I've been re-reading early DP zine issues and in #5, there's the mention of a then-recently found proto for The Last Starfighter for Atari 5200. Since I was curious about it and wondered whether it was a 5200 version of Solaris, I did some research and I realized that the history of games based on this movie franchise is almost as convoluted as the history of Wonder Boy games (ok, not nearly as convoluted, but still...).
The only game officially released under the name The Last Starfighter came out in 1990 for the NES. In reality, it's a modified port of the C64 game called Uridium.
The Atari 2600 proto of the game, programmed by Star Raiders' creator, Doug Neubauer, was released as Solaris with few changes made to the game.
http://www.atariprotos.com/2600/software/tlsf/tlsf.htm
The Atari 5200 version of the game was never released, whereas the 8-bit computer version was eventually released as Star Raiders II. Despite similarities between Solaris and Star Raiders II, they are two distinct games, the latter being programmed by Gary Stark and Bruce Poehlman rather than Neubauer. What remains to be seen is whether they were truly independently developed or not (Neubauer implies on his website that Solaris was truly his creation). I think it'd be worth asking him what he knows of the 5200/8-bit versions of TLS/Star Raiders II.
http://www.atariprotos.com/8bit/software/tlsf/tlsf.htm
http://dougneubauer.com/atarisolarismanual/