00:00Have you ever wondered why rockets are launched right next to the equator or the sea?
00:05Or why do we launch them vertically and not like airplanes?
00:09Let's answer all the possible, not stupid, questions about rockets.
00:15Question 1. How does the Earth affect the rocket's launch?
00:19Let's remember some school physics.
00:21The gravity of the Earth is incredibly strong.
00:24To overcome this force, we need to develop a huge speed.
00:28Fortunately, rockets are capable of developing it.
00:31But it would be much more difficult if the Earth itself didn't help it.
00:35The Earth rotates around the Sun at a speed of 67,000 miles per hour.
00:41Very fast, to put it mildly.
00:43And we are all moving with it.
00:45So getting off the Earth is like getting out of a moving car.
00:48For some time, the rocket will move along our planet by inertia.
00:52It's like a helpful push.
00:54The rocket takes off from Earth at a certain speed already.
00:58And then it just needs to accelerate a bit more with the help of its fuel.
01:03By the way, this isn't the only scientific trick in launching rockets.
01:08To get to the maximum benefit from this push, they're launched into Earth's orbit from west to east.
01:15Why?
01:15Because the Earth rotates from west to east, of course.
01:18This way, the rocket receives maximum inertia.
01:24Question 2.
01:25Why are rockets launched next to the equator?
01:28The answer is related to the previous question.
01:32Believe it or not, the Earth's surface is moving faster at the equator.
01:36The school lied to us a little.
01:38The Earth isn't perfectly round.
01:40Rather, it's a flattened ellipse.
01:42And the equator is the widest point on our planet.
01:46Now, what is speed?
01:49It's the distance divided by time.
01:51And since the distance at the equator is the largest, about 25,000 miles, then the rotation speed there will be higher.
01:59So, imagine that you and your friend were standing at two different points of the Earth.
02:04You are at the equator, and your friend is closer to the North Pole.
02:07After standing there for the entire day, you would fly more miles than your friend, which technically means that you moved faster.
02:16So, yep, the rotation speed at the equator is higher.
02:20Naturally, it's most profitable for us to launch rockets from places where the initial thrust velocity will be as high as possible.
02:28And launching from the equator causes the spacecraft to move almost 300 miles per hour faster.
02:34Question 3.
02:37How do scientists choose the places for the launch pads?
02:41Rockets are gigantic, complex monsters weighing several thousand pounds.
02:46Needless to say, dozens of errors may occur during startup.
02:50Probably the most dangerous one is a mid-flight failure.
02:53That's when something goes wrong in a rocket that's still in the sky.
02:57If the burning debris falls to the Earth, it may cause a huge disaster.
03:01Now, let's look at a map of the location of launch pads in the world.
03:07You can see that many of them are located near the coast.
03:10For example, the Kennedy Space Center in Florida, USA, or the Satish Dalwan Space Center in Sriharakota, India.
03:18That's the way to minimize, and ideally eliminate altogether, the risk of debris falling on your head.
03:24If something goes wrong during the launch, it will fall into the ocean waters, far from densely populated areas.
03:31And yeah, there are a bunch of launch pads located far from the sea.
03:35That's because many other things also play a role in choosing the location.
03:40For example, the availability.
03:43The launch pad should be ideally accessible from land, air, and sea.
03:47For more than 70 years, NASA has been launching rockets from Cape Canaveral, Florida.
04:01It's because Florida has a very humid and tropical climate.
04:05There are more thunderstorms a year than in any other place.
04:09This can greatly interfere with rocket launches.
04:12It's very dangerous.
04:13Moreover, one time, it actually happened.
04:17In 1987, lightning struck an AC-67 rocket before takeoff.
04:22Its systems failed, and eventually, the rocket was destroyed.
04:26Fortunately, there were no people on board.
04:28Another big weather threat is hurricanes.
04:31And yes, they also happen in Florida more often than in any other state.
04:36But despite all this, NASA still chose this cursed place to launch their rockets.
04:41Why?
04:41Well, probably because all the crazy things, including rocket launches, must happen in Florida.
04:47But on a serious note, before NASA moved to Cape Canaveral, rockets were launched from another place.
04:54From the White Sands test site, located in New Mexico.
04:58Back then, since White Sands was located in a remote area of the country, everything was more or less safe.
05:04If the rockets had fallen, they wouldn't affect or destroy anything.
05:08But as time went on, our technologies developed.
05:12The rockets got bigger and needed much more space for their launches.
05:16As a result, the danger zone also increased.
05:19White Sands was just 26 miles from Las Cruces, New Mexico, and 70 miles from El Paso, Texas.
05:27In other words, it was surrounded by settlements.
05:29Therefore, scientists began to look for safer places.
05:33The East Coast seemed like the best option.
05:36Can you guess why?
05:38Not only is the East Coast closer to the equator, but it's also located near the Atlantic Ocean.
05:44We already know that this actually adds plus one to the security.
05:48That's why in the 1950s, NASA moved its launches to Florida.
05:53The first one was the launch of the Bumper 8 rocket, which took place on July 24, 1950.
05:59And then, this place became a full-fledged spaceport.
06:05Question 5.
06:06Why are rockets launched vertically?
06:09Rockets are thin, cylindrical tall things that go into space vertically and leave behind a giant cloud of smoke.
06:15But why are they launched that way and not like airplanes, for example?
06:20Well, this sounds a bit crazy.
06:23To implement it, we'd have to make a lot of changes to the current rocket designs.
06:27But the most important thing is that it would waste a lot of resources.
06:32This may surprise you, but planes and rockets are designed a little differently.
06:37The plane's main task is to fly in the atmosphere.
06:40The rocket's main task is to leave the atmosphere as soon as possible.
06:44Due to the air resistance in the sky, the rocket loses most of its energy while flying.
06:51Therefore, we need to make sure that it has left the Earth's atmosphere before its fuel is completely used up.
06:57And since it needs a lot more fuel than an airplane, it's easier and more economical to launch it straight up.
07:04So, it will use a minimum of fuel.
07:06Just what it takes to kick gravity in the face.
07:09Remember that we said that the rocket's main task is to escape gravity by any means and reach space?
07:22Now forget about it.
07:23Technically, it's true, but it doesn't show the full picture.
07:26The very task of getting into space isn't particularly difficult.
07:31The space isn't actually that high.
07:34You'll officially become an astronaut if you go to an altitude of about 60 miles above Earth.
07:40But it's all about staying in orbit.
07:42The orbit is the boundary of two worlds.
07:45Here, the gravitational pull of the Earth is still large enough that the rocket doesn't fly into outer space,
07:51but at the same time, low enough that it doesn't fall back to Earth.
07:55So, if you reach it, there's no need to waste fuel anymore.
08:00The spacecraft will simply fly in zero gravity by inertia.
08:04If the rocket flies purely in a straight line, it will simply fly into outer space.
08:09To enter orbit, it needs to fly in an arc.
08:13Therefore, after starting, it begins to tilt to the side and gradually increases this slope.
08:18Getting into orbit is a very difficult task, actually.
08:21The fuel should be enough to reach an insane speed of 18,000 miles per hour.
08:27That's why we invented this optimization method.
08:30Smart people call it gravitational reversal.
08:33So, a rocket bends its trajectory after launch because it has to go into Earth's orbit.
08:38Congrats!
08:39That was a long journey.
08:41But now you, hopefully, learned a bit more about rocket launching.
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