The second book in the Colony Mars series is out as an audio book. You can get it on Audible or iTunes, and a raft of other places I believe.
The third book is finished and should hit the virtual shelves mid August. That will complete the trilogy.
Personally, I’m extremely happy with the series and Nicol Zanzarella did a fantastic job of bringing the characters to life. I really enjoyed listening to it… and I hope you do too.