In most STEM fields, and in most of the quantitative social sciences, the format of articles (or conference papers, especially in computer science) is the most important way to find scholarly information about a research topic. Space exploration is a very broad field; more engineering-specific applications will need to consult a very wide array of documents, while some others might have a more limited scope to hunt through.
I have highlighted a few books and article databases of possible interest below. There may be other places besides these that are better for you. If you need help, visit the "Getting reference assistance" tab to find support.