If you look up during a clear night, you will see thousands of twinkling lights — only some of those twinkling lights are not stars but artificial satellites. So how many satellites are in space and why?
Let’s find out.
There are hundreds of satellites revolving in the low-earth orbit (LEO), along with over 13,000 man-made objects. It is the job of the US Space Surveillance Network to keep track of any item that is larger than 4 inches. These include everything from the gigantic Hubble Space telescope to the International Space Station (ISS), to obsolete decayed satellites, rocket debris, and even things like a human glove.
For over 60 years, humans have been launching satellites into the orbit around the Earth. Soviet’s Sputnik 1 launched the very first satellite in October 1957, which orbited for three weeks and then died. In February 1958, the United States launched the Explorer 1, which actually had the useful task of transporting scientific instruments into space.
Since then, 2,218 satellites have been sent to orbit around the Earth, and almost half of them belong to the United States, according to the Union of Concerned Scientists. Some of the most famous once include the aforementioned ISS and Hubble Telescope, the Russian Mir Space Station, the 27-satellite Global Positioning System, Voyager, and Iridium. There are also a host of other satellites that are meant to provide communication, internet access, radio and TV broadcasts, and weather forecasts.
All these satellites circle the Earth from as near as 150 miles to a whopping 22,500 miles. However, most satellites around the earth are found in the LEO space. Since they are so close to Earth’s atmosphere, they need to orbit extremely fast (17,000 miles an hour) so that they are not dragged in by gravity and fall into the earth.
Some objects, however, are spent deeper into space into what is known as the geosynchronous orbit. This enables the satellite to match the orbiting speed of Earth so that it remains in the same relative position. These include the TV and weather satellites.
Hovering From the Heavens
There is a reason why satellites worth thousands, millions, and even billions of dollars are sent into space — with the exception of Sputnik 1 which was sent by the Soviets just to let the US know they did it first.
However, most other satellites have allowed humans to do a whole host of extraordinary things, from making a minutely-detailed map of Earth to making sure you can stream Netflix to trying to understand the size of the universe. In fact, satellites are often sent in groups so that they synchronize their functions and provide a service that makes our lives more comfortable.
Beyond basic consumer applications like GPS and radio and TV broadcasts, these satellites also provide a lot of benefits to governments, including collecting intelligence and military communications. Of course, since these satellites hold classified secrets and hence their exact locations are shrouded in mystery. But we do know that hundreds of such satellites currently orbit our planet.
Satellites can also do very cool things involving planet conservation. They can monitor and track the migration of birds, mark the trajectory of forest fires, prevent poaching and illegal fishing, and check carbon footprints, sea level data, and temperature trends to find out about global warming.
As technology advances and more and more companies, both private and government deploy satellites, they are becoming more and more cheap. There are tiny satellites that are worth a paltry (in satellite terms) $25,000 and even though launching them into space still takes a toll of millions of dollars, the barrier to entry for launching objects in space is getting increasingly low.
This means that more and more satellites are getting into space every year.
Elon Musk has already launched 180 satellites into space and SpaceX became the operator of the world’s biggest satellite constellation earlier this year. This is just the beginning for Starlink, Musk’s enterprising project to provide broadband internet access to every inch of the planet. In order to get that kind of capability, the company wants to launch a stunning 42,000 satellites in the next 10 years.
That’s about 17 times more than all the active satellites combined in space currently.
In January, SpaceX sent 60 more Starlink satellites into space, clinching the title of the biggest satellite operator in the world. By 2027, SpaceX is expected to launch 42,000 more satellites to create low-cost high-speed broadband that would provide global coverage, granting access to remote rural communities as well.
The satellite constellations will be deployed at three different LEO altitudes. Although the satellites are relatively small at just 200 kg, each constellation of 60 offers 1 terabit per second of bandwidth. This type of speed is enough to stream 4K HD videos by 40,000 people at the same time.
Dove by Planet Labs
Planet Lab’s is a relatively new startup that has already launched Dove satellites, which takes pictures of the planet every day. The company is set to launch a constellation of these cubesats, which only weigh a few pounds and are launched in batches.
The company sent 88 Doves into orbit in 2017, which was the largest one-time deployment of satellites on record. These satellites take 2 pictures per second of the Earth’s surface and place them in an archive. These images are used to monitor the growth and health of crops, detect illegal forestation, and provide intelligence to the military.
GPS III by Lockheed Martin
The enormously useful GPS technology was first developed in the 1970s to aid the military. But in 2000, it became commercially available to civilians, and today we use it to find the nearest café or locate the venue for a job interview.
The GPS III is the most innovative version of this technology and the company claims they are three times more accurate and resistant to hackers. The technology also provides better reception to people inside buildings.
By 2023, Lockheed Martin hopes to deploy nine more satellites so that they can complete the A block of their constellation.
While space companies are launching more and more satellites, there is a danger attached to it. Although small space debris that enters the earth’s atmosphere typically burn up, as the number of satellites grows, the risks only increase.
With thousands of active satellites and even more obsolete corpses of satellite drifting in space, it could make the LEO too crowded. As a result, the debris could interfere with satellite monitoring and future space missions. Space junk moving at thousands of miles per hour can crash into active satellite or hit an astronaut with devastating effect.
Some of the space junk also enters the earth’s atmosphere and even though NASA says no one, fortunately, has been hurt by this debris, every day a piece of junk makes its way back to Earth.
NASA has also taken some countermeasures and has blasted the junk much farther away into a graveyard orbit. This orbit is located 200 miles farther than our most distant satellite at 22,400 miles. Hopefully, this junk will not be pulled closer by the Earth’s gravity anytime soon. Now you know how many satellites are in space and why.