Many satellites orbiting Earth are tiny, like this cubesat released by the International Space Station.
This article was first published by The Conversation. Space.com's Expert voices: Op-Ed and Insights was contributed by the publication.
Supriya Chakrabarti is Professor of Physics at University of Massachusetts Lowell
Every week it seems that another rocket launches into space with tourists, rovers to Mars and, most importantly, satellites. Although the idea of "space getting crowded" is a well-known fact, how crowded is it really? How crowded will it get?
Professor of Physics and Director of the Center for Space Science and Technology, University of Massachusetts Lowell. Although many satellites have been lost to the atmosphere after being placed into orbit, thousands of them remain. Although the exact numbers are not always reported by the same groups that track satellite launches, the overall trend is consistent and impressive.
(Image credit: The Conversation).
Every year, mankind has been steadily putting more objects in orbit since 1957 when the Soviet Union launched Sputnik, the first human-made satellite. From the beginning of the 2000s, the number of satellites launched per year was between 60 and 100.
Since then, however, the pace has been steadily increasing.
In 2020, there were 114 launches that carried more than 1,300 satellites into space. This surpasses the original 1,000 satellites per annum mark. 2021 is a year that stands out from the rest. Since September 16, approximately 1,400 satellites had already started to circle the Earth. This number will continue to grow as the year progresses. SpaceX has launched 51 Starlink satellites to orbit just this month.
Technology has become ever smaller, which has resulted in tiny satellites such as the one that students are currently working on. (Image credit to Edwin Aguirre/University of Massachusetts Lowell. CC BY ND.
Access to orbit via small satellites
Two main reasons explain this rapid growth. It is now easier than ever to launch a satellite into orbit. On Aug. 29, 2021, the SpaceX rocket carried several satellites, including one that I built with my students, to the International Space Station. These satellites will be placed into orbit on October 11, 2021. The number of satellites will then increase.
Second, rockets are able to carry more satellites faster and more cheaply than ever before. This is not due to rockets becoming more powerful. Electronics revolution has made satellites smaller. The majority of spacecraft that were launched in 2020 comprised smallsats satellites weighing less than 600 kilograms (around 1,320 pounds).
Most of these satellites can be used to observe the Earth, or for internet communications. Two private companies, Starlink By SpaceX and OneWeb, launched nearly 1,000 smallsats together in 2020 with the goal of connecting the world's underserved areas. Each company plans to launch more satellites than 40,000 in the next few years in order to create mega-constellations low-Earth orbit.
Other companies are also eyeing the US$1 trillion market. Amazon is one of them, with Project Kuiper.
Un crowded sky
The fears of a crowded skies are beginning to be realized with the rapid growth in satellites. Astronomers started to notice that the satellites were blocking out stars just a day after SpaceX launched its 60 Starlink satellites. Although the impact on visible astronomy can be understood, radio astronomers worry that they could lose 70% of their sensitivity to certain frequencies because of interference from megaconstellations such as Starlink.
Experts are currently discussing potential problems and possible solutions with satellite companies. These include reducing satellite brightness and sharing their locations, as well as supporting image-processing software that is more accurate.
As low-Earth orbit becomes more crowded, there is greater concern about space debris and the possibility of collisions.
Future trends
The goal of democratizing space was not realized until less than ten years ago. With student projects on the space station, and over 105 countries possessing at least one satellite in orbit, it is possible to argue that this goal is achievable.
Each disruptive technological advance requires changes to existing rules or the creation new ones. SpaceX has developed ways to reduce the Starlink constellations' impact, while Amazon plans to deorbit its satellites in 355 days. These actions and others by other stakeholders give me hope that commerce, science, and human endeavours will find sustainable solutions for this potential crisis.
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