Audience: Middle and High School Students
Fun fact: While some satellites fit the stereotype of being huge and the size of a school bus, others are so tiny that they can fit in your hand. Photo by NASA from Unsplash.
Can you imagine a huge, gleaming rocket, poised to leap into the sky before the eyes of the world? Can you picture the cloud of white exhaust, soft and powerful at the same time, spreading like flower petals around a bud as the rocket launches? It zooms into space, an empty black void, lit only by the twinkling of tiny stars. A smaller satellite ejects from it, into an unending orbit around the Earth. It seems too beautiful to picture. It’s a good thing you don’t have to imagine this scene – it’s real, and it’s the launching of a satellite.
Although a glittery blue chunk of metal is the stereotypical perception of a satellite, not all satellites are man-made machines. A satellite can actually be anything that orbits a planet or star – the Moon itself is a satellite! However, colloquial usage of the term typically references machines that are launched into space on a rocket. Some, like the famous Hubble Space Telescope, are used to photograph phenomena in space, while others help predict the weather and maintain communications. There are even satellites like the International Space Station that carry people. Satellites are launched by government space agencies, such as NASA and ISRO, and private companies. A few of the more famous companies include SpaceX, Blue Origin, and United Launch Alliance.
But sending the satellite into space is not as simple as it looks; it doesn’t just enter a high altitude and then cruise through space. Before that, it needs to be launched with a rocket. The rocket gets explosive power from the propellants, or fuels, that it’s loaded with. The propellants are burned, resulting in exhaust that fumes out of the bottom of the rocket, forming the huge white cloud that’s very characteristic of rockets. The force of the exhaust pushes the rocket in the opposite direction, lifting it off the ground. Aimed straight up to penetrate through the thickest layer of Earth’s atmosphere, the rocket goes extremely fast to surpass the escape speed or escape velocity of Earth, which is the minimum amount of velocity needed for an object to escape into space – about 11 kilometers per second. After the rocket clears the atmosphere, it adjusts its nozzles to tilt itself and stay on course. When the time is right and the air is thin enough, the satellite is released.
While the rocket gets its initial momentum from the launch, it is able to stay aloft because of specific forces that push it up and down simultaneously. Throughout the journey, the force of gravity tries to pull the rocket down to Earth. However, an upward force called thrust, created when the rocket pushes out exhaust, combats the gravity. The rocket remains in the air if it has enough propellants to generate a thrust greater than gravity.
However, there is still one more force to consider: momentum. Momentum from the release pulls the satellite in a slanted direction, away from the Earth, while gravity tugs at it from the other direction. The result is the satellite orbiting around the Earth. There are about five different types of orbits, actually! The different orbits are characterized by their position and proximity to Earth. Their specific orientations and properties make them suitable for different uses, such as communications, navigation, military use, and more, making the orbit one of the satellite’s most important features.
Obviously, launching a satellite is a very delicate operation. Even if scientists make sure that every screw is tightened properly and that the satellite is fortified enough to withstand the brutal conditions of space, a single piece of space debris, an object that floats in space without function, can derail the entire mission. Debris travels through space at high speeds, so even though it is small, it can inflict a brutal amount of damage. And the effects don’t end there: when a satellite is destroyed by debris, it becomes debris itself! It’s like a hydra – take away one head and end up with even more. Space debris is a huge threat to satellites.
It’s probably clear by now that satellites are amazing feats of engineering. They are present in our daily lives, although we rarely give them the credit they deserve. Satellites are part of essential communication and navigation systems. They even help predict the weather, which is much more indispensable than it seems; try to envision not being able to check the weather with one tap of a finger — it’s hard to picture such a thing! So remember to give satellites and the rockets that carry them some respect. Don’t leave them waiting in the dark — or rather, in space — longing for credit.
Bibliography:
Erickson, Kristen. “How Do We Launch Things into Space? | NASA Space Place – NASA Science for Kids.” Spaceplace.nasa.gov, 6 Feb. 2023, spaceplace.nasa.gov/launching-into-space/en/. Accessed 14 Mar. 2024.
https://www.howstuffworks.com/hsw-contact.htm, and https://www.howstuffworks.com. “How Satellites Work.” HowStuffWorks, 19 May 2000,
science.howstuffworks.com/satellite5.htm. Accessed 14 Mar. 2024.
NASA. “Launch - NASA Science.” Science.nasa.gov, science.nasa.gov/learn/basics-of-space-flight/chapter14-1/. Accessed 14 Mar. 2024.
---. “What Is a Satellite? | NASA Space Place – NASA Science for Kids.” Spaceplace.nasa.gov, spaceplace.nasa.gov/satellite/en/. Accessed 14 Mar. 2024.
“What Are SmallSats and CubeSats? - NASA.” nasa.gov, www.nasa.gov/what-are-smallsats-and-cubesats/. Accessed 14 Mar. 2024.
NASA. “Hubble Home.” HubbleSite.org,
hubblesite.org/home. Accessed 18 Mar. 2024.
NASA. “International Space Station - NASA.” NASA,
www.nasa.gov/international-space-station/. Accessed 18 Mar. 2024.
Urban, Ria. “Top 10 Rocket Launch Companies to Look for in 2023.” Space Impulse, 16 Jan. 2023,
spaceimpulse.com/2023/01/16/rocket-launch-companies/. Accessed 20 Mar. 2024.
NASA. “Gravity and Escape Speed.” NASA,
https://spacemath.gsfc.nasa.gov/weekly/10Page61.pdf. Accessed 20 Mar. 2024.
“Types of Orbits.” The European Space Agency, 30 Mar. 2020, www.esa.int/Enabling_Support/Space_Transportation/Types_of_orbits#GEO. Accessed 20 Mar. 2024.
“What Is Space Debris? - Darwin Innovation.” Darwin Innovation, darwincav.com/what-is-space-debris/. Accessed 20 Mar. 2024.
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