This thread reminded me of the Antares series by Michael McCollum that I read back in school around 1996 say. But the second book really didn't have an ending as such and there didn't seem to be another one.
I looked the author up again, only to find out that he's written a sequel in 2002. So now the Antares trilogy's books were published in 1986, 1987 and 2002.
I borrowed them from a friend so I'm not sure how much I'd like them now, but I remember that they were among my favorite scifi books. Unfortunately, they're out of stock everywhere apart from one amazon.com marketplace seller in Arizona. However I'm not going to pay $47.50 for the books
and $41 for shipping.
I wonder if anyone else has ever heard of this author. He doesn't appear to have been as successful as others mentioned here.
Edit: Apparently that marketplace seller is the author himself. And he sells ebook versions for $5 each on
his website.

I'm probably going to buy them at some point, but I still have a few unread books to go through (such as Hyperion).
You can read descriptions and a short excerpt there as well. However, as I said, I'm not quite sure whether 27 year old me would still like them as much as when I was 15.