Martian Water — Greg M. Hall

For the first humans on Mars, everything is a challenge. But nobody on the team expected the most vicious struggles to be against the politicians back home. Mission funding is threatened, and asking for fresh supplies may cause the plug to be pulled on the whole thing. This is no time for Curtis to discover he has feelings for Molly. And it's certainly no time to discover a crisis that may leave the new Martians too dead to care about their budget.