But before that we still have a high demand for new satellite designs. Satellites are spacecraft as well and we rely on them for our current exploration of space. Not to mention our current global communications network. If you think about it most of the things that we take for granted such as the internet, GPS systems, wireless communication, and military surveillance are all linked to satellites.
We constantly need people to design new models, after all getting up there to repair and maintain existing ones is still a bit too costly at the moment. That being said you need to design the most durable model possible at the lowest cost possible. However you can still contribute to the industry even if you're not into designing these things.
The good thing about the aerospace industry and aerospace companies in general is the amount of people they require. You simply can't build something like this with just one type of worker. You need engineers, designers, programmers, 3D modelers, 3D animators, simulation programmers, and many more. This being said anyone in these categories can find employment in the industry.
However in order to design anything related to space you have to be good. Education alone won't get you into these jobs. You have to have a tremendous amount of actual skill, and at least 5 years experience. Remember this field only accepts the best minds, and doing something halfheartedly is not tolerated.
That being said the more experience you have the better. It also helps to have some work samples of your previous projects to show that you can do what you say you can do. When designing a space craft the one thing that you need most is an imagination. Even if the craft can't be built with currently existing technologies it might be feasible down the line.
Concept drawings done by engineers and designers that look workable are kept in the aerospace industry for some time. Aerospace companies will also file away designs that look like they might work exceptionally well for future dates. The important thing to remember when designing these craft is to make them look realistically futuristic. Having a good knowledge of today's technology and being able to predict what future techs might be like is a skill that is essential to designing new spacecraft.
As we continue to advance our technology the need for new and innovative spacecraft designs will increase as well. Many other nations are starting to invest heavily in space development and if we don't stay competitive we'll be left behind. This being said we need the best and brightest in the field, and ideas that may seem odd now may be completely workable down the road.