When the UK’s first motorways opened, they were sparsely populated and unrestricted in terms of achievable top speed.
Fast-forward a few decades, and the motorway network has become congested and mired in controversy.
A similar phenomenon is taking place thousands of miles above our heads in an area of the upper atmosphere known as low Earth orbit, or LEO.
A once-empty tract of inner space is becoming crowded with thousands of broadband satellites, launched in direct competition by companies, governments and startups alike.
It’s been calculated that over 1,400 satellites were launched throughout 2021, and this record could be broken by Christmas.
Needless to say, not everyone is happy about this.
LEO speed wagons
Until the millennium, satellites belonged in geostationary orbit, 35,000 kilometres above the surface of the Earth.
At this altitude, they caused no interference to space-bound rockets, radio astronomers or stargazers.
However, the round-trip time needed to distribute data to and from GEO satellites is around two seconds.
That’s insignificant for many communication tasks, but latency of two seconds would render most online activities impractical.
As a result, when scientists and engineers have been developing satellite broadband services, they’ve favoured megaconstellations of LEO satellites, hovering 600km in the air.
Latency can be slashed to as little as 20 milliseconds, providing there’s an extensive array of satellites and ground stations.
As a result, the race is on to fill the skies with compact satellites which to deliver high-speed domestic broadband via space:
These will join thousands of other satellites already in orbit courtesy of foreign governments or companies, disruptive start-up enterprises, and so forth.
It’s been calculated that over 100,000 satellites are currently proposed for launch, though the Rwandan Space Agency has tentatively proposed its own megaconstellation of 327,230.
It’s hard to imagine why any country would need one satellite for every 39 citizens, but the International Telecommunication Union can’t reject Rwanda’s application simply for being overly ambitious.
So what’s the problem?
The atmosphere around Earth has historically been empty enough to allow unhindered space exploration and observation.
Tens of thousands of LEO satellites will affect everything from the use of space telescopes to radio astronomy and future exploration of the solar system.
A 2021 study on light pollution suggested eight per cent of the light in future night skies could eventually come from satellites.
Rocket launches may become harder, because trajectories will have to avoid densely-packed lattices of proprietary satellites, each travelling at up to 25,000 kilometres per hour.
There’s also concern about what happens when these satellites need to be decommissioned – as evidenced by the controversy last year when Russia blew up one of its own satellites.
Amazon has talked about ‘atmospheric demise’ meaning its satellites will be ‘actively deorbited’, but the potential for space junk remains.
There are already 128 million pieces of circulating LEO debris, with around 36,500 measuring over ten centimetres in length.
The International Space Station has previously been struck by flying debris which smashed straight through a robotic arm.
There are concerns that in a heavily congested LEO environment, one wayward or disintegrating satellite could create an unstoppable chain reaction of impacts and damage.
This might result in a scenario known as the Kessler syndrome, where the sky becomes so full of debris that GEO satellites can’t be launched, and space travel is forcibly halted.
The final frontier
Despite the complaints of astronomers and the concerns of scientists, the LEO space race is intensifying.
Satellite broadband (the primary reason for future launches) has a great deal of merit, offering fast, affordable broadband connectivity to parts of the planet which would be inaccessible by ground cables or relay stations.
It remains to be seen whether 100,000 satellites can comfortably co-exist without damaging one another, especially as they approach the end of their operational lives.