Hi Niki,
You have lots of options...
If you want to put together your own curriculum, I'd recommend the Home School Buyer's Co-op because you'll save money and can customize your curriculum.
If you're looking for an accredited school, there are also lots of options. However, your school district may or may not accept your DS's placement if you decide to return to public school.
Check to see if your state/district offers independent study or a home school/charter school program. With that option, you'll likely enroll for free and maybe receive a stipend for extracurricular activities.
I have several home school students enrolled in my academic enrichment course, which covers English, Math, Science and History for grades K-12. Students can also take a foreign language through PowerSpeak.
I hope that helps and good luck!
Cornell site for cosmology/astronomy. Nasa cosmology/astronomy. Kid's Astronomy Site 
