Linking to other sites is totally fine, I heartily encourage it. And Heavens Above is a great website.
http://www.heavens-above.com
What we want to avoid is when people sign up to the forum with their only objective to advertise some other website. What's called a "post and run". You've got 200+ posts under your belt, so you're not going to be using the UT forums as a place to advertise.
Make sense?