Does Rocketry Work beyond Earth's atmosphere?

[SacredCowSlayer]

Do you think then one would be travelling "gravitationally" downhill if you planned your trip so that the moon for example was inetween earth and the moon on the way there and the opposite for your return journey?

Do you mind please re-reading your posts before posting? This doesn't make sense.

To my mind it does make sense. If it's so that the sun's gravity vastly "outweighs" that of earth, even out here at 150 000 km form the sun, surely any trip in a direction away from the sun would require a great deal more thrust than one where you travel essentially towards the sun, not so?

Without speaking for HP, I think he was perhaps referring to what I can only assume you are TRYING to say here. And that is, it would be "gravitationally" downhill (so to speak) going to the moon when IT is between the earth and the sun. Is that what you meant? If so then it makes sense to me, at least conceptually.

Also, I don't think anyone around here has issued a blanket rejection of any and all things coming from NASA. Just because it is a propaganda outfit doesn't necessarily make it incapable of stating a truth that can be independently confirmed. Of course, if it's a claim that originates with NASA and cannot be independently confirmed or otherwise repeated, then there is a problem.

[MagicFlame007]

Evening hoi.polloi.
Heeding your call to cite an official source and then dissemble, let me attempt to do so. https://www.grc.nasa.gov/www/k-12/airplane/rockth.html
Apologies, I don't know how to make that a link. Hope its automatic.
On that rather well known official site NASA attempts to show the process and equation dealing with rocket thrust.
The equation: F = m dot * Ve + (pe - p0) * Ae has a term: p0 that accounts for the ambient atmospheric pressure. Solving the equation with arbitrary figures (since the actual figures are unavailable to me) "proves" that more thrust is created in a vacuum (when p0 is zero). NASA has long sought to show that this was indeed the case. This is the sort of thing that clearly demostrates how NASA misleads by cloaking their deception in half truths.
My point is that though the equation appears to be correct, there is a second equation required. This second form of thrust is well known by NASA and is in fact discussed here: https://www.grc.nasa.gov/www/k-12/UEET/ ... gines.html
Although the latter site deals with jet engines, it is rather obvious that rockets do also develop thrust like a jet engine while being "pushed forward" (NASA uses that expression several times there) when in an atmosphere, in addition to the thrust described by the general equation quoted above.
Even a child who has ever put his hand out of a moving car knows the amount of force that the rushing air can produce. Likewise the huge volume of rushing air gas from the exaust of a rocket engine must produce enormous additional thrust.
By the way, I love this little gem from that site:
"The ramjet is the most simple jet engine and has no moving parts. The speed of the jet "rams" or forces air into the engine. It is essentially a turbojet in which rotating machinery has been omitted. Its application is restricted by the fact that its compression ratio depends wholly on forward speed. The ramjet develops no static thrust and very little thrust in general below the speed of sound. As a consequence, a ramjet vehicle requires some form of assisted takeoff, such as another aircraft. It has been used primarily in guided-missile systems. Space vehicles use this type of jet."
In the words of Ace Ventura: re-e-e-ally?

[allancw]

Simon and I had a back and forth a couple years ago that I'll briefly repeat -- I haven't gone back on this thread to see if something similar has been posted, so forgive the possible redundancy.

I asked Simon to imagine the two of us floating in space, me with a loaded 9mm pistol. Would it be ok if I pointed it at him and pulled the trigger. Simon said, sure, it wouldn't shoot in the vacuum (this may be a bit oversimplified).

If you go to Youtube you'll find a vid wherein a pistol shoots just fine underwater. Mmmmm. See, the bullet plus casing contains all needed to go off, so being underwater is not a problem.

Yes, a vacuum is a bit different, but those who feel that rocketry won't work in a vacuum... are you sure enough to say 'OK' to my pulling the trigger? (I think Simon changed his mind.)

The point here isn't the bullet coming out of the barrel -- which I am sure it would -- but rather the recoil. The recoil is the point. Imagine a hundred shots per second.... via the continuous recoil you have a rocket, no?

Again, sorry if this is redundant.

[brianv]

Simon and I had a back and forth a couple years ago that I'll briefly repeat -- I haven't gone back on this thread to see if something similar has been posted, so forgive the possible redundancy.

I asked Simon to imagine the two of us floating in space, me with a loaded 9mm pistol. Would it be ok if I pointed it at him and pulled the trigger. Simon said, sure, it wouldn't shoot in the vacuum (this may be a bit oversimplified). etc...

How did the two of you get into space in the first place - on one of your kangaroo rockets? Slightly circular but never mind.

In the old days when somebody came along and offered to build a bridge across the river or ravine that would allow the farmers to get their livestock and goods to market more efficiently, when finished, the builders of the bridge would be required to stand under the bridge while a fully laden cart was wheeled over the top - from whence comes the origins of the word "understand".

You are asking the the farmers to stand under the bridge when you should be asking the the bridge builders - or the Rocket Builders in your case. Let the NASA clowns stand in front of a big gun in "space" if they can get there!

Would you be first to "understand" the bridge having been shown a film showing the bridge in operation - and made by the bridge builders themselves? Never mind shooting Simon would you get on one of those rockets and allow yourself to be shot into Space - if such a thing exists?

[Flabbergasted]

Imagine a hundred shots per second.... via the continuous recoil you have a rocket, no?

A hundred times nothing is .... nothing. Reminds me of the dialogue in Monty Python´s Holy Grail where it is said that rocks will float if only they are small enough.

Ok, I admit that, unlike thrust, recoil is different from zero, but the whole point is futile once you leave controlled lab conditions and handy vacuum chambers and place your rocket in the [allegedly] near-infinite, near-absolute vacuum of space --- and that´s assuming you have a way of getting it up there in the first place, as brianv points out.

[allancw]

I loved the given etymology of 'understand' so much I almost didn't verify it... but alas, before quoting to someone else and so forth, I did... unfortunately:
http://www.etymonline.com/index.php?all ... understand

But kudos for creativity, nonetheless. (Or perhaps provide your source; I'd love to be able to repeat that one.)

Although it's only been a day since the posting and possibly more input is in the offing, it looks like I made a point, since - respectfully - the above replies, having nothing to do with the principles of rocketry, reads red herringish.

Lest you guys think I have any love for or belief in NASA and it's frauds, here are a few of my videos on the subject:

https://www.youtube.com/watch?v=UP0TQ99bMrw

https://www.youtube.com/watch?v=0tAAsyBYczs

https://www.youtube.com/watch?v=OmcwW-8CC6E

https://www.youtube.com/watch?v=CXRXHyNFRh8

https://www.youtube.com/watch?v=KV9tG2jnUzI

https://www.youtube.com/watch?v=-4PBgq8PfPQ

In spite of their naive acceptance of NASA data, I'm a fan of Electric Universe. Maybe someone can respond to my confusion re the following (posted elsewhere on CF):

'I attended the 2015 EU conference and was even asked to speak there -- my novel Cosmic Banditos (a cult semi-hit) plus my weird sense of humor was behind the invite. In the end I declined -- I realized that they will have nothing to do with 'conspiracy theories'. They even invited Michael Shermer to speak! (I know!) Had I actually spoken I would have pissed everyone off, which I didn't want to do.

I got to know Dave Talbott and found him genuine though super naive. I could not even talk to him about NASA frauds, but, again, this is/was due to his own brand of cognitive dissonance. I was tossed out of the online forum for bringing up Apollo.

They are afraid to be lumped together with 'conspiracy' types; yes that is dumb in the extreme but I suggest we all give them a break and not toss the baby, etc. The EU has been behind many epiphanies for me, especially re the f-ing big bang and all the expanding space and GR nonsense.

A detail: Wal Thornhill predicted there would be arcing between the (whatsis) probe that supposedly collided with the comet (I'm blanking the name/details, sorry!) I too see NASA as a complete fraud but why would they 'find' and report the exact arcing that Thornhill did predict, and which, if anything, ends up an embarrassment to NASA? Given NASA's total ignoring of EU, I don't see why they would do this. NASA/JPL's treatment of Anthony Peratt after his petroglyph (etc) studies tell us that no way would NASA do anything to help EU. I don't know what to make of the comet/Thornhill prediction issue. Whaddya think?

If you need details on any of the above, I'd be glad to provide them, but I suspect you all know to what I am referring. (I'm at the end of a long day so excuse my sloppiness here...)'

No one at that thread answered, btw...

[brianv]

Weasel all you like.

The meaning is clear - it's called proving a negative. It is not incumbent on the farmers to prove the worthiness of the bridge that you are selling them! NASA's fairy tales rely on very dubious video footage to "sell their bridge", that, and an army of liars and Space "fanboys".

Your problem is that of belief itself. Have you been on a rocket in space?

[allancw]

Ahhh, right. Brianv. Sounded familiar. The guy who likewise made little sense while spouting hostile shill-talk on the Miles Mathis thread. If you wanna aggravate me, best not use language like 'from whence comes the origins of the word "understand".

Aside from your scattered sentence structure and metaphor-mixing and dishonesty re etymology, since 'from' and 'whence' are synonyms, using them together is redundant, not to mention repetitive

[brianv]

Ahhh, right. Brianv. Sounded familiar. The guy who likewise made little sense while spouting hostile shill-talk on the Miles Mathis thread. If you wanna aggravate me, best not use language like 'from whence comes the origins of the word "understand".

Aside from your scattered sentence structure and metaphor-mixing and dishonesty re etymology, since 'from' and 'whence' are synonyms, using them together is redundant, not to mention repetitive

Ok I'm a literary twat - does that make rockets work in space?

edit : It would appear that "from whence" does appear in Shakespeare, the King James Creation Yarn, Robinson Crusoe but it's use is in decline. You didn't read past the first post when you googled it.

This thread is about whether combustion rockets work in space, despite the ambiguous title, not about the preoccupation some members have with my choice of words and punctuation. It rather points to a combined effort. And regarding the "understand" business, if that's not where the meaning came from - it should be, because it works fine.

[aa5]

There is the thought that simply dropping the weight out the back can make the ship go forwards. But that is not true, I can be travelling at 50km/hr in a car, and lift up a suitcase, maneuver it so it is hanging over the back bumper of the car, then drop the suitcase so it falls on the ground behind the car, that causes no forwards push on the car.

As I pick up the suitcase, and put some force on it, to move it so it is hanging in my hands over the back bumper - this causes no forward acceleration in the car, because the suitcase is still attached to me, and I am still in the car. To offset me going backwards from moving the suitcase forwards as I extend it out over the back bumper.. I must be securing myself by pushing in the opposite direction on another part of the car. So the directional forces on the car will balance out, as long as I am still in the car and still holding onto the suitcase.

[ObamaSimLaden]

Simon and I had a back and forth a couple years ago that I'll briefly repeat -- I haven't gone back on this thread to see if something similar has been posted, so forgive the possible redundancy.

I asked Simon to imagine the two of us floating in space, me with a loaded 9mm pistol. Would it be ok if I pointed it at him and pulled the trigger. Simon said, sure, it wouldn't shoot in the vacuum (this may be a bit oversimplified).

If you go to Youtube you'll find a vid wherein a pistol shoots just fine underwater. Mmmmm. See, the bullet plus casing contains all needed to go off, so being underwater is not a problem.

Yes, a vacuum is a bit different, but those who feel that rocketry won't work in a vacuum... are you sure enough to say 'OK' to my pulling the trigger? (I think Simon changed his mind.)

The point here isn't the bullet coming out of the barrel -- which I am sure it would -- but rather the recoil. The recoil is the point. Imagine a hundred shots per second.... via the continuous recoil you have a rocket, no?

Again, sorry if this is redundant.

I'm new here and skimmed some of this thread. I also question whether rocketry would work in a vacuum. I used to take it for granted, but not so sure. Interesting question. A gun is different than a rocket, though I get your analogy. Imagine floating in space and you fire a gun. The bullet (gasses) will push back on the chamber, which in turn pushes back on the shooter. I can see the recoil pushing the shooter back, but the bullet would probably also fire...perhaps at a lesser speed than in gravity environment (simplified for no atmosphere), but maybe still enough to be fatal. The bullet/gasses are going to take the path of least resistance, but also you have an equal and opposite reaction. You can feel the recoil of a gun, and I have no doubt it would propel you backwards in space.

A rocket just floating in space firing a rocket engine I'm not so sure. There's nothing to push against. I know they say the rocket is pushed upward by the thrust, but I wonder if it would just fire and fizzle in space? If the gun were to be free floating in space and could spontaneously fire the gun and bullet would presumably shoot off in opposite directions and I'm sure a formula can prove that.

Now imagine you are flying towards the moon in outer space at 25,000 mi/hr and you need to stop quickly and your engine happens to be facing forward and you fire it at full thrust. Is that going to slow you down to a halt in a vacuum? I'm not convinced yet. There's still the question of igniting the rocket in space, but we can assume the fuel is self contained. Seeing the Movie gravity made my eyes roll constantly. Like the whole Fire extinguisher propellant. I don't think that would happen period...without even considering the other stupid assumptions.

All that said, I don't think we could have gotten a lander to the moon and back....and it would have been far to risky to try.

Another thought is imagining an airplane (or helicopter) in space. The propellers or jet engines would have no atmosphere to Push. They would just spin and spin and go nowhere, no matter the angle of attack of the blades/wings. Imagine swimming in space. Your arms spinning and legs kicking, but you go nowhere. This is always a pet peeve with sci fi movies like Star Wars, Armageddon, buck rogers, with x wings and tie fighters banking and turning like they are on earth in a vacuum. Not possible. I think maybe the same with rocket engines. They just fire and you float stationary.

[Vera Obscurata]

I just had an amazingly interesting discussion with a 75-80 year old astrophysicist. The very humble and decent old man allowed me to outline my arguments why Space Travel is impossible. The points from this topic plus more of my own, not published anywhere before I threw at him in a mature manner and his responses have given me new input for a new thread I planned already to create.

My last question of the hour long talk we had was "do you believe that from 1969 to 1972 6 times people were sent to the Moon and after that never again?"

He responded me with a "yes", which of course formed the basis for a new flow of objections from my side.

The old man ended the discussion with the words "I don't have any scientific arguments against your points".

Wow, what an amazing hour this was. Will be continued in a new topic soon.

[aa5]

I'm looking forward to that thread you plan to create! That old scientist sounds like someone you want to keep as a friend. It is so hard to find people who are willing to have open scientific debate, where nothing is sacred, the logic just goes where it will.

At the end of a discussion a friend can still be leaning in the other direction for their belief, than you. That is ok, sometimes even beneficial as he will challenge your arguments!

[theyBOUGHTit!]

EXTREMELY SIMPLE:

Home science experiment.

Go to sea level with several "Estes" rockets on some sort of track, and a way to measure the time it takes for the rockets to go from point A to point B.

NOW-- take your set up to the highest elevation you can reach, and perform the experiments again.

WHICH ROCKETS will reach the end of the track the fastest? the ones at SEA LEVEL, or say perhaps you found a place higher than some 20,000 feet. Will the high elevation launches be faster than the sea level launches? Will the high elevation launches be SLOWER because there was less air to push from?

If the rockets are IN FACT slower at high elevation, THEN YOU HAVE PROOF that the thinner the air gets, the less thrust can result.

NO BRAINER!

How can it be this easy to confirm, and nobody seems to have tried this?

VERY simple.

[hoi.polloi]

EXTREMELY SIMPLE:

Home science experiment.

Go to sea level with several "Estes" rockets on some sort of track, and a way to measure the time it takes for the rockets to go from point A to point B.

NOW-- take your set up to the highest elevation you can reach, and perform the experiments again.

WHICH ROCKETS will reach the end of the track the fastest? the ones at SEA LEVEL, or say perhaps you found a place higher than some 20,000 feet. Will the high elevation launches be faster than the sea level launches? Will the high elevation launches be SLOWER because there was less air to push from?

If the rockets are IN FACT slower at high elevation, THEN YOU HAVE PROOF that the thinner the air gets, the less thrust can result.

NO BRAINER!

How can it be this easy to confirm, and nobody seems to have tried this?

VERY simple.

Please don't use all-caps unless you are justified in doing so. Your posts are rather irritating to read when you are typing as though you are speaking. Please, try to compose your writings as if they will be read and not acted, if you could at all help this. I am sorry if that seems prejudiced of me.

I am not sure this would be an excellent proof because there may be a threshold that makes rocketry much less viable.

It would also be difficult and expensive to test. High elevations have different climates, air movements and all sorts of variables that a pure vacuum is theoretically said to not have. I don't know about you but I don't get up to extremely high elevations very often anyway.