Some of my thoughts on contracts for 1.12
Edit: Monopropellant refining
Warning: this trick is game breaking, don't ruin your fun in career!
You can exploit the fact that ore is cheaper than monopropellant. Using a Convert-O-Tron 250, converting ore into monopropellant yields profit. No need for drilling, just fill the ore tanks in the SPH. Roll out a refinery rig onto the runway, let it convert, and recover. Have an engineer on board to speed up the conversion.
Money Farm I (for low level engineer): https://steamcommunity.com/sharedfiles/filedetails/?id=2957871112
Money Farm II 'Pro' (for 5* engineer)
https://steamcommunity.com/sharedfiles/filedetails/?id=2957973350
Tourists
Why fly around the Mun all by yourself if you can take some paying customers along for the ride? Just slap on some Inline Mk1 Crew Cabin.
I also build all my landers with 2-3 Mk1 Pods for this reason (and to keep them more flat and squat for easier landing).
Low tech Mun lander that seats 3:
https://steamcommunity.com/sharedfiles/filedetails/?id=2933040208
Mid tech lander for two: https://steamcommunity.com/sharedfiles/filedetails/?id=2954892369
Contract advances
These can be massive if you just start out. Want me to build a rover that can support 11 Kerbals and land it on Eve? I don't have the tech to do this right now because I am just starting out. But I will gladly take your advance of 579,150 now and revisit this problem later in the 35 years I have to complete the contract!
Experimental parts
Want me to test a Mainsail engine landed on the Mun? I can't get it there right now, but thanks for the experimental heavy lift engine I can now use on all my flights even though I did not unlock the science for it.
Reusability
You don't need fancy Rapier engines to return parts of your launchers from Orbit. Actually a pure SSTO solution can be much more expensive than a cheap two stage launcher with some parachutes stuck on. Keep it light and simple, use an expendable cheap solid booster as first stage to get high enough to fully benefit from an efficient vacuum engine.
Cheap launcher to get to low Kerbin orbit for launch costs of 5,435 and recover 4000:
https://steamcommunity.com/sharedfiles/filedetails/?id=2934324370
Cheap unmanned Mun rover for 8,740:
https://steamcommunity.com/sharedfiles/filedetails/?id=2954906948
Cheap satellite/relay for 5,818:
https://steamcommunity.com/sharedfiles/filedetails/?id=2933174672
In Situ Resource Utilization
Launching missions from Kerbin is expensive because of the high delta-v requirements. If you can keep the equipment for the orbital parts of a mission on location, it can be reused by follow-up missions, so they can be cheaper. This is done by using a separate craft to return to Kerbin.
In my current early campaign where I mainly explore the Mun I use the following setup:
- Base of operations is a station in low Mun Orbit (55 km). Contains labs and serves as fuel and cargo depot. All traffic to the Mun surface goes through here.
- Fuel is supplied to the station by heavy miners (~ 50t) which refine fuel on the surface of the Mun. Make sure to have an engineer on each of these. These can seat up to 8 and take along tourists to the surface.
- Contracts (e.g. rover repairs) and science exploration are done by small agile landers ( ~ 10t) that seat two. These are docked at the station and used as needed.
- Cargo (e.g. rover wheels, new tech) and personnel/tourists are brought from and to Kerbin with small SSTOs (~ 20t).
- Science is returned from Mun to the station and stored in the tourist SSTOs for return to Kerbin. None of the other craft return to Kerbin.
- Equipment is refitted in Mun orbit through EVA construction if newer parts become available (e.g. install new science experiments in the small landers).
- Communications is established with 2x 3 small relays brought in with Cargo SSTO.
- Transfer from Mun to Minmus is available every 7,5 days for ~300 m/s. I transfer personnel and cargo there via small shuttle.
Now that this infrastructure is in place I can crunch Mun contracts indefinitely with basically no launch costs (only Kerbals and cargo go up and down via SSTO).
Edit:
I thought hard how to extend this 'stay where you already are' approach to contracts to the later career and designed some solutions. All require advanced tech.
'Maia': a huge fully integrated stack that provides all the functions mentioned above in a single launch (of considerable mass of 149 tons to orbit). High delta-v, mass, cost.
https://steamcommunity.com/sharedfiles/filedetails/?id=2955311353
'Sandworm': independent exploration rover, all functions for half the mass of 'Maia'.
https://steamcommunity.com/sharedfiles/filedetails/?id=2963570208
'Giraffa': a medium sized rover that provides all the functions (except the orbital lab/fuel depot/relays) in a single compact package (18.2 tons). Medium delta-v, mass, cost.
https://steamcommunity.com/sharedfiles/filedetails/?id=2957028339
'Samaritan': medium refueling rover, if you were tricked into using 'Giraffa' and don't want to wait forever for refueling to complete.
https://steamcommunity.com/sharedfiles/filedetails/?id=2962898533
'Mentha': complete Minmus exploration in a single launch, 56t to orbit, mid-tech
https://steamcommunity.com/sharedfiles/filedetails/?id=2961100481
'Teardrop': mid range shuttle SSTO (4 crew; 28.5 tons; 3500 m/s left after LKO insertion; WARNING: EXPLOITS)
https://steamcommunity.com/sharedfiles/filedetails/?id=2958826733
'Sancus': long range shuttle SSTO (8 crew; 69.2 tons; 6050 m/s left after LKO insertion; WARNING: EXPLOITS)
https://steamcommunity.com/sharedfiles/filedetails/?id=2958894696