Long term, we probably want to have facilities at the Earth/Moon and Earth/Sun Lagrange points. These can be used as part of a system for cheap (but slow) interplanetary transport network (ITN). (See [1]). When we have that we can start sending supplies ahead on a regular schedule to places that we want to establish human occupied facilities at later.
The idea is that if we plan to put humans at X, we start sending cargo drops to X every few months via the slow but cheap ITN.
After those start arriving at X, we send the humans. The ship for transporting humans only has to carry enough supplies to keep the humans alive during the trip. It doesn't have to carry supplies to keep them alive at X, or equipment to set up their base or colony at X, because those have already been sent via the ITN. The ship for the humans can be optimized for one task: moving humans fast.
Setting all of the above up working with materials from the Moon and from bases on the Moon will be a lot less expensive than doing it from Earth. First, the gravity difference makes it a lot cheaper to get something from the Moon to an arbitrary point (like one of those Lagrange points) than it does to get it from Earth to there.
Second, because the Moon has no significant atmosphere you can do things on the surface that would not work well on Earth. For instance, on the Moon you could build a long linear electric motor on the surface and use it to speed a vehicle up to escape velocity. Try that on the surface of the Earth and your vehicle is going to get destroyed by friction in the atmosphere.
The Moon is the key to long term human utilization of the rest of the solar system.
The idea is that if we plan to put humans at X, we start sending cargo drops to X every few months via the slow but cheap ITN.
After those start arriving at X, we send the humans. The ship for transporting humans only has to carry enough supplies to keep the humans alive during the trip. It doesn't have to carry supplies to keep them alive at X, or equipment to set up their base or colony at X, because those have already been sent via the ITN. The ship for the humans can be optimized for one task: moving humans fast.
Setting all of the above up working with materials from the Moon and from bases on the Moon will be a lot less expensive than doing it from Earth. First, the gravity difference makes it a lot cheaper to get something from the Moon to an arbitrary point (like one of those Lagrange points) than it does to get it from Earth to there.
Second, because the Moon has no significant atmosphere you can do things on the surface that would not work well on Earth. For instance, on the Moon you could build a long linear electric motor on the surface and use it to speed a vehicle up to escape velocity. Try that on the surface of the Earth and your vehicle is going to get destroyed by friction in the atmosphere.
The Moon is the key to long term human utilization of the rest of the solar system.
[1] https://en.wikipedia.org/wiki/Interplanetary_Transport_Netwo...