I first mentioned in the Oregon Trail section that the correct order for settling a new frontier is to establish desirable destinations first, THEN build the efficient transportation infrastructure to connect them to the rest of civilization. The current paradigm is going at this backwards. A lot of smart people have spent decades trying to figure out how we can build a profitable cis-Lunar transportation system BEFORE there are places that need it. And obviously, they’ve failed every time because we still don’t have one.
The initial Homesteads don’t need an efficient transportation infrastructure. Like settlements throughout history; all the physical products and people are headed one way (to Luna) and there won’t be enough in the beginning to warrant the expense of building the infrastructure. It will take a while for Homesteads to have enough resources, equipment, and people to justify the expense and effort of building an efficient transportation system. When that time comes, the private sector will eagerly jump in because there will be an existing market willing to pay for their services.
Cis-Lunar Transportation Infrastructure
What would a cis-Lunar transportation infrastructure look like? I haven’t done a lot of research on this yet. Honestly, researching the transportation component is near the bottom of my list. There are a lot of people smarter and richer than me working on this problem so I’d rather work on stuff that very few people are researching. Let me know if I’ve got something wrong.
- Earth to Low Earth Orbit (LEO) – There are several private sector companies already supplying this service. The SMIC and SpaceX are the obvious ones. Blue Origin is almost ready. And several other companies are working on reusable space planes. We (humans) could stop working on this component of the cis-Lunar infrastructure and we’d probably be fine. Of course, we won’t stop and that’s great because more efficient tech is always a good thing.
- LEO to Earth – This component presents an interesting problem. Let’s look at “America’s Space Truck”. The Space Shuttle could bring 16,050 kg (35,380 lbs.) to the International Space Station (ISS) . It could also bring back 14,400 kg (31,700 lbs.) . The Shuttle could also fly 8 crew during normal operations and 11 in an emergency . The only spacecraft currently able to return cargo to Earth is SpaceX’s Dragon capsule . Dragon is capable of launching 7 passengers and 6,000 kg (13,228 lbs.) to the ISS and returning 3,000 kg (6,614 lbs.) to Earth . A mature architecture will require vehicles that can shuttle significantly more people and cargo between Earth and LEO.
- LEO Station – We have one right now. The International Space Station. Sure, it’s not equipped to handle the needs of a cis-Lunar transportation system (transferring goods and people, refueling, maintenance and repair, construction, etc.) or in the most efficient orbit but it’s what we have. The Chinese are planning on building a much smaller LEO station (1/5th the size of the ISS) starting in 2021 but it doesn’t look like it’s designed as a transportation hub . Someone is going to have to build a dedicated transportation station in LEO once there is a market to support increased cis-Lunar activity.
- LEO – Geostationary Earth Orbit (GEO) (also called geosynchronous equatorial orbit) Transfer Vehicle – LEO is fine but the real action is in GEO. Communication, observation, navigation, and power generation satellites (and stations!) can all be placed in GEO. And there are obvious military opportunities in GEO as well. It takes a specialized vehicle to make the Earth-LEO-Earth run. Requiring it to also make the trip to GEO is asking a lot. A specialized LEO-GEO “tug” shouldn’t be that difficult to design and build. All it really needs is enough fuel and thrust to move modules/spacecraft/whatever between orbits (not just LEO and GEO); it doesn’t even need to be crewed. More mass can be delivered to GEO from Earth using a LEO-GEO Transfer Vehicle than if it all had to be delivered from a “single-throw” vehicle.
- GEO Transportation Station – A large transportation hub in GEO makes a lot of sense. From there it would be easy to send out robots or teams to repair and maintain unmanned satellites in GEO. We could use it to build large orbital structures (like Solar Power Satellites) or interplanetary cyclers (basically large stations that orbit between planets). This station could also conduct substantial zero-g and vacuum manufacturing using Lunar materials.
- GEO – Earth-Moon Lagrangian Point 1 (EML1) Transfer Vehicle – Also just called L1. The Lagrangian points (named for Joseph-Louis Lagrange) are relative stable points in orbit near two large bodies. EML1 is located between the Earth and Luna (85% of the distance to Luna ) and is the current favorite for a Lunar transportation hub. I won’t get into the details here but the primary reasons are favorable energy requirements and orbital mechanics for a wide variety of missions. Anyway, our Homesteaders will eventually need to have a vehicle to take them and/or their goods from their neighborhood (the EML1 station) to Earth’s neighborhood (either the GEO or LEO transportation hub).
- EML1 Transportation Hub – This station could become even more important that the GEO and LEO stations. It can do everything that those stations can do as well as be the launching point for spacecraft bound for anywhere in the Solar system (by requiring some of the lowest energy requirements) . I imagine massive shipyards in EML1 building orbital Homesteads using Lunar material.
- EML1 – Lunar Surface Lander – This would be another specialized vehicle. There’s no point using a spacecraft designed to land on the Lunar surface for anything else. The lander can be optimized for mass (humans and cargo) transport since the travel time, and radiation exposure, between facilities would be pretty short.
- Lunar surface mass driver – This would be one of the end-game transportation components (a skyhook or elevator would be as well). Individual Homesteads might not have their own mass drivers but multiple ones could share one. They could construct cargo capsules using Lunar iron and launch bulk cargo to a variety of orbits using only electricity. It doesn’t get more efficient than that.
For the initial Lunar Homesteads all we really need is a single-use rocket powerful enough to land several tons of cargo on the Lunar surface. Launching a handful of these to establish a Homestead will be much less expensive than building all the infrastructure I just described. Also, increasing the number of launches of a standardized launch vehicle will significantly decrease the overall cost of each launch. We don’t really need reusable (like the Falcon), complex (some of the space plane designs), or expensive (I’m looking at you SLS) vehicles to make this happen. Mass produced, dumb rockets will do just fine.
Let’s look at two examples besides the Oregon Trail.
The U.S. Pacific Railroad
Also known as the Overland Route . Started in 1863, the Pacific Railroad (PR) was the world’s first transcontinental railroad linking Council Bluffs, Iowa to the Oakland Long Wharf in San Francisco, California . The 3,077 km (1,912 mile) rail line was constructed by three private companies (Western Pacific Railroad Company, Central Pacific Railroad Company, and Union Pacific) and primarily financed by federal and state money. The route was finished and opened for business in 1869 .
The primary reason for constructing the PR was to connect the U.S. East coast with the West coast, making transporting goods and passengers considerably cheaper, faster, and safer . Coast to coast travel time was reduced from 6+ months to a single week  and cost about $65 per adult . And the number of people taking the hazardous Oregon and California Trails by wagon train and stagecoach declined dramatically soon after it was built .
The PR brought several other benefits. By connecting it to a northern city, it aligned the western territories and states with the northern Union states . It forced the federal government to mandate standardized equipment parameters (such as track gauge) . Finally, the PR enabled the settling of the “Great American Desert” (aka the Midwest prairies) by providing access to efficient transportation and the East and West coast markets .
While the construction of the Pacific Railroad was considered one of America’s greatest 19th century technical feats ; the key point is that it wasn’t constructed until there were two places that needed linking.
Like the Pacific Railroad, the primary purpose of the Panama Canal (PC) was to replace a long and dangerous route with a quicker and safer one. The PC connects the Atlantic Ocean to the Pacific Ocean through the Isthmus of Panama. Ships using the PC could avoid the hazardous route around Cape Horn (at the southern tip of South America) or the route through the Arctic Archipelago and the Bering Strait . What used to add months to a difficult trip can now be as fast as 12 hours .
Many people consider the Panama Canal to be one of the seven wonders of the modern world . And they’d be right. The PC was “one of the largest and most difficult engineering projects ever undertaken” . It took a long time (1881 to 1914) , required massive effort (56,307 people involved overall) , and killed a lot of people (5,609) . The PC was also the “single most expensive construction project in United States history to that time” , costing $375,000,000 at the time  (over $8 billion in today’s dollars ) with the federal government footing the entire bill.
Obviously, we can do big projects when we really want to. When the time comes, building the cis-Lunar transportation architecture might require a similar effort. Or maybe the private sector, working with Lunar Homesteaders, will build it out in pieces over time. Either way, initial Homesteaders don’t need it.