{"678877":{"#nid":"678877","#data":{"type":"news","title":"How Does the International Space Station Orbit Earth Without Burning\u00a0Up?","body":[{"value":"\u003Cdiv class=\u0022theconversation-article-body\u0022\u003E\u003Cp\u003EFlying through Earth\u2019s orbit are thousands of satellites and two operational space stations, including the International Space Station, which weighs as much as 77 elephants. \u003Ca href=\u0022https:\/\/www.nasa.gov\/international-space-station\/\u0022\u003EThe International Space Station\u003C\/a\u003E, or ISS, hosts scientists and researchers from around the world as they contribute to discoveries in medicine, microbiology, Earth and space science, and more.\u003C\/p\u003E\u003Cp\u003EOne of my first jobs in aerospace engineering was working on the ISS, and the ISS remains one of my favorite aerospace systems. I now work at Georgia Tech, where \u003Ca href=\u0022https:\/\/ae.gatech.edu\/directory\/person\/kelly-griendling\u0022\u003EI teach aerospace engineering\u003C\/a\u003E.\u003C\/p\u003E\u003Cp\u003EThe ISS travels very quickly around the Earth at 5 miles per second (8 kilometers per second), which means it could fly from Atlanta to London in 14 minutes. But at the same time, small chunks of rock called meteoroids shoot through space and burn up when they hit Earth\u2019s atmosphere. How is it that some objects \u2013 such as the International Space Station \u2013 orbit the Earth unscathed, while others, such as asteroids, burn up?\u003C\/p\u003E\u003Cp\u003ETo answer why the ISS can stay in orbit for decades unscathed, you first need to understand why some things, such as meteoroids, do burn up when they enter our planet\u2019s atmosphere.\u003C\/p\u003E\u003Ch2\u003EWhy Do Meteoroids Burn Up in the Atmosphere?\u003C\/h2\u003E\u003Cp\u003E\u003Ca href=\u0022https:\/\/science.nasa.gov\/solar-system\/meteors-meteorites\/\u0022\u003EMeteoroids are small chunks of rock and metal\u003C\/a\u003E that orbit the Sun. These space rocks can travel between 7 and 25 miles per second (12 to 40 km per second). That\u2019s fast enough to cross the entire United States in about 5 minutes.\u003C\/p\u003E\u003Cp\u003ESometimes, the orbit of a meteoroid overlaps with Earth, and the meteoroid enters Earth\u2019s atmosphere \u2013 where it burns up and disintegrates.\u003C\/p\u003E\u003Cp\u003EEven though you can\u2019t see them, the atmosphere is full of a combination of particles, primarily nitrogen and oxygen, which make up the air you breathe. The farther you are from the surface of the Earth, the lower the density of particles in the atmosphere.\u003C\/p\u003E\u003Cp\u003EThe \u003Ca href=\u0022https:\/\/scied.ucar.edu\/learning-zone\/atmosphere\/layers-earths-atmosphere\u0022\u003Eatmosphere has several layers\u003C\/a\u003E. When something from space enters the Earth\u2019s atmosphere, it must pass through each of these layers before it reaches the ground.\u003C\/p\u003E\u003Cp\u003E\u003Ca href=\u0022https:\/\/sites.wustl.edu\/meteoritesite\/items\/meteors\/\u0022\u003EMeteoroids\u003C\/a\u003E burn up in a part of Earth\u2019s atmosphere \u003Ca href=\u0022https:\/\/scied.ucar.edu\/learning-zone\/atmosphere\/mesosphere\u0022\u003Ecalled the mesosphere\u003C\/a\u003E, which is 30 to 50 miles (48 to 80 kilometers) above the ground. Even though the air is thin up there, meteoroids still bump into air particles as they fly through.\u003C\/p\u003E\u003Cp\u003EWhen meteoroids zoom through the atmosphere at these very high speeds, they are destroyed by a process that causes them to heat up and break apart. The meteoroid pushes the air particles together, kind of like how a bulldozer pushes dirt. This process creates a lot of pressure and heat. The air particles hit the meteoroid \u003Ca href=\u0022https:\/\/science.howstuffworks.com\/transport\/flight\/modern\/hypersonic-plane.htm\u0022\u003Eat hypersonic speeds\u003C\/a\u003E \u2013 much faster than the speed of sound \u2013 causing atoms to break away and form cracks in the meteroid.\u003C\/p\u003E\u003Cp\u003EThe high pressure and hot air get into the cracks, \u003Ca href=\u0022https:\/\/doi.org\/10.1029\/2020JA028229\u0022\u003Emaking the meteoroid break apart\u003C\/a\u003E and burn up as it falls through the sky. This process is called \u003Ca href=\u0022https:\/\/www.youtube.com\/watch?v=r4roWT1SD2s\u0022\u003Emeteoroid ablation\u003C\/a\u003E and is what you are actually seeing when you witness a \u201cshooting star.\u201d\u003C\/p\u003E\u003Ch2\u003EWhy Doesn\u2019t the Space Station Burn Up?\u003C\/h2\u003E\u003Cp\u003ESo why doesn\u2019t this happen to the International Space Station?\u003C\/p\u003E\u003Cp\u003EThe ISS does not fly in the mesosphere. Instead, the ISS flies in a higher and much less dense layer of the atmosphere \u003Ca href=\u0022https:\/\/spaceplace.nasa.gov\/thermosphere\/en\/\u0022\u003Ecalled the thermosphere\u003C\/a\u003E, which extends from 50 miles (80 km) to 440 miles (708 km) above Earth.\u003C\/p\u003E\u003Cp\u003E\u003Ca href=\u0022https:\/\/www.britannica.com\/science\/Karman-line\u0022\u003EThe K\u00e1rm\u00e1n line\u003C\/a\u003E, which is considered the boundary of space, is in the thermosphere, 62 miles (100 kilometers) above the surface of the Earth. The space station flies even higher, at about 250 miles (402 km) above the surface.\u003C\/p\u003E\u003Cp\u003EThe thermosphere has too few particles to transmit heat. At the height of the space station, the atmosphere is so thin that to collect enough particles to equal the mass of just one apple, you would need a box the size of Lake Superior!\u003C\/p\u003E\u003Cp\u003EAs a result, the ISS doesn\u2019t experience the same kind of interactions with atmospheric particles, nor the high pressure and heat that meteoroids traveling closer to Earth do, so it doesn\u2019t burn up.\u003C\/p\u003E\u003Ch2\u003EA High-Flying Research Hub\u003C\/h2\u003E\u003Cp\u003EAlthough the ISS doesn\u2019t burn up, it does experience large temperature swings. As it orbits Earth, it is alternately exposed to direct sunlight and darkness. Temperatures can reach 250 degrees Fahrenheit (121 degrees Celsius) when it\u2019s exposed to the Sun, and then they can drop to as low as -250 degrees F (-156 degrees Celsius) when it\u2019s in the dark \u2013 a swing of 500 degrees F (277 degrees C) as it moves through orbit.\u003C\/p\u003E\u003Cp\u003EThe engineers who designed the station carefully selected materials that can handle these temperature swings. The inside of the space station is kept at comfortable temperatures for the astronauts, the same way people on Earth heat and cool our homes to stay comfortable indoors.\u003C\/p\u003E\u003Cp\u003E\u003Ca href=\u0022https:\/\/www.nasa.gov\/missions\/station\/20-breakthroughs-from-20-years-of-science-aboard-the-international-space-station\/\u0022\u003EResearch on the ISS\u003C\/a\u003E has led to advancements such as improved \u003Ca href=\u0022https:\/\/www.esa.int\/Science_Exploration\/Human_and_Robotic_Exploration\/International_Space_Station_Benefits_for_Humanity\/Advanced_NASA_Technology_Supports_Water_Purification_Efforts_Worldwide\u0022\u003Ewater filtration technologies\u003C\/a\u003E, a better understanding of Earth\u2019s \u003Ca href=\u0022https:\/\/www.nasa.gov\/earth-science-at-ames\/missions\/water-and-energy-cycle\/\u0022\u003Ewater and energy cycles\u003C\/a\u003E, \u003Ca href=\u0022https:\/\/www.nasa.gov\/exploration-research-and-technology\/growing-plants-in-space\/\u0022\u003Etechniques to grow food in space\u003C\/a\u003E, \u003Ca href=\u0022https:\/\/www.nasa.gov\/humans-in-space\/three-space-station-studies-helping-scientists-understand-the-early-universe\/\u0022\u003Einsights into black holes\u003C\/a\u003E, a better understanding of how \u003Ca href=\u0022https:\/\/theconversation.com\/spending-time-in-space-can-harm-the-human-body-but-scientists-are-working-to-mitigate-these-risks-before-sending-people-to-mars-210761\u0022\u003Ethe human body changes\u003C\/a\u003E during \u003Ca href=\u0022https:\/\/theconversation.com\/does-a-year-in-space-make-you-older-or-younger-111812\u0022\u003Elong-duration space travel\u003C\/a\u003E, and new studies on a variety of diseases and treatments.\u003C\/p\u003E\u003Cp\u003ENASA plans to keep the ISS active until 2030, when all of the astronauts will return to Earth and the ISS will be \u003Ca href=\u0022https:\/\/www.nasa.gov\/news-release\/nasa-selects-international-space-station-us-deorbit-vehicle\/\u0022\u003Edeorbited\u003C\/a\u003E, or brought down from orbit by a specially designed spacecraft.\u003C\/p\u003E\u003Cp\u003EAs it comes down through Earth\u2019s atmosphere in the deorbiting process, it will enter the mesosphere, where many parts of it will heat up and disintegrate.\u003C\/p\u003E\u003Cp\u003ESome spacecraft, such as the crew capsules that bring astronauts to and from the ISS, can survive reentry into the atmosphere using their \u003Ca href=\u0022https:\/\/www.sciencedirect.com\/topics\/engineering\/heat-shield\u0022\u003Eheat shield\u003C\/a\u003E. That\u2019s a special layer made up of materials that are able to withstand very high temperatures. The ISS wasn\u2019t designed for that, so it doesn\u2019t have a heat shield.\u003C\/p\u003E\u003Cp\u003EIf you\u2019d like to see the space station as it passes over your area, you can \u003Ca href=\u0022https:\/\/spotthestation.nasa.gov\/\u0022\u003Echeck out NASA\u2019s website\u003C\/a\u003E to find out when it might be visible near you.\u003C!-- Below is The Conversation\u0027s page counter tag. 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More info: https:\/\/theconversation.com\/republishing-guidelines --\u003E\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cem\u003EThis article is republished from \u003C\/em\u003E\u003Ca href=\u0022https:\/\/theconversation.com\u0022\u003E\u003Cem\u003EThe Conversation\u003C\/em\u003E\u003C\/a\u003E\u003Cem\u003E under a Creative Commons license. Read the \u003C\/em\u003E\u003Ca href=\u0022https:\/\/theconversation.com\/how-does-the-international-space-station-orbit-earth-without-burning-up-240412\u0022\u003E\u003Cem\u003Eoriginal article\u003C\/em\u003E\u003C\/a\u003E\u003Cem\u003E.\u003C\/em\u003E\u003C\/p\u003E\u003C\/div\u003E","summary":"","format":"full_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EFlying through Earth\u2019s orbit are thousands of satellites and two operational space stations, including the International Space Station, which weighs as much as 77 elephants.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Flying through Earth\u2019s orbit are thousands of satellites and two operational space stations, including the International Space Station, which weighs as much as 77 elephants."}],"uid":"27469","created_gmt":"2024-12-16 15:34:36","changed_gmt":"2026-03-19 13:14:58","author":"Kristen Bailey","boilerplate_text":"","field_publication":"","field_article_url":"","location":"Atlanta, GA","dateline":{"date":"2024-12-16T00:00:00-05:00","iso_date":"2024-12-16T00:00:00-05:00","tz":"America\/New_York"},"extras":[],"hg_media":{"675860":{"id":"675860","type":"image","title":" The International Space Station orbits Earth. NASA\/Roscosmos","body":"\u003Cdiv\u003E\u003Cp\u003EThe International Space Station orbits Earth. \u003Ca href=\u0022https:\/\/www.nasa.gov\/international-space-station\/\u0022\u003ENASA\/Roscosmos\u003C\/a\u003E\u003C\/p\u003E\u003C\/div\u003E","created":"1734364444","gmt_created":"2024-12-16 15:54:04","changed":"1734364444","gmt_changed":"2024-12-16 15:54:04","alt":" The International Space Station orbits Earth. NASA\/Roscosmos","file":{"fid":"259534","name":"file-20241030-15-lsj7ed.png","image_path":"\/sites\/default\/files\/2024\/12\/16\/file-20241030-15-lsj7ed.png","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/2024\/12\/16\/file-20241030-15-lsj7ed.png","mime":"image\/png","size":1172087,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/2024\/12\/16\/file-20241030-15-lsj7ed.png?itok=AXQPMQ19"}}},"media_ids":["675860"],"related_links":[{"url":"https:\/\/theconversation.com\/how-does-the-international-space-station-orbit-earth-without-burning-up-240412","title":"Read This Story on The Conversation"}],"groups":[{"id":"660364","name":"Aerospace Engineering"},{"id":"658168","name":"Experts"},{"id":"1214","name":"News Room"},{"id":"1188","name":"Research Horizons"}],"categories":[],"keywords":[{"id":"187915","name":"go-researchnews"}],"core_research_areas":[],"news_room_topics":[{"id":"71911","name":"Earth and Environment"}],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Ch5\u003EAuthor:\u003C\/h5\u003E\u003Cp\u003E\u003Ca href=\u0022https:\/\/theconversation.com\/profiles\/kelly-griendling-2225547\u0022\u003EKelly Griendling\u003C\/a\u003E, Lecturer of Aerospace Engineering, Georgia Institute of Technology\u003C\/p\u003E\u003Ch5\u003E\u0026nbsp;\u003C\/h5\u003E\u003Ch5\u003EMedia Contact:\u003C\/h5\u003E\u003Cp\u003EShelley Wunder-Smith\u003Cbr\u003E\u003Ca href=\u0022mailto:shelley.wunder-smith@research.gatech.edu\u0022\u003Eshelley.wunder-smith@research.gatech.edu\u003C\/a\u003E\u003C\/p\u003E","format":"limited_html"}],"email":[],"slides":[],"orientation":[],"userdata":""}}}