Please take a moment and update your account profile. If you have an updated account profile with basic information on why you are on Air Warriors it will help other people respond to your posts. How do you update your profile you ask?
As stated below, if you are planning on enlisting and going to boot camp, a recruiter will have you take ASVAB. If you are seeking an aviation contract through PLC or OCS, then OSO will have you take ASTB.
If you didn't take the SAT you may have to take the ASVAB. When I was having troubles rounding up my SAT score he said I could take the ASVAB, as you need a minimum score on EITHER one to qualify for OCS.
If you do not have your SAT scores you must take the ASVAB. No you are not enlisting, but you will need a 74 minimum to be eligible for the Marine officer program. Once you show that you pass then you are able to take the ASTB.