This is why with the space tourism like the flights with Spaceship 1, which went up 200 kilometers a

Have you ever wondered what it takes to get a spacecraft apartment rentals winnipeg off the Earth and into space. And how managers at NASA can actually navigate a spacecraft to another planet? And how does a gravity assist work? And how do they get them into orbit? And how do they land? So many questions
Fraser: Wonderful. Good. All right, let s get on to this week s show. Have you ever wondered what it takes to get a spacecraft off the Earth and into Space? And what are orbits? How does that work? What s the difference between a polar and an equatorial orbit? And how do managers at NASA actually navigate spacecraft to another planet half a Solar System away? And who does these gravity assists? How do they get spacecraft into orbit around another planet? And how do they land? [Laughter]
All right, I ve got so many questions. Okay, so this week the plan is we re going to talk about every way that spacecraft get from the Earth out into Space and do their job. So let s bring it right back home and let s start with what are the mechanics of actually getting something off of the Earth?
Pamela: Well you need to actually fire more than just once. There s this fascinating notion that if you give a rocket a big enough burst of energy that it will fly off into Space and happily orbit. But when you look at what NASA rockets actually do, they fire and fire and fire…and keep firing and the rocket makes it into Space and they keep firing and the rocket is in Space and then they shut off.
To our network television trained mind, it looks like the rocket takes off perpendicular to the Earth, flies straight into Space and the engines turn off and as soon as they turn off the rocket starts going around the planet. apartment rentals winnipeg That s not actually apartment rentals winnipeg what happens.
apartment rentals winnipeg You actually take off and you fling yourself in the direction of the Earth s rotation. So you re adding your velocity to the velocity that you already get from the planet s motion and you take off such that you re heading on an arc into Space.
Fraser: I think that s a misnomer as you said. People imagine a rocket ship taking off and going straight up and out into Space. That never happens. The rocket apartment rentals winnipeg takes off and almost immediately starts to angle itself downrange so that it s almost flying parallel to the Earth s surface and going faster and faster and faster, and getting higher and higher altitude. But in the end, it s more that the rocket is going parallel to the Earth at 18,000 kilometers per hour, not straight up at 18,000 kilometers per hour.
This is why with the space tourism like the flights with Spaceship 1, which went up 200 kilometers and came back down, it went straight up, reached the limits of Space and then came back down. People said, “Oh, well then we re really close to getting into orbit.� But in fact it s a tremendously different amount of energy and velocity required to be going 18,000 kilometers sideways around the Earth.
Pamela: The fact is that if we didn t have that extra firing, that extra maneuver, once you get up to the top of your arc that sets you going sideways, you just fall straight back down. Orbits are shaped like ellipses and they are perfectly happy to have one end of that ellipse hit the planet. To take an orbit and make it from one that goes up past the top of the atmosphere and comes back down and crashes onto the planet, you have to fire the engines up at the top of the arc, up at the top of the atmosphere apartment rentals winnipeg beyond the atmosphere and set you moving sideways.
Pamela: Well, that might be a bit devastating to the asteroids. It comes down to how much acceleration can any one thing handle? If I wanted to, I could (and I had the technology which I don t think we have right now), I could accelerate a rocket over the course of perhaps 30,000 feet such that it had all the velocity it needed to get to orbit, it would still have to do an extra firing once it got up to the correct altitude to get it going sideways.
apartment rentals winnipeg I can get it going fast enough that we d get to that highest point but I d have to accelerate so fast that it would shake the tar out of the spacecraft and probably kill the astronauts by accelerating too fast.
Fraser: That s what happens when a spacecraft is coming back through the atmosphere. It s hitting the solid atmosphere at huge velocity and it s heating up. So, if you were actually to try and accelerate to that speed right of way, I m sure you would just vaporize it in the atmosphere.
Pamela: It would be bad. So, instead we do constant acceleration. By firing constantly, you don t have to get going to a velocity that will carry you through the atmosphere you can keep pushing yourself through the atmosphere.
One way to think of this is if you ve ever ridden a bike. You can get your bike going down the hill so fast that you don t have to pedal up the next hill. But, you might have to get yourself going so fast that you re a bit scared of what might happen if you hit a rock. If instead you go down that first hill a little bit more slowly, you can pedal up the next hill and you never have to get going as fast and you ll still get to the top of the next hill.
If we gave the rocket enough energy close to the planet Earth to carry it all the way up through the atmosphere it would have to be going frighteningly fast. It would slow down and slow down as it goes through the atmosphere and encounters drag until it eventually pops out in orbit. By instead accelerating all the way through the atmosphere, it s just a little bit friendlier to everyone.
Fraser: With that rocket apartment rentals winnipeg firing constantly, the bulk of the energy that is coming out of the back of the rocket is just counter-acting its pull back from the force of gravity. If you take the amount of energy required to hold the rocket steady in mid-air that would be most of the energy that is coming out of the back of the rocket. Then you re left with just a little bit of extra force and that s what pushes apartment rentals winnipeg it up.
As the rocket is going faster and faster, more and more of that energy that is coming from the rocket is used to accelerate it. That s why when you see a space shuttle, especially like a Saturn 5, sitting on the pad when they first turn it on, it barely seems to move and then slowly inches up. Later on, it s going faster and faster, much faster. The acceleration is increasing. [Laughter]
Pamela: One of the other things happening is you start off and the poor innocent engines not only have to pick up the spacecraft but they have to pick up all of the fuel. The higher up you go, the less fuel you re trying to move. You re firing engines to move smaller and smaller masses you go and that helps as well.
Pamela: The most common orbit for human beings is your standard run of the mill, low Earth, and kind of sort of equatorial orbit. These are orbits that pass over Cape Canaveral, that pass over the Soviet launch facilities.
Pamela: And Hubble too. They re staying over the equator and they re criss-crossing. They re passing over Florida, they re passing over Mid-America, and they re passing apartment rentals winnipeg over the plains apartment rentals winnipeg of Russia. These are just nice happy little orbits, about 300 miles up that take about 90 to100 minutes to go round and round and round. What s neat about these inclined orbits is every orbit they pass over a slightly different part of the planet.
You have an orbit and you can imagine a hula-hoop going around the planet where it crosses the equator apartment rentals winnipeg in two places and then it has a high point and low point. Well, as the Earth rotates inside that hula-hoop, and in fact as the hula-hoop apartment rentals winnipeg itself slowly rotates that high point is over a different point on the planet every moment.
That allows different parts of the planet to have the International Space Station straight overhead at different times, which is cool for amateur observers who like to go out and look at these things.
Pamela: That s exactly correct. Depending on where you are on the planet, you re going around the center of the planet at a slightly different speed. The entire surface of the planet rotates once every 24 hours relative apartment rentals winnipeg to the sun. If you re at the equator you have to travel a much larger distance than you have to travel if you re up near the pole.
That extra velocity that you have by being near the equator helps throw you into orbit and gives you an extra boost as you re taking off. So, Florida is a great place (if you want to stay in the continental United States) to stick a space facility because it s pretty much as close to the equator as you can get in our country.
Fraser: Well, I think Sea Launch has the best one. [Laughter] They take a boat and an oilrig down to the equator in the ocean and they launch rockets right in front of the equator. Now let s compare that with the polar orbits. How is that different?
Pamela: With a polar orbit you launch yourself into space and not only when you get into orbit do you give yourself a boost sideways to get yourself staying in orbit around the planet, but you also do an extra transfer so that you re going over the North Pole and over the South Pole. There are a lot of different reasons to do this different type of orbit.
First of all, with a polar orbit you re constantly passing over different parts of the planet. This allows you to slowly apartment rentals winnipeg map the entire surface of the planet as you go around and as the planet rotates beneath it. You can still have a low earth orbit.
In general, we don t have orbits that go exactly over the North Pole and exactly over the South Pole, just because that starts to get a little complicated. Our Earth isn t actually a perfect sphere, we wish it was but it s not.
Its rotation causes it to bulge out a little bit at the Equator and this affects orbits and it s just a little bit simpler to have something that s tilted slightly apartment rentals winnipeg relative to North and South. It tends to get tilted naturally by this extra torque from going over the equatorial bulge.
Pamela: Well, once you re in space you can get the extra boost to get into space from launching near the equator, but then you have to tilt y