How do "build a base" and "build a station" contracts work ?

[Zamolxes77]

I'm at the stage when I get such contracts and they're very lucrative.

Question is, once you built the station or the base, do you lose control of the facility ? All contracts seem to request 2 pilots, do I "lose" them as well ? Or the base remains under my control ? If I lose the facility, where do I get so many pilots ? From rescues ? 

[HvP]

@Zamolxes77 In the stock game any bases or stations you create are yours and stay under your control as long as they are in stable orbits or landed on the surface and aren't suborbital. The only possible exceptions would be if you forget to add a command pod or probe core, in which case they would be tagged as debris by the game. There are some mods out there that significantly change how stations and base contracts operate, however.

As long as your base has a command pod or probe core the vessel will be visible in the tracking station and you should be able to switch to it at any time from there or visit it with other craft. Any crew you leave on the station are also still a part of your space program and you will still have control of them when you switch back to the station. In fact, once you complete the contract you don't have to leave your craft or Kerbals there. You can do anything you want with them. (keep in mind that some contracts require the station to meet all requirements for an extended period of time before the contract will be fulfilled.)

Also, be aware that most contracts require a base or station to be launched AFTER you accept the contract. So you probably won't be able to use the same craft to complete any "build new station" contracts you've accepted after you launched it. And some contracts will be offered later on asking you to add to the original station or base with additional modules or crew. You may want to do so if it advances your plans for that world, and if so then don't forget to add a couple of extra docking ports for later expansion.

If you do take a lot of these contracts then it can be difficult to supply enough Kerbals to crew them. Since each new hire costs more than the last it can eat up your funds. Rescue missions will help you replenish your crews without having to pay for new hires. I often make a rescue ship capable of going to low Kerbin orbit which has space for anywhere between 3 to 6 Kerbals, and enough delta-v to make rendezvous with several craft on one flight. An extra 600 to 800 delta-v after making orbit should do. This lets me accept several LKO rescue contracts in advance and then go and bring them all down in one flight. It's the cheapest way of doing it, if a bit tedious.

Edited December 31, 2019 by HvP