Sky Matters: Space tourism and climate change

Mon, 11 Oct, 2021 - 14:00

Niall Smith

It has been interesting to watch the first excursions of “ordinary people” into “space” recently. Possibly a different definition of “ordinary” than the one I’m used to, especially when I compare my bank balance with theirs. That aside, it does underline just how quickly the accessibility to space is moving away from being the sole preserve of the large space agencies. Firstly Virgin Galactic, then Blue Origin and finally Space X – these companies have all brought “ordinary people” into “space”. And it’s that word “space” that need some careful thought. When do you actually go into “space”?

The idea of a boundary line where the Earth’s atmosphere ends and space begins evoked a lot of discussion in the early 1960’s, because spacecraft and aircraft are subject to different laws. The idea of the “Karman Line” – a height of 100km above the average sea level on Earth – was brought into being to deal with this. If you were below 100km you are an aircraft – if above 100km a spacecraft. In reality the Earth’s atmosphere peters out slowly rather than ends abruptly, so the 100km has no meaningful basis in science, only in law (and even then it’s not universally accepted – space law is an absolute minefield!).

However, the existence of the Karman line introduced a new idea – that of being an astronaut, namely someone who went into “space”. Clearly there is some kudos in being able to say that your spacecraft went above 100km, because anyone on board can then claim they are an astronaut. In the case of the recent Virgin Galactic flight, the peak altitude was nearer to 85km, while Blue Origin reached 106 km about a week later. Ostensibly the Blue Origin crew hold the bragging rights, but both flights followed the adage that ‘what goes up, must come down’ …. as they both did in less than an hour. This simple fact tells us that neither spacecraft escaped earth’s gravity sufficiently to stay aloft.

Then, in September, Space X launched a crew of four to an altitude of 575km for a period of three days. Actually, at that height the spacecraft would have stayed in orbit for years with only the very light drag of a very tenuous Earth’s atmosphere eventually causing it to return. The spacecraft had to fire a small rocket to bring it back to earth at the required time so it would land at its ocean destination and ensure safe recovery of the crew. Impressive as the Virgin Galactic and Blue Origin flights were, the Space X flight was undeniably “going into space” and in a whole different league. The four crew members can feel wholly justified in saying they went “into space” and in calling themselves “astronauts”.

Richard Branson poses for media on his Virgin Galactic Space craft at the Farnborough International Airshow 2012 in Hampshire.

All three flights represent examples of space tourism. It’s a growing area of interest amongst the mega-rich. Being super-rich isn’t yet rich enough to join this elite cohort. Given the challenges we face with combating climate change, one could argue that using a lot of energy to fly people skyward, be that into “space” or otherwise, sends mixed messages or worse. In reality, it may accelerate the development of greener propulsion technologies because rich crew members might not want to associated with anything but the most environmentally friendly spacecraft. Such technologies may be useful for high-flying super-fast aircraft, for example, that will use less fuel because they’re almost flying in space. These would be especially useful for long-haul flights, but probably less useful for a short hop across the Irish sea. For the first time since Yuri Gagarin completed a single orbit of the Earth in 1961 we’re seeing motivated, talented and determined individuals in private companies working on new modes of space transportation. And that can only give us all encouragement for the future.