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

I didn't read the whole thread, I'm a little stunned that there are 5 (possibly more) pages to this. [edit] ok, so there are 14... [/edit]

Think of it this way:

If I were floating in space and I had a bag of basketballs, I could throw them in some direction and I would be pushed in an opposite direction. Maybe slowly, but it would undoubtedly happen. Did I need air for that? NO. If anything the air would have impeded my acceleration. So if you swap out my basketball fuel for rocket fuel (and me for a rocket) you have the same result.

[edit on 18-8-2008 by an0maly33]

reply to post by an0maly33


anOmally.....how are you going to get a bag of basketballs up into space????

Sorry, I had to do that....it was irresistable!

Point is, any mass that is expelled, whether it be rocks or basketballs or a bunch of gases.....will impart a reactive force, as it is expelled.

IT IS THAT simple, folks!!

THE action of the mass is what pushes against where it is being held, or where it WAS being held.....

A balloon in a vacuum will behave differently than a balloon in an atmosphere....don't know why no one understands this simple concept yet....

The balloon, in a vacuum, will fly a direct and straight line, unless the exhaust, as it exhausts, caused it to divert course. HOWEVER, the last bit of exhaust willsend the balloon in one final direction.....

If there is Gravity involved, then the Balloon will fall to the 'ground'.

How hard is this for people to understand??

Post removed.

[edit on 18-8-2008 by sanctum]

reply to post by calcoastseeker


calcoast....what an incredibly stupid question!

The ass is near the Center of Gravity!!!

BUT, to answer your incredible question....no. The fart is contained in the EVA suit....it has no effect. The smell won't even reach the nose of the Astronaut, that's how good the suits are!!!

AND, of course....if a person were exposed to the vacuum of space, and farted....then they're dead anyway.....duh!!!!

Woldt it be very plausable to assume that the particles from the propulsion, could be bouncing off say..each other..each one pushing on the one that came before? Sounds liek that would be the simplest explanation to understand.

Originally posted by THIseNdsnowoldKings
Woldt it be very plausable to assume that the particles from the propulsion, could be bouncing off say..each other..each one pushing on the one that came before? Sounds liek that would be the simplest explanation to understand.

I didn't read the whole thread (14 pages somehow about a simple physics question?), but this is the explanation that is correct.

The truth is that the rocket does have something to push against: namely, its own fuel. Let's illustrate with an example you kids can try at home. First, you need to get yourself into some sort of frictionless situation. Wearing ice skates on a slippery ice rink would be good, or maybe your office has a chair that rolls really well on a hard surface. Next, you'll need a medicine ball. You are the rocket and the medicine ball is your fuel. Toss the medicine ball. You'll notice that as you shove the medicine ball forwards, you yourself lurch backwards. Ta-da, the miracle of physics! (If you think this is because the medicine ball pushed on the air, then try the experiment without the medicine ball--just push on the air with your hands, see how far you lurch backwards.)

The whole article can be found here.

[edit on 19-8-2008 by OnionCloud]

[edit on 19-8-2008 by OnionCloud]

reply to post by OnionCloud


Sorry, OnionCloud....it has taken 14 pages to come to this....'fart' jokes!

See, the premise is so obvious, that some resort to jokes....myself included....we in fact, this nonsense should just die.

The concept, in the OP, is wrong. We tried to help, by providing good science....either the OP will learn, or they won't.

Simple as that.

I once had a student pilot....who simply COULD NOT LEARN!!!!

This person, even after six hours of lessons....still could not understand how to taxi a Cessna 150!

We flew....and this person could not understand the concept of 'Straight and Level'!!

Please keep in mind....I tried....I really tried. I had had difficult students before, but usually there was a language barrier....or they were progressing into an Instrument Rating....or some higher Category....

BUT this person could not even, after six lessons, understand the basics of the rudder pedals, and the 'toe brakes'.....this is not a person you want to be allowed to fly an airplane!!

Plus....well, basic ENGLISH is a requirement, in order to qualify for a Pilot's License.

I tried, I really tried....but eventually I had to tell this person.....'Flying an airplane is not for you'

In my entire time as an Instructor....this person is the only one I shooed away.....besides ONE other.... a guy who was so arrogant....but completely incompetent. A guy who had been spurned from other schools....and thought he should 'solo' just because he had 14 hours!!!

Well...I flew with him....and his arrogance was so obvious....he had nbo business flying an airplane. Sent him on his way, I did!

HE had 14 hours.....most people will 'solo' before ten....usually about eight....yet, he had NONE of the basi skills, needed to solo.....

SO...three years of teaching....two potential 'students' thrown out....not bad, eh????

Of course, atfer teaching, had a couple of decades flying airplanes, for a living.....with passengers back there.....

SO....I have a bit of knowledge on the topic......

Didn't read all the posts but here's some food for thought..

1. If space is an "absolute vacuum" or anything close then what force makes it that way?
2. If so, then what force around a planet keeps the absolute vacuum of space at bay? Why isn't the atmosphere sucked up and evenly distributed across the solar system or beyond? IE a vacuum is a very, very powerful force.
3. Equal and opposite reaction really means that there is an equal reaction to proportional to the resistance offer to the thrust. In a vacuum resistance would be much lower as ie nothing there to resist and everything there eager to receive. In fact in an absolute vacuum the environment would welcome the thrust with open arms, so to say. The thrust would be a small attempt at quenching the thirst of the vacuum.

Originally posted by ReelView
Didn't read all the posts but here's some food for thought..

1. If space is an "absolute vacuum" or anything close then what force makes it that way?
2. If so, then what force around a planet keeps the absolute vacuum of space at bay? Why isn't the atmosphere sucked up and evenly distributed across the solar system or beyond? IE a vacuum is a very, very powerful force.
3. Equal and opposite reaction really means that there is an equal reaction to proportional to the resistance offer to the thrust. In a vacuum resistance would be much lower as ie nothing there to resist and everything there eager to receive. In fact in an absolute vacuum the environment would welcome the thrust with open arms, so to say. The thrust would be a small attempt at quenching the thirst of the vacuum.

You've got this all wrong.

Vacuums don't "suck" anything at all. gas is pushed into vacuums by other gas molecules. the vacuum doesn't have anything in it, so it can't push back. our air is just 14.7 psi above a vacuum, so little a difference that it doesn't matter in many applications.

You wouldn't say that our atmosphere sucks the air out of a CO2 canister. You'd say that the gas was under pressure, and escaped the cylinder; by being forced out by the pressure. The same is true of a vacuum vis a vis anything at a higher pressure.

a vacuum isn't a force at all, let alone a powerful one. a vacuum is a lack of gas. The force of air molecules against the walls of containers can be a powerful force, and is the only force involved when talking about a vacuum.

.

point by point:

1. Space is nearly a vacuum simply because there isn't much stuff in it compared to how huge it is. Gravity tends to clump most of what there is into bodies like planets and stars. which brings us to:

2. Gravity keeps atmospheres around planets. same way the vacuum of space doesn't suck away all the oceans and rocks and everything else

3. It doesn't mean that at all. Forget everything that lead you to say that, and then read the wiki article or something.