Environmental Management in Space
On Earth, my heritage work was often part of an Environmental Impact Study (EIS), whether for a road, mine, dam or residential development. An EIS considers all kinds of impacts: heritage, flora, fauna, noise, dust, water, employment, fire management, waste disposal, and many more.
Heritage was one small part of working out how to make sure that the development, whatever it was, didn’t do more damage than good. Governments and developers often talk about these processes as unnecessary red tape getting in the way of economic growth, but it’s all about making sure that as few people or things as possible are left worse off when something is built. I’m not saying the environmental impact process is perfect, but without it – well, you can imagine. Profit would trump every time.
For industry in space, like launching a new satellite constellation or developing a lunar settlement or mine, all of this is stripped away to bare bones. The impacts considered are liability for damaging another nation’s space assets when your space asset collides with it, or the impacts of rocket exhaust fumes on the upper atmosphere, which may have a long-term effect. People might reasonably object to space activities damaging the atmosphere or believe that adverse impacts on terrestrial ecologies are not an acceptable price to pay for a space industry. It’s pretty clear that impacts are only considered where they might affect living things.
In orbit, the equivalent of environmental management is ‘space situational awareness’. This military concept means being aware of everything around you so you can make the right strategic decisions now and into the future. It means knowing where things are in orbit – the functioning satellites and the junk, and understanding conditions, like space weather – in order to safely maximise the human use of space. Space situational awareness is the framework that people are using to try and mitigate the impacts of space junk. This is all good. However, there are no ethical obligations embedded in this concept in the same way that there are for terrestrial environments, and there’s little room for heritage or social impacts.
I suppose the difference between space situational awareness and environmental management is something like this. Think of someone running a high-precision Internet of Things operation on the farm where I grew up. An automated farm vehicle is using a sophisticated navigation device and all kinds of sensors to traverse the sand hills. It takes water measurements from the soil and determines that driving on the track after recent rains might be a bit risky and lead to getting bogged. (My father was the champion of getting bogged, and it was usually my mother who had to pull him out with the tractor.) It would pick up the location of ‘the tip’ and the obstacle course of the farm machinery graveyard. All these things are noted and avoided on the way from the house paddock to the back paddocks. In a remote office somewhere, a person receives the log of the vehicle’s trip and thinks, ‘We need to get rid of that junk.’
The first thing to note is that the presence of ‘the junk’ did not impede the vehicle’s journey; it simply had to avoid the old rotting machinery and the little fenced-in paddock. No damage had been caused, no-one and nothing was hurt. The assumption is made that because it’s abandoned, it has no value. But unlike litter, it’s not out of place: it’s as much in its place as it could be. The vehicle could detect the locations and materials, but it couldn’t relay the history or the meanings of the objects or places. It didn’t register that the machinery included a stump-jump plough from the 1870s and a 1980s Massey Ferguson header, or that little kids played on these silent behemoths in the 1970s. The junk in ‘the tip’ was not seen as the accumulated evidence of generations of women marrying into the land and battling isolation, mouse plagues, children dying of measles before the vaccines were invented, poverty when the rains didn’t come, and working from dawn until midnight seven days a week. Beyond the limits of the vehicle’s sensors were the stone tools discarded by Wiradjuri people before they were driven off or killed in frontier violence. Without a human eye to see the telltale angles and curves of human manufacture, they’re just broken rocks, and the hearths where people cooked dinner and chatted about the day before turning in could be from any bushfire event.
If this junk was ‘cleaned up’, the landscape would be less rich, but no less shaped by human hands. This doesn’t mean that the objects need to be conserved, though. The Burra Charter says we should do ‘as much as is necessary and as little as possible’ to retain cultural significance. Every family farm has its machine graveyard and rubbish tip. It’s OK to let them decay, to let the wind and the rain take them. We don’t need to destroy everything currently classed as space junk either – over 95 per cent of all the stuff up there– to reduce the risks of collisions from orbital debris. We can do it in a smart way by thinking through all the heritage and environmental issues.
To study the junkyard of Earth orbit, I use documents and images that record the early spacecraft, as if they were stone tools, and use them to reconstruct the rest of the story. In other words, the world view that made a spacecraft look like this and not that. I have to think about what they meant back then, and what they mean now, as well as their significance as individual objects and as an assemblage. To work out what they look like en masse, my tools also include tracking data, simulations and visualisations.
So far, the existence of cultural heritage values for the stuff we now call space junk has barely been considered. But when you think about it, some of the artefacts that hurtle through space, far above our heads, are among the most significant in human history. Those artefacts represent the technologies and trajectories that shaped the world we live in, the era in which humanity truly became spacefaring.
Heritage management is now a routine part of any terrestrial industry or development, and space industry should be no different. This doesn’t have to mean compromising mission safety or the space environment – we just need to plan for the removal of space junk in the right way. Not all space junk was created equal; some bits are clearly more significant than others. Part of what makes these satellites significant is that they are still up there. Do we really want to send them back into the atmosphere or remove them from their original orbit if we don’t have to? No matter what kind of orbital debris removal scheme is implemented, it must be designed to avoid operational spacecraft anyway, so it’s a small leap to ensure precious artefacts are also preserved in their natural setting.
It will be a while before we see large-scale space debris removal. We should use this time to plan a cultural heritage management strategy that will be both effective and practical. Our approach should be not to look at the amount of debris in orbit, but at the risk instead: how likely is a collision with space junk? Most of the space junk in Earth orbit is actually very tiny – millions of fragments less than a centimetre in size. Collisions with the small stuff happen constantly but don’t generally cause mission failure or explosion. The middle-sized stuff (1–10 centimetres across) is more of a problem: there’s a higher likelihood of collision, and the damage caused will be greater. However, whole spacecraft are numerically in the minority so while a collision would be catastrophic, it’s much less likely to happen.
The risk factors also depend on the orbit, as some orbits have a much higher density of debris than others. For instance, near-circular orbits below 2,000 kilometres, at around 20,000 kilometres, and at 36,000 kilometres from Earth have the highest density of large debris over 10 centimetres. The risks of collision are obviously greater in these locations. If we’re going to make decisions about what to destroy, let’s do it from an informed position. We need to know which objects do have cultural significance in orbit, from local, national and global perspectives. And we need to understand how their changing orbits may relate to collision risks. But before we do this, it might be as well to think more about the definition of space junk as something that does not now, or in the foreseeable future, serve a useful purpose. Isn’t representing the cultural heritage of a nation or a community, and making people feel involved in space, useful? If we acknowledge this, then many of the old defunct satellites have a very important function indeed. Like the gods who don’t die as long as people believe in them, you might question whether these satellites are really as dead as they seem.
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Alice Gorman is a leader in the emerging field of space archaeology. Her work has been featured in National Geographic, the New Yorker, and the Atlantic. She is a Senior Member of the American Institute of Aeronautics and Astronautics and Senior Lecturer at Flinders University, Adelaide. She tweets as @drspacejunk.