What does a rocket push against in space?

Can someone explain this? I was watching a the beginning of Star Wars movie the other day. They were in space starting to reenter the atmosphere. Their rocket engines were on full. Then they deployed some sort of closure behind the engines. I was thinking like how they launch fighters off of aircraft carriers with that wall, maybe. It was to slow the descent? I was perplexed as to the science behind this.

a reply to: NicSign

How is it different if you substitute a high pressure fire hose or fire extinguisher for the medicine ball.

How do you think a rifle works? Are you saying a bullet with enough oxidizer to support the burning of the powder in a vacuum would not send a bullet flying?

Ann rides a fire extinguisher powered cart VID00046
m.youtube.com...

High powered co2 bottles attached to office chair
m.youtube.com...

WATER JET PACK
m.youtube.com...

High school physics 1, NicSign big fat zero.

a reply to: NicSign

What is it like to still have zero credibility and zero understanding of Newton’s laws. By the way, please quote where Newton’s laws are pressure gradient dependent.

a reply to: buddha

Duh, space-mud obviously.

Seriously though, and as others have already said, rocket engines in space behave according to Isaac Newton's third law of motion "Every action produces an equal and opposite reaction".

When a rocket shoots fuel out one end, this propels the rocket forward, no air nor other medium is required.

a reply to: NicSign

Think about this way. A shotgun shooting a blank cartridge will still kick. Is that a false statement. How is a shotgun that kicks any different than a very short duration rocket?

a reply to: NicSign

not one person can prove rockets work in space without having to point at things like NASA space program and other fakery.

Just because you are all derp-a-derp doesn't mean everyone else is.

a reply to: Grimpachi

you do realize what a vacuum is right? If the chamber was under vacuum, you wouldn't see the smoke come back and start moving in the same direction as the rocket. If it were a vacuum, the smoke would be very quickly cleared away.

a reply to: NicSign

Cleared away to where??

a reply to: NicSign

I understand what a vacuum is. It looks like you don't.

And as Vonclod asked just where do you think it should clear away to?

Maybe one of you eloquent writers can write a request to NASA or ESA to do the experiment in space (If they don't laugh at you while dismissing your claim)

Isn't Humans are not in space because rockets don't work there part of the idea here.

Or is there someone who can throw stuff really fast and long so it ends up in space.

a reply to: NicSign

What is pressure gradient force? Please explain it in your own words how you understand it.

originally posted by: buddha
Yes rocket use earth to build up speed to leave earth.
sling shot around earth then the moon.
but in deep space there is NOTHING Vacuum.

Space outside the atmosphere is made up of many gases

Is it cuz space is flat?

^ _ _ _ ^

Seriously do people - masses - actually believe flatulence into the relative vacuum of space is a reliable PROPELLANT?

so weird to see h/o gases from combustion being sucked out into space counted as a force. by so many.

and even being compared to a gun firing a bullet - which is clearly PROJECTILE combustion off the back of its barrel, not space PROPULSION.

a combustion-driven rocket in space would work - but only with a launchpad matter!

alas, 40K rockets launched into space from ground so far and still never any footage of a propulsion initiated in space clearly begs the question: deny ignorance?

a reply to: Artesia

apollo 15 lift off



why are you asking the same question and ignorning answes

^ Launchpad.

From like 1st grade science, moon is made of matter

and has thin atmosphere of gases.

a reply to: Artesia

a more complex anwer - propellant gasses are NOT " sucked out " by the vacum of space - they are violently ejected from the combustion chamber by thier own pressure

the best way i can demonstrate this is :



its a video of pressurised gas cylinder valve failures

the atmospheric air pressure [ 101.3 KPA ] does NOT " suck the gas out of the cylinder

but in line with basic newtonian physics [ did you not learn this at school ? ]

the internal cylinder pressure forces gas out - resulting in " an equal and oposite reaction

the cylinder goes airborne - QED

a reply to: Artesia

1 - luna atmospheric pressure = negligable

2 - how does the " launch pad " maintain its " effect " all the way to orbit ?????????????

a reply to: Artesia

direct reffution :



LM and CM docking sequence - thruster burns can be seen at various points

no " launch pad " -and in lunar orbit

your willfull ignorance is disturbing