How Does A Rocket Move In Space?

how does a rocket move in space rockets are our shuttles to the final frontier but how do these star exploring vehicles move in space rockets always seem to be firing us into the future but their basic technology is rooted far in the past in firework-like missiles developed almost 800 years ago in 13th century china since the first modern liquid fueled rockets soared into the sky in 1926 rockets have ferried about 500 people several thousand satellites and quite a few unmanned probes to the deep darkness beyond earth while exploring space is obviously the main point of all that effort it's worth remembering that stepping outside of earth gives us a better understanding of our own planet weather forecasting climate research and navigation are just three of the things we can do better thanks to the development of the space rocket now rockets are useful things but they're also very complex and highly dangerous so strap on your spacesuit and buckle up as we blast off away from earth to discover how rockets move in space if you want to understand space rockets you need to understand space there's no neat dividing line between our end of earth and the beginning of space that's because gravity the force that sucks air molecules toward our planet creating earth's atmosphere reaches out to infinity in other words earth's atmosphere ends gradually blurring invisibly with the start of space most jet planes don't fly above 15 kilometers or 9.5 miles or 50 000 feet where there's still enough oxygen to burn fuel in their engines and keep them flying but that's nowhere near the start of space space is generally defined as starting at about 100 kilometers or 60 miles above the earth which is where conventional planes would struggle to make enough lift to stay in the air that doesn't mean earth's atmosphere is all done and dusted by that point far from it the lowest satellites known as low earth orbit or leo satellites fly at heights above 160 kilometers or a hundred miles from earth which is over ten times higher than planes fly even so they still feel some drag from the outer reaches of our atmosphere which fizzles on up to 800 kilometers or 500 miles higher you might think space is a long way away but a hundred kilometers is not so far a car hurtling along at highway speed would take just an hour to get you there a rocket will get there about 20 times faster in just three minutes from beyond the point of someone designing a rocket space is the place effectively beyond earth's reach beyond most of its gravity and atmosphere although we tend to think of it as a vacuum it's not completely empty there's radiation zipping through it there must be how else would we see all those distant stars and planets meteorites nipping past cosmic dust and even bits of space junk broken bits of satellites and rockets perhaps the best way to think of space is as a place of wild extremes emptiness weightlessness one minute deep darkness and extreme cold when you're shaded from the sun the next blinding light dangerous cosmic radiation and extreme heat mostly we're interested in the interplanetary space of our own solar system which is measured in distances of millions of kilometers but space telescopes and unmanned probes also study the further reaches of what's called interstellar space measured in vastly greater distances called light years the distance light travels in one year which is almost 10 trillion kilometers the milky way galaxy of which our solar system is just one part measures about 100 000 light years or 1 million million million kilometers across space if you haven't figured it out already is a pretty big place now we know what space is and so it's easier to understand what a rocket is and how it works a space rocket is a vehicle with a very powerful jet engine designed to carry people or equipment beyond earth and out into space if we define space as the region outside earth's atmosphere that means there's not enough oxygen to fuel the kind of conventional engine you'd find on a jet plane so one way to look at a rocket is as a very special kind of jet powered vehicle that carries its own oxygen supply what else can we figure out about rockets straight away they need great speed and huge amounts of energy to escape the pull of gravity and stop them tumbling back down to earth like stones vast speed and energy mean rocket engines have to generate enormous forces how enormous according to nasa's calculations the saturn v moon rocket generated 34.5 million newtons or 7.6 million pounds of thrust at launch creating more power than 85 hoover dams rockets are great examples of how forces make things move it's a common mistake to think that rockets move forward by pushing back against the air and it's easy to see that this is a mistake when you remember that there's no air in space to push against space is literally that empty space when it comes to forces rockets perfectly demonstrate three important scientific rules called the laws of motion which were developed about 300 years ago by english scientist isaac newton first a space rocket obviously doesn't go anywhere unless you start its engine as newton said still things like rockets parked on launch pads stay still unless forces act on them and moving things keep moving at a steady speed unless a force acts to stop them second newton said that when a force acts on something it makes it accelerate change direction or both so when you fire up your rocket engine that makes the force that accelerates the rocket into the sky third rockets move upward by firing hot exhaust gas downward rather like jet planes or blown-up balloons from which you let the cold air escape this is an example of what's often called action and reaction or another name for newton's third law of motion the hot exhaust gas firing down the action creates an equal and opposite force the reaction that speeds the rocket up the action is the force of the gas the reaction is the force acting on the rocket and the two forces are of equal size but pointing in opposite directions and acting on different things which is why they don't cancel out two important factors when it comes to a rocket's movements are thrust and drag the force that pushes a rocket upward is called thrust it depends on the amount and speed of gas that the rocket fires and the way its exhaust nozzle is shaped to squirt out that gas in a high pressure jet when a rocket's engine develops enough power the thrust pushing it upward will be bigger than its own weight pulling it down so the rocket will climb into the sky as the rocket climbs air resistance drag will try to pull it back too fighting against the thrust in an upward climbing rocket thrust has to fight both drag and weight this is slightly different to an airplane where thrust from the engines makes the plane fly forward drag pulls the plane backward and the forward motion of air over the wings generates lift which overcomes the plane's weight so a key difference between a rocket and a jet plane is that a rocket engine lifts it directly upward into the sky whereas a jets engine simply speeds the plane up forward so that its wings can generate lift a plane's jet engines fire it forward so its wings can lift it up a rocket's engines lift it up directly the faster things move and the more their shape disturbs the air the more drag they create and the more energy they waste uselessly as they speed along that's why fast moving things jet planes high speed trains space rockets and even leaping salmon tend to be long thin and tube shaped compared to slower moving things like boats and trucks which are less affected by drag rockets burn huge amounts of fuel very quickly to reach escape velocity of at least 25 000 miles per hour or 7 miles per second or 40 000 kilometers per hour which is how fast something needs to go to break away from the pull of earth's gravity velocity suggests a rocket must be going that fast at launch or it won't escape from earth but that's a little bit misleading for several reasons first it would be more correct to refer to escape speed since the direction of the rocket isn't all that relevant and will constantly change as the rocket curves up into space second escape velocity is really about energy not velocity or speed to escape from earth a rocket must work against the force of gravity as it travels over a distance when we say a rocket has escaped velocity we really mean it has at least enough kinetic energy to escape the pull of earth's gravity though you can never escape it completely finally a rocket doesn't get all its kinetic energy in one big dollop at the start of its voyage it gets further injections of energy by burning fuel as it goes quibbles aside escape velocity is a quick and easy shorthand that helps us understand one basic point a huge amount of energy is needed to get anything up into space so we've talked about space and how a rocket works but once the rocket gets to space how does it move with no air rockets and engines in space behave according to isaac newton's third law of motion every action produces an equal and opposite reaction like we discussed earlier rockets moving upward are an example of this law of motion the hot exhaust gas firing down is the action which creates an equal and opposite force to speed it up this law also applies in space when a rocket shoots fuel out one end the action this propels the rocket forward the reaction no air is required now let's do a brief recap of what we've discussed in this video space is an infinitely huge place of extremes in order for a rocket to get through our atmosphere and into space it must generate an enormous amount of speed and energy to escape the pull of gravity and once it arrives in space it uses isaac newton's third law of motion about action and reaction to propel itself along a great example of this is if you stand on a skateboard and throw a bowling ball forward that force will push you and the skateboard back however because your weight on the skateboard is heavier than that of the bowling ball you won't move far that's pretty cool if you want to check out more space related videos make sure to watch the recommended video on your screen and make sure to subscribe if you want to suggest a topic head over to www.howdoes.net thanks for watching and we will see you next time

Channel: How Does

Views: 34,080

Keywords: how does, nature, earth, planet earth, space

Id: SXV7NyNSLNw

Length: 14min 19sec (859 seconds)

Published: Thu Sep 02 2021