One of the problems you encounter on your journey trough space is that your crew is getting older every interstellar jump. Even thought you are flying much faster then light, every 1000 light years will take your engine to make in one year. You can notice that your crew has tree parameters. One of them is age. Every time you come out of the ftl your crew gets older. So how to prevent your crew to die out before you find your new home?
In your first level you will find the cryogenics module. Using it, you can put your crew members to sleep. Sleeping crew members will not age during travel and they do not consume any life support. But someone will always needs to stay awake to manage the ship. There is a second option. In a bridge you can allow your crew to make children while traveling.
How many children will be born depends on the number of awake crew members, their age, gender balance, time that passed from last ftl jump and also chance. If you put too many crew members to sleep, no children will be born, but if you let your crew awake, they will get older and consume more life support. You need to find balance.