to en.wikipedia.org]

The Saturn V reached 400 feet per second (120 m/s) at over 1 mile (1,600 m) in altitude.

Does anyone know how much liters per second the Saturn V rocket did blow away?

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yes, my bad, KE is scalar, no direction vector.

I guess I was meaning to say something like: in free space, the centre of gravity of the rocket and exhaust remains fixed. I think this might even hold true regardless of how crazy the rockets path was.

Depends on the model. The F1 The fuel pump produced 15,471 US gallons (58,560 litres) of RP-1 per minute while the oxidizer pump delivered 24,811 US gal (93,920 l) of liquid oxygen per minute.
[link to en.wikipedia.org]

I should have said:

"The total integrated momentum of the complete system (rocket and exhaust) remains zero, the rocket exhaust speeding one way, the rocket body the other."

Thanks for the correction, refreshing to brush against someone with brains.

A. better question is how would you vent heat in space during prolonged flight.

As Sir Isaac said.

"If a body impinges upon another, and by its force changes the momentum of the other, that body also (because of the equality of the mutual pressure) will undergo an equal change, in its own momentum, toward the contrary part"

So you could save a lot of typing by just saying in a rocket , momentum is conserved, that's the easiest way to think about rockets.

:)

Don't be a bloody fool, man!

In Talmud it is said: sky consists of Fire and Water (atomic energy, ether).
Did you know, that ppl in closed capsule after 14 hours lose feeling of time. Did you noticed, that most astronauts are stupid rednecks. That most shuttles lift empty. That NASA shows you on TV computer game.

Heat pumps and radiators, the heat pump establishes a large thermal potential between the radiators. The hot radiator allowed to "radiate" infra red EM into space.

Much management can be done for free, fat heat pipes allowing radiators to transfer heat from hot side to cold side of craft.

I suppose you think heat cannot be transferred through a vacuum, did you ever stop to think that the sun feels warm to us, that warmth travelling across the vacuum?

Or maybe you think the sun is within our atmosphere, the whole "sun being 93 million miles away" thing being a giant conspiracy lol.

TIP: The internet can be used for reading as well as writing.

Rockets work specifically BECAUSE of Newton's third law. The rocket expels mass in the direction opposite its acceleration.

I think it would have to be:

in a rocket , momentum is conserved when also considering exhaust gasses.

Otherwise the reader might not consider the exhaust and think it a false statement. Because when considering only the rocket it's momentum increases relative to it's launch point.

That's actually a major issue in space electronics, since there is no air for convective heat transfer. You have to rely on conduction to get heat to radiators, then radiation for the heat to leave the system.

I actually worked on a cubesat project with 3 FPGA's all needing sinking. The obvious answer was using 3 heat pipes out to a radiator, which is what we ended up doing.

Technically, the mechanism of heat transfer inside of a heat pipe is convection, but that's just splitting hairs.

Here's below an interesting vacuum tube test about the heat:


[link to www.youtube.com (secure)]

If you told us that, you would be an idiot.

A gas undergoing Joule free expansion does no work. Someone should tell NASA.

 

Yes, look at the engine bells of the Saturn V 1st and 2nd stage engines...they are significantly different in their shape, as the 2nd stage engines operate in a different atmospheric pressure than the 1st stage engines. Each stage is optimized for it's general operating environment.

Rocket science...with gobs of math, physics and who knows what all behind it...

Do you even Robert H. Goddard, bro?