Keeping Track of Satellites

The topic of satellite broadband has been heating up lately. Elon Musk’s StarLink now has over 540 broadband satellites in the sky and is talking about starting a few beta tests of the technology with customers. OneWeb went into bankruptcy but it being bought out by a team consisting of the British government and Bharti Airtel, the largest cellular company in India. Jeff Bezos has continued to move forward with Project Kuiper and the FCC recently gave the nod for the company to move ahead.

These companies have grandiose plans to launch large numbers of satellites. Starlink’s first constellation will have over 4,000 satellites – and the FCC has given approval for up to 12,000 satellites. Elon Musk says the company might eventually grow to over 30,000 satellites. Project Kuiper told the FCC they have plans for over 3.300 satellites. The original OneWeb plan called for over 1,200 satellites. Telesat has announced a goal of launching over 500 satellites. A big unknown is Samsung, which announced a plan a year ago to launch over 4,600 satellites. Even if all of these companies don’t fully meet their goals, there are going to be a lot of satellites in the sky over the next decade.

To put these huge numbers 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 reported at the end of 2019 that there have been 8,378 objects put into space since the first Sputnik in 1957. As of the beginning of 2019, there were 4,987 satellites still in orbit, although only 1,957 were still operational.

There is a lot of concern in the scientific community about satellite collisions and space junk. Low earth satellites travel at a speed of about 17,500 miles per hour to maintain orbit. Satellites that collide at that speed create many 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, 900,000 objects between 1 and 10 square centimeters, and 22,000 pieces of debris larger than 4 inches.

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 could 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.

There has only been one known satellite collision when a dead Russian satellite collided with an Iridium communications satellite over a decade ago. That satellite kicked off hundreds of pieces of large debris. There have been numerous near misses, including with the manned Space Station. There was another near-miss in January between the defunct Poppy VII-B military satellite from the 1960s and a retired IRAS satellite that was used for infrared astronomy in the 1980s. It was recently reported that Russia launched a new satellite that passed through one of StarLink’s newly launched swarms.

The key avoiding collisions is to use smart software to track trajectories of satellites and provide ample time for the satellite owners to make corrections to the orbital path to avoid a collision. Historically, that tracking role has been done by the US military – but the Pentagon has made it clear that it is not willing to continue in this role. No software is going to help avoid collisions between dead satellites like the close-call in January. However, all newer satellites should be maneuverable to help avoid collisions as long as sufficient notice is provided.

A few years ago, the White House issued a directive that would give the tracking responsibility to the Commerce Department under a new Office of Space Commerce. However, some in Congress think the proper agency to track satellites is the Federal Aviation Agency which already tracks anything in the sky at lower levels. Somebody in government needs to take on this role soon, because the Pentagon warns that its technology is obsolete, having been in place for thirty years.

The need for tracking is vital. Congress needs to decide soon how this is to be done and provide the funding to implement a new tracking system. It would be ironic if the world solves the rural broadband problem using low orbit satellites, only to see those satellites disappear in a cloud of debris. If the debris cloud is allowed to form it could take centuries for it to dissipate.

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