How many satellites are orbiting Earth?
It seems like every week, another rocket is launched into space carrying rovers to Mars, tourists or, most commonly, satellites. The idea that "" has been around for a few years now, but just how crowded is it? And how crowded is it going to get?
I am a and director of the at the University of Massachusetts, Lowell. Many satellites that were put into orbit have gone dead and burned up in the atmosphere, but thousands remain. that track don't always report the same exact numbers, but the overall trend is clear—and astounding.
Since the Soviet Union launched Sputnik—the first human-made satellite—in 1957, humanity has steadily been putting more and more objects into orbit every year. Over the the second half of the 20th century, there was a slow but steady growth, with .
But since then, the pace has been increasing dramatically.
By 2020, 114 launches carried around 1,300 satellites to space, surpassing the 1,000 new satellites per year mark for the first time. But no year in the past compares to 2021. As of Sept. 16, roughly 1,400 new satellites have already begun circling the Earth, and that will only increase as the year goes on. Just this week, SpaceX into orbit.
Small satellites, easy access to orbit
There are two main reasons for this exponential growth. First, it has never been easier to get a satellite into space. For example, on Aug. 29, 2021, a carried several satellites—including one —to the International Space Station. On Oct. 11, 2021, these satellites will deploy into orbit, and the number of satellites will increase again.
The second reason is that rockets can carry more satellites more easily—and cheaply—than ever before. This increase isn't due to rockets getting more powerful. Rather, satellites have gotten smaller thanks to the electronics revolution. The vast majority—94%—of all spacecraft launched in 2020 were smallsats—.
The majority of these satellites are used for observing Earth or for communications and internet. With a goal of bringing the internet to underserved areas of the globe, two private companies, and together launched almost 1,000 smallsats in 2020 alone. They are each in the coming years to create what are called "mega-constellations" in low-Earth orbit.
Several other companies are , most notably .
A crowded sky
With the huge growth in satellites, fears of a crowded sky are starting to come true. A day after SpaceX launched its first 60 Starlink satellites, astronomers began to . While the impact on visible astronomy is easy to understand, radio astronomers fear they may like Starlink.
Experts have been studying and discussing the and ways the . These include reducing the number and brightness of satellites, sharing their location and supporting better image-processing software.
As low-Earth orbit gets crowded, increases, as does a of .
Future trends
Less than 10 years ago, the . Now, with and more than having at least one satellite in space, one could argue that that goal is within reach.
Every disruptive technological advancement requires updates to the rules—or the creation of new ones. SpaceX has tested ways to , and Amazon has disclosed plans to . These and other actions by different stakeholders make me hopeful that commerce, science and human endeavors will find sustainable solutions to this potential crisis.
Provided by The Conversation
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