Science & Nature

How many satellites are orbiting Earth?

Thousands of the satellites orbiting Earth are small – like this cubesat seen here being released from the International Space Station.

Thousands of the satellites orbiting Earth are small – like this cubesat seen right here being launched from the International Space Station.
(Image credit score: NASA, CC BY-NC)

This article was initially printed at The Conversation. The publication contributed the article to’s Expert Voices: Op-Ed & Insights.

Supriya Chakrabarti, Professor of Physics, University of Massachusetts Lowell

It looks as if each week, one other rocket is launched into house carrying rovers to Mars, vacationers or, mostly, satellites. The concept that “house is getting crowded” has been round for a couple of years now, however simply how crowded is it? And how crowded is it going to get?

I’m a professor of physics and director of the Center for Space Science and Technology on the University of Massachusetts, Lowell. Many satellites that had been put into orbit have gone useless and burned up within the ambiance, however 1000’s stay. Groups that observe satellite tv for pc launches don’t all the time report the identical precise numbers, however the general development is evident — and astounding.

number of satellites orbiting Earth

(Image credit score: The Conversation)

Since the Soviet Union launched Sputnik — the primary human-made satellite tv for pc — in 1957, humanity has steadily been placing an increasing number of objects into orbit yearly. Over the the second half of the twentieth century, there was a sluggish however regular development, with roughly 60 to 100 satellites launched yearly till the early 2010s.

But since then, the tempo has been growing dramatically.

By 2020, 114 launches carried round 1,300 satellites to house, surpassing the 1,000 new satellites per 12 months mark for the primary time. But no 12 months previously compares to 2021. As of Sept. 16, roughly 1,400 new satellites have already begun circling the Earth, and that may solely improve because the 12 months goes on. Just this month, SpaceX deployed one other 51 Starlink satellites into orbit.

The ever-shrinking size of technology has led to tiny satellites like the one students are working on here.

The ever-shrinking measurement of expertise has led to tiny satellites just like the one college students are engaged on right here. (Image credit score: Edwin Aguirre/University of Massachusetts Lowell, CC BY-ND)

Small satellites, easy accessibility to orbit

There are two most important causes for this exponential development. First, it has by no means been simpler to get a satellite tv for pc into house. For instance, on Aug. 29, 2021, a SpaceX rocket carried a number of satellites — together with one constructed by my college students — to the International Space Station. On Oct. 11, 2021, these satellites will deploy into orbit, and the variety of satellites will improve once more.

The second cause is that rockets can carry extra satellites extra simply — and cheaply — than ever earlier than. This improve isn’t as a consequence of rockets getting extra highly effective. Rather, satellites have reduced in size due to the electronics revolution. The overwhelming majority — 94% — of all spacecraft launched in 2020 had been smallsats — satellites that weigh lower than round 1,320 kilos (600 kilograms).

The majority of those satellites are used for observing Earth or for communications and web. With a purpose of bringing the web to underserved areas of the globe, two non-public corporations, Starlink by SpaceX and OneWeb collectively launched virtually 1,000 smallsats in 2020 alone. They are every planning to launch greater than 40,000 satellites within the coming years to create what are known as “mega-constellations” in low-Earth orbit.

Several different corporations are eyeing this US$1 trillion market, most notably Amazon with its Project Kuiper.

A crowded sky

With the massive development in satellites, fears of a crowded sky are beginning to come true. A day after SpaceX launched its first 60 Starlink satellites, astronomers started to see them blocking out the celebs. While the impression on seen astronomy is straightforward to know, radio astronomers concern they might lose 70% sensitivity in sure frequencies as a consequence of interference from satellite tv for pc megaconstellations like Starlink.

Experts have been finding out and discussing the potential issues posed by these constellations and methods the satellite tv for pc corporations might handle them . These embody lowering the quantity and brightness of satellites, sharing their location and supporting higher image-processing software program.

As low-Earth orbit will get crowded, concern about house particles will increase, as does a actual chance of collisions.

Less than 10 years in the past, the democratization of house was a purpose but to be realized. Now, with scholar initiatives on the house station and greater than 105 international locations having at the very least one satellite tv for pc in house, one might argue that that purpose is inside attain.

Every disruptive technological development requires updates to the foundations – or the creation of recent ones. SpaceX has examined methods to decrease the impression of Starlink constellations, and Amazon has disclosed plans to deorbit their satellites inside 355 days after mission completion. These and different actions by completely different stakeholders make me hopeful that commerce, science and human endeavors will discover sustainable options to this potential disaster.

[The Conversation’s science, health and technology editors pick their favorite stories. Weekly on Wednesdays.]

This article is republished from The Conversation beneath a Creative Commons license. Read the authentic article.

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Professor of Physics, University of Massachusetts Lowell

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