How hard is it to design things?

The process of designing a spacecraft (or anything new really) can feel larger than life so it can feel impossible to know where or how to start. And with spacecraft, you must be able to ensure that it can survive the harsh and unforgiving environment of space which is no easy task. But with any great idea or product, a good design starts with having a strong foundation in understanding design principles.

As an engineer who designs spacecraft, you can learn these principles through your education, experience, and network. Your education gives you the knowledge required to understand the technical basics of how spacecraft work. By learning about propulsion, flight software, controls, thermal, communication, power, and other subsystems, you gain insight into first principles that form the building blocks of your design. This education never ends since new technological is always discovered to improve the way we create things for space.

Your experience supplies you a wealth of knowledge. Experience can come from internships that allow you to get hands-on experience to work alongside experts who can mentor and teach you how the concepts you learned in school apply in real life. It can also come from working on different missions across time. The way you build a spacecraft for Saturn is different than how you build it for the Moon. All of these experiences allow you to improve your knowledge and, importantly, learn from mistakes so that you can improve on the next iteration. 

And lastly your network are all the people in your life who are helping you achieve your goal. These are your coworkers, former classmates, peers in the industry, and supportive community members who help make large tasks seem possible because they are there to help. In other words, no one designs a spacecraft alone. Instead they lean on their teammates, friends, and family to get the job done instead.

I hope this helps!