Pros
Exciting work - a great chance to gain experience in many aspects of a startup, from engineering, to project management, to business/strategy. Global mindset - we get to work with engineers from Luxembourg and Japan (and all over the world), very unusual in the space industry. Clear/inspiring vision and recent improvements in management - recent turnover was definitely for the better, company is trending upwards and deftly handling the transition from startup to scale-up.
Cons
Like others have said - a bit too lean. Many times you have to chart your own course and be OK working in ambiguity - it's not for everyone. As always, there is tension between employees and management, but not even close to the level of dysfunction I've seen at other startups.