If there is no air in space, how do they use rockets to position the space shuttle?

WOW!!! THIS KID'S RETARDED...

QUICK! SOMEBODY SHOOT ME!!!

Originally posted by defiance
As an aerospace engineer, I will simplify why ROCKETS produces thrust in space for those who don't know. The rocket engine exhaust gas propellant at a very high velocity and in return accelerates the rocket in the opposite direction with an equal force. Same effect on a gun's recoil...bullet has a small mass but exits the gun at a very high velocity, in return the gun gets pushed back. Using intuition, do you think firing a rifle in a vacuum will have no recoil?

A gun would not fire in space because there is no oxygen, therefore stopping the firing pin from igniting gunpowder. But your an aerospace engineer

reply to post by lingk007


no, lingk007

You may have remembered seeing some artist's depictions, or something. Sit down, and try to remember.

The hypergolics used for Apollo produced no visible 'flames'

The best video, not sure how to link it, was on Apollo 17, as the Ascent Module of the LM was captured, during...well...ascent.

There is no 'flame' of course, but plenty of indications of the thrust, as it blew off the mylar on the Descent Stage, and disrupted other parts of the landing area.

The Apollo 17, the final mission of Apollo (to the Moon) Ascent was captured after earlier failed attempts of 15 and 16....see, they mounted a camera on the LRV (the Rover).....and there was a learning curve for the operator of the camera....from Earth. The time delay. Should have thought of it beforehand, but ya know, hindsight is 20/20. The intent was to be able to video the AM all the way up....they got it right on 17.

15 and 16, at least saw the separation, and lift-off. BUT you don't see those images much....hence, the mis-conceptions abound.

ANYWAY, hypergolic fuel, in a vacuum, is invisible to the human eye (or the camera). You were expecting, maybe....a tail of flame??? Only in an atmosphere.

reply to post by LeeHawt


Leehawt....it's an ANALOGY!!!!!

Gunpowder needs O2....duh. It's the 'recoil' effect he was trying to explain!!

Really....nitpicking, when an intelligent post is offered....is not a good tactic.

[edit on 8/14/0808 by weedwhacker]

EDIT....7 pages. I think it's done. Lots of good posts, by many....some have resorted to oneline insults....no harm, no foul in this case, in my opinion.

Now, it's up to the gods.....errrrr, I mean the 'Mods'.....(my bad)

AND.....I am up on the altar, as well.....duh!

[edit on 8/14/0808 by weedwhacker]

reply to post by Manasseh


You could always just use Google to find your answer..

Originally posted by Manasseh

Originally posted by ScienceDada

Originally posted by Manasseh
reply to post by Phage

 

OK smarty pants, then you tell me. What is the burning of the rocket fuel pushing against to move the space shuttle.

Either this is a joke, or "serious" discussion between a bunch of guys stoned, or you are infants or retards.

What are you talking about? A rocket burns fuel in space in a chamber, this produces pressure, the hot/pressurized gas shoots out the cone. The force is transmitted through the pressurized gas from the cone, so that is where the rocket gets its acceleration from.

To create pressure, don't you need some sort of atmosphere.

Forgive me if I'm wrong. LOL

No, you don't need an atmosphere to create pressure. Think of it like this, if your feeble mind can do so: Imagine a box. Completely sealed and made of glass, the box would be brittle if you applied some sort of a force on it correct? It being glass and all. Now, imagine again, if you can do so, that you can pump large amounts of, say, water or air into the box from the outside into the box, thus creating pressure inside it until the box shatters, releasing the pent up water/air. The pressure is caused by the molecules of said air/water pushing against each other inside of the box, until there is no more room for them, and they cause a massive failure of the glass box itself. Pressure is not derived from air and air alone, it could be caused by anything pushing on itself. Take for instance, you push on your arm with your index finger, this causes pressure on your arm because the molecules are repelling each other, and they aren't actually touching, opposite magnetic polarities keep them from coming in contact with each other. You have heard of the "Atom Bomb" correct? That is what happens when atoms hit each other, they explode so to speak, causing other atoms to then create a chain reaction of explosions until you get the desired effect, i.e. masses of dead people, or huge holes in the ground.

Now please, take your senseless banter elsewhere and leave us alone, the community has spoken and answered your question and you refuse to accept the answer, no matter how true it may be.

And by the way, before you begin pointing fingers and saying that I don't believe in God because I also believe in science, you are sadly mistaken. Heaven is not a physical place that we can see/touch, it is a state of being which only our souls can reach, in my opinion. The same applies to Hell. The so called "heavens" HAVE been reached sir/ma'am, we HAVE been to the moon, and nothing you say can change those facts.

Originally posted by lingk007
You definitely won't get fire or "thrust" on the surface of the moon becuase it doesn't have any atmosphere of oxygen like here on earth........doh !!

Thrust is a force. You cannot see a force on the moon or on Earth. As has been pointed out the rocket thrusters on the ascent stage of the LM were fueled with a propellant which produced no visible flame or residue.

Originally posted by LeeHawt
A gun would not fire in space because there is no oxygen, therefore stopping the firing pin from igniting gunpowder. But your an aerospace engineer

Guns can be fired underwater as well as in a vacuum since the propellant contains its own oxidizer.

In the case of black powder it's the Potassium Nitrate.

Edit: Fix quote

[edit on 8/14/2008 by EnlightenUp]

reply to post by EnlightenUp


Enlighten.....oops. See! Even I can learn something!!!

Good point!!!

WW

reply to post by LeeHawt


I was hoping someone would say that...a gun WOULD fire because the gun powder reaction is a chemical reaction NOT combustion (requires oxygen). Also the firing pin does not require oxygen to create the sparks because I believe they are hot particle discharge not something that is burning.

[edit on 14-8-2008 by defiance]

Originally posted by Manasseh
Release the baloon in space.

Then what happens??

No air to push against, baloon goes nowhere.

What do you mean no air to push against? Did you forget that there's air in the baloon?

The moment the baloon is released, the airless space suddenly gains air directly behind the baloon, so now the remaining air in the balloon has something to push against.

Hows that!?

Originally posted by EnlightenUp

Originally posted by LeeHawt
A gun would not fire in space because there is no oxygen, therefore stopping the firing pin from igniting gunpowder. But your an aerospace engineer

Guns can be fired underwater as well as in a vacuum since the propellant contains its own oxidizer.

In the case of black powder it's the Potassium Nitrate.

Edit: Fix quote

[edit on 8/14/2008 by EnlightenUp]

Interesting, just looked it up looks like you are correct. www.nennstiel-ruprecht.de...
Dont think NASA has tested it but, it would be cool if they shot a shotgun in space

Originally posted by defiance
reply to post by LeeHawt

 

I was hoping someone would say that...a gun WOULD fire because the gun powder reaction is a chemical reaction NOT combustion (requires oxygen).

Combustion is a chemical reaction but the propellent contains its own oxygen bound up in a compound. When heated the oxidizer (KNO3 for black powder) breaks down and releases oxygen which allows the propellant to burn without an external source such as the atmospheric oxygen. This of course applies to solid rockets.

One type of monofueled rocket is a hydrogen peroxide rocket which uses a silver mesh and pure H2O2. The H2O2 coming in contact with the mesh causes spontaneous calalyzed breakdown of the H2O2 into H2O, O2 and heat. This provides thrust without combustion. That old personal jetpack you may have seen film clips of uses this type of engine.

[edit on 8/14/2008 by EnlightenUp]

there's an air'n space museum

Originally posted by Manasseh
reply to post by windwaker

 

Bet you I can beat you at "stroids"

I was playing that before Star Wars had diapers.

Atari released Asteroids years after Star Wars was released in 1977..so I wonder how you did that.

*Feeds the troll some more slop*

[edit on 14-8-2008 by Mcloud313]

reply to post by EnlightenUp


I agree, but the point I was trying to make to the poster was that the reaction does not require an external oxygen source as in combustion.

reply to post by styxxz


That's what I was thinking lol, not that I know much on the subject but is it right to simplify it by saying that the rocket puts out a 'wave' of thrust which contains some air, then the next 'wave' pushes against the first 'wave', and so on?

or am I misunderstanding it?

P.S. I think this discussion could be a lot more educational without all the flaming and holier than thou God and Heaven posts...

reply to post by LeeHawt


If an Astronaut could fire a shotgun....it would behoove him to make sure the recoil was directed at his C/G....in that case, it would propel him in the opposite directon. A llittle bit off, and he would start to spin....hope he has a MMU to save himself!!!

edit....usually, with an acronym such as 'MMU', and an article such as 'a'....in English you'd make the 'a' an 'an'. BUT, the first word of MMU is 'Manned'....hence I used 'a'....

Just thought I'd clarify......

[edit on 8/14/0808 by weedwhacker]

i cudnt bother to read thru all the 7 pages. but i saw a few ppl mention mass and momentum. Well has everyone here forgotten the fundamental law of conservation of Momentum????? MV(1) = MV(2). the mass of the burned fuel particles X its phenomenal velocity will equal the slower velocity of the spacecraft X its mass.. now there will be drag forces of many kinds which explains a growing acceleration instead of an instant one.
Hope that helps.. im just a silly engineer.
Mustangman.

Maybe it's been hinted at in one of the posts but the simplest way to understand this is that there is no air pushing needed, only pushing against the rocket ie the rocket is being pushed. Think of ice skating as an imperfect example but enuf to illustrate...If you grab a bowling bowl and head out onto the ice and toss it away from you, you go the opposite direction. The inhibitor in the ice skating example would be the friction between the ice and skates...With the rocket, there would be very little friction due to the vacuum although the inertial mass would still inhibit initial motion.
I didn't quite through reading all the posts so I am hoping I am not stepping on someone else's idea or miss a simpler explanation.