8

Several things that KSP does not model: The challenges of actually docking two things mechanically together without a handy human such that the plumbing works (leaks have a tendency to go bang) The extra instrumentation required to dock with enough reliability to not risk the mission (need duplicate equipment). Notably for the ISS many craft just take ...


5

The difference in loading a flown booster and a brand new booster is the same. SpaceX starts loading RP1 and first stage LOX at T-35 min. RP1 fueling on the first stage finishes around the T-3 min and second stage around T-2 min time. For LOX fueling, they never really finish loading, they will keep topping off the LOX that's boiled off til about liftoff. So ...


5

So the basic fact is that the delta-V from LEO to LLO (low lunar orbit) using a high-thrust system is about 4 km/s and using a low thrust system it's about 8. source So, using something like a vacuum raptor engine ($I_{sp}$ 382s) you need a mass ratio of about 2:1. That is, for every ton you want to deliver to LLO you need 2 tons of methalox in LEO. Using ...


3

The big problem with sending supplies and fuel ahead is that there's many ways it could go wrong which would end up with the crew being dead. There's no major advantage to sending supplies ahead of the mission to orbit another body, and a lot of risk. The thought is that you can split the cargoes and launch them in smaller, cheap rockets rather than ...


3

The ISS can be refueled with UDMH and N2O4 by visiting vehicles, initially the ATV: http://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/ATV/Premiere_for_Europe_Jules_Verne_refuels_the_ISS The propellant transfer is done through the docking connector, through pipes that run outside the pressurized portions of the ISS.


3

Making a drill rig mobile is easy; it simply gets mounted on a tracked or wheeled platform. Mineral exploration companies & water borers have used truck mounted drill rigs for decades. The technology can be adapted for use on other celestial bodies. As to ground stability issues, this would potentially be a major issue if drilling sub horizontal holes ...


3

There are multiple designs for rovers and robots which are designed to pick up regolith from the surface and transport it for water extraction. For example, in this video, a rover is shown which has dual drum-excavators and is picking up the surface material in the simulated martian environment. For such a rover to work, the water would need to be rather ...


1

I came to a similar conclusion. One launch to put the spaceship into orbit, 10 or more tankers to "fill the tanks". Maybe a dozen launches all together, each launch the equivalent of a Saturn V. There were only 13 Saturn V launches in all before they pulled the plug on the whole program. Direct ascent and Earth Orbit Rendezvous (EOR) were rejected in favor ...


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