Any serious attempt to take large numbers of people from the Earth to the Moon will require at least the following three major components.
First off, we’ll need a fleet of trans-atmospheric vehicles (TAV’s). A TAV is any shuttle specifically designed to transport people and cargo from Earth to Low Earth Orbit (LEO). Skylon from Reaction Engines is a TAV, so is Sierra Nevada’s Dreamchaser. There will be more, many more when the world realizes there will be a destination up there for all of those who can get to The Gateway.
Second, we’ll need a facility where passengers can transfer from their TAV to a Cis-lunar shuttle – A Gateway. This facility could be something as simple as the ISS, but it’s important to keep in mind that after a 3G liftoff and approximately two days in a low-earth orbit, paying customers would love the opportunity to stretch their legs, take a shower, and use a normal bathroom. This is where The Gateway comes in, perfectly satisfying all those needs and others as well.
– Larry Niven
Third, we’ll need a fleet of Cis-lunar shuttles. These Cis-lunar shuttles won’t be something as simple as Apollo era Lunar Landers, we’re going to have to build a fleet Athena type lunar landers. These Landers would carry 20 passengers, 10 tons of cargo, and a crew of four. These new landers would have to be of a multiengine design with many levels of redundancy much like long-range passenger jets are built today.
Each time a new Lander joins the fleet, we will increase our volume of people we take from the earth to the moon and back until, eventually, we’ve reached traffic capacity for the LGA stage of The Gateway which is about 100 people a day, 3000 each month, 36,000 per year. When we build the MGA that number will raise to almost 100,000 people per year.
Each of these three crucial components are well within our technological capability.
The time to build The Gateway is now. We need to start designing, fabricating, and testing.
It’s time has come.