They were a century late, but the gleaming dreams of the 1950s and 60s finally came true. By 2050, space travel was at that delicate moment between adventure and commonplace, a time when tens of thousands lived and worked in orbit, and millions travelled up and down the gravity well in spaceplanes, laser launchers, and vertical take-off and landing (VTOL) rockets.
'Orbit' didn't simply describe a path around Earth; it had become a place that provided unparalleled freedom and immunity. If you were rich or smart or valuable enough, you could earn yourself a spot on the frontier — but unlike the old American frontier, orbit had all the comforts of home with none of the downsides. There was no climate change, no disease, no violence to fear, and advanced automation to spare in the form of self-replicating drones and soft AIs. Orbit held out the promise of a limitless future, uncoupled from Earth.
There were a few unique risks, though. Much collective effort was spent cleaning up debris to prevent it from colliding with any of the hundreds of space stations. This process had begun decades earlier, with the mandatory (and occasionally forcible) de-orbiting of obsolete and errant satellites, and culminated in 2049 with the introduction of the laser 'space cleaner', a ground-based system that would fire laser pulses at debris, causing it to slow down and eventually burn up in the atmosphere.*
The space cleaner, however, did not herald an age of orbital safety. Quite the opposite: it gave orbital administrators a dangerous overconfidence in their abilities. When combined with an unusual lack of accidents in the past two decades, this overconfidence led to a runaway boom in orbital manufacturing and construction. No-one wanted to spend any more on cleanup than they were legally required to, and unfortunately, the laws were written with the manufacturers’ financial interests in mind.
At 04:38:14 UTC on July 28th, 2052, the Cascade began.
A meteoroid the size of a golf ball smashed into the fuel tank of an unmanned construction vessel. The vessel exploded, shattering the kilometre-wide solar power station it was attached to. More than 250,000 pieces of shrapnel, from tiny flecks of paint to metres-long truss segments, were sent careening across low Earth orbit.
The collision was quickly identified as an ablative cascade, a runaway disaster that posed a major threat to all orbital structures between 300 kilometres and 600 kilometres from the Earth’s surface. While the shrapnel could take weeks to fully spread across orbit, every station made the immediate decision to evacuate or, in a few cases, to boost their way above the main debris cloud**. Within 48 hours, more than 90 percent of the orbital population had descended on emergency inflatable re-entry vehicles, creating thousands of shooting stars in the skies across the globe.
A few stayed in orbit to oversee the evacuation and to help those who couldn't safely leave. They spoke of solar panels sheared in half, radiators splintering apart, windows spiderwebbed with thousands of tiny cracks. Habitable modules in orbit were generally well-shielded against meteoroids, but without solar power or radiator heat sinks they would become coffins. Every impact only added to the cloud of debris.
In total, 692 people died in the first two weeks of the Cascade out of the 53,819 who had been in orbit. Many of those deaths were due to re-entry damage or lifeboat recovery problems. Despite a Herculean international effort, not all of the thousands of survivors who splashed down in the oceans could be rescued in time.
The Cascade also destroyed a significant proportion of humanity's high-tech research and mining infrastructure, plunging the world economy into a brief recession. Luckily, the majority of essential orbital infrastructure remained untouched in their higher geosynchronous or L5 orbits, so it could have been much worse. As it was, the thousands located on the Moon and in higher orbits had essential supplies cut off for months as launches were too risky. Not even the largest stations and bases were truly self-sufficient yet, so the lack of supplies hit living standards hard.
Efforts to clean up orbit began immediately, with agreement quickly reached on a major international expansion of the laser 'space cleaner' programme. By 2054, enough debris was removed or naturally de-orbited that more substantial unmanned debris-catchers could be launched; and by the early 60s, much of the orbital infrastructure had been rebuilt, with a renewed emphasis on active safety mechanisms, including station-based debris defence systems.
Today, we don't allow any piece of debris to last in orbit for longer than a few hours. It is hard to imagine that the Cascade could happen again — but in case we forget the fragility of orbit, all we need to do is to look up into the night sky. There, we'll see a brilliant, lonely star, a monument made of 692 mirrors.
The monument is a living archive. Every day, it transmits the memories of the Cascade's victims, such as this one, over and over again.
x Today's menu will - ALERT ALERT ALERT. Please evacuate to IRV-A35 immediately. This is not a drill. Repeat, this is not a drill.
x 60 seconds until undocking. Life support online. Shall I place a call to your husband?
- ...Yes, I’m there now, don’t worry! These IRVs have been tested dozens of times. I'll see you soon, I will. I promise. I love you. I have to go now, we’re launching.
x Communications disrupted. Attempting to reconnect.
x Heat shield inflation successful. Beginning de-orbit burn in 25 seconds. Prepare yourself for high G acceleration. You may pass out.
x Beginning re-entry. Communications may be restored briefly.
- ...can you still hear me? I just want you to know, I'm so proud of you. I know we haven't talked much since you left, but I couldn't have asked for a better -
x Warning, heat shield has been compromised. Navigation attempting to compensate. Prepare for extreme -
*The basic technology had been worked out years before, but getting everyone to agree on how it would operate took much longer due to fears about how unscrupulous organisations might choose to use it.
**Practically all stations had advanced Whipple shielding against debris, but they hadn't been prepared for an event of this scale.