Design the mechanical structure, put some electronics inside and top the whole thing off with a nice piece of software. That’s pretty much all you need for a space project, right?
Well, not quite. These are the obvious main tasks, but there is a whole lot more to do. I realised that once again yesterday, when we handed in our Student Experiment Documentation, SED version 1.2. It struck me that the experiment description, which includes the mechanical, electronics and software design, is only one chapter out of seven (not including appendices and so on). Sure, it is the biggest chapter, but what is in the six other chapters? I will pick and explain a few that are maybe not obvious, but play an important role in all space projects.
First of all, before you dig into the design, you have to figure out what you actually want to do. That isn’t as simple as it sounds: you have to list all your requirements, every single function, performance and feature of your final product. Of course without even knowing yet how it will look like. And to make sure that these requirements are carefully worded, precise and testable could almost be considered an art. In our case, the requirements fill one chapter. In a bigger project, like ESA’s Columbus module the requirements are in a separate document (the “statement of work”), which can easily reach 500-600 pages.
And then, when you begin to actually design your product, you already have to think about what will happen to it after it is built. The first thing here is of course testing, and testing relates a lot to the requirements mentioned above. Every single requirement shall be verified, and that’s why we have already now a long list of tests that we will need to do.
After the testing finally comes the flight, the very moment we are working towards. And with it comes another chapter in the SED about the launch campaign. What preparations do we have to do at the launch campaign? What equipment do we need? What exactly happens during countdown, flight and recovery? What risks are involved with the operation of the experiment? These questions need to be answered early, because they influence the design.
And after the flight, there is still a very important task to do: the analysis of the collected data. Guess what: there is a chapter on this in the SED, and it already has some content now.
As you can see now, there is much more to a space project than just the design process itself. A good thing of REXUS is that we students get an insight in all these tasks, as they are all included in our SED, and therefore get a little taste of what it means to build a real spacecraft.
But I’m really happy that we don’t have to keep track of 600 pages of requirements.