STAR LIGHT, STAR BRIGHT

I’m a real sucker for a dark, clear, moonless sky. Standing under a sky like that, the breeze cool on your face, a hush over the landscape, the constellations hard to spot due to an abundance of fainter stars in all directions, and the Milky Way arching over you with so much detail it looks three-dimensional, it can be simply breath-taking. A balm to the soul in a troubled and relentless world.

We all know skies like this can be hard to find now — as towns have grown and spread, they have brought with them their streetlights and illuminated buildings, as well as the dust and airborne pollutants that then reflect and scatter that light. Many people in the UK have never even realised what they’re missing, have never stood out under such a magnificent sky — and a startling fact is that 80% of the worlds population now live with light pollution of some sort or another. The impact goes far wider than aesthetics — extraneous light is linked to impaired sleep patterns and increased risks of some cancers in humans, to quite dramatic impacts on the natural ecosystem that go well beyond moths immolating themselves on your nearest light bulb at night, and of course the immense carbon cost of all that wasted energy. This is serious at a time when we need to effect a transition to net zero, and at pace. Thankfully there are campaigning organisations such as the International Dark-Sky Association (https://darksky.org/), and closer to home Dark Skies Matter (https://www.darkskiesmatter.org.uk/) and the Commision for Dark Skies (https://britastro.org/dark-skies/) and I would urge anyone wanting to know more to check out their websites. On a positive note, the combination of carbon cost and financial cost (especially now) does seem to be bearing some fruit. For example, near where I’m sitting typing this, a rural section of the A4 sees its streetlights turned off in the wee hours of the morning when, frankly, they’re really not needed. Between actions like that, a move to LEDs, and better shielding of lights, we can make a difference.

However, another threat is brewing. I first got an inkling when listening to an episode of that excellent radio show, The Infinite Monkey Cage. One of the guests was Carolyn Porco, that amazing planetary scientist who has given us so many stunning images from the Voyager and Cassini probes amongst others. It was a good natured and positive discussion, as is generally the case on that show with Dr Brian Cox and Robin Ince affably riffing off each other, but at one point Carolyn get very animated and angry at what private space exploration was doing to our night sky.

That caught me out. In general, I’ve had a very positive view of private exploration of space, seeing it as a necessary development that moves space exploration onto a sustainable footing rather than being at the whim of taxpayer funded national space agencies whose budgets can fluctuate based on the politics of the day. Back in the early days of space exploration, NASA absolutely blazed a trail, and it is still capable of amazing feats. Just look at what is coming back from the Juno probe around Jupiter, the Curiosity and Perseverance rovers currently traversing Mars, or the James Webb Space Telescope. But in other areas, such as the grunt work of hoisting payloads into orbit, I’m not sure they should be playing that game now. The current programme to return humans to the Moon (Artemis) is a case in point. I do wonder whether NASA would already have got back had it elected to use two of Elon Musk’s existing Falcon Heavy boosters (a large amount of which is reusable), docking in earth orbit before heading off to the moon, rather than developing their own new booster which so far has not successfully flown, is inordinately expensive and is not reusable. The middle bit is critical. If it’s expensive and bespoke to this project, what happens if NASA gets asked to tighten its belt? Ouch.

But mention of Musk’s Space X does bring up issues. I am not the only astronomer troubled by their Starlink programme. With approaching 3000 satellites already launched — and thousands more still planned — and aiming to give near global internet coverage, Starlink’s aims are arguably laudable and certainly the Ukrainians would agree, leaning on it as they do for critical internet coverage during the ongoing tussle with Russia. But these thousands of satellites, whilst relatively rapidly fading from naked eye view after launch, do turn up in, I would suggest, 1 in every 2 of any wide-angle photographs of the sky (including in the photo I’ve added to this article, just below the Milky Way in the centre of the image). For professional astronomers with sensitive equipment, these are more than a nuisance, ruining not just observations but potentially sensitive and expensive equipment. More worrying still, other companies are getting in on the same act. Amazon have their proposed Kuiper network, and the UK government has a share in OneWeb that has already hoisted several hundred satellites into orbit. All this is just for internet coverage, of course. Combined with all the other commercial and national space activity, from weather forecasting to spy satellites to GPS, it’s getting very busy up there.

But I don’t think this was what Carolyn was upset about. The reason I think she was upset popped through my letterbox a few days later in the 17th September edition of New Scientist. Under the headline “Massive satellite could outshine all the starts and planets in the night sky”, it discussed BlueWalker 3, a satellite from Texas-based AST SpaceMobile that was launched by, what else, one of Elon Musk’s Space X Falcon boosters. This is a test satellite for 4G cell phone coverage, but the kicker is that it requires an antenna 64 square meters in size. The size of a squash court, it would reflect a lot of light, making it brighter than Venus and, as any astronomer knows, Venus is bright enough to cast a faint shadow from very dark sites. This one is bright enough to be seriously disruptive for professional astronomy, will stand out under any dark sky for anyone just looking up, and on top of the visual brightness, it’s expected to generate enough energy in its beam to seriously impact any attempts at radio astronomy whilst it’s passing overhead. But, if the test is successful and the planned deployment of 100 larger satellites goes ahead, these larger satellites could be getting closer to the brightness of the moon. Now we’re starting to get well past just an irritant to space imaging and rather to be seriously impacting the night sky full stop. Never mind worrying about cowled streetlights — these will be multiple lights you can’t shield from as they will be hundreds of miles up and there, every night, washing out the fainter stars and potentially triggering many of the health and environmental impacts we see with artificial light down on earth.

The Federal Communications Commission in the US granted the licence for BlueWalker3 and there is no guarantee they will allow the licence for the full deployment later planned, but clearly AST believe they would, otherwise they wouldn’t fork out for such a trial. And this comes to the nub of the problem — we don’t have a developed Space Law sufficient to handle and decide on these issues. Space Law does exist, codified in the Outer Space Treaty, and the UN has a committee on the Peaceful Uses of Outer Space, but understandably the UN’s powers are limited and as no-one owns Outer Space, per se, (be they nations or corporations) we end up with the Tragedy of the Commons I mentioned in my previous article “Just because you can, doesn’t mean you should”. Right now, to an extent, it’s a free for all up there. A whole raft of spacecraft creating an enormous amount of light could be proposed, and so far the law cannot really put limits on what is done. On several occasions there have been proposals for giant solar power stations in orbit that yes, could seriously help the move to net zero, but potentially could do so at the cost of completely losing the night in the process.

Critically, though, this is about more that light. I mentioned it’s getting busy up there. That’s an understatement. As well as operational satellites in orbit, there are dead or obsolete satellites, spent rocket boosters, lost gloves, a monkey wrench, and lots of debris including that from spent boosters that have then exploded as the propellants left in them corroded the structure, came into contact, and detonated. Sure, space is big, and some of these things are small, but the dangers are very real. A fleck of paint moving at a relative speed of 30,000 mph has enough momentum to puncture an astronaut’s space suit with lethal implications for the unfortunate occupant, and the aforementioned wrench could easily puncture a nice big hole in the walls of the International Space Station (the ISS). NASA and others are increasingly busy trying to track all this debris — more than 27,000 items currently are tracked by NASA, but only the larger items (generally larger than 10cm in size) are effectively trackable. As it is, the International Space Station now needs to manoeuvre two or three times a year as there is an incoming piece of debris that just looks too close for comfort — and that’s only the times when they find out in enough time to make the manoeuvre, and it’s big enough to spot.

The nightmare scenario is that we lose control over what’s happening in orbit completely, and potentially lose access to the whole region — something known as Kessler Syndrome. That is when debris impacts with other satellites in space, destroying those satellites and creating more debris. The result is a chain reaction that rapidly fills Low Earth Orbit with fast moving and lethal debris, making it completely unsafe to use. Never mind no more manned spaceflight. It would mean no weather satellites, no communications satellites, no GPS, nothing. We would be thrown back to the 1950s in a world that has come to depend on the services supplied from space. This is not an idle threat — it’s one taken very seriously by NASA and other national agencies. In 2009 a defunct Russian spacecraft collided with a US Iridium commercial satellite and the results added 2,300 trackable pieces of debris to orbit. A 2007 Chinese test of an anti-satellite missile destroyed an old, defunct weather satellite, but added a further 3,500 pieces. And even now, it goes on. Last November, Russia launched an anti-satellite missile that destroyed one of their satellites in a test that was so successful, the resulting cloud of debris quickly threatened the ISS, forcing the astronauts (including some Russian cosmonauts) to shelter in the Dragon and Soyuz capsules for two hours, fearing they might have to abandon the outpost altogether. Whilst they did later return, some planned activities subsequently needed to be delayed or scrubbed, and the risk is clear. If a piece of that debris hit another satellite and destroyed that, the exponential rise in debris being created could get out of control very quickly. Even if it doesn’t happen just yet, sooner or later an astronaut will likely lose their life to one of these pieces of debris

Space Law needs to be developed rapidly, whether to counter the environmental threat of BlueWalker and its proposed successors, or the physical threat to access to space from the Kessler Syndrome. Work is ongoing, for example the projects led by the McGill Institute of Air and Space Law (such as https://spacelawpedia.com/). There is even an ISO on space junk — 24113 — but it’s absolutely a voluntary code. But it’s going to be tough to make rapid progress given the diverse nature of threats, the fast pace of progress in the commercialisation of space, and the not 100% helpful geopolitical situation the world finds itself facing currently. Things don’t look good with Russia threatening to withdraw from the ISS, and with China never joining in the first place, pursuing their own Tiangong space station programme instead. To the pessimist, it feels like we’re moving away from co-operation, not towards it. But optimism states we will get there — law often seems to proceed in fits and starts, with major shifts coming once a disaster happens. Maybe something that threatens to trigger Kessler syndrome but doesn’t, or the launch of BlueWalker and the clear implication of what this could mean, will move things forward. We can hope, in the same way the Titanic disaster quickly tightened up regulations around lifeboats. Maybe not how you’d rather it was done, but at least it was done.

Until then, I leave you with one final uplifting thought. The October 2022 edition of Prospect magazine came with the nugget of information that, over the next decade, there’s a roughly 10% chance that debris from rocket launches and landings will kill someone on earth. Duck, everyone.