Welcome to Hard Mode. You’ve planned a mission and executed Hohmann transfer orbits and brought your Kerbals farther afield than any human has ever dared. Now: did you remember to bring water?
TAC Life Support asks you to account for Kerbals’ biological needs, which means that oxygen, food, and water go in, CO2, waste, and waste water come out. Electricity has to be maintained or Kerbals freeze to death. Run out of air and they’ll asphyxiate in a couple of hours. With this new time pressure, missing an orbit window could mean a cold, lonely death for brave Jebediah.
Suddenly, you can see how combining mods would make KSP a much more horrible game. Thanks to Dang It!, a part on your Duna orbiter fails. Unable to come home, Kerbals are stuck in orbit while you launch a rescue mission, eating through their supplies of food and water. Your rescue mission? Well, thanks to Construction Time, it won’t be ready to launch for six months. Time to start planning a memorial.
Get it: Curse, CKAN
Don’t forget: A calculator in the VAB tells you how long your Kerbals will live with the provided supplies.