Why a Rocket Bends Its Trajectory + 5 Questions About Rockets

Bright Side

Ever wondered why rockets seem to bend their trajectory during launch? It all comes down to something called gravity turn, where the rocket gradually tilts to follow the curvature of the Earth. It's like taking the scenic route to space! And trust me, there's more where that came from—rocket science is full of intriguing questions, like why do rockets have multiple stages, or how do they steer in the vacuum of space? So grab your space helmet and get ready to blast off into a world of discovery! With these five burning questions about rockets, we'll unlock the secrets of space travel one curiosity at a time.

Transcript

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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