Engineering Connections (Richard Hammond) - Space Shuttle | Science Documentary | Reel Truth Science

NASA's

space

shuttle

is the most complex machine ever built, making it one of the most expensive vehicles in the world, but it travels 25 times faster than a bullet and carries cargo worth tens of millions of dollars. It is the world's first reusable

space

craft on every mission. It flies about four and a half million miles, but no matter how smart the scientists behind it are, this incredible feat of

engineering

wouldn't have been possible without a church organ, a German submarine tram tracks a camera, a mega cannonball , the Apollo missions to the moon. They were a resounding success, but even when man walked on the moon the question was what NASA would do next.

The answer was that this space

shuttle

launches into the Florida sky from the platforms behind it and, as the world's first reusable space ticket, has turned the final frontier into another. destination a fleet of five shuttles has taken off from the Kennedy Space Center more than 130 times they have delivered more than a thousand tons of cargo, including most of the International Space Station and the Hubble telescope not bad for a delivery truck, wouldn't it be enough? an expensive one, a new one will cost you $1.7 billion and taking it out for a spin costs about $450 million, but NASA designed the shuttle to reduce the cost of space exploration, so the shuttle is reusable. all trades part playing part rocket I've come to look behind the scenes of the astronauts or rocket engineers get up close to the shuttle this is where it starts so the next stop is space but as they prepare for the latest launches of the shuttles, NASA has given me special access to see how it works to really get familiar with the shuttle on a much smaller scale. the gift shop is very useful.

What most of us think of as the shuttle is this part of the white plane that carries astronauts and cargo. It's actually called an orbiter and that's the part that goes to space in the back, it's got three engines, they're big and they're thirsty and the fuel for them is stored here in this orange fuel tank, but even together, that whole combo It is not enough for solid rocket boosters to be installed on the side to provide more thrust, so there are two different forms of propulsion on orbiters. The three main engines burn furiously during the eight and a half minute climb to orbit.

They are extremely powerful. 37 million horses. to be precise and they propel the 2,000 ton shuttle up to 650 kilometers above the surface of the Earth NASA has allowed me to enter the workshop where they inspected the engines this is our main engine workshop this is where everything happens this is where we prepare all these engines after they have flown to reinstall and prepare to go back online and this is them Mike Cosgrove is not just any grease monkey he is one of NASA's elite rocket scientists these are the next set of engines we will be installing we are finishing processing. in those that flew in and stopped by our store here and they will be completely renovated and we are just putting the finishing touches on them.

This will be used below. This is not a one-time deal. No? This is a reusable engine that we have some of these engines have flown up to 25 times four million miles Irv and its trip this could be 100 million gallons absolutely it was time to service these engines not only travel enormous distances, they withstand extreme temperatures without no protection, they would self-destruct, temperatures exceed three thousand three hundred degrees C or six thousand degrees Fahrenheit at 6000 degrees, what would they do? Normal battles would melt, yes, and that's a problem. Motors that melt will never do the job they are supposed to do.

It's like trying to make a chocolate teapot and we start with the very definition of uselessness a chocolate teapot chocolate teapots, of course, famously useless because to heat the water until it's hot enough to make a decent cup of tea, along the way you will melt the chocolate teapot is designed to melt in your mouth, in other words, I had simply had a low body temperature, so just to prove the point, I will now try to make the delicious cup of tea. Yes, he's clearly already having problems. Yes, its reputation is clearly deserved. Useless NASA shuttle engineers.

They faced the same problem: engines made of most metals melted at operating temperatures. To prevent this from happening, rocket scientists turned to much simpler machines, the ones that blasted air through church ovens in 19th century Britain, and this is the work those machines had to do for work, this It's the lever, those are the bellows, I pump the lever, it puts air in the system and there you have it, the original Hammond organ, you see, yes, I can resist, so inevitably, after a while, how long did it take? in replacing a machine, but I, the person who pumped the organ in the 1880s the internal combustion engine was still in its infancy the one first used to pump air into the Church organs introduced an ingenious new invention and it would have been a machine very similar to this one that replaced me operating the bellows to provide air for the organ, it is a single cylinder internal combustion engine, but it had a problem like all internal combustion engines and the track is in the name internal combustion, there is an explosion inside here and that makes the engine dangerously hot, so it is lined with water there is a water jacket around it and never a cylinder filled with water to cool cold water constantly circulates around the Hot engine removing heat This was the first cooling system for an internal combustion engine It is a primitive version of what NASA uses on the shuttle, but while water can cool one of these engines, it will never do the job for NASA , but at shuttle temperatures most metals would get so hot that they wouldn't just melt, but vaporize, so rocket scientists had to take engine cooling to a whole new level, luckily, NASA.

I already had excellent coolant available inside the giant orange tank. The fuel is super cold liquid hydrogen at -253 degrees Celsius. It is perfect for cooling engines. This is where you see the big fireball coming out the back. Yes, this is not crazy on television. says the arc we're going to cool this bad boy down and what we're going to do is take a tap off that liquid hydrogen that's being pumped through the engine and we're going to funnel it down the side of the nozzle here, through these nozzles, these distribution tubes, it will fill this manifold and then it will flow back through one thousand and eighty tubes into the main combustion chamber and burn it to send the actual fuel that you were using. along these pipes here and on top of all these I thought they were just marks these are actually these are tubes these are the ones that cool this yes this heat exit from the right end and then it goes in and it burns right which one is one of The secrets to this engine's incredible efficiency is that you are actually using the fuel before you burn it.

The reasons why shuttle engines do not melt is due to a principle that was first used in an engine like this to drive the bellows of a church organ a cooling system heat removal the cooling system Shuttle fuel is so efficient that it keeps the engines cool at 54 degrees Celsius but can all it be rocket

science

help me boil water with a chocolate teapot to test NASA's system? I've built a radical new prototype. What we have here is something quite special because it is a NASA-inspired chocolate. I have improved even more. In fact, this isn't just a chocolate cat, it's a chocolate ice cream cat, because that's what chocolate ice cream is. the challenge is to keep my ice cream from melting while the water heats up this is how it works this is the fuel for the burner down here the liquid propane runs along this narrow tube up here just like the shuttle i'm using ice fuel to cool for me, then travel up here to the Burnet, which is the real fuel of our music because it stays cool here despite being full of now boiling water, along with the ice cream, it stays frozen, yes, 100 degrees by inside. below zero outside, but it's still not a perfect kettle.

One thing I in no way designed to be poured. It is refinement. I'll work on that, as will my ice cream. The space shuttle's main engines do not melt. Even though they should be very very hot, but even the amazing power produced by the world's most efficient engine is not enough on its own to get the shuttle into space on takeoff, the shuttle is too heavy, the engineers needed more power , but they had to limit the weight, it's complicated to do it right to get more power, you need more engines and more fuel, more engines and more fuel means it's heavier, that's why the shuttle is equipped with these boosters, they are rocket boosters solids or SRB, and they have an excellent power-to-weight ratio and, as the name suggests, the fuel they burn is not liquid, it is soft and very explosive.

The height in a 15-story building. These are the largest solid rocket boosters ever flown when the fuel is ignited. All of those elements produce around 1,300 tons of confidence, about the same as 17,000 Formula One car engines. To get that amount of energy, the fuel has to be burned at incredible temperatures. The secret ingredient takes us back to the tram tracks in the 19th century. The tram tracks had just been screwed in. next to each other and the gaps between them made for a bumpy ride, then in the 1890s German chemist Goldschmidt invented a way to weld tracks together.

Fed mourners discovered that it could create intense heat by burning something you didn't expect to burn at all. Hallam mininum was first used in Essen, Germany. Aluminum welding made riots much smoother and revolutionized tram lines around the world. It's the intense heat from burning aluminum that NASA exploits. Burning even a small amount can be hot enough not only for a few steels but also for cutting. That's why I have one of these: it's an aluminum spear made of aluminum foil, like you find in the kitchen, lots and lots of it rolled very tightly here into thin tubes wrapped in more aluminum foil, obviously this is something you don't know. does.

I want to try it at home in your kitchen, but you probably don't have the other ingredient you need, which is compressed oxygen that's in the tanks, so the oxygen flows along the pipes along my aluminum lance. Here I lit the aluminum burns. Theory: Once lit, they should burn it at at least two thousand five hundred degrees C, so it should be about half as hot as the Sun, but can my homemade spear have an impact on solid steel? What anyone went to discover. I'm talking. do it, sometimes you can see theories and numbers on paper and sometimes you just need to see solid evidence and I think the cans clearly that were quite hot burning aluminum provide enough heat to cut steel and weld tram tracks and is the vital ingredient for rocket boosters Shuttle solids, of course, SRBs aren't just filled with aluminum foil, there's other stuff in there too, although you don't want to wrap your sandwiches in ammonium perchlorate to provide oxygen for iron combustion.

Oxide oxidizes to help it burn, it is the powdered aluminum that creates super high temperatures. The high temperatures convert the solid fuel into large amounts of gas and it is this gas that makes the rocket move because when you force a large amount of gas through a narrow nozzle, you get Push is the same thing that happens when you let go. a balloon, the air inside squeezes and shoots out this way, so it's a push, there's an equal and opposite reaction, which means a push this way, so the balloon goes in that direction. Sorry for the challenge.

NASA was going to build a rocket that would have the highest possible thrust directly toward the stars when the shuttle is at its heaviest, in an attempt to find out how they do it. I asked rocket man David Beaton to help me build my own Great British Astronaut underway, and like the shuttle rocket boosters, we're using solid fuel made from powdered aluminum, so this is the co-carrier for fuel, yes, dangerous, no, there is the same amount of fuel in each rocket that will burn along its entire length, but the fuel with the hole in the middle should burn faster, more fuel will burn at a time, so The rocketIt should fly faster out of the box, so because it burns faster, same charge, same load, you're burning faster, yes, it gives you more power. quickly, this will give a really good peak power and as it burns it will also progressively increase the thrust, yes, and that will make a visible difference.

Oh yes, yes, if we can, can we have a race? I think so, apart from the position of the ignition slot and the color of these two rockets they are identical. I'm letting it slip that this is bad, right? Yeah, it's going to be bad, yeah, okay, so to get this right, this one has the fastest burning chair that has the fastest burning offender. That's yours, okay, yeah, boy, jump, this is mine, look at that five, four, three, two, one, in just 10 seconds, the red rocket shoots 600 meters into the air. I think it was pretty clear that the red one was much faster than the red rockets.

Fuel burns much faster because more fuel is burned at once, meaning more hot gas is produced in a shorter time, giving this rocket more thrust. The blue rocket eventually reaches about the same height, but it takes much longer to get there, although it had a bit of an advantage it was visibly faster just a faster burn that's right notice the quick burn but the same energy released the same energy released a faster release gotta find it Elvis Lee yes yes NASA shuttle engineers need maximum thrust so they go for a bigger, faster burn, like the red rocket at launch, each booster burns fuel at the incredible speed of 5 tons per second, burn for about two minutes and then jettison 30 miles a day, drift away from the shuttle and back to Earth, crash. land in theAtlantic Ocean here and this is the beauty of the system that NASA picks them up to refuel on dry land, so thanks to a welding technique that smoothes their tram rides, the thrust provided by the rocket's solid propellants is enough to remove the shuttle from the launch pad. and on their own journey of hundreds of kilometers into space, but the rockets are so powerful that they create a very dangerous problem in themselves and take off.

The exhaust gases that generate thrust also generate phenomenal sound energy. This is so powerful that it can have fatal consequences. and this is the launch pad where everything happens during a launch this place is just full of energy flames scorching gases incredible amounts of noise I'm below where the shuttle is on the launch pad this is the flame trench I can only be here because the shuttle is not in place right now, you certainly wouldn't want to be here when the countdown hits zero and this trench was also used on some Apollo missions, just to think about the incredible amounts of energy these walls have taken on The years, like it boggles the mind, the rockets fired create a thunderous sand that crashes to the bottom of this trench this sound is energy and systems engineer John Lord knows how powerful this can be even from three miles away you can feeling that energy just exploding in your chest, you know, and it's just amazing the amount of energy injected, all this energy would bounce off the ground straight into the ship, the vibrations would be so powerful that they would leak the sky on the first shuttle mission they broke up heat-resistant. tiles on the surface of the orbiter that time, the orbiter returned to Earth safely, but it could have burned up on re-entry, so engineers needed to find a way to protect the shuttle from the reflected energy, to do so they had to absorb the energy of sound. that roared down here and then bounced off and hit the shuttle at the UK's Hammond Space Center.

I can't replicate the thunderous sound of the shuttle, but I can give you an idea of ​​its destructive power. I'm going to build a wall here and I'm going to tear it down with a pulse of air just like that, bigger, much bigger. I'll only use half in the end. Look, I did a job Inc. That's the wall built and here's what I expect. He's going to fly it over a vortex cannon first we have to do a little test three two one that's up there the most amazing things I've ever seen an explosion at the base of the cannon creates a single pulse of air in the shape of a different donut to the sound that moves in a wave the vortex flies through the air like a missile the vortex has a lot of energy but it can knock down mine wood Jim is now loading it with a fixed end I am ready to make our explosion you will never do it, this It will have to be a 1 foot puff of air.

Thank you so much. If we're ready, all in three, two, this is your slow motion, it allows us to see the vortex as it travels through the air at over 200 miles per hour and as you can see, it creates a huge amount of destruction. The ferry problem is much bigger. Its exhaust gases come out at about four thousand kilometers per hour, producing large amounts of sound energy in the form of vibrations. It takes an engineer to find a way. To protect the shuttle, NASA turned to a system that connects the shuttle to submarines via bubblers. Acoustics expert Tim Layden from the University of Southampton shows me how what we have here is our own mini solar system, a water tube, a speaker at the bottom that plays sound jeeps and at the top a special underwater microphone that will pick them up, you can hear the sound chips and they're represented on the screen here.

I'm going to introduce bubbles here because bubbles are really powerful at absorbing sound, so This is the key to watching cheap is going away, so here we go, you're literally blowing bubbles like this, yeah, okay, I can hear that , but look at the screen, there are no longer the bubbles that you can see in the The pipes are eliminating that sound completely. We are still playing the sound chips through the water, but even the smallest bubbles prevent the microphone from picking them up. There is nothing yet, Mr. enough to stop it, yes, so these tiny, but almost microscopic bubbles, they kill a lot and they kill the sound there.

The bubbles absorb sound when they heat up, making them so dirty that the sound comes out of here, which are jets of waves, this movement comes from here, yes. when you find air bubbles in water, yes the waves crush the air bubbles which heats them up, yes the energy of the sound wave is converted into energy into heat so the bubbles absorb the sound but How does that help the submarines of World War II, the Germans? -The fleet of ships is under attack. The Germans want their submarines to be untraceable to Allied destroyers and their sonar systems.

Allied sonar worked by sending sound chips from their ships and then waiting for the echo to bounce off a solid object that could detect it. where the german submarines were if the germans could absorb sonar chips without echo they would be invisible so they created rubber tiles to stick to the sides of their service tiles with bubbles. This and this is a genuine World War II liner from a German submarine. and you see it attached to the submarine like this, this side is smooth but this side has holes like voids in houses, the trapped air creates thousands of small bubbles when a sonar ping comes and hits, these absorb sound in the same way That those bubbles did, bubbles can make German submarines invisible, but the shuttle is not underwater, obviously, and has to deal with more than just chunks of sand to absorb the phenomenal noise of the rocket engines.

NASA turns sound absorption on its head. instead of air in water, they put water in the air. Tim has another tube with just air. We're still sending sand sheep through it, but this time we're going to try to block them with a mist of water droplets. This water. in ice, okay sir, pour that in there and it forms fog. I can't really see where I'm pouring, hopefully that's in the tube, yes it's going in, doesn't it feel like a wizard and my spell seems to be working? Oh, look. That totally knocked it out of the park, so this is just dad, I'm not dumping actual water into microscopic water droplets in the air that vibrate, converting sound energy into heat.

NASA protects the orbiter the same way it does. Let's say the NASA system is a little more complicated, it looks like a warehouse, it's actually the mobile launch pad, the random set sits on top of those three, one, two, three, they are the rainbirds and, At maximum flow, nine seconds after launch, water rushes through them at a rate of nine hundred thousand gallons, that is, three and a half million liters per minute, releasing so much water so quickly through the rain, Birds form millions of water droplets suspended in the air and it is these water droplets that absorb the phenomenal sand it contains, the system to unleash that.

The amount of water is incredibly simple, a water tower, ha, this is essentially a really big explosion of the type of water tank you see outside a town or city, it's really just a sleek and simple design to get the flow rate we need when the valves open. More than a million liters of aquatic plants are sprayed beneath the rocket engines and absorb the thunderous sound so the water can work against the vortex cannon. It's time to see if what's good enough for the shuttle is good enough for my wall first, obviously the same building that follows us.

I need water, this is our rainbow, a pretty simple setup. I'm not saying every house has one, but essentially you have pumps here that pump water from the lake through those pipes and up to the top where a sprinkler system basically creates a wall of water, so let's try it, we have to get into position, bring it in, the bursts I'm about to fire have exactly the same path as before, but this time there's a curtain of water between the cannon and the blocks, okay, if we're ready, all in three two. one and in slow motion you can see how the pulse of the air hits the water and loses energy.

I think we can safely say the best ratings now. Very well done your theory works as I just proved you will be grateful but it really worked using billions. and billions of water droplets to interrupt the energy pulse, NASA engineers can protect their precious orbiter and its payloads and all thanks to the power of the bubble eight and a half minutes after liftoff, the orbiter is at more than three hundred kilometers high. the earth is in space just a few minutes later the crew is preparing to begin their mission the orbiter was basically designed to be a delivery van they are very expensive a very technologically advanced delivery van their job is to deliver things to space so far it has put satellites, telescopes and most of the international space station up there, but you can't just open the back and take out your cargo, especially when it's probably a chunk of the space station satellite, it's not the easiest object to move and is quite expensive if you drop something. so each shuttle cargo bay is armed with a helping hand, don't worry I'm not going to be unloaded into space, this is a full scale model at Kennedy, even if the astronauts could physically lift and manipulate the cargo in the space, walking is very dangerous.

So NASA turned to robots for help, specifically a robotic arm called the Canada Arm built by those famous space scientists. Canadians faced a real problem: how to grab something in space without accidentally throwing it across the galaxy? The Answer Was Found in a Camera Lens Camera lenses, like our eyes, have viruses that control the amount of light allowed through a camera lens. They are made of a series of interlocking metal plates that, when rotated, change the size of the opening or hole in the middle, but how did this end up in Canada aboard the space shuttle?

The Canada's early designs gripped objects like a handle, but engineers quickly realized there was a fundamental problem: the smallest of accidental nudges could send any load flying. air resistance in space, so when something starts moving it doesn't stop for some reason. NASA wouldn't let me play with their hundred million dollar arm in orbit, so to find out how big the problem really is, I asked Neil Billingham. To introduce myself to one of his robots I move him like this, so that's what's a little scary. What I'm doing is pretty much what shuttle astronauts have to do in space and I'm starting to understand it.

The end can be opened and closed, making it a perfect tool for grabbing things. Tap the Faucet and then the other.I'll open it. I didn't do that when my nose was in, so this claw. The fixes here are clearly very useful. Specific purpose device here on Earth, how would it work in space? Well, we can find out because I built my own satellite here. The helium balloon behaves a bit like a weightless satellite in space, so it's very difficult to grab and I'm not making this up. Peter's Dib Rani is an expert in Canada, he is fine, so he is in position.

I'm going to try to grab it well, that doesn't hurt at all and also gives us a little chef. I guess in space that would be really bad news, wouldn't it? You could push your target away from you and if we were in space it would have kept making one wrong move with the real 50 foot long arm and it could send millions of dollars worth of satellite running out of reach someone would be mad NASA needed a new way to grab things in space with 100% precision then one of the engineers working on the robotic arm had a unique moment an enthusiastic photographer his inspiration was the iris of the camera and I have a mini version of which he helped to design to go into space like the iris of a camera.

It rotates but instead of interlocking plates it has three cables that close and almost immediately I captured what I'm looking for. I think so, but the Space Telescope took me a few seconds to do, why is it so much easier with that? It was with just a normal grip. The initial volume it can capture is very large, so all you have to do is make sure your target is somewhere there and you don't have to align much. The end of the actual Canada is 20 centimeters in diameter within that area. Yes, it can possibly only be cool because you just squeeze it and pull out the right side. place and it could be at the wrong angle it could be off it could be backwards or forwards and it really doesn't matter much that one is closed and tight the astronauts can maneuver it easily had chosen the satellite since 1981 the astronauts have used Canada to grab the transport of the Hubble telescope More than 200 tons of space station in orbit and travel in style thanks to simple cameras.

The Canada arm is now a vital part of all shuttle missions, but once the mission is complete, there is still the pressing problem of returning to Earth in one piece. The journey is one of the most dangerous parts of any shuttle mission and can be fatal, as all astronauts know, in 2003, the Columbia orbiter burned up when Erie entered Earth's atmosphere, killing all seven members of crew. The problem is the incredible speed of re-entry. the orbiter travels at 27,000 kilometers per hour high speeds in space another problem there is no atmosphere but it begins to hit billions of tiny particles in the upper atmosphere and things change hitting all those particles creates friction a lot of friction and that generates heat airplanes missiles and bullets They are typically streamlined so they can glide through the air creating as little friction as possible, and early scientists thought that approach would work for rockets, but in the 1950s, space scientist Harvey Allen realized that the speed of rockets comes with its own problem: traveling at five times the speed of sound. and higher and the friction is too intense, no matter how elegant the design, no known substance could survive the heat that Apollo was at the beginning.

I heard something quite radical instead of making the nose of anything that needs to go back in Now I know that a round cannonball doesn't have the perfect shape for flying, but its ultimate goal is not to fly, but to smash as much of something as possible and that's exactly what Alan thought the reentry vehicle should do: smash the air out of the way, no. Trying to cut it off, this was throwing the usual rules of aerodynamics out the window, but how does crashing into air help the orbiter on re-entry? This is the University of Manchester, but it's a very specific little corner of the university because these machines are dedicated to serving another very, very special machine through there, it's a wind tunnel, but these winds will travel at hypersonic speeds of up to Mach 6, which is six times the speed of sound, obviously that kind of performance involves the release and control of stupendous amounts of energy, so the wind tunnel itself is not as big as some you're used to , so to enter I have a mini orbiter with a pointed nose and another with a blunt nose.

Costas Cantus is the head of first aerospace research. I want to see exactly why a pointy nose design is such a bad idea for the orbiter. I guess it has to be pretty firmly fixed, of course, because we don't want them flying around, you know, it's very dangerous, what if what if this tunnel blows up? my hands there lose your hands literally just fly away of course I don't want that to happen come on it's over quickly at these speeds you can only see what is happening with an elaborate system of mirror lenses and high speed photography so If you can turn off the lights please, there is a lot of energy about to be released.

There is no 6000 kilometers per hour radius, a jet of air to be precise, that was strangely terrifying. Well let's look at another image, so this is where the pointy nose, that's right, with this system you can see exactly the shock wave, the air around the nose is compressed so much that it forms superheated shock waves, it actually hits its wings , so that's the hard part because it's quite dangerous, the damage will be very high, so this chakra goes through air and it's actually ice. I thought it was good to kiss him making a small hole. It's elegant, but where that line is weak exactly, a lot of energy is deposited.

Yes, the wingtips are exposed to high speed air. of friction and at orbiter speeds the shock wave reaches thousands of degrees Celsius literally due to the shape of its nose it can tear off its own wings exactly yes and the wings are quite important until the Rhian tree the shuttle has been a rocket but now it is a plane that has to glide back to earth, so totally contrary to what we would expect the pond to say, doesn't work, so how will the blunt nose fare? Okay, okay, the right moment of

truth

illuminates, this is where we see.

Hopefully there's a difference Coleman, okay, let's press the button, okay? It couldn't be clearer. Could it be with a blunt tip? The shock wave misses the wings completely and deflects high-speed air away from the orbiter wings, so there is no friction and it is completely deflected. Counterintuitive, I just wouldn't guess that if I were sitting down to design something to re-enter the atmosphere, who owes me that? You think aiming is better, that guy runs against everything your gut tells me, so thanks to a cannonball. Blunt is better for re-entry, but as seen in these real images of the orbiter's cabin, the shock wave around the ship is glowing at Mach 25, it is superheated to 5500 degrees.

It may not touch the orbiter, but as you can imagine, it still makes it pretty warm. So, at NASA's Kennedy Space Center, scientist Martin Wilson is in charge of producing heat-resistant tiles to protect the space vehicle. It's very hot, so this is essentially an oven. Yes, this is one of the ovens that we use in the various heat treatments of the tiles. during manufacturing and most of the temperature is there, the temperature inside the kiln is 2200 degrees, approximately one thousand one hundred and sixty centigrade and these are actually the materials that the tiles are made from.

You know, pure silica, but it just came out of there. It came out a few seconds ago, it's still very, very hot, do you have special hands? I can do that? No, you can do that and touch it just in the corners. That just came out. That kills. It's amazing. You can still see the energy bouncing around inside. Silica cools very quickly at its edges, but because the slabs are effectively a silica foam, they are also filled with air, making them excellent insulators, so thanks to these heat-resistant slabs and cannonballs heat, the orbiter completes our entry and glides to land.

It lands at just 350 kilometers per hour, so after a journey of about four million miles and about twenty-three times the speed of sound, the final part of the shuttle is safe here on Earth for three decades. NASA's shuttle fleet has traveled more than five hundred million miles, taken humanity into space to orbit our world and expand the frontiers of our knowledge, and owes its

engineering

DNA to a church organ, a German submarine carries a camera and a cannon