[plt-scheme] Dumb Question about Dr Scheme Environment

I have a lot of (require...)s that I need to load before I can begin experimenting - takes a while.

Is there are way to keep this "environment" of required stuff and also use the Dr Scheme editor and
"Execute"? I tried a simple (load...), but it appears that every time I hit Execute, I end up with a
"fresh" environment. I continually refine the code I run after loading the environment.

Thanks,

Alex