Question: What do you have to consider when designing your instruments?

Darren Yau answered on 23 Sep 2022:

Hi there

That’s a good question and there are a number of considerations. Typically, the science carried out in our laboratories use equipment that can fill a room. A space craft is never quite as big so you have to minaturise, or shrink, the instrument. This is a huge challenge as the science still has to work.

Mass, or the weight of the instrument, is also very important as a rocket is only able to launch so much. If a space craft is too heavy, because the scientific instruments haven’t been designed properly, it’ll never take off (literally!).

Next we have the environment(s), which involves everything the instrument has to experience in its lifetime. First there’s the launch environment where the space craft is subjected to extreme vibration, shock and acceleration during lift off. Once in space, you have extreme hot and cold environment as a satellite orbits the earth (night and day). This heating and cooling can have devastating effects on an instrument as electronics don’t like the temperature extremes. Materials (metals and plastics) can also expand/contract when hot/cold and this can cause serious problems.

For my current Lunar missions, they are landing on the surface of the moon so there will be a landing envrionment, which will be similar to launch but as it’ll be in space, the temperature extremes will also be added.

Assuming the instrument survives some or all the above environments it will then have to work faultlessly for the duration of the mission. For a satellite, the lifetime may be 15-20 years with no maintenance as we can’t yet send engineers to repair things that don’t work. Therefore, reliability is another important consideration for all space missions (science or communications) as none of us want unreliable streaming/mobile phone/Sat Nav operation.