Photo Credit: NASAA few years later than expected, the European Columbus module for the International Space Station has been launched to space a few hours ago on what the space shuttle (aka the most spectacular Helvetica carrying vehicle). That’s great, not only for the sheer excitement of such a rocket launch and the experiments they’ll be able to carry out in the module. But also because I’ve been quite interested in the project since doing an internship at the company building Columbus some years ago.
While I didn’t exactly design or build the thing myself (surprise!), I did research some of the strategies for maintenance of the module as well as ways to simulate them. While this probably is fairly standard engineering stuff it still was a rather interesting project to work on. Let’s just say that getting a decent level of reliability in space is fiendishly difficult. Not just because everything is technically more difficult than it would be down on earth with gravity and an atmosphere, but also because you face plenty of additional constraints.
Just think about this: Space on the ISS is extremely limited and likewise is the amount of mass you can lift up there. Thus you can’t just cram huge numbers of redundant systems on there to make things more reliable. And you also can’t just keep spare parts for everything that might break around. So now assume that a part breaks which leads to the failure of some part of the system. Quite possibly you won’t have a spare part around. As you are in space you can’t just call your automobile club and they’ll show up within a few hours. You’ll have to wait for the next rocket, quite possibly the Space Shuttle being launched in your direction the next time. As things were originally planned that meant up to six months of waiting. And possibly more as it could be possible that the part in question can’t be prepared or even manufactured before the next launch or, if Murphy’s Law strikes badly, that the capacities for taking spare parts along are already used for other parts.
This is turn means that – with an assumed mission time of a decade – a system’s failure can easily lead to a downtime of that system which amounts to five per cent of the whole mission time, thus reducing its availability to a meagre 95%. Bang! Just imagine that a certain percentage of errors a web server runs into would cause a service not to be available for a few months. That’d certainly make it harder to achieve 99, 99,9 or 99,99% availability rates…
Anyway when working there I also had to research a number of things from NASA websites. Perhaps not all of them have arrived in the 21st century design-wise, but it quickly became apparent that they are well made and filled with plenty of information. A real marvel on the web. It really made me wonder whether you’d see the same dedication and quality if things were run by private companies rather than a proverbially inefficient government organisation. As things are the former’s priorities would certainly include making money for their shareholders in the short term. While government organisations have to do their jobs and stick to all sorts of rules about informing the public, providing education and so on and so on. Of course this can be seen as a giant PR machine as well, but at the end of the day it seems too long-term a thing and too much public accountability for that to be the only thing they’re working at.
I conveniently ignored all the issues that make spaceflight a bit dodgy – from the military industry angle to the question whether manned space flight makes that much sense.
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