Well, what kind of ideas? NASA actually hires very few research scientists compared to university astronomy departments, so NASA might not be the place to go for an idea on dark energy or exoplanet searches. If you're talking about the space program - satellites going into orbit, manned missions to the moon, probes sent to faraway planets and the like, that's NASA. That said...
In your other post, you mentioned you're a high school student. Be realistic: if hordes of professional scientists are working on something, it's highly unlikely a high school student is going to be the one to come up with a breakthrough. However, high schools students can and do publishable research under the mentorship of professional astronomers - it's pretty uncommon and not very easy, but it happens, and if you're especially interested in that then PM me. I took that route myself and would highly recommend it to an aspiring astronomer.