Pros
Coolest company on the planet, and you will have an opportunity to contribute and make a difference. Every month we do something amazing, and every day you learn more about the space business. The company is still small enough that you can have a decent idea of what's going on, but big enough that there's plenty to learn and do. Management is focused on execution, and I have seen very little of the crazy bureaucracy that can ruin jobs at other companies. Corporate dumbness is not tolerated and every employee has the right to call it out and fix it.
Cons
The stories are true - it's a lot of hard work, but go in with open eyes and it's worth it. The feeling of being a startup means that direction can change on a dime, and attrition can be a problem.