After Glow by Jayne Castle
First of all, I can not be held responsible for keeping track of Amanda Quick/Jayne Castle's noms de plume. Meg has a lot of affection for the romantic-couple-solves-mystery, but in space! thing this book has going on. Laine wishes it made more sense and/or that the romance was given more development. Marriage of convenience is fun trope, you just have to know what you're getting into.