There are many ways to solve for this problem. For my science platform, I have a priority splitter on iron plates going to science production. Anything that takes the other path goes into cargo and gets sent down.

I couldn't find a vanilla method to limit sending stuff down though, so that can be an issue. For iron, it isn't a problem. I was making far more space science packs than I could consume though and they started building up in my logistics storage. I downloaded Earendel's AAI Signal Transmission mod to allow sending requests to the station. If anyone know a vanilla method to handle this, I'd love to know it, but I couldn't find it. It feels like it should exist.