Ensuring that a Mars Colony has a solid supply chain will be a difficult task. The average distance between Earth and Mars is around 225 million kilometers, and transit times – even with greatly improved rockets – are several months. Light itself can take nearly half an hour to travel the distance, depending on how far apart the two planets are. And there is little margin for error, as tens of thousands of lives will be at stake.
Supply Chain Management
In general, supply chain management is a vast and complex topic, best described by people with far more expertise than I. There are a few specific points that I wanted to discuss here though.
The Mars colony will likely be supplied by a number of relatively large ships that travel back and forth between Earth and Mars.
At each end of the trip, they will remain in space, and will be loaded and offloaded by a number of other craft. In order for the process to be economically feasible, they will need to be able to transport a large amount of cargo – for the sake of simplicity let’s assume a minimum of around a kiloton of supplies, equipment and passengers.
Since the rockets that travel up and down the gravity well can carry much smaller loads (the largest rockets on Earth can currently carry a few tens of tons to Low Earth Orbit), it will take numerous trips in order to complete the process at either end.
It is conceivable that the loading process may take weeks to complete – and this means that even a ship that can travel significantly faster than anything we can currently build will have a practical minimum turn-around time on the order of months. This point is important.
Earthly manufacturing processes have tended in the past few decades towards something called Just In Time (JIT) Manufacturing.
The concept is that components arrive in sufficient quantities at just the right moment for them to be used in the assembly of more complex items (I’ll use the acronym SKU – or stock keeping unit – below). Manufacturers use JIT because it costs money to keep large supplies of components on hand – both with regards to purchase and storage costs.
JIT is controlled by complex computerized systems that communicate between the manufacturers of different components, and that have detailed models for how long it will take for things to arrive, and when things are needed.
Shipping delays can cause havoc in a tightly timed and intertwined process. If there are several levels of manufacturers that use each others’ components, and any number of retailers relying on specific numbers of SKUs at specific times, a minor delay can result in empty shelves.
A supply chain to Mars is going to be complicated in a number of ways:
- It takes several months for parts to arrive. There is an enhanced risk of components being delayed, or not arriving at all.
- There are far fewer craft making the journey, so a delay can mean bumping other critical SKUs off of the next trip.
- There is little margin for error since the items being sent are likely to be critically important.
The implication is that JIT methods will either have to be abandoned or heavily modified in order to supply the colony. Significant stockpiles of critical components will be needed, and in addition there will need to be an early emphasis on setting up local manufacture for as many SKUs as feasible.
Another quick point before I move on:
Much of the equipment required is going to be bulky and heavy. A heavy bulldozer can weigh more than 15 tons. That’s before adding a pressurized compartment, and heavy battery packs (petroleum powered bulldozers aren’t likely to be feasible).
Equipment on this scale will likely be delivered in pieces, and then assembled on site.
Even a ship with cargo capacity of a thousand tons will only be able to carry limited numbers of such SKUs, particularly when the primary emphasis is going to be transporting things like food.
Balancing items that are necessary for the long term (i.e. construction, mining and manufacturing equipment) with short term necessities is going to be tricky.
We’re all familiar with how poorly designed cities can make life uncomfortable and inconvenient for their inhabitants. On Earth this is a nuisance, but in an inhospitable place like Mars, this can cause serious, life-threatening problems.
Good urban planning often tries to mix usages, in order to minimize travel times (i.e. a community would have a mixture of residences, stores and offices, for instance).
Maintaining a significantly high enough residential density will be critical on Mars, because the infrastructure for individual vehicles within cities isn’t going to be available for a long time. With no petroleum, batteries being largely imported at great cost, and electricity required for life support and manufacturing, the colony will initially need to largely commute by foot.
This implies a design that minimizes distances.
However, there are converse requirements as well – nobody wants to live next to a mine (even one that supplies the air you breath) or a manufacturing plant, and furthermore there will need to be a heavy emphasis on multiple redundancy, which may require separating parts of the colony from each other.
The design for the layout of the colony will need to balance these, as well as many other requirements in order to create a functional and viable community.
One possibility would have several dense residential areas in a cluster, with separate clusters for mining and manufacturing. These would need to be connected by some form of mass transit system – which again would either need to be imported at great cost, or built locally.
Mars Colony Administrator’s Handbook – Navigation:
- Part 1 – Introduction
- Part 2 – Resources, Water
- Part 3 – Air, Food
- Part 4 – Energy, Raw Materials, People
- Part 5 – Supply Chain Management, Urban Planning
- Brief Intermission
- Part 6 – Jurisdiction and Law, Economics
- Bonus Post
- Part 7 – Manufacturing, Communications
- Part 8 – Emergency Services, Failure Modes