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The Industry

Is Space Getting Too Busy?

Satellite broadband made the news again recently when the Chinese government said it had to adjust the orbits of the Chinese space station to avoid collisions with Starlink satellites. China claims it had to make adjustments in July and October of last year.

The Chinese are not the only ones making this claim. In 2020, the CEO of Rocket Lab said that it is becoming increasingly difficult to plot a clear trajectory when launching a rocket. The head of the European space agency recently accused Starlink of “making the rules” for everybody else in the way the company is launching satellites. The recent reaction by Elon Musk to these criticisms is that space is huge and can accommodate tens of billions of satellites.

What seems to be in play here is that there are no international regulations in place to define parameters for space launches. The last international treaty on space is over fifty years old and never envisioned the huge number of satellites we’re already starting to see. Starlink alone already has over 1,700 satellites and plans to launch new satellites twice per month throughout 2022. One earlier Starlink business plan called for over 30,000 satellites.

There have already been a few notable collisions between satellites. The most recent was when the Yunhai-1 Chinese satellite was apparently destroyed in March 2021 from pieces of debris from a Russian Satellite. There is a huge amount of space debris. There are over a million pieces of debris between 1 and 10 centimeters (4 inches) in size. The U.S. Space Surveillance Network was actively tracking 15,000 objects larger than 4 centimeters as of November 2021.

Debris matters because orbiting objects are moving fast – at 150 miles above the earth, a satellite needs to be going 17,500 miles per hour to maintain orbit. A collision with even a small object can be devastating.

Scientists have been warning about space debris for a long time. In 1978, NASA scientist Donald Kessler warned that collisions in space could result in a cloud of debris that would create an effective barrier to launching rockets or sending people into space.

This is no longer a theoretical problem since much of what we do on earth is now reliant on satellites. Most of our cable TV signals are launched from space. GPS relies on a series of satellites. Ships and airplanes navigate with support from satellites. Satellites are used to track weather patterns. There are now satellites tracking and monitoring everything from the movement of foreign armies to the water temperature of the oceans.  There will soon be millions of broadband customers using low-orbit satellites.

It’s hard for any layman to understand the real risks. Some of the controversy likely stems from international wrangling between nations. But there are also a lot of notable scientists that are worried that we might make space unusable.

It will be ironic if the world solves rural broadband with satellites only to find one day that there is too much debris to launch more satellites. It seems like a remote possibility, but some scientists say it’s possible. It makes sense for the international community to come together and work out rules that everybody can agree to.

Categories
Technology

The Busy Skies

I was looking over the stated goals of the broadband satellite companies and was struck by the sheer numbers of satellites that are being planned. The table further down in the blog shows plans for nearly 15,000 new satellites.

To put this into perspective, consider the number of satellites ever shot into space. The United Nations Office for Outer Space Affairs (NOOSA) has been tracking space launches for decades. They report that there have been 8,378 objects put into space since the first Sputnik in 1957. As of the beginning of 2019, there were still 4,987 satellites still in orbit, although only 1,957 were still operational.

There was an average of 131 satellites launched per year between 1964 and 2012. Since 2012 we’ve seen 1,731 new satellites, with 2017 (453) and 2018 (382) seeing the most satellites put into space.

The logistics for getting this many new satellites into space is daunting. We’ve already seen OneWeb fall behind schedule. In addition to these satellites, there will continue to be numerous satellites launched for other purposes. I note that a few hundred of these are already in orbit. In the following table, “Current” means satellites that are planned for the next 3-4 years.

Current Future Total
SkyLink 4,425 7,528 11,953
OneWeb 650 1,260 1,910
Telesat 117 512 629
Samsung 4,600 4,600
Kuiper 3,326 3,326
Boeing 147 147
Kepler 140 140
LeoSat 78 30 108
Iridium Next 66 66
SES 03B 27 27
Facebook 1 1
 Total 5,192 9,300 14,492

While space is a big place, there are some interesting challenges from having this many new objects in orbit. One of the biggest concerns is space debris. Low earth satellites travel at a speed of about 17,500 miles per hour to maintain orbit. When satellites collide at that speed, they create a large number of new pieces of space junk, also traveling at high speed. NASA estimates there are currently over 128 million pieces of orbiting debris smaller than 1 square centimeter and 900,000 objects between 1 and 10 square centimeters.

NASA scientist Donald Kessler described the dangers of space debris in 1978 in what’s now described as the Kessler syndrome. Every space collision creates more debris and eventually there will be a cloud of circling debris that will make it nearly impossible to maintain satellites in space. While scientists think that such a cloud is almost inevitable, some worry that a major collision between two large satellites, or malicious destruction by a bad actor government could accelerate the process and could quickly knock out all of the satellites in a given orbit. It would be ironic if the world solves the rural broadband problem using satellites, only to see those satellites disappear a cloud of debris.

Having so many satellites in orbit also concerns another group of scientists. The International Dark Sky Association has been fighting against light pollution that makes it hard to use earth-based telescopes. The group now also warns that a large number of new satellites will forever change our night sky. From any given spot on the Earth, the human eye can see roughly 1,300 visible stars. These satellites are all visible and once launched, mankind will never again see the natural sky that doesn’t contains numerous satellites at any given moment.

Satellite broadband is an exciting idea. The concept of bringing good broadband to remote people, to ships, and to airplanes is enticing. For example, the company Kepler listed above is today connecting to monitors for scientific purposes in places like lips of volcanos and on ocean buoys and is helping us to better understand our world. However, in launching huge numbers of satellites for broadband we’re possibly polluting space in a way that could make it unusable for future generations.

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