Help with upgrade station contract

[TheFlyingKerman]

An alternative is sending an empty tank and then filling it up with fuel mined from Minmus or the Mun.

[Neil Kermstrong]

2 minutes ago, TheFlyingKerman said:

An alternative is sending an empty tank and then filling it up with fuel mined from Minmus or the Mun.

Ive thought about doing that too, but I'm lazy because I'll also need to get a ore to LF/Oxidizer converter to the station.

However, laziness and KSP shouldn't stay in the same sentence

[TheFlyingKerman]

The station doesn't need a converter. Do the conversion on the surface where you mine (and there maybe a base contract for that). Then you can get the fuel anywhere you like.

[king of nowhere]

the cheapest way to fulfill those contracts is to mine fuel directly on mun and minmus. which, if you are getting the contracts for enlarging space stations, you should have the technology for it. in fact, if you have the facilities to mine fuel, you'll want to refuel most of your vehicles in orbit to save weight at launch.

this way, you don't need to send 36 tons of full fuel tank on mun orbit, you only need to send 4 tons of the empty tank. but wait, it gets even better! why send a rocket with its own fuel tanks to lift an empty fuel tank? you can use this fuel tank as part of your second stage (or whatever stage you send to orbit). then, when it is in orbit, instead of jettisoning it, you send it farther to mun. perhaps you could jettison the engine alone, and have a smaller engine for orbital manuevering. regardless of the specifics, you can send a fairly cheap rocket for 20-30k that includes a few empty tanks, send those empty tanks to the space station, and refuel the station with a mining vehicle.

here is an example of one such mining vehicle. it's a bit expensive, but mostly because it has 4 RTG. the older version is less efficient, but it cost 170k including launcher, and it holds 64 tons of fuel; 15-20 of those are needed for takeoff and landing from mun, the rest you can use for other vehicles, and it refills in a few days. so, with the 280k from the contract you can make a mining vehicle for 170k, a few fuel tanks to add to your station for 20-30k, and you're not only left with 80k gain, but the mining vehicle is fully reusable.

before this, to launch interplanetary missions i needed 3 stages; one for liftoff, two for getting to orbit, and a third one with all the fuel for interplanetary travel, which is quite expensive. No more. now i have two stages, the second stage goes to mun orbit directly (it's much lighter without a third stage), it gets refueled, and it goes interplanetary. it saves a stage, and it lets the first stage be significantly smaller. as an added bonus, that mining vehicle can also collect science, so wherever you land for refueling, you also gain science.

I even improved on that by launching a giant 600-ton tank. it wasn't even that expensive, i put two S4-256 fuel tanks together with a mammoth engine and a few boosters. in orbit i detached the mammoth, and i had a more efficient wolfhound (5, actually, on an adapter tank) underneath. i sent it to mun to get refueled, which i did with multiple trips of the mining vehicle. then i sent the giant tank back on kerbin orbit. now i only need enough fuel to get to orbit, where i refill my ships on the giant fuel tank before sending them off again. so i can make my rockets even lighter and cheaper.

if you are concerned with money, it definitely pays off in the long run. it's also more elegant. on the down side, you need to make a lot of rendez-vous manuevers.

Edited August 25, 2020 by king of nowhere

[Spricigo]

16 hours ago, king of nowhere said:

the cheapest way to fulfill those contracts is to mine fuel directly on mun and minmus. which, if you are getting the contracts for enlarging space stations, you should have the technology for it.

Not really. Those contract can come much earlier than mining/refining tech. (I get offering before setting foot on Mun/minmus).

Also, if one don't have a mining base may not be really worth the time to setup(and manage) one just for those contracts. Usualy at this point, funds is not a big issue anymore.