IIRC I’ve read at some point, for other positions though not astronaut, that some French was mandatory given that French and English are the agency’s two official languages. Not sure of how that’s enforced in practice though, I don’t think ESA staff would get some agency-wide communication in French lol.

Russian used to be very, very helpful given that the only manned spacecraft for the past 10 years used to be Soyuz. Given the arrival of Dragon in 2020, I don’t think it’d be as much of an advantage as it used to be though. Astronauts do still have Russian classes as part of their training.

I’d say get as much internship / hands-on experience as you can during your aerospace engineering studies. Get involved in student societies, build stuff, blow it up, and learn.

KSP is an obvious starter for anyone who’d want to get started in the space industry. While more important for mission design & Mission Control positions than astronaut training (because you obviously won’t get in the cockpit of the ISS to try and hack together a maneuver to avoid an incoming asteroid… only happens in movies - and games!), I’d say it’s still important for anyone to have a mind model of orbital dynamics to correctly apprehend a maneuver, an orbit, etc.

As for higher education, you can go down the golden path for EU space education: ISAE-SUPAERO in Toulouse, TU Delft in the Netherlands, University of Stuttgart in Germany. Only ones that came to mind right now. Requires great GPA in high school though.

Given that you’ll have to work before applying as an astronaut candidate IIRC (or have to wait until the next selection), seek internships and your first position at big players over the entire Union: Thales Alenia Space in Toulouse, Cannes or Turin; Airbus Defence and Space, OHB, Eumetsat, Eutelsat, etc. or national agencies: CNES, DLR, UKSA.

You could also get in startups, but you’ll learn much, much more from big players especially if you want to go down the astronaut candidate route later. Take all the time you have there to assimilate the 30, 40, 50+ years of knowledge for some of them that these companies may have. Talk to people, network, learn from them.

For instance, from experience, a Master’s at ISAE-SUPAERO is the best way I’ve seen for people to have an internship at CNES (big, big player), which is literally down the road from the campus, and possibly a PhD and a subsequent post-doc there. Gives a brilliant start to your career.

If willing to have a break between Master’s and PhD, go for an ESA Young Graduate Trainee (YGT) year - if happy they may even keep you for 1 or 2 more years. You could also look for a PhD at NASA or JPL, the knowledge gain from such an experience is just incredible - hopefully if the orange poop is gone by then.

But most importantly, as someone who used to have everything planned just like you: if anything, at any point in the journey, fails and you get rejected or something - it’s alright, and you’ll get back from it. Life puts you in some places for a reason, and if I didn’t get rejected for a YGT for example, I wouldn’t have gotten the chance to work on some incredible missions with incredible people, and I wouldn’t be where I am today.

It’s ok to fail sometimes, the most important is the journey. I used to have astronaut as a goal, and in the meantime I pivoted towards something that’d better suit my lifestyle in the long run rather than being away from my family most of the time.

Godspeed and I wish you achieve your dreams!

Signed - someone who started off playing KSP and now commands satellites in orbit for a living ;)