Orbiting on a thread

It’s winter in Australia, and I’ve just returned from a week walking the icy trails of Tasmania, a picturesque escape that I highly recommend.  Part of the appeal was disconnecting: no meetings, no messages, just crisp air and remote tracks beyond mobile range.

Then, mid-step on a frosty path, my phone buzzed.  And buzzed again.  Satellite messaging had been quietly switched on, and even here, messages found me.  Our lives are now inseparable from our devices including camera, map, emergency beacon, and relentless inbox all in one pocket-sized tether.

When satellite internet first appeared on planes, it felt like a novelty, occasionally useful.  Now, it’s essential, and flights without it feel like an inconvenience to work around.  The same shift is happening on the ground.  Satellite coverage is reducing the need for full-service terrestrial networks and deepening our reliance on the small boxes orbiting just hundreds of kilometres above us.

But what happens if, or when, they stop?

The impact would be far more dramatic than we think.  If our satellites suddenly stopped working, society would experience immediate and widespread disruption.  Global positioning systems (GPS) would fail.  Remote communications would drop out.  Financial markets would falter as the precise timing signals used for transactions disappeared.  Weather forecasting would become drastically less accurate, reducing our ability to prepare for storms or monitor climate patterns.  Surveillance and early warning systems for national security would go dark.  But worse, as the satellite services improve, we become more reliant and gradually transfer terrestrial infrastructure to the sky, increasing the risk if something were to go wrong.

There are alternative technologies to most satellite services: communications via terrestrial fibreoptic cable and cellular towers, locations via beacons, timing via ground-based devices, weather observations from geostationary or terrestrial observations, and so on.  However, the rapidly falling cost of launching ever-smaller assets into low Earth orbit has meant that this space immediately above our heads (160 to 2000 kilometres) is quickly rendering older technologies redundant.  Legacy infrastructure is either being shut down or not expanded at the same rate.

The most immediate threat is bad solar weather.  Solar flares have long been known to disrupt Earth-based systems.  The most powerful on record disrupted early telegraph networks in 1859, the “Carrington Event,” named after the astronomer Richard Carrington, who happened to observe it.  We still don’t know if that was a once-in-a-millennium anomaly or a warning of more to come.  In 2022, even a modest flare caused the largest single satellite loss to date, when 40 newly launched Starlink satellites burnt up after being dragged into the atmosphere.

But even more dangerous than a flare is the potential for catastrophic gridlock surrounding our planet.  As early as the 1970s, Donald Kessler and Burton Cour-Palais warned of cascading satellite collisions, creating a dense, self-sustaining debris field in low Earth orbit.  If triggered, this “Kessler syndrome” (as this scenario is commonly called) could render critical orbital zones unusable for decades, if not longer.

How worried should we be?  A major solar flare could cause hundreds of billions, even trillions, of dollars in damage, knocking out power grids, satellite systems, and communications for weeks, months or even years.  Yet our understanding is based on just a handful of data points including the 1859 Carrington Event, evidence of a similar level flare in 774 AD detected in tree rings, and a near miss in 2012 when a massive solar storm narrowly avoided Earth.  Based on this limited evidence, NASA has estimated about a 10% chance per decade of a Carrington-level event, a roughly 50/50 probability over the next half century.  It’s not inevitable, but it’s a risk too large to ignore, and one we should be preparing for now.

Even more serious is the risk of realising the Kessler syndrome, where cascading satellite collisions create a storm of space debris that fragments and renders the orbits we rely on unusable.  NASA and the European Space Agency track over 30,000 objects in orbit, and SpaceX has reported more than 25,000 collision-avoidance manoeuvres for its Starlink satellites.  If debris density crosses a tipping point, safe navigation through low Earth orbit could become little more than a lottery.

And then there are the risks we don’t even know about given how new our space-based technologies are.  For example, some media reports suggest that while asteroid 2024 YR4 is no longer a direct threat to Earth, it could hit the Moon in 2032 and shower Earth with debris.  These small rocks would cause little harm to us within the atmosphere but could be a deadly risk to anything in space.

These risks are not independent.  With satellite operators active in collision avoidance, the chances of catastrophe exponentially increase if satellites are even temporarily without ground-based guidance while recovering from a solar flare or other damage.  While it is hard to truly know the chances of these events occurring, the one thing that is certain is that reducing space junk and providing greater ability to manoeuvre space-based assets will reduce the risk and provide options in the event of the worst occurring.

Companies like Astroscale and ClearSpace are developing robotic capture systems designed to remove defunct satellites and large debris.  Meanwhile, Space Machines Company, based in Australia, has launched its Optimus servicing vehicle, capable of inspecting, repositioning, and even refuelling satellites on demand, laying the foundation for an orbital maintenance economy.

At the same time, firms such as LeoLabs are building the tracking infrastructure that underpins safe navigation in increasingly crowded orbits.  Others, like Starfish Space and D-Orbit, are investing in “space tugs”, autonomous vehicles that can relocate assets or shepherd them to deorbit.  These technologies represent a vital layer of redundancy and control in an ecosystem that has historically been passive once launch is complete.

As commercial activity in space accelerates, these capabilities won’t just be valuable, they’ll be essential.  Perhaps managing our immediate space neighbourhood matters more than planning future missions to the Moon or even Mars!