The logical container size is standard twenty foot unit used in international shipments all over the world today. 3 abreast and stacked 3 or 4 high they would easily fit in the expected vehicle and when un2l8oaded from the MCT/lander they will be movable by truck (something no one else seems to be thinking of)0.Pressurized habitation modules might be larger, about the size of the Destiny module or a MPLM and carry an integrated 'cage' frame which allows them to be bolted down f8or transport. I believe most cargo will be un-pressurized and pressurized containers will be almost exclusively for crew.
Cubic pressurised containers do not work well.
Why not hexagonal standard container to allow for a better use of the available volume? Also for pressurised cargo, a cylindrical pressure container inside a hexagonal frame does not waste too much space or mass. Cylinder inside a standard shipping container sounds much more wasteful, both on the inside as well as for fitting in the BFS outer frame.
Standard 20ft containers are ideal because they would be movable AFTER getting to Mars,
a single massive pressurized container is essentially immovable once landed
Agreed, for cargo. People won't be coming or living in a container though.
Quote from: envy887 on 06/08/2016 01:28 amAgreed, for cargo. People won't be coming or living in a container though.Google "shipping container homes" it's not just doable but downright trendy.
Standard 20ft containers are ideal because they would be movable AFTER getting to Mars, a single massive pressurized container is essentially immovable once landed and landing zones will need to be re-used so you need to clear out everything as the vehicle unloads not simply leave it strewn about. If you tried to connect the large pressurized module to the existing base via some kind of tunnel-tube then that would force the MCT to land dangerously close to the settlement. Thus the only viable container is one that is easily road transportable over the several miles that connect landing zone to the settlement. While a smaller container say the size of a pallet might work for very small settlements the shipping container has already been found to be ideal on Earth in exactly this situation where a large vehicle needs to be unloaded quickly and the cargo distributed by roads.These shipping containers will be dimensionaly identical to Earth ones, but built of far more light weight materials such as lithium-aluminum or carbon-fiber. They will need to be strong enough to take several g's when underneath a stack of ~3 other containers, they may also need to take significant tensile loads depending on what then entry orientation of the MCT is.They will not be pressurize and will carry only building materials equipment or smaller containers which are air-tight, most food-stuffs are pouched and dried and can be exposed to vacuum or kept in a larger container at very low pressure, just enough to prevent out-gassing, wrapped frozen foods, dry goods like cereal grains, vegetables etc all would be fine in vacuum. Everything else man-made we can think of is likewise going to be fine, electronics and machinery even if they are intended for use in pressurized space so long as they are off and not generating heat will be fine.I think people are misunderstanding the ISS resupply process, they send most cargo in pressurized containers because of the pressurized berthing process and the by-hand unloading, not because the cargo itself can't withstand a vacuum. Once your into large logistical volume you would be unloading pallets from a 20ft container using pallet-jacks, with either the whole container put into an air-lock for shirt-sleeve unloading, or the containers can be dropped next to the base and a pallet-jack robot can move them into a small air-lock and a person inside unloading the airlock each cycle.
It won't be trendy in places where the air inside is trying to blow the container in every direction with over 1,000,000 lbf of net force.
So you want different container shapes for pressurised vs unpressurised? Because at some point you ARE going to need pressurised containers, and box shaped ones are not going to work (too heavy).
...Leveraging these cargo containers to the point that they can serve double duty as habitable volume is the best solution IMO, unless the MCT can be built in such a way that it can land cargo modules an entire order of magnitude larger.
There's no real reason to return an empty cargo hold or pressure vessel to Earth. Just bring back the fuel tanks and engines.