Welcome to the campaign!
Campaign 1: It’s NOW. You have been selected to be the first Astronauts to Mars. With the new, fusion engine your group can get there in a month! Equipment has been sent ahead of you and you must build the first Mars colony.
Campaign 2: Just as you are finishing up the Mars Colony and new colonists are arriving monthly, a fantastic discovery is made and the RAMJet propulsion system has become possible! Your group, being the most experienced astronauts of the human race, have been asked to be the Alpha team to Captain the Jet to KOI 172.02 and explore the first earth like planet outside our solar system!
Campaign 3: It’s hundred of years later (not for you since you’ve been in cryogenic sleep) and the FTL drive is finally a reality! Earth sends out a ship to pick your team up. As the first voyagers into the greater galaxy, Earth needs they’re Best most experienced Astronauts, That’s You.
After that, take a look at your wiki. There is some more helpful info there.