Destination: Hub-based Space Transportation
My post at Destination: Moon describes the first stage of settlement off Earth: 28 souls leave Earth on 4 ships to travel about a week to the Moon landing on the lunar surface to create a habitat.
While that will work for the Moon, it will NOT work for Mars or anywhere else in deep space. Sending a few people at a time, even the 7 that SpaceX dragon can accommodate, will never work out economically to develop a settlement as far away as Mars. Why would we spend the estimated price of $5 billion PER SHIP TO MARS to do anything? And that doesn’t include the supply shipments both before and after the human trip.
First, is the issue of launching from the ground on Earth a single super massive ship directly to Mars. The SLS, and SpaceX MCT are examples of the “One-Shot” method of sending a handful of people to Mars at an unreasonable cost – and with NO return on that investment.
Second, is the prospect of delivering sufficient habitat and supplies so they can survive the two years until the next shipment arrives. That means at least one more ship launched from the ground at $5 Billion direct to Mars.
And Third and Fourth … Neither NASA nor her sister agencies have resolved the the threats associated with radiation and lack of gravity.
Positioning and Function
Enter Earth-Moon Lagrange Points. There are two of specific interest, EML-1 between us and the Moon, and EML-2, on the other side of the Moon from us. From a business standpoint both of these afford tremendous advantages when considered in a transportation architecture.
EML-1, located between the Earth and the Moon affords a hub location much like St. Louis provided for the westward migration in the U.S. during the 1800’s. Last supplies, final mail, and last touch of civilization before entering the hard frontier. So too, would the EML-1 Station-Hub provide that last point of call for those departing for the frontier, for those returning from the frontier, and for cargo transferring for destinations to Earth, or outbound to the Moon, Mars, or beyond.
From a transportation architecture point, spacecraft can be designed for the hops from Earth-ground to orbit, others would be designed for long term use as shuttles and cargo carriers to EML-1, and still others as “hoppers” – to service Moon-to-EML service. As a hub, EML-1 provides a vital link between the frontier and Earth. As time goes on, it would become a bustling metropolis serving the millions who would be travelling between Earth and the outer systems.
EML-2 provides the port-of-call for all arrivals and departures between deep space and the Earth system (including the Moon). Those Craft arriving from other planets would put in at EML-2 leaving cargo and/or passengers for destinations at the Moon, EML-1, or Earth. As well, those departing for deep space and the other planets would board at this station for the ride down through Earth’s gravity well, and outward to their next destination, whether inward toward the Sun, or outward towards Mars and the outer regions.
The Long Trek to Deep Space (Mars, Jupiter, Saturn, and Beyond)
Launching to Mars from the ground on Earth for any long-term plan is economic poppycock. From a sustainability standpoint, it is ludicrous, and nonsense! $5 Billion per launch at current estimates. It has been suggested on numerous occasions that launching from EML2 would make more sense. But that presents a host of other issues like …. getting the ship up there?
Modularity and Reuseability
Well, suppose we didn’t send the ship up all at once, but rather in pieces. AND suppose that we didn’t build a new one – special purpose for Mars, but rather re-purposed components already proven space-worthy?
For example, if you look at the history of the ISS, there have been nearly 75 supply ships delivered to the ISS since 2000. And nearly every one of them burned up on reentry. Not only is that a lot of modules just discarded for a lot of money spent – but a huge quantity of raw materials just wasted.
Also, note that there have been personnel arriving originally in the Shuttle, then the Soyuz nearly every 6 months for 20 years. While the shuttles came home intact (mostly) the Soyuz jettisoned 2/3 of their components to burn up in the atmosphere. AND those Soyuz are One-Use craft, either trashed, melted down for scrap, or to become the occasional museum piece. Soon, Dragon and Starliner will be delivering astronauts. But only the Dragon is designed for reuse. In addition, consider the large quantity of “waste” that is packed into the departing cargo units to burn up in the atmosphere … More stuff that could be repurposed!
So we propose repurposing most of the ships and components that are delivered to the ISS, to be ferried to lunar orbit, and EML2. To be assembled into a larger Mars Ship. Now while this will get supply/storage components to EML2, it will not necessarily get people … lots of people there for the large ship to carry to Mars.
But by using the EML-1, EML-2, and Lunar Settlements as both passenger and cargo terminals, we can move larger groups of both between Earth and Deep Space more economically, efficiently, and most importantly – sustainably.