<p>The Space Shuttle Discovery lifts off from NASA's Kennedy Space Center in 1984.</p>
Das Space Shuttle Discovery hebt 1984 vom Kennedy Space Center der NASA ab.
Das Space Shuttle Discovery hebt 1984 vom Kennedy Space Center der NASA ab.
Photo by John A. Chakeres
Learn everything you need to know about the rockets that send satellites into orbit and beyond.
Posted on January 4, 2019
•9 minutes read
Since the invention of gunpowder in China more than seven centuries agoPeople sent top hats to the skyusing controlled explosions. These ships and their engines, called rockets, took on many functions such as fireworks, beacons, and weapons of war.
But since the 1950s, rockets have also allowed us to send robots, animals, and humans.in orbit around the earth- and even beyond.
How do rockets work?
As tempting as the logic may be, rockets don't work by "pushing air", they also work in the vacuum of space. Instead, rockets use the momentum, or amount of energy, that a moving object has.
When no external forces act on a group of objects, the combined moment of the group must remain constant over time. Imagine you are standing on a skateboard with a basketball in your hand. If you throw the basketball in one direction, you and the skateboard will roll in the opposite direction to save momentum. The faster you throw the ball, the faster you make it roll back.
rockets workspewing hot exhaust gases that behave like the basketball. The exhaust molecules don't weigh much individually, but they come out of the rocket nozzle very quickly, giving them a lot of boost. This causes the rocket to move in the opposite direction of the exhaust with the same total force.
Rockets produce exhaust gases by burning fuel in a rocket engine. Unlike jet engines on airplanes, rockets are designed for use in space: they do not have air intakes and bring their own oxidizers, substances that play the role of oxygen in burning fuel. The fuel and oxidizer in a rocket, called propellant, can be solid or liquid. The Space Shuttle's side boosters used solid propellants, while many modern rockets use liquid propellants.
What are the steps to launch a rocket?
Today's large space rockets are made up of sections of at least two stages stacked in a common cylindrical envelope. Each stage has its own engines, the number of which can vary. The first stage of SpaceX's Falcon 9 rocket has nine engines, while the first stage of theNorthrop Grumman Antares-RaketeI have two.
A rocket's first stage elevates the rocket from the lower atmosphere, sometimes with the help of additional side boosters. Because the first stage must lift the entire rocket, its payload (or payload), and any unused fuel, it is the largest and most powerful section.
The faster a rocket flies, the more drag it encounters. But the higher the rocket flies, the thinner the atmosphere. Taken together, these two factors cause the stress in a rocket to increase and then decrease during launch, reaching a pressure known as max q. too SpaceX Falcon 9miun United Launch Alliance Atlas Vthat the maximum occurs 80 to 90 seconds after takeoff, at altitudes betweensevenminine miles.
Once the first stage has completed its task, the rocket releases that part and launches its second stage. The second stage has much less load to carry and doesn't have to fight in the dense lower atmosphere, so it usually has a single engine. At this point, rockets also lose their fairings, the spiked cap on the nose of the rocket that protects what the rocket is carrying, its payload, during the first phase of launch.
In the past, most discarded rocket parts were dropped on Earth and burned in the atmosphere. But since the 1980s withNASA space shuttle, engineers designed rocket parts that could be salvaged and reused. Private companies like SpaceX and Blue Origin are even building rockets with first stages that return to Earth and land. The more parts of a rocket that can be reused, the cheaper rocket launches can be.
What types of rockets are there?
Just as cars come in many shapes and sizes, rockets vary depending on their task.
Sonic missiles are launched into the air in ballistic arcs and curve through space for five to 20 minutes before falling back to Earth. They are most commonly used for scientific experiments that don't require a lot of time in space. For example NASAused a sounding rocketin September 2018to test parachutes for future missions to Mars. (Where exactly is the edge of space? The answer is surprisingly complex..)
suborbital rockets likeThe new shepherd of blue originThey are powerful enough to temporarily invade space, either for scientific experimentation or space tourism. Orbital-class rockets are powerful enough to launch objects into Earth orbit. Depending on the size of the payload, they can also send objects beyond Earth, such as scientific probes (the sports cars).
Carrying satellites into orbit or beyond requires a lot of energy. In order for a satellite to stay in a circular orbit 500 miles above the earth's surface, it must be acceleratedover 16,600 miles per hour. The Saturn V rocket, the most powerful rocket ever built, was launchedover 300,000 pounds of payloadin low earth orbit during the Apollo missions.
Im Moment SpaceXhawk heavye da United Launch AllianceDelta IV heavyThey are the most powerful rockets in the world, but even bigger ones are on the way. Once NASAspace launch systemsurpass yoursDelays and Excessive Costs, it will be the most powerful rocket ever built. Meanwhile, SpaceX is buildinga test version of your spaceship,the giant rocket formerly known as the BFR (Big Falcon Rocket). Russia tooannounced his goalLaunch a "super heavy" rocket in 2028.
While some rocket manufacturers are growing, others are shrinking to accommodate the growing boom in cheap-to-build satellites.no bigger than refrigerators. rocket labselectron rocketIt can only lift a few hundred pounds in low Earth orbit, but for the small satellites it carries, that's all it needs.
What is a launch pad?
A launch pad is a platform from which a rocket is launched and is located in facilities called launch complexes or spaceports. (Explore a map of the world's active spaceports.)
A typical launch pad consists of a platform and a launch pad, a metal structure that keeps the rocket vertical before launch. The launch assist umbilicals provide the rocket with power, coolant and propellant reload before launch. The structure also helps protect the rocket from lightning strikes.
Different launch complexes have different ways of getting the rockets to the launch pads. At NASA's Kennedy Space Center, the space shuttle was assembled vertically and driven onto the launch pada tank-like vehicle called the Tracker.the Russian space programTransport your rockets horizontally with the trainto the launch pad, where they ascend vertically.
The launch pads also have features that minimize the damage done by launching the rocket. When a missile is first launched, valves lining the launch pad spray hundreds of thousands of gallons of water into the air around the exhaust, helping to muffle the missile's deafening roar. The trenches under the launch pad also direct missile exhaust outward and away from the ship, preventing flames from rising up and engulfing the missile itself.
Where are the rockets fired?
There are many starting places around the world, each with different advantages and disadvantages. In general, the closer a launch site is to the equator, the more efficient it is. This is because the equator moves faster than Earth's poles as the planet spins, like the outer rim of a spinning disk. Higher latitude launch sites more easily place satellites in orbits that fly past the poles.
Between 1957 and 2017, 29 spaceports put satellites or humans into orbit. Many of the sites are still active, including the only three facilities to put people into orbit. More spaceports are on the way, both public and private. In 2018, US-New Zealand company Rocket Labs launched satellites from its own private launch pad on New Zealand's Mahia Peninsula.
Where can I watch a rocket launch?
In the United States, NASA's Kennedy Space Centerprovides visitors with regular access.NASA Wallops Flight Facilityin Virginia you can also see the launch at the visitor center. The European Space Agency's spaceport in French Guianais open to visitors, but the agency encourages travelers to plan ahead. Tourists can visit the Baikonur Cosmodrome in Kazakhstan, the famous home of the Soviet and Russian space programs, but only if they book a tour. installationstay well guarded. (View photos of villages near the Plesetsk Cosmodrome in Russia, where salvaging discarded rockets is a way of life..)
If you can't visit a spaceport in person, don't worry: many public space agencies and private companies doOffer live online broadcasts of your releases.