Space shuttles

[cheesegraterdude]

just wondering, probably a silly question (oh well, i am 13) , how does a space shuttle move through space if there are no particles in space?

 

[MeteorWayne]

Look up "Newton's Laws of Motion"<br /><br />"An object in motion continues in motion unless acted upon by an outside force." <br /><br />In fact, the shuttle passes through the thin outer reaches of the atmosphere which do slow it down. <br />The same thing happens to the ISS (International Space Station), which is why it has to be reboosted every so often to keep it from falling into more atmosphere, slowing down more, and falling back to earth.<br /><br />If you click here there's a chart which shows the height of the ISS orbit, notice every onve in a while the line goes upward; that is when a reboost has occurred.<br /><br /><br />Welcome to Space.com!!<br /><br />Meteor Wayne <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[MeteorWayne]

That is probably indeed what was being asked. Thanx shuttle_guy. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[heyscottie]

To expand on shuttle_guy's answer, think of what happens when you fire a gun. The bullet flies in one direction, and the gun recoils in the opposite direction. This is not because the bullet is pushing on the air, but is because "for every action, there is an equal and opposite reaction." The gun puts a large force on the bullet to shoot it out, and the bullet puts an equal and opposite force on the gun. It would happen just the same in a vacuum as it does normally.<br /><br />The same works with rockets, but instead of shooting bullets, they are shooting propellant. The rocket puts a force on the propellant by combusting it and allowing it to expand at great velocity out a nozzle. The propellant places an equal and opposite force on the rocket, thrusting it forward.

 

[qso1]

Expanding on shuttle guys answer...it is the escaping gasses that pushes the rocket engine in the opposite direction. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[derekmcd]

I'm no rocket scientist <img src="/images/icons/smile.gif" />, but my understanding is combustion engines in rockets provide thrust via an internal force actually pushing the rocket. The exhaust is exiting at such extreme pressures that within the combustion chamber, the forces are so incredible that they actually push the vehicle forward. <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[usn_skwerl]

another question, something ive never come across in any books i've read....<br /><br />is there even a semi-airtight seal on the PLBD's? ive never heard a mention of it one way or the other. <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

PLBD's??<br />(Payload Bay Doors?) <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[jimfromnsf]

The payload bay is not airtight. There are vents on the sides to let air in and out during ascent and descent. <br /><br />The doors could never hold the pressure differential. Also they don't really seal

 

[usn_skwerl]

ok, thank you s_g, jim, and MW. i came onto this board thinking i knew a good bit about the shuttle, but this board has clearly shown me im missing a lot of great knowledge about the brick bird. i think im just going to save up all of my questions and open a thread for folks to throw their answer in...stuff that i havent seen mentioned anywhere else...im not a huge fan of making or reading repeat posts. <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> </div>

 

[jimfromnsf]

This probably will get deleted but there is a huge shuttle Q&A thread on NASAspaceflight.com

 

[nec208]

To expand on shuttle_guy's answer, think of what happens when you fire a gun. The bullet flies in one direction, and the gun recoils in the opposite direction. This is not because the bullet is pushing on the air, but is because "for every action, there is an equal and opposite reaction." The gun puts a large force on the bullet to shoot it out, and the bullet puts an equal and opposite force on the gun. It would happen just the same in a vacuum as it does normally. <br /><br />===============<br /><br />Take a big gun and if you not holding the gun you will be pushed to the left well the bullet are push to the right.<br /><br />If you could make a gun bigger than a car and put lots of power in it I could stand on it and it will push be up in space well the bullet puch down to the ground.<br /> <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

Well gee whiz, 5 days later and it's still there. Who's paranoid? <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[usn_skwerl]

heh, ive gotten pretty deep on the Q&A threads over at NSF...a LOT of good gouge there!! janks for pointing me in that direction, jim <div class="Discussion_UserSignature"> </div>