I interviewed in Stevenage, January 2019. The assessment centre is pretty straight forward - a group task and an interview. The group task is pretty simple. We had to negotiate a little robotic toy collecting 'supplies' from a certain area and delivering it to a base, incurring penalties for bumping into things. Just be yourself and get amongst it while listening and interacting with your peers. The interview is ok. Do not bother overly researching the company, know the basics but the interview is very much a technical interview. For me, the questions mainly consisted of thermodynamics and heat transfer, from the laws of thermodynamics, radiation and answering a basic heat transfer question on pen and paper. They will also throw a stick into the works and ask you about something you have no idea about, for me this was about a type of heat protecting layered material that they often wrap around satellites. Use your basic knowledge and figure out how it works, i did this from thinking about heat transfer through a wall with insulation in the centre. i would suggest reading 'The Laws of Thermodynamics: A very short introduction' by Peter Atkins if you haven't studied thermodynamics or heat transfer recently. Be prepared for some simple programming questions. i got asked to write a simple code in any language on paper, i had a complete brain freeze and blanked - probably because this was the first technical question they asked me and i wasn't expecting it. The program they wanted me to write was simple, and in hindsight i can't believe i couldn't produce it on the spot, so brush up some basic coding. Finally, the technical interview had a large focus on space related systems, orbits and the like. If you haven't studied space units in your bachelors i suggest you read 'How Spacecraft Fly' by Graham Swinerd - Expect questions about particular orbits, effects of the planet on satellites etc. The last crucial tip i will give you is look after your body the week before the interview, i had a stinking cold and a terrible nights sleep the night before and subsequently i wasn't at my best. Have a 'stiff' night cap the night before to make sure you sleep and don't lie awake thinking questions over until 5 o'clock in the morning. The interview is not bad, the staff are friendly and approachable. Be yourself and stay relaxed!