Author Topic: Standardized container cargo system for Cargo MCT  (Read 23440 times)

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Since it is the intent of the cargo MCT for it to be reused by sending it back to Earth, the cargo must be offloaded at Mars. If it is in a standard container pressurized or unpressurized then to handle all cargo only requires a single simple system to perform the offload.

Further since half of all cargo at first will be pressurized it will need a container complete with thermal control, power (batteries) and hookups as well as airlock like hatch entry to maintain internal pressure. This container can also be a habitat module just that it is shipped on a cargo flight full of supplies. If the cargo to crew flight ratio is 10 to 1 and half containing habitat modules full of crew supplies then the Mars base will be quite roomy 5X the size per person of the crew MCT. If the MCT has a capability of transporting a container of 1000m^3 volume then the initial base could have several 1000m^3 of habitat volume for the first crews. Growing by 10s of 1000m^3 of volume each synod.  It is possible that by the 5th synod the base could have as much as 50,000m^3 of habitat volume. Enough space for 500 persons to have a person to volume ratio of 1 person to 100m^3.

If the pressurized containers utilize CBM like hatchways and a hexagonal shape as new cargo arrives it is delivered to the base and mated to an external CBM growing the complete size of the base covering more and more area. Also by concentrating radiation shielding only in the top and much less in the sides to almost none, a lot of weight and more efficient use of volume can be saved. Also the containers could then be unpacked by the base personnel just by opening the hatch once connected to the base. This does bring up the question on what to do with the trash?

But it would also be advantageous to also use a container for the unpressurized cargo as well. Some of it may be specialized factories that would become a part of the base but is best not pressurized. It could still have the CBM connections and possibly even airlocks for easy crew access to its internals. These would be unique singe item designs but of a standard external shape and size. Other containers would have outside equipment that would require probably human teams to unpack either in space suits or through teleoperated robots. But still the biggest problem is offload and transport from landing/takeoff field to the base. If all use a single set of handling equipment design then operations at Mars become significantly easier.

Offline The Amazing Catstronaut

  • Full Member
  • ****
  • Posts: 1071
  • Arsia Mons, Mars, Sol IV, Inner Solar Solar System, Sol system.
  • Liked: 755
  • Likes Given: 628
Re: Standardized container cargo system for Cargo MCT
« Reply #1 on: 06/06/2016 04:03 AM »
I like this suggestion - it provides an easy road to expansion by vastly simplifying the volume requirements laid upon the the different colonial elements. In addition, the habitats could be widely reconfigurable. Recreational/residential equipment could fold sideways into the floor and walls, maximising volume for cargo stowage during flight, and providing the option for the area to be repurposed later on. Hell, most of the equipment within the base could have common attachment nodes to the floors of the habitats, permitting a habitat to become a gym, an aquaculture, a warehouse, a family residence, a hospital, a lab, a factory, depending on the requirements of the colonists. They can reconfigure the colony according to their needs.
Resident feline spaceflight expert. Knows nothing of value about human spaceflight.

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo MCT
« Reply #2 on: 06/06/2016 05:10 AM »
Too often the logistics considerations take a back seat, but for Mars they should be front and center. Cargo MCTs should be loaded and unloaded like container ships at a port.

The only problem I see is that first Cargo MCT being unloaded to get the unloading equipment out to unload the other cargo MCTs.

Offline GWH

Re: Standardized container cargo system for Cargo MCT
« Reply #3 on: 06/06/2016 05:30 AM »
Yes. I posted very similar ideas in other threads. Personally I've worked on a few projects designing sawmill equipment to be containerized or built in a manner where the structure does double duty for loading with shipping containers. Different environment but same principle of building for cost effectiveness within shipping constraints.
It is a very efficient method of construction in remote areas and modularity like that will be key to build a colony IMO.

Offline biosehnsucht

  • Full Member
  • *
  • Posts: 181
  • Liked: 44
  • Likes Given: 52
Re: Standardized container cargo system for Cargo MCT
« Reply #4 on: 06/06/2016 06:11 AM »
TL;DR: Interplanetary Intermodal containers

I think there's an argument to be made for habs-as-containers (instant hab, pressurized cargo, etc), but there may also be uses for cargo containers that aren't pressurized.

For example, if you wanted to move some large construction equipment, you could either just tie it down to the cargo floor as-is or containerize it (making loading and unloading easier, as well as using the negative spare around it since you could pack the space around it and have it attached to the walls of the container).

Once you get said container down, you could in theory pop the walls off (so it's just edges and some cross braces), easily detaching the wall-attached items from the frame, drive the equipment out, etc, and now you have a reasonably sturdy frame... you could then put a few of these next to each other, with all but the 'interior' walls attached, slap an airlock or two on some ends instead of the regular ends, bury it in martian soil and go in and seal up the walls to make a larger hab space.

Granted, expandable habs may be a better bet ...

Another possible use is you could also not seal it, but use it as a garage (so still martian pressure, but more or less out of the way of dust etc, opening it only when needed to move equipment in and out).

In either case, I think it's almost guaranteed there will be some kind of standardized shape/size of cargo for handling (so that there's one side fit all crane to get it out, if the cargo hold is above the propellant tanks rather than below it, or PODS-style container movers can be used to move them into position away from the MCT). There would most likely be more than one kind of container, but they would all be interchangeable in exterior dimensions.

Offline Hotblack Desiato

  • Full Member
  • ***
  • Posts: 339
  • Austria
  • Liked: 64
  • Likes Given: 40
Re: Standardized container cargo system for Cargo MCT
« Reply #5 on: 06/06/2016 08:12 AM »
From what I have gathered (there is a thesis presentation somewhere on the forum, regarding retropropulsion during atmospheric reentry, and someone asked Musk on Twitter, he confirmed that it will work somehow like this), the MCT has a cylindrical container below the actual MCT (the part that will go back into space). The craft lands, gets refuelled, detaches from the container and lits its engines, leaving the container back on the surface.

This means, that the container must have its own heatshield, and that the MCT just uses its own heatshield for earth atmosphere reentry. But this also means, that the MCT-container dimensions are tied to the diameter of MCT, much like the standard TEU containers are tied to the dimensions for road transportability.

For cargo, the system should be quite simple, just have either a pressurized or unpressurized compartment, both with basic power supplies (even unpressurized goods may require heat or electricty).

The pressurized cargo container could have some sort of expandable outer hull (bigelow-style), so it can increase its storage volume. Obviously, the system can only expand its hull after MCT departed (otherwise the engines would burn a few big fat holes into that skin). This could be useful for fuel storage by installing flexible bladder tanks inside. Since fuel just requires a gas-tight structure, and some thermal insulation, it doesn't need to be very thick (5cm would be enough).
With a thicker expandable hull, it could be even suitable as extra internal space for living quartiers. It needs obviously some sort of floor installed.

Those containers are challenging from an engineering point of view, because they might even require some sort of air lock (or multiple air locks) as part of that expandable hull. And they may remove sharp rocks around it prior to expanding.

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo MCT
« Reply #6 on: 06/06/2016 03:15 PM »
This is something like what you described. It was posted on the MCT thread.
http://forum.nasaspaceflight.com/index.php?topic=37808.msg1545272#msg1545272

Go back to that Max Fagin (former SpaceX intern) retropropulsion thesis defense video.

Whole vehicle lands, but only an upper portion returns to Earth. If the propulsion is in the upper portion (Dragon 2 heritage) the left behind cargo section can be used for most anything; habitation, cargo, or perhaps a dual  purpose.

How about some stripped down cargo sections hauling expandable & repurposeable tanks full of distilled water (thinking Thin Red Line's expandable tank tech.) AKA, 'how to ship hydrogen and oxygen without cryocollers', and the cargo bay volume could be repurposed for colony use later.



Offline the_other_Doug

  • Senior Member
  • *****
  • Posts: 2490
  • Minneapolis, MN
  • Liked: 1520
  • Likes Given: 2687
Re: Standardized container cargo system for Cargo MCT
« Reply #7 on: 06/06/2016 04:58 PM »
Too often the logistics considerations take a back seat, but for Mars they should be front and center. Cargo MCTs should be loaded and unloaded like container ships at a port.

The only problem I see is that first Cargo MCT being unloaded to get the unloading equipment out to unload the other cargo MCTs.

Um, yeah.  It's the old conundrum -- the first factory you build has to be a factory for building other factories.  Only after your first factory builds other factories do you actually start producing the materials you need.

It's almost a chicken-and-egg situation.  In this case, though, you can design a one-time unloading system that lets you deliver and set up your big, efficient unloading system for the second cargo ship.  The only question is, can all of these operations be not only automatic but fully autonomous?

We'll have to wait and see how SpaceX wants to handle it.  Which, of course, means waiting until at least this coming September... sigh...
-Doug  (With my shield, not yet upon it)

Offline Kansan52

  • Full Member
  • ****
  • Posts: 867
  • Hutchinson, KS
  • Liked: 259
  • Likes Given: 307
Re: Standardized container cargo system for Cargo MCT
« Reply #8 on: 06/06/2016 05:15 PM »
The CBM like (lite?) hatches are a good idea. A pressurized vehicle come up to the CBM, latches, you open from the pressurized vehicle. This vehicle could be stored in and unpressurized container, have an expandable body, and away you go.

The containers could be attached to nodes. One node could have an airlock so all the containers in the group can share that airlock.

Of course, you now have a trailer park in an area with lots of swirling winds!  ;)

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo MCT
« Reply #9 on: 06/06/2016 05:35 PM »
There is another aspect to the container system that is overlooked by the traditional space launch and that is simplified LV/payload processing.

The down side for the Cargo MCT is that the container could be very big (up to 15m diameter and up to or more than 15m tall) and not be able to be transported easily. This then would suggest another co-located factory with the one that makes BFR's and BFS's to assemble the container and to then fill them with the cargo prior to the short trip to the launch site for loading on the next launch. Initially I see the rate of container manufacture to be ~1/month. At Musks 10:1 cargo to crew mission ratio this would be only enough to support 2 maybe 3 crew missions per synod. The whole thing here is to get the costs down from end to end of the cargo costs delivery to Mars:
- Purchasing (or building) the cargo in mass quantity in nearly OTS (off the shelf industrial quality)[if it breaks replace it so send replacement parts or even replacement complete systems]{NOTE: for use inside the pressure habitat industrial quality as long as it meets safety requirements makes OTS hardware even though it may weigh more than specifically designed lightweight systems in the long run be cheaper},
- Assembly of container near launch site,
- Container cargo launch to be contents agnostic [same shape, connections (power, thermal, comm), weight, moments and CG],
- Handling can be more automated because of the external sameness of all containers, and
- No LV integration required on most containers (there will always be a few exceptions)

The whole intent is to accomplish the task of building a colony for the lowest costs, not trying to minimize weight or to pack more stuff per trip or anything else. What results in lowest costs overall.

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo MCT
« Reply #10 on: 06/06/2016 05:48 PM »
The CBM like (lite?) hatches are a good idea. A pressurized vehicle come up to the CBM, latches, you open from the pressurized vehicle. This vehicle could be stored in and unpressurized container, have an expandable body, and away you go.

The containers could be attached to nodes. One node could have an airlock so all the containers in the group can share that airlock.

Of course, you now have a trailer park in an area with lots of swirling winds!  ;)
The containers used as habitats would need some sort of leveling system to level the add on container to the others already there and also there will need to be some sort of anchoring method to attach to the feet to the ground similar to the systems used to anchor pre-manufactured homes. They are certified to Hurricane CAT 2-3 level winds (120mph). There is some safety in this in that each container/habitat can be made to be briefly (several days) of stand alone life support. The CBM like connections between container/habitats is the same double hatch system as used on the ISS that alow atmosphere isolation from either side. Basically if the pressure starts to drop more in one side vs the other the doors close using the pressure differential to secure the door. There will need to be a few airlocks also included in the design to handle going outside or for when a container has depressurized and a crew needs to enter and fix the leak or to escape the depressurized container.

Offline Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8621
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 5370
  • Likes Given: 3555
Re: Standardized container cargo system for Cargo MCT
« Reply #11 on: 06/06/2016 05:51 PM »
in this scheme does the entire long side of a container need to be airtight when mated to an adjacent one and the interior walls removed? That's a fairly tall order I think. Requires some very stable foundations I would expect.

Not undoable. But I could see them using something flexible and a several centimeter gap, so that the joins don't have to be perfectly aligned. Put bridge plates on the floor at the joint and put plates on the walls and ceiling to protect the flexible material.

Think how an articulated tram/streetcar/bus has accordion pleating joints between sections.
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline the_other_Doug

  • Senior Member
  • *****
  • Posts: 2490
  • Minneapolis, MN
  • Liked: 1520
  • Likes Given: 2687
Re: Standardized container cargo system for Cargo MCT
« Reply #12 on: 06/06/2016 06:00 PM »
- Container cargo launch to be contents agnostic [same shape, connections (power, thermal, comm), weight, moments and CG]

The one thing you note that will likely be impossible is a common CG in each container.  With the vast variety of things that will be packed into these containers, the best you'll be able to hope for is an accurate assessment of the CG of each container, so each one can be loaded appropriately to try and trim up the CG of the BFR/BFS as a whole.

Also, these containers will have much more stringent tie-down requirements than any shipboard or even airborne containers out there today.  It needs to sustain, what, at least 5G acceleration and an instantaneous change from 5G to zero-G and back to something like 1G or 2G when the second stage kicks in, and then from the stage 2 max acceleration back to instantaneous transition to zero-G.  Your tie-downs have to be designed to handle that kind of stress.  Not to mention the deceleration stresses upon EDL at Mars.

But as for the CG issue, I think SpaceX will need to stretch the current state of the art a bit to get the accuracy they will need for the CG and mass distribution of each container, along with a proper analysis of maximum stress points within each container (and thus, where to check for strong-enough tie-downs in each container).  It may be a challenge initially -- I hope we don't lose an entire BFR upon launch because either the containers' CGs weren't figured correctly, or because a tie-down broke and mass shifted...
-Doug  (With my shield, not yet upon it)

Offline the_other_Doug

  • Senior Member
  • *****
  • Posts: 2490
  • Minneapolis, MN
  • Liked: 1520
  • Likes Given: 2687
Re: Standardized container cargo system for Cargo MCT
« Reply #13 on: 06/06/2016 06:08 PM »
Also, I think that these "CBM-like hatches" that are being discussed for the containers should be modified in our thinking to something more like "submarine-type hatches".  They will be supporting people walking between chambers, not floating.  They will likely have shin-breaking 50cm tall bottom sills, but should be more like two to two and a half meters tall, to allow even your tallest crewperson to walk through them without also risking head trauma... ;)

I like the idea of the containers being inflatable and, once emptied of surface equipment (and unstowed of in-hab equipment) become your hab spaces.  Economies of all kinds inherent in that concept... :)
-Doug  (With my shield, not yet upon it)

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo MCT
« Reply #14 on: 06/06/2016 06:27 PM »
in this scheme does the entire long side of a container need to be airtight when mated to an adjacent one and the interior walls removed? That's a fairly tall order I think. Requires some very stable foundations I would expect.

Not undoable. But I could see them using something flexible and a several centimeter gap, so that the joins don't have to be perfectly aligned. Put bridge plates on the floor at the joint and put plates on the walls and ceiling to protect the flexible material.

Think how an articulated tram/streetcar/bus has accordion pleating joints between sections.
The envisioned is a slightly flexible CBM like connection between containers at 60 degree intervals around the circumference to account for temperature effects of shrinkage and expansion. This could simply be a flat plate area that can flex in and out like a drum head. Normally the pressure would exert a significant force pushing the CBM connections together. Use of an accordion would not really be necessary if the modules are place correctly and pushed together and anchored. Additionally a centrally located CBM top and bottom could also be done with sufficient structural elements around the sides to be able to stack the containers. Instant condo ;D

The sides are not expected to be removed. A ~1500m^3 container of ~14m diameter would be 10m tall. That is a very large empty space compared to the ISS experience. Three stories of 153m^2(1660 sqft) of floor space each level. Each level is equivalent of a 3 bedroom house. These things are not small.

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo MCT
« Reply #15 on: 06/06/2016 06:33 PM »
Also, I think that these "CBM-like hatches" that are being discussed for the containers should be modified in our thinking to something more like "submarine-type hatches".  They will be supporting people walking between chambers, not floating.  They will likely have shin-breaking 50cm tall bottom sills, but should be more like two to two and a half meters tall, to allow even your tallest crewperson to walk through them without also risking head trauma... ;)

I like the idea of the containers being inflatable and, once emptied of surface equipment (and unstowed of in-hab equipment) become your hab spaces.  Economies of all kinds inherent in that concept... :)
Yes, envisioned would be exactly like you described vs the ISS round CBM except for top and bottom CBM ports if they are added to the container design.

There would also be the possibility of a slight ramp that retracts down when the door closes to eliminate the trip factor and sill damage for airtight seal. This allows use of wheeled carts for movement of items between habitat/containers.

Offline Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8621
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 5370
  • Likes Given: 3555
Re: Standardized container cargo system for Cargo MCT
« Reply #16 on: 06/06/2016 07:38 PM »
in this scheme does the entire long side of a container need to be airtight when mated to an adjacent one and the interior walls removed? That's a fairly tall order I think. Requires some very stable foundations I would expect.

Not undoable. But I could see them using something flexible and a several centimeter gap, so that the joins don't have to be perfectly aligned. Put bridge plates on the floor at the joint and put plates on the walls and ceiling to protect the flexible material.

Think how an articulated tram/streetcar/bus has accordion pleating joints between sections.
The envisioned is a slightly flexible CBM like connection between containers at 60 degree intervals around the circumference to account for temperature effects of shrinkage and expansion. This could simply be a flat plate area that can flex in and out like a drum head. Normally the pressure would exert a significant force pushing the CBM connections together. Use of an accordion would not really be necessary if the modules are place correctly and pushed together and anchored. Additionally a centrally located CBM top and bottom could also be done with sufficient structural elements around the sides to be able to stack the containers. Instant condo ;D

The sides are not expected to be removed. A ~1500m^3 container of ~14m diameter would be 10m tall. That is a very large empty space compared to the ISS experience. Three stories of 153m^2(1660 sqft) of floor space each level. Each level is equivalent of a 3 bedroom house. These things are not small.

Someone in this thread said something about taking entire walls off from adjacent containers to make larger work spaces. So that's what I was referring to there.

I would dispute that you can get away without accordions, unless you are sure that there will never be any quakes, any settling, any shifts, etc.
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo MCT
« Reply #17 on: 06/06/2016 08:04 PM »
in this scheme does the entire long side of a container need to be airtight when mated to an adjacent one and the interior walls removed? That's a fairly tall order I think. Requires some very stable foundations I would expect.

Not undoable. But I could see them using something flexible and a several centimeter gap, so that the joins don't have to be perfectly aligned. Put bridge plates on the floor at the joint and put plates on the walls and ceiling to protect the flexible material.

Think how an articulated tram/streetcar/bus has accordion pleating joints between sections.
The envisioned is a slightly flexible CBM like connection between containers at 60 degree intervals around the circumference to account for temperature effects of shrinkage and expansion. This could simply be a flat plate area that can flex in and out like a drum head. Normally the pressure would exert a significant force pushing the CBM connections together. Use of an accordion would not really be necessary if the modules are place correctly and pushed together and anchored. Additionally a centrally located CBM top and bottom could also be done with sufficient structural elements around the sides to be able to stack the containers. Instant condo ;D

The sides are not expected to be removed. A ~1500m^3 container of ~14m diameter would be 10m tall. That is a very large empty space compared to the ISS experience. Three stories of 153m^2(1660 sqft) of floor space each level. Each level is equivalent of a 3 bedroom house. These things are not small.

Someone in this thread said something about taking entire walls off from adjacent containers to make larger work spaces. So that's what I was referring to there.

I would dispute that you can get away without accordions, unless you are sure that there will never be any quakes, any settling, any shifts, etc.
I think he was referring to using the unpressurized containers to build a larger open space by using the structural elements of the container without the sides if they had any to begin with. By stacking several and by logically orienting them, a large open space could then be created by welding plates on the sides top and bottom. An area of some multiple of the container volume could be created (it would still have the structural supports in the inside to hold up the the sides and roof) so that say a park could be created that is like 50,000-100,000m^3 of open space. An open space of say 30m high by 75m in diameter. Would involve ~57 container frames.

Offline Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8621
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 5370
  • Likes Given: 3555
Re: Standardized container cargo system for Cargo MCT
« Reply #18 on: 06/06/2016 08:10 PM »
ok.

I would still dispute that for regular container to container joints that you would just use a press-fit or even bolts, because as you got bigger and bigger, the end containers will be under increasing strain if things shift.

Even here on earth, large buildings get expansion joints or earthquake fault line joints.
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo MCT
« Reply #19 on: 06/06/2016 08:21 PM »
ok.

I would still dispute that for regular container to container joints that you would just use a press-fit or even bolts, because as you got bigger and bigger, the end containers will be under increasing strain if things shift.

Even here on earth, large buildings get expansion joints or earthquake fault line joints.
Yes a definite problem such that there may be a max number of clustering of containers with a significant expansion joint connection between clusters. But once the base has gotten big enough for that to be a problem (number of containers >7 there will be over a hundred inhabitants possibly several hundred. Each cluster being a community almost with clusters customizing for a particular activity.

Offline Impaler

  • Full Member
  • ****
  • Posts: 1283
  • South Hill, Virgina
  • Liked: 362
  • Likes Given: 0
Re: Standardized container cargo system for Cargo MCT
« Reply #20 on: 06/07/2016 01:16 AM »
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.

Offline Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8621
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 5370
  • Likes Given: 3555
Re: Standardized container cargo system for Cargo MCT
« Reply #21 on: 06/07/2016 01:37 AM »
Making the containers the same standard size as terrestrial ones, as long as there are no serious technical impediments, is really thinking ahead to when there is so much cargo volume that it matters. Good point, Impaler.
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline biosehnsucht

  • Full Member
  • *
  • Posts: 181
  • Liked: 44
  • Likes Given: 52
Re: Standardized container cargo system for Cargo MCT
« Reply #22 on: 06/07/2016 05:55 AM »
I will be surprised if they go with the concept of dropping off one giant 15m container, I took Elon's response of being "something like that" or whatever he said to mean the overall architecture of sending and landing a 2nd/upper stage from Earth to Mars, then sending it back as single stage to earth landing. That requires a lot of additional mass (structure for carrying G-loads between them, cosine losses and more propellant or complicated engines that can articulate out beyond the craft .. and more propellant, large parts of the MCT which are left on the surface that must be built new each flight, extra heatshield, etc...). Seems at odds with the simple and cost and/or mass optimized approach SpaceX normally takes.
Having said that, being able to directly deposit a 15m hab module or nuclear reactor etc is pretty compelling.

Regardless of how they get them there, since they can't use off-the-shelf intermodal containers, I would expect exact dimensions to be tweaked a bit (probably using purely metric and sane dimensions for starters, rather than weird odd # of mm in a given dimension because it was originally specced in imperial). They would probably also be optimized for reducing wasted volume in the cargo bay (whether it is integral to the BFS or dropped off as a separate module).

As far as moving them around on the ground, I was suggesting something like the PODS "Podzilla" : - only I would change it a bit to attach to the top of the container (much like container cranes can attach to the top of an intermodal container) rather than lift with chains hooked to the bottom (less wobbly). BEV and/or series hybrid (CH4/GOX, I'd assume) power unit on a 4-post frame with each post having a set of wheels, and method of lifting/leveling the corners (so you can pick up, move, and level the container) - possibly a hydraulic system, but possibly a pure electrical system (depending on how the trades for mass vs complexity vs ... etc go for that).

I wasn't suggesting that you could indefinately "stack" containers horizontally, but a few containers (3-5 surely) could be done this way. I wouldn't make any direct assumption about air tight seals just by bolting them together. Instead, after bolting them and covering as much exterior area as possible in soil and/or martian 'concrete' made from martian soil (leaving openings just where necessary for power/data/hatches/etc).

I would then go around all areas where there are joints (including the joints internal to a given container, not just between adjacent ones) with some sort of semi-flexible sealant appropriate to a Martian-adjacent environment (temps / pressures / etc) which would have enough give in it to not crack under the various stresses (flexing of containers as loads are moved around, temperature changes, etc), sort of like caulking around a bathtub (you don't want to use rigid grout, but a flexible seal).

Making some assumptions for what material science can provide for "martian container caulk", this should give you an air tight space, though this alone might not provide for a huge pressure differential, it should help keep dust out and provide a space with controlled environment (no wind, such as it is on Mars, and lighting whenever you need it).

Turning this into a pressure vessel may require either fancier material science than merely forming a seal, or covering it with an additional layer of some kind that would prevent pressure differentials from blowing it out. I don't think these are unsolvable problems, but probably best to leave habitats to habitats designed for it. Perhaps you could at least generate enough pressure safely to perform maintenance work on vehicles in just a jump suit of some kind with an oxygen mask (though you would need to go through a de/repressurization airlock like deep sea divers do in that case).

Offline JamesH65

  • Full Member
  • ****
  • Posts: 626
  • Liked: 364
  • Likes Given: 8
Re: Standardized container cargo system for Cargo MCT
« Reply #23 on: 06/07/2016 08:08 AM »
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.

I disagree. This is something that needs to be thought about without the preconceptions of existing container systems.

As an analogy, the F9 diameter is limited by road transport considerations, which were determined by height of bridges and tunnels which are determined by sizes of vehicles going back to Roman times. (http://www.snopes.com/history/american/gauge.asp). Well, not quite true, but you get the gist.

Point is, here we have no prior history to adhere to. It's an opportunity to make the optimum mechanism.


Online MikeAtkinson

  • Full Member
  • ****
  • Posts: 1680
  • Bracknell, England
  • Liked: 453
  • Likes Given: 53
Re: Standardized container cargo system for Cargo MCT
« Reply #24 on: 06/07/2016 08:15 AM »
Cubic pressurised containers do not work well.

Online envy887

  • Senior Member
  • *****
  • Posts: 2707
  • Liked: 1248
  • Likes Given: 780
Re: Standardized container cargo system for Cargo MCT
« Reply #25 on: 06/07/2016 12:54 PM »
Cubic pressurised containers do not work well.

And I doubt anyone would seriously propose them.

Online Semmel

  • Full Member
  • ****
  • Posts: 1124
  • Germany
  • Liked: 802
  • Likes Given: 2270
Re: Standardized container cargo system for Cargo MCT
« Reply #26 on: 06/07/2016 02:42 PM »
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.

Online envy887

  • Senior Member
  • *****
  • Posts: 2707
  • Liked: 1248
  • Likes Given: 780
Re: Standardized container cargo system for Cargo MCT
« Reply #27 on: 06/07/2016 03:47 PM »
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.

If SpaceX is adopting a system similar to the 100t lander roughly outlined in the video embedded upthread, then there might not be a need for individual pressurized modules. The lower half of the ~10m diameter spaceship would be left on the surface, and it could just be one large pressure vessel which is FAR more mass-efficient.

The concept changes a lot ideas around cargo handling since the tanks and engines return to Earth while the whole cargo hold is left on Mars, presumably to be entirely re-purposed and used. A passenger hab could just remain a hab, while a cargo module could have the aeroshell split off so containers could be lifted and carried away.

Offline ThereIWas3

  • Full Member
  • ****
  • Posts: 613
  • Liked: 262
  • Likes Given: 212
Re: Standardized container cargo system for Cargo MCT
« Reply #28 on: 06/07/2016 09:47 PM »
That was my thought - don't unload it at all, if what you are delivering is a "factory".  The only thing that has to unload from the first landings will be robot mechanical things that are presumably self-powered - they just drive off from a garage space at the lowest level.   ISRU machinery, tanks, and such can just stay where they are.
"If you want to build a ship, don’t drum up people to collect wood and don’t assign them tasks and work, but rather teach them to long for the endless immensity of the sea" - Antoine de Saint-Exupéry

Offline Impaler

  • Full Member
  • ****
  • Posts: 1283
  • South Hill, Virgina
  • Liked: 362
  • Likes Given: 0
Re: Standardized container cargo system for Cargo MCT
« Reply #29 on: 06/08/2016 12:34 AM »
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.


Online envy887

  • Senior Member
  • *****
  • Posts: 2707
  • Liked: 1248
  • Likes Given: 780
Re: Standardized container cargo system for Cargo MCT
« Reply #30 on: 06/08/2016 01:28 AM »
Standard 20ft containers are ideal because they would be movable AFTER getting to Mars,

Agreed, for cargo. People won't be coming or living in a container though.

Quote
a single massive pressurized container is essentially immovable once landed
Why? Once people and consumables are removed, it won't mass over 50 tons, which is less than 20 tons of weight on Mars. That's readily moveable with similar equipment to what container handling would require.
« Last Edit: 06/08/2016 01:46 AM by envy887 »

Offline biosehnsucht

  • Full Member
  • *
  • Posts: 181
  • Liked: 44
  • Likes Given: 52
Re: Standardized container cargo system for Cargo MCT
« Reply #31 on: 06/08/2016 01:40 AM »
It's entirely possible that each humans + cargo launch (and possibly also cargo only launch) will only fit (assuming ~20ft intermodal size) 4-6  containers in a single horizontal plane, with none stacked above them.

It's not hard to hit 100 tons with only 4-6 containers with some clever packing, especially if you can take the long sides off to more easily pack/unpack and fill "empty" space.

Offline GWH

Re: Standardized container cargo system for Cargo MCT
« Reply #32 on: 06/08/2016 06:50 AM »

Agreed, 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.

Online envy887

  • Senior Member
  • *****
  • Posts: 2707
  • Liked: 1248
  • Likes Given: 780
Re: Standardized container cargo system for Cargo MCT
« Reply #33 on: 06/08/2016 12:47 PM »

Agreed, 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.

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.

Offline JamesH65

  • Full Member
  • ****
  • Posts: 626
  • Liked: 364
  • Likes Given: 8
Re: Standardized container cargo system for Cargo MCT
« Reply #34 on: 06/08/2016 12:53 PM »
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.

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).

I would be interesting to know how much cargo can be transported unpressurised.

Offline GWH

Re: Standardized container cargo system for Cargo MCT
« Reply #35 on: 06/08/2016 04:13 PM »
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.

Of course they would need to be built to withstand internal pressure.  My point is specific to what can be done to increase the utilization of a mass manufactured goods transportation enclosure.  One that by it's own inherent construction simplifies the logistics of moving goods so that manufactured product can be moved in and out of shipping bottlenecks with as little fuss and cost as possible.

I disagree that these shipping containers should be built to be unpressurized as a majority.  It goes against the principle of using the transported goods enclosure and support structure to the greatest possible utilization as habitable volume.   Reducing the internal structure within an MCT to the bare minimum, shifting the task of load distribution to individual containers would go a long way to minimizing return mass and delivering the greatest usable volume to Mars surface.
If Mars Colonization is to happen the logistics of getting freight loaded on and off an MCT needs to be as cost efficient and expedient as possible, right down to road transport on Earth as the primary delivery mechanism of cargo containers.  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.   

Offline GWH

Re: Standardized container cargo system for Cargo MCT
« Reply #36 on: 06/08/2016 04:18 PM »

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).

A more mass efficient means (cylindrical) of building a pressurized container within a rectangular shipping frame isn't a deal breaker, see attached.  More elegant construction methods are very doable.

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo MCT
« Reply #37 on: 06/08/2016 04:28 PM »
My current WAG is 50% split initially. Without a great deal of self sufficient systems (farm, 3D printers, feedstock melters/formers, atmosphere recycle and production from Mars atmosphere) the base will need a lot of pressurized supplies. As the base matures more supplies/cargo will be un-pressurized (mining equipment, material processing, solar arrays, etc).

Having these supplies used inside the base shipped as un-pressurized will mean it all has to transition through an airlock. This is extremely time consuming and waste a lot of base atmosphere in purge Mars atmosphere and pressure cycling. Also dust control will be very difficult to manage as well with so many cycles.

If you design your pressurized container/habitat so that most of it can be manufactured from ISRU, this will also shift the % of type of cargo as well from bulk materials to complex machines/electronics. This would allow the base to increase its volume and provide even greater m^3 space per person than what was available initially.

The containers need to be simple constructable on Mars even though they may weigh more. Its not weight but costs that is important in the $/effective task/utility:
-cost of the equipment,
-shipping costs [trip on MCT to Mars $/kg, NOTE: SpaceX goal is to get this below $500/kg, initially it will be ~$8,000/kg],
-handling time loading and unloading [this is probably the most precious resource both on Mars and Earth], and
-other considerations such as multi use so that there is little dead weight shipped everything has a use on Mars especially pressurized containers)

Online envy887

  • Senior Member
  • *****
  • Posts: 2707
  • Liked: 1248
  • Likes Given: 780
Re: Standardized container cargo system for Cargo MCT
« Reply #38 on: 06/08/2016 04:46 PM »
...
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.   

I'm personally convinced MCT will do both of these, by landing a single 10m-ish container and leaving it on the surface. Unpressurized cargo versions would have aeroshells that readily be split in half and turned into 10m Quonset huts, while pressurized versions could just be inhabited without further construction.

There's no real reason to return an empty cargo hold or pressure vessel to Earth. Just bring back the fuel tanks and engines.

Offline GWH

Re: Standardized container cargo system for Cargo MCT
« Reply #39 on: 06/08/2016 07:12 PM »
There's no real reason to return an empty cargo hold or pressure vessel to Earth. Just bring back the fuel tanks and engines.

Only if said cargo hold was an intrinsic part to the required surface area and aerodynamic profile of the vehicle and it's re-entry to Earth.
That's where I'm split on the MCT and what I'm especially interested in for the September reveal.  The architecture loosely pictured by Max Fagin posted above would enable some truly massive modules to be deposited given the size of MCT that was leaked (enabling small apartment building sized modules).  But the HOW is a massive question, as that picture doesn't lend itself to efficient in-space propulsion that an entirely self contained architecture would.

Online envy887

  • Senior Member
  • *****
  • Posts: 2707
  • Liked: 1248
  • Likes Given: 780
Re: Standardized container cargo system for Cargo MCT
« Reply #40 on: 06/08/2016 08:00 PM »
The cosine losses from always having the engines gimballed way outboard do get annoying, but they are only ~3.5% if the gimbal is about 15 degrees. And once lift isn't a factor (which is a LOT of the flight profile for MCT), you can shut down all but 1 engine and thrust close to or right through COM... and the cosine loss goes close to zero.

If that allows you to always accelerate in the same direction (nose first launch, tail first reentry), then the savings on structure mass might more than make that up. And not having to return a huge, empty, cargo container to earth is a huge benefit, probably worth more than 3.5%, since the return fuel is a lot more expensive than Earth launch fuel!

Offline Impaler

  • Full Member
  • ****
  • Posts: 1283
  • South Hill, Virgina
  • Liked: 362
  • Likes Given: 0
Re: Standardized container cargo system for Cargo MCT
« Reply #41 on: 06/09/2016 03:25 AM »

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).

I would be interesting to know how much cargo can be transported unpressurised.

My current WAG is 50% split initially. Without a great deal of self sufficient systems (farm, 3D printers, feedstock melters/formers, atmosphere recycle and production from Mars atmosphere) the base will need a lot of pressurized supplies. As the base matures more supplies/cargo will be un-pressurized (mining equipment, material processing, solar arrays, etc).

Having these supplies used inside the base shipped as un-pressurized will mean it all has to transition through an airlock. This is extremely time consuming and waste a lot of base atmosphere in purge Mars atmosphere and pressure cycling. Also dust control will be very difficult to manage as well with so many cycles.

If you design your pressurized container/habitat so that most of it can be manufactured from ISRU, this will also shift the % of type of cargo as well from bulk materials to complex machines/electronics. This would allow the base to increase its volume and provide even greater m^3 space per person than what was available initially.

The containers need to be simple constructable on Mars even though they may weigh more. Its not weight but costs that is important in the $/effective task/utility:
-cost of the equipment,
-shipping costs [trip on MCT to Mars $/kg, NOTE: SpaceX goal is to get this below $500/kg, initially it will be ~$8,000/kg],
-handling time loading and unloading [this is probably the most precious resource both on Mars and Earth], and
-other considerations such as multi use so that there is little dead weight shipped everything has a use on Mars especially pressurized containers)


People are literally the only things that will travel pressurized, the pressurized containers will be different but they are not part of this topic because this is a topic about CARGO CONTAINERS.

So far no one has articulated a single type of cargo that actually NEEDS pressure, just a nebulous 'need' unsupported by any reasoning, or at best reflexive copying of ISS methodology.  The gap between the logistical paradigm need to do colonization and most commenters suggestions is huge.  We are not talking about an initial landing here were talking about logistics to support hundreds of thousands of tons of cargo a year.

Atlas Guy points to logistics of moving into and out of airlocks, but this ignores the fact that connecting a large pressurized container to a habitat is a very slow process, it takes hours in zero-g.

The kind of air-lock I'm suggesting would naturally be the size of a shipping container (cause it probably is a specialty container similar to the tank posted earlier) and hold nearly it's entire contents.  Dust is controlled by having a large tented garage like space covering the whole 'yard' where the containers being unloaded sit, containers enter the yard by truck through a dust trap, robots unload pallets and place them in the air-locks.  Or if we can send a large enough airlock (perhaps inflatable) then the whole container can go into it directly off the transport truck.

Empty containers are going to be accumulating on Mars clearly, but their are a million uses for them other then trying to LIVE in them, which is incredibly shortsighted because habitation on Mars is not just having a pressure vessel, it's having several tons of life-support equipment too.  Uses for disassembled containers would include using them as foundation slabs, roofing to support regolith over real habitats, melting down the aluminum and making simple rods and spare parts for virtually every other piece of machinery.  Their is literally no end of things you would do BEFORE trying to live inside a cargo container.

Now naturally their WILL be pre-fabricated living units sent to Mars and these could be in the shape of a container, but it's more likely to be an expandable Bigelow type habitat folded up inside the container.  Again that's a topic for another thread.

Offline JamesH65

  • Full Member
  • ****
  • Posts: 626
  • Liked: 364
  • Likes Given: 8
Re: Standardized container cargo system for Cargo MCT
« Reply #42 on: 06/09/2016 09:46 AM »

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).

I would be interesting to know how much cargo can be transported unpressurised.

My current WAG is 50% split initially. Without a great deal of self sufficient systems (farm, 3D printers, feedstock melters/formers, atmosphere recycle and production from Mars atmosphere) the base will need a lot of pressurized supplies. As the base matures more supplies/cargo will be un-pressurized (mining equipment, material processing, solar arrays, etc).

Having these supplies used inside the base shipped as un-pressurized will mean it all has to transition through an airlock. This is extremely time consuming and waste a lot of base atmosphere in purge Mars atmosphere and pressure cycling. Also dust control will be very difficult to manage as well with so many cycles.

If you design your pressurized container/habitat so that most of it can be manufactured from ISRU, this will also shift the % of type of cargo as well from bulk materials to complex machines/electronics. This would allow the base to increase its volume and provide even greater m^3 space per person than what was available initially.

The containers need to be simple constructable on Mars even though they may weigh more. Its not weight but costs that is important in the $/effective task/utility:
-cost of the equipment,
-shipping costs [trip on MCT to Mars $/kg, NOTE: SpaceX goal is to get this below $500/kg, initially it will be ~$8,000/kg],
-handling time loading and unloading [this is probably the most precious resource both on Mars and Earth], and
-other considerations such as multi use so that there is little dead weight shipped everything has a use on Mars especially pressurized containers)


People are literally the only things that will travel pressurized, the pressurized containers will be different but they are not part of this topic because this is a topic about CARGO CONTAINERS.

So far no one has articulated a single type of cargo that actually NEEDS pressure, just a nebulous 'need' unsupported by any reasoning, or at best reflexive copying of ISS methodology.  The gap between the logistical paradigm need to do colonization and most commenters suggestions is huge.  We are not talking about an initial landing here were talking about logistics to support hundreds of thousands of tons of cargo a year.

Atlas Guy points to logistics of moving into and out of airlocks, but this ignores the fact that connecting a large pressurized container to a habitat is a very slow process, it takes hours in zero-g.

The kind of air-lock I'm suggesting would naturally be the size of a shipping container (cause it probably is a specialty container similar to the tank posted earlier) and hold nearly it's entire contents.  Dust is controlled by having a large tented garage like space covering the whole 'yard' where the containers being unloaded sit, containers enter the yard by truck through a dust trap, robots unload pallets and place them in the air-locks.  Or if we can send a large enough airlock (perhaps inflatable) then the whole container can go into it directly off the transport truck.

Empty containers are going to be accumulating on Mars clearly, but their are a million uses for them other then trying to LIVE in them, which is incredibly shortsighted because habitation on Mars is not just having a pressure vessel, it's having several tons of life-support equipment too.  Uses for disassembled containers would include using them as foundation slabs, roofing to support regolith over real habitats, melting down the aluminum and making simple rods and spare parts for virtually every other piece of machinery.  Their is literally no end of things you would do BEFORE trying to live inside a cargo container.

Now naturally their WILL be pre-fabricated living units sent to Mars and these could be in the shape of a container, but it's more likely to be an expandable Bigelow type habitat folded up inside the container.  Again that's a topic for another thread.

Cargo that need to be pressurised and possibly heated (unpressurised means no heating)? Few things off the top of my head.

People
Basic Electronics (unless hardened)
Food stuffs (unless you really really ensure there are no air pockets in the packets)
Anything with mechanical bearings for surface use (can get round this)
Some plastics. In fact anything that cannot withstand very very low temperatures.

Sure there are lots more.


Online Lumina

Re: Standardized container cargo system for Cargo MCT
« Reply #43 on: 06/09/2016 10:41 AM »
It makes most sense if there is a single standardized pressurized module master design for everything, people, factories, workshops, garages and cargo.

- Because you would want to interconnect every module to create a large walkable interior space

- Because you want to maximize the pressurized volume and total extent of the base:
   
    - for psychological and comfort reasons

    - for safety reasons (multiple redundant options)
   
    - for productivity reasons (minimize EVA's required for equipment maintenance)

    - to maximize the growth rate of the size of the base

- Because you would prefer to minimize spare parts and design complexity to keep maintenance reqs down

- Because you would prefer almost all the base equipment to be operating "inside" in Earth-like conditions

- Because this is aligned with current SpaceX practice: the current cargo Dragon is pressurized.

So it makes sense that the cargo/hab/factory modules that BFS will be leaving behind on Mars might be standardized, modular, pressurized and ready to connect to the rest of the base using a standard system. In turn, to the extent that the standardization, modularity etc. become compelling design features for the future colony, this would inform the design of the entire MCT architecture so that the BFS can reliably deliver such modules to Mars surface, refuel and then return to Earth for more.

Of course a robotic system to pick up the modules from the point they were dropped off and walk them a few hundred metres to the base will also be needed. A square grid layout for the base would work well enough - hexagonal is probably more trouble than it's worth.

The master design of the module should probably have a water tank as its roof (which doubles as radiation shield) and a ground level consisting of all the "public" spaces, walkways and connection ports to adjacent modules. The middle level(s) and to some extent the ground level would be customized depending on the intended function of the module (e.g. hab, factory, medical center, etc). Alternatively, it might be better to put all the public spaces and walkway interconnections at high level just below the roof and locate the constantly inhabited areas closer to the ground. More radiation protection, and clearance between modules for rovers and robots to have access to any module from the outside.

(Note for Impaler: this is one articulation of reasons why everything should be pressurized. There are plenty more.)
« Last Edit: 06/09/2016 11:04 AM by Lumina »

Offline GWH

Re: Standardized container cargo system for Cargo MCT
« Reply #44 on: 06/09/2016 03:21 PM »
One thought I just had regarding benefits of pressurized cargo vessels is on the ground (Earth) processing.  Given the expectation or requirement that this is a multi-national effort one would reason that pre-processing of cargo and outfitting of habitats would be handled at a multitude of facilities and shipped to the launch site.  If the cargo vessel is a fully sealed and pressurized unit it can be shipped in a sterile state internally where only the exterior would need to be sterilized prior to loading.  In small scales I would think this would be overkill, but if one were looking at dozen's of MCT flights per synod the cost reduction through simplified logistics at the launch site could really add up.

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo MCT
« Reply #45 on: 06/09/2016 04:29 PM »
I just had an additional thought and that was increasing the MCT cargo content agnostic factor.
- Cargo container
   - Un-pressurized
   - Pressurized
     - Un-manned
     - Manned

The pressurized container/habitat module has all the equipment for support of humans during the flight it only need internal outfitting for human transport. Thus the basic MCT for manned and unmanned is identical only whether the container is outfitted to transport humans or just cargo.

The other thought is that if the pressurized containers are in 25mt load size (1/4 of the cargo volume) with each representing what amounts to a single floor when at Mars, 4 are shipped and only 1 is returned (100 people out only 25 back). This is the ultimate agnostic standpoint. The MCT is not specialized at all for any of its payload that it carries only the container are outfitted internally different. This also makes it possible to use for the trip back a different MCT (one that shipped plain cargo) than what was used on the trip out (that transported humans) without requiring any modifications. Just load the container with humans in it and launch from Mars surface.

Offline Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8621
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 5370
  • Likes Given: 3555
Re: Standardized container cargo system for Cargo MCT
« Reply #46 on: 06/09/2016 04:49 PM »
A lot of things can't handle zero pressure.  embryos and live animals, for example. A lot of foodstuffs. A lot of materials that would outgas.... I think pressure is going to make things a lot simpler, actually.
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo MCT
« Reply #47 on: 06/09/2016 07:36 PM »
A lot of things can't handle zero pressure.  embryos and live animals, for example. A lot of foodstuffs. A lot of materials that would outgas.... I think pressure is going to make things a lot simpler, actually.
Yes the farm. Seeds, shoots, algae, and fish embryos. Possibly other stuff such as dry fertilizers which if not pressurized will out-gas. These would be sealed up anyway but a flexible airtight bag vs a rigid container is a big difference. In fact the entire farm with all its stuff to get it going would be shipped probably as a special outfitted pressurized container. The farm has a great deal of complex equipment that it would be better to ship as a complete ready to use. Only a small amount of setup should be required by the residents.

Many of the confusion factors for foods comes from the term vacuum packed foods. This does not mean packed at 0 pressure but at a reduced pressure from sea level usually the 10Kft level or a bit higher. Packing at 0 pressure would destroy the food or basically supper freeze drying it. It would then take a lot of work to re-hydrate prior to being edible an even then it still may not be edible.

Offline Lobo

  • Senior Member
  • *****
  • Posts: 6674
  • Spokane, WA
  • Liked: 518
  • Likes Given: 313
Re: Standardized container cargo system for Cargo MCT
« Reply #48 on: 06/09/2016 10:09 PM »
in this scheme does the entire long side of a container need to be airtight when mated to an adjacent one and the interior walls removed? That's a fairly tall order I think. Requires some very stable foundations I would expect.

Not undoable. But I could see them using something flexible and a several centimeter gap, so that the joins don't have to be perfectly aligned. Put bridge plates on the floor at the joint and put plates on the walls and ceiling to protect the flexible material.

Think how an articulated tram/streetcar/bus has accordion pleating joints between sections.

Perhaps something like NASA envisioned some time ago.  But it wouldn't need to land itself.  Just have the wheels and legs that can be jacked up and leveled on feet.  Multiple units connected together with semi-flexible connectors.  Each unit could have up to four ports for connecting on 1, 2, 3, or 4 sides.


Offline Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8621
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 5370
  • Likes Given: 3555
Re: Standardized container cargo system for Cargo MCT
« Reply #49 on: 06/10/2016 01:34 AM »
I definitely think flexible couplings and doors to separate if there are issues but wonder about whether trenching is needed long term...
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo MCT
« Reply #50 on: 06/11/2016 02:04 PM »
I don't think trenching is the way to go for an expanding Base. Even if the clusters are all in a row. But the earlier suggestion of the water tanks on a layer at the top may be better in short term with then a solid sheet of something thin that is then cover with regolith on top over the older base clusters so that no regolith is between the modules only on top. The requirement would be a significantly sized flat plain separated by small hills from other significantly sized flat plains that can be used as the landing a launch areas. if the hills are more like sand dunes with access routes around them even better else the digging equipment would have to cut a S shaped access route to maintain protection of the base from launch and landing craft.

Alas I think we are getting to far away from just container discussion and into Mars Base design. I did not find any specific Mars SpaceX colony base design thread but several specific architecture designs threads most without regards to the SpaceX effort.

 It may be time for another SpaceX thread on discussion of "Spacex Mars base/colony design/architecture". The container thread and MCT design threads would affect and it would affect the other two.

Offline MickQ

  • Full Member
  • ****
  • Posts: 481
  • Australia.
  • Liked: 45
  • Likes Given: 132
Re: Standardized container cargo system for Cargo MCT
« Reply #51 on: 06/12/2016 12:38 AM »
in this scheme does the entire long side of a container need to be airtight when mated to an adjacent one and the interior walls removed? That's a fairly tall order I think. Requires some very stable foundations I would expect.

Not undoable. But I could see them using something flexible and a several centimeter gap, so that the joins don't have to be perfectly aligned. Put bridge plates on the floor at the joint and put plates on the walls and ceiling to protect the flexible material.

Think how an articulated tram/streetcar/bus has accordion pleating joints between sections.

Perhaps something like NASA envisioned some time ago.  But it wouldn't need to land itself.  Just have the wheels and legs that can be jacked up and leveled on feet.  Multiple units connected together with semi-flexible connectors.  Each unit could have up to four ports for connecting on 1, 2, 3, or 4 sides.

Once these modules are jacked up and connected together they will likely not be moved again so the wheels could be re-used on later arriving modules and/or vehicles such as trailers made on site to move people from the LZ to the base.

Offline biosehnsucht

  • Full Member
  • *
  • Posts: 181
  • Liked: 44
  • Likes Given: 52
Re: Standardized container cargo system for Cargo MCT
« Reply #52 on: 06/12/2016 02:59 AM »

Once these modules are jacked up and connected together they will likely not be moved again so the wheels could be re-used on later arriving modules and/or vehicles such as trailers made on site to move people from the LZ to the base.

This is why I proposed something like the PODS Podzilla, something that attaches to the container, moves it in place, then goes elsewhere. You could get by with just one in a pinch, but more would be helpful to speed things up.

Offline lamontagne

  • Full Member
  • ****
  • Posts: 1032
  • Liked: 1427
  • Likes Given: 232
Re: Standardized container cargo system for Cargo MCT
« Reply #53 on: 06/12/2016 03:50 AM »
Here is my suggestion for a standard container:
Fits snugly in a Skylon cargo Bay.
Fits in a Falcon 9 fairing.
A group of them could fit in an MCT cargo bay.
Pressurized, self heated, self powered, self cooled.  Insulated with multilayer insulation.
Connectable, stackable, buryable.
Has standard cargo ports at the ends, one male, one female.
Orange band is solar cells, black bands are radiators.
I've also included a view of an eventual nuclear OTV with a stack of them.

What do you think?



« Last Edit: 06/12/2016 03:54 AM by lamontagne »

Offline biosehnsucht

  • Full Member
  • *
  • Posts: 181
  • Liked: 44
  • Likes Given: 52
Re: Standardized container cargo system for Cargo MCT
« Reply #54 on: 06/13/2016 07:01 AM »
How do you place those cylindrical contaniers on Mars surface, or move them about? How do you unload them? It seems they'd be unstable (being round and long) in any orientation.

I think a more or less standard intermodal-style container is likely (in terms of being rectangular and having standardized attachments of some kind, though the standard may be unique to MCT/SpaceX), or at least something with at least one flat side. That doesn't mean the contents can't be round (such as pressure vessels built into a intermodal style frame, etc).

Here's a rough idea of how you could move around intermodal style containers. Basically the teal part attaches to the container using ISO standard twistlock at the top and bottom. The orange section is where all the brains and power would be mounted, and it can move linearly against the teal part (effectively to raise/lower the container) as well rotate against the green part (to rotate the wheel assembly). Electrically power the wheels and you could drive this thing as a self balancer over to the container, hook up, then once you have 4 (or as many as 8, if they're completely separate as depicated rather than pairs operating together at each end) connected to a container, team them and drive them as one big martian RC car. Software-wise, that's all super easy. The same ISO style twist locks and such can be used to tie the containers to the cargo deck, etc.

You'd still have to get them off the MCT to begin with, so unless your cargo hold is on the bottom and you have a way of getting a sufficiently low angle ramp to drive down, the best bet is an overhead crane with spreader bar attachment system (again, using those ISO attachment points).

When placing the containers in-place, you could help in leveling by having "foot" modules that attach via the ISO connectors on the bottom, and either serve to minimize the area that must be leveled (allowing for some gap underneath elsewhere that isn't necessarily flat) or having a leveling mechanism built in (so that the ground doesn't need to be prepared). You could built the leveling into the containers, but not all containers may need them all the time, and by making them modular you can add them on once at Mars as needed and not have them either take up cargo container volume or cargo hold volume.

Some great reference imagery of all this ISO nonsense:

http://www.william-cook.co.uk/assets/files/William%20Cook_Intermodal_Container_ProductsCHANGED.pdf

http://www.william-cook.co.uk/assets/files/William%20Cook_Intermodal_TwistlocksCHANGED.pdf

Offline lamontagne

  • Full Member
  • ****
  • Posts: 1032
  • Liked: 1427
  • Likes Given: 232
Re: Standardized container cargo system for Cargo MCT
« Reply #55 on: 06/13/2016 10:08 AM »
Thanks for the comments biosehnsucht,

I've changed the structure so the container are more ISO.
I believe that answers the worries about turning, without compromising how they can fit in existing and future fairings.

Containers are not strong in torsion, the single wheel arrangement proposed would twist them out of shape.
They are always handled and supported using spreader beams, than hold them at their ISO corners, so the forces are always normal.  Even on trailers, they are actually supported by a small structural frame beneath the container.

In an MCT architecture, they would be handled by cranes with spreader beams, as they are on Earth.
I expect there would be shorter half length versions as well.

Offline lamontagne

  • Full Member
  • ****
  • Posts: 1032
  • Liked: 1427
  • Likes Given: 232
Re: Standardized container cargo system for Cargo MCT
« Reply #56 on: 06/13/2016 10:28 AM »
A few more stiffeners added

Offline Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8621
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 5370
  • Likes Given: 3555
Re: Standardized container cargo system for Cargo MCT
« Reply #57 on: 06/13/2016 11:28 AM »
A few more stiffeners added
If you make the spaceframe 6 sided, it wastes a bit more space around the cylinder than an 8 sided one, but the containers can be packed much more easily as a regular hexagon tiles a surface, but a regular octagon does not, it leaves square shaped hollows.

I like rectangular containers better, and will again advocate for standard 20 foot sizes that are compatible with the current terran system. we want there to be so much freight that avoiding transship repack or difficulties interfacing with terran container handlers becomes important.
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline JamesH65

  • Full Member
  • ****
  • Posts: 626
  • Liked: 364
  • Likes Given: 8
Re: Standardized container cargo system for Cargo MCT
« Reply #58 on: 06/13/2016 12:55 PM »
A few more stiffeners added
If you make the spaceframe 6 sided, it wastes a bit more space around the cylinder than an 8 sided one, but the containers can be packed much more easily as a regular hexagon tiles a surface, but a regular octagon does not, it leaves square shaped hollows.

I like rectangular containers better, and will again advocate for standard 20 foot sizes that are compatible with the current terran system. we want there to be so much freight that avoiding transship repack or difficulties interfacing with terran container handlers becomes important.

Why on earth (!) would you need to be compatible with Terran containers? So they fit on trucks, or trains, or ships?  No reason to do that, and very likely to damage the containers anyway. Make the containers fit the task, not the task fit the containers.

And as for measuring in Feet - I though the world had got over using imperial for things like this?

Offline lamontagne

  • Full Member
  • ****
  • Posts: 1032
  • Liked: 1427
  • Likes Given: 232
Re: Standardized container cargo system for Cargo MCT
« Reply #59 on: 06/13/2016 03:32 PM »
A few more stiffeners added
If you make the spaceframe 6 sided, it wastes a bit more space around the cylinder than an 8 sided one, but the containers can be packed much more easily as a regular hexagon tiles a surface, but a regular octagon does not, it leaves square shaped hollows.

I like rectangular containers better, and will again advocate for standard 20 foot sizes that are compatible with the current terran system. we want there to be so much freight that avoiding transship repack or difficulties interfacing with terran container handlers becomes important.
Iso containers are sized in mm, that just happen to correspond to exact measurements in feet ;-)
I chose 8 sides because this gives us two contact points with a side container when packing laterally, but 6 sides only gives us 1 point, for a less robust stack.  I also plan do illustrate an interface 'dock' that allows a group of these to be connected into various shapes as habitats or stations.

Rectangular containers would need to have at least semi-curved walls to reduce the need for stiffeners, as a straight wall cannot withstand 15 psi without considerable reinforcement.  They would necessarily be heavier.  However, we could have rectangular ends, like stackable ISO liquid containers already do.  That might create problems with some narrow fairings though, and not fit as well in circular rockets.

I think that creating a new infrastructure in space and on Mars is a opportunity to standardize on larger containers.  These are easier to repurpose than the relatively narrow containers of today, that have constraints due to the history of road construction and not necessarily for logical reasons.
Might be better to go with 4m diameter x 6,8 or 12m though.  I originally sized these containers for a Skylon Cargo hold, and I freely admit that since they don't exist yet they are hardly a solid design criteria!!





« Last Edit: 06/13/2016 04:11 PM by lamontagne »

Offline lamontagne

  • Full Member
  • ****
  • Posts: 1032
  • Liked: 1427
  • Likes Given: 232
Re: Standardized container cargo system for Cargo MCT
« Reply #60 on: 06/13/2016 04:45 PM »
Image of the connector, would mostly be needed for changes in direction in a multicomponent assembly.
It might be shipped as is, since it is basically a mini container itself, or perhaps as a set of shell parts to be assembled.

Offline Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8621
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 5370
  • Likes Given: 3555
Re: Standardized container cargo system for Cargo MCT
« Reply #61 on: 06/13/2016 04:53 PM »
A few more stiffeners added
If you make the spaceframe 6 sided, it wastes a bit more space around the cylinder than an 8 sided one, but the containers can be packed much more easily as a regular hexagon tiles a surface, but a regular octagon does not, it leaves square shaped hollows.

I like rectangular containers better, and will again advocate for standard 20 foot sizes that are compatible with the current terran system. we want there to be so much freight that avoiding transship repack or difficulties interfacing with terran container handlers becomes important.

Why on earth (!) would you need to be compatible with Terran containers? So they fit on trucks, or trains, or ships?  No reason to do that, and very likely to damage the containers anyway. Make the containers fit the task, not the task fit the containers.

And as for measuring in Feet - I though the world had got over using imperial for things like this?

20 foot containers are a worldwide standard[1]. I didn't set it. I'm just aware of it... you can measure them in mm if you want. But people worldwide refer to them that way.

As to why conform to a terran standard? To avoid transshipment. There is PLENTY of reason to fit on trucks, trains or ships IF you posit millions of people living on Mars and the concomitant freight traffic you'd see.  YMMV. And making them stackable and interlockable efficiently is important. 

1 - The TEU:  https://en.wikipedia.org/wiki/Twenty-foot_equivalent_unit .. more on intermodal containers: https://en.wikipedia.org/wiki/Intermodal_container
« Last Edit: 06/13/2016 04:55 PM by Lar »
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 27025
  • Minnesota
  • Liked: 6916
  • Likes Given: 4879
Re: Standardized container cargo system for Cargo MCT
« Reply #62 on: 06/13/2016 05:05 PM »
It will still cost on the order of $100-1000/kg to ship stuff to the surface of Mars, even with full-scale colonization. That means it's worth putting stuff in much lighter containers, more optimized for Mars.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8621
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 5370
  • Likes Given: 3555
Re: Standardized container cargo system for Cargo MCT
« Reply #63 on: 06/13/2016 05:08 PM »
It will still cost on the order of $100-1000/kg to ship stuff to the surface of Mars, even with full-scale colonization. That means it's worth putting stuff in much lighter containers, more optimized for Mars.
Maybe. Perhaps these lighter containers are then mated to a more rugged frame they can ride inside of, when they are on Terra. Because I'm thinking ahead to millions of tonnes/year level traffic and you want to do almost anything to avoid having to unload and reload things.
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 27025
  • Minnesota
  • Liked: 6916
  • Likes Given: 4879
Re: Standardized container cargo system for Cargo MCT
« Reply #64 on: 06/13/2016 05:10 PM »
At the very least, use carbon fiber shipping containers. They're 42% lighter than aluminum containers, which are themselves lighter than steel. The difference in cost is only about $5000.
http://compositesmanufacturingmagazine.com/2014/04/can-carbon-fiber-composites-future-material-shipping-containers/

You'll save at least a ton or so, which works out to just $5/kg, easily worth it. Don't haul heavy steel shipping containers to Mars. Mars has a lot of iron already.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Burninate

  • Full Member
  • ****
  • Posts: 1129
  • Liked: 343
  • Likes Given: 72
Re: Standardized container cargo system for Cargo MCT
« Reply #65 on: 06/13/2016 05:27 PM »
I think ISOtainer compatibility is silly because of the weight thing, but also because the moldline of these containers is going to be a limiting factor on all sorts of infrastructure.  We don't ship mining equipment in 8'x8x20' boxes.  We especially don't ship pressure vessels in a packed down configuration to be assembled onsite.

Also, 8'x8'x20' is used less often in shipping than 8'x8'x40'.

In cross section, a 15m diameter full-diameter MCT system would fit six cylindrical/hexagonal/octagonal containers of diameter <5m.

The big question is how you integrate them - do they come with heatshielding?  Are they reused?  How do they reach the ground?

And very significantly: How does the cargo departing and propellant being spent modify the center of mass during entry events?  Because having the CoM in the wrong place at any part of the mission is going to mean you aren't permitted to reenter, and it's going to move more and more the lower the dry mass of the empty MCT;  Conversely, the higher the dry mass the worse payload mass fraction you'll get reaching low Earth orbit.  Do you use a propellant depot made of cargo pod tanks?  There's a whole family of questions here.
« Last Edit: 06/13/2016 05:34 PM by Burninate »

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo MCT
« Reply #66 on: 06/13/2016 05:36 PM »
Unlike the Moon, Mars has lots of available carbon. So ISRU manufacture of carbon-carbon containers on Mars would be more easily accomplished than an aluminum one.  Just ship the resins.  Possibly use some aluminum by vacuum deposition on the inner surface for increasing pressure integrity or for handling cryo liquids like LOX. Would not require a lot and the aluminum feedstock could also be shipped. Result would be more containers for a lot less total weight and volume used in shipping.

The intent is to initially start being able to manufacture habitats and storage locally using same designs and materials that the containers are built from. So this means picking materials for the container that are easily obtainable early in the colonization process. Later new designs using other materials with new shapes and sizes not previously shippable would be possible. This also means that in the long run its not the weight that is so important for the containers but what and how they are made. Later after the colony has started being able to use ISRU for their own container manufacture the ones being shipped from Earth can change to a new material (lighter) to increase effective cargo shipped. This also means that the most important item for containers are their shape size and fittings, not the materials they are made from. The materials can change but not shape, size and fittings.

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo MCT
« Reply #67 on: 06/13/2016 06:05 PM »
As far as manipulation of containers on the Mars surface (or on the Moon for that matter), a self deploying crane (it basically crawls out of the one of the first MCT's to land) which is a self contained rover like vehicle but is very tall and has the single item lift capability of >100mt mass (on Mars weight is only >33mt). It has services capability for the attached containers to provide them power and cooling. You could even use it to transport a crew container full of people, so that no one leaves the crew compartments to get to the base the crew containers are moved to the base. No crew transport vehicles are needed. Also with these lift capabilities the crane can also move empty MCTs (contingency, decommissioned, broken, etc) from the launch and landing field to a storage/processing area.

Such a crane is primarily contingent on standard containers to make its design simpler as well as the robotic programming for most actions. If the MCT is designed such that the nose opens to the at most two sides and the connections attaching the container to the MCT are the same on the MCT as the lift point connections on the top of the container the crane just connects to the these same MCT connections in order to lift and MCT.

This crane would be the complete Mars infrastructure for the manipulation and movement of not only containers but also landed MCTs. With other special purpose attachments the crane could do other heavy lift and movement tasks in between synods. An open top container for transport of regolith.

The crane can raise and lower its height for stowage/protection during adverse weather (dust storms) or for other tasks.

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo MCT
« Reply #68 on: 06/13/2016 06:19 PM »
My ideas keep coming.

If you ship a exploration/scientific container capable of housing a scientific team (100mt of habitat and scientific instrumentation equipment), the crane can then transport them far out and away from the base on a year+ total out and back journey between the use of the crane for MCT servicing. AT a speed of just 10km/hr for 10hrs per Mars day that is a distance away from the base of up to 1,800km. 8)

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 27025
  • Minnesota
  • Liked: 6916
  • Likes Given: 4879
Re: Standardized container cargo system for Cargo MCT
« Reply #69 on: 06/13/2016 06:34 PM »
Unlike the Moon, Mars has lots of available carbon. So ISRU manufacture of carbon-carbon containers on Mars would be more easily accomplished than an aluminum one.  Just ship the resins.  Possibly use some aluminum by vacuum deposition on the inner surface for increasing pressure integrity or for handling cryo liquids like LOX. Would not require a lot and the aluminum feedstock could also be shipped. Result would be more containers for a lot less total weight and volume used in shipping.

The intent is to initially start being able to manufacture habitats and storage locally using same designs and materials that the containers are built from. So this means picking materials for the container that are easily obtainable early in the colonization process. Later new designs using other materials with new shapes and sizes not previously shippable would be possible. This also means that in the long run its not the weight that is so important for the containers but what and how they are made. Later after the colony has started being able to use ISRU for their own container manufacture the ones being shipped from Earth can change to a new material (lighter) to increase effective cargo shipped. This also means that the most important item for containers are their shape size and fittings, not the materials they are made from. The materials can change but not shape, size and fittings.
Actually, the matrix material (some sort of thermoplastic) may be easier to make on-site than the carbon fiber.


Here's a few firms that have polyolifin production SBIR grants, just announced recently:

http://sbir.nasa.gov/SBIR/abstracts/16/sbir/phase1/SBIR-16-1-H1.01-8453.html
http://sbir.nasa.gov/SBIR/abstracts/16/sbir/phase1/SBIR-16-1-H1.01-8191.html
http://sbir.nasa.gov/SBIR/abstracts/16/sbir/phase1/SBIR-16-1-H1.01-8380.html
http://sbir.nasa.gov/SBIR/abstracts/16/sbir/phase1/SBIR-16-1-H1.01-8046.html
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline apirie98

  • Member
  • Posts: 37
  • United Kingdom
  • Liked: 16
  • Likes Given: 33
Re: Standardized container cargo system for Cargo MCT
« Reply #70 on: 06/13/2016 07:05 PM »
I'd like to suggest that whatever container design that is developed might be sized (and shaped) to tessellate in the large hypothetical cargo hold of a BFS as laid out above but ALSO be sized to fit inside the payload fairing of the F9/FH system.

Currently the fairing is sized for payloads up to 4.6m in diameter (according to the F9 user guide) but I'd propose that it may be possible to squeeze something like a 5m diameter (corner to corner) hexagonal structure into an outer shell that has the same external dimensions as the current fairing - or at least shares the 5.2m external diameter to retain commonality.

ISTM that something along these lines would allow F9/FH to stay relevant in the event that these containers become an in-space standard. Admittedly it's not exactly Mars-optimised but there's no reason why sizing for existing launch vehicles has to preclude effectiveness on Mars.
"It's Quite Big"  - Elon Musk

Offline lamontagne

  • Full Member
  • ****
  • Posts: 1032
  • Liked: 1427
  • Likes Given: 232
Re: Standardized container cargo system for Cargo MCT
« Reply #71 on: 06/13/2016 07:38 PM »
As general information, all you ever wanted to know, and quite a bit more, about containers, can be found in a web site called 'The container handbook".  From german insurers concerned about container damage.

I think it is unlikely that there will be much intermodal transportation of containerized materials to Mars.  Containers on Earth are designed for cheap use and are at best spray proof.  The quality required for space cointainers are orders of magnitude greater.  And the launch costs remain high, so bringing up cheap containers makes no sense. 
So it is more likely that materials and equipment will be shipped to packaging buildings (staging areas) where specialized crews will transfer them and pack them adequately into space containers.  These are probably very likely to be repurposed as habitats if they go to another planet, unless in situ building proves easier than expected.  fuel depots seems another likely usage, if the piping isn't too difficult to do.

A question I have is the level of radiation protection the containers should provide.  None?  Variable? Radiation protection is heavy, so perhaps the containers should be designed so radiation protection, perhaps in the form of water, can be added latter.  As the containers probably aren't as much volume constrained as mass constrained, it might make sense to have double walls with open cell insulation than can be saturated with water?











Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo MCT
« Reply #72 on: 06/13/2016 07:38 PM »
I'd like to suggest that whatever container design that is developed might be sized (and shaped) to tessellate in the large hypothetical cargo hold of a BFS as laid out above but ALSO be sized to fit inside the payload fairing of the F9/FH system.

Currently the fairing is sized for payloads up to 4.6m in diameter (according to the F9 user guide) but I'd propose that it may be possible to squeeze something like a 5m diameter (corner to corner) hexagonal structure into an outer shell that has the same external dimensions as the current fairing - or at least shares the 5.2m external diameter to retain commonality.

ISTM that something along these lines would allow F9/FH to stay relevant in the event that these containers become an in-space standard. Admittedly it's not exactly Mars-optimised but there's no reason why sizing for existing launch vehicles has to preclude effectiveness on Mars.
Once MCT is flying often the F9/FH would likely stop. There would be only a short time where containers that could be used on all three (15mt 4+m diameter container (use 7 on an MCT) or 2 on an FH with a long faring). Plus the reason behind using containers on F9/FH is that there is a cis-Lunar destination where they could be unpacked prior to the full operation of the MCT. Which is not that likely being that most of the proposed station expansions and usage require a 100mt launcher capability to get the elements up to make a F9/FH sized container useful.

Offline biosehnsucht

  • Full Member
  • *
  • Posts: 181
  • Liked: 44
  • Likes Given: 52
Re: Standardized container cargo system for Cargo MCT
« Reply #73 on: 06/14/2016 12:09 AM »
Containers are not strong in torsion, the single wheel arrangement proposed would twist them out of shape.
They are always handled and supported using spreader beams, than hold them at their ISO corners, so the forces are always normal.  Even on trailers, they are actually supported by a small structural frame beneath the container.

In an MCT architecture, they would be handled by cranes with spreader beams, as they are on Earth.
I expect there would be shorter half length versions as well.

If you mean "single wheel" as in the render I posted, that was just one unit. You'd hook one (or potentially two, 90 degree to each other) at each corner, so you'd have at least 4 (and possibly 8 ) wheel-sets to carry them. The assumption that the load can be carried from the ISO attachment points in the corners is based on the fact that's where they'd be lifted from normally (at least for shorter containers like 20ft - longer containers sometimes are lifted from ISO points inboard of the ends, but I don't think we'll be fitting 53' containers on MCT)
« Last Edit: 06/14/2016 01:22 AM by Lar »

Offline biosehnsucht

  • Full Member
  • *
  • Posts: 181
  • Liked: 44
  • Likes Given: 52
Re: Standardized container cargo system for Cargo MCT
« Reply #74 on: 06/14/2016 12:20 AM »
On the subject of maintaining exact ISO container compatibility or using ISO containers directly - I don't think this is likely to happen. The cost of moving things from the container that brought the goods to the spaceport into a space-going container is not significant compared to the savings of using optimized containers for the purpose of space travel and mars surface operations.

However, using ISO container style attachments can leverage existing production infrastructure and know-how, without having to reinvent the wheel. Carbon composite or perhaps fancy lightweight aluminum variants etc are surely more likely to be used than regular steel for these containers, even if they do adhere directly to ISO sizes.

I do think the 20' size is reasonably close to a good overall size (since you could fit 4 next to each other in a 15m diameter with several meters of space around for structure, cargo doors (if they open by moving inwards and sliding around the inside like an inside out van door), etc. Would likely end up not being exactly ISO sized, might be taller, might be shorter, might by wider, narrower, etc, but the 20' container is a pretty good starting point.

Offline Impaler

  • Full Member
  • ****
  • Posts: 1283
  • South Hill, Virgina
  • Liked: 362
  • Likes Given: 0
Re: Standardized container cargo system for Cargo MCT
« Reply #75 on: 06/14/2016 01:02 AM »
At the very least, use carbon fiber shipping containers. They're 42% lighter than aluminum containers, which are themselves lighter than steel. The difference in cost is only about $5000.
http://compositesmanufacturingmagazine.com/2014/04/can-carbon-fiber-composites-future-material-shipping-containers/

You'll save at least a ton or so, which works out to just $5/kg, easily worth it. Don't haul heavy steel shipping containers to Mars. Mars has a lot of iron already.

That's what I said back when I introduced the idea, the ISO standard is for a SHAPE and a load-bearing capacity for the container so it can be stacked, the actual materials and mass are completely customizable and we would naturally use the lightest possible ones for any space-flight application.

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 27025
  • Minnesota
  • Liked: 6916
  • Likes Given: 4879
Re: Standardized container cargo system for Cargo MCT
« Reply #76 on: 06/14/2016 03:15 AM »
Part of the whole point about the shipping containers is that they somewhat protect the cargo inside. This way, the containers don't need a roof. They can be moved around during rain or snow or wind. They don't need to be constantly protected from the elements.

I personally think you'd want the containers at least partially pressurized, maybe even with some semi-passive thermal shielding (or carefully chosen paint). This way they can be left outside totally exposed to vacuum and even the harsh sunlight of space and the dusts of Mars. You could have, say, an BFS launch a bunch of these things into LEO, they can be stacked and interlocked. Multiple loads. Say, 6 BFS landings worth (600t). Then a single BFS can dock with the stack, boost from LEO toward Mars, do a small aerocapture or propulsive maneuver for capture. Then the MCT leaves the stack in Mars orbit, goes to the surface with one payload, drops it off, refuels, goes back up, repeats the process.

The advantage there is that you can use one MCT per couple synods for multiple payloads. And in this could be extended by refueling in high orbit, allowing you to send like 10 or 20 MCT landings' worth per MCT. Again, it'd take like 2 synods per round-trip, but by stacking the cargo like this, you could vastly increase the amount of cargo you could send per MCT in its lifetime.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Retired Downrange

  • Member
  • Full Member
  • ****
  • Posts: 941
  • Turks & Caicos Islands
  • Liked: 78
  • Likes Given: 115
Re: Standardized container cargo system for Cargo MCT
« Reply #77 on: 06/14/2016 03:48 AM »
If the containers were developed as Robotbeat suggests above... They could include some integrated solar panels.

Offline CuddlyRocket

Re: Standardized container cargo system for Cargo MCT
« Reply #78 on: 06/14/2016 03:53 AM »
I do think the 20' size is reasonably close to a good overall size (since you could fit 4 next to each other in a 15m diameter with several meters of space around for structure, cargo doors (if they open by moving inwards and sliding around the inside like an inside out van door), etc. Would likely end up not being exactly ISO sized, might be taller, might be shorter, might by wider, narrower, etc, but the 20' container is a pretty good starting point.

Perhaps it would be useful to size any new Cargo MCT standardised container so that it fits inside an ISO container? That way the former can be easily shipped around on Earth where necessary while minimising any loading/unloading between the two systems. (I'm assuming there will be little need to ship an ISO container to/from/on Mars!)

Offline Impaler

  • Full Member
  • ****
  • Posts: 1283
  • South Hill, Virgina
  • Liked: 362
  • Likes Given: 0
Re: Standardized container cargo system for Cargo MCT
« Reply #79 on: 06/14/2016 04:56 AM »
Part of the whole point about the shipping containers is that they somewhat protect the cargo inside. This way, the containers don't need a roof. They can be moved around during rain or snow or wind. They don't need to be constantly protected from the elements.

I personally think you'd want the containers at least partially pressurized, maybe even with some semi-passive thermal shielding (or carefully chosen paint). This way they can be left outside totally exposed to vacuum and even the harsh sunlight of space and the dusts of Mars. You could have, say, an BFS launch a bunch of these things into LEO, they can be stacked and interlocked. Multiple loads. Say, 6 BFS landings worth (600t). Then a single BFS can dock with the stack, boost from LEO toward Mars, do a small aerocapture or propulsive maneuver for capture. Then the MCT leaves the stack in Mars orbit, goes to the surface with one payload, drops it off, refuels, goes back up, repeats the process.

The advantage there is that you can use one MCT per couple synods for multiple payloads. And in this could be extended by refueling in high orbit, allowing you to send like 10 or 20 MCT landings' worth per MCT. Again, it'd take like 2 synods per round-trip, but by stacking the cargo like this, you could vastly increase the amount of cargo you could send per MCT in its lifetime.

That's been my mission architecture for the last year but with SEP performing all in-space transport, it will be slow yes, maybe a whole synod to move the cargo block but the LEO launch mass can be 80% cargo and 20% propellants rather then 10% cargo and 90% propellant under a chemical architecture.

At Mars the landing craft BFS stays at Mars a whole synod and if it can manage a 1 week turn-around it can do 100 surface to orbit cycles.  The vehicle probably needs to return to Earth for major refurbishment and will miss a synod or 2 before it goes back into service, assuming only 1/3rd active work over a 30 year vehicle lifespan still yields 1000 payloads to the surface.  This blows the single-synod direct architecture out of the sky because such a vehicle could do only around 15 payloads in the same lifespan.

Offline chalz

  • Full Member
  • *
  • Posts: 168
  • Austrangia
  • Liked: 77
  • Likes Given: 999
Re: Standardized container cargo system for Cargo MCT
« Reply #80 on: 06/14/2016 05:06 AM »
Regarding inter compatibility with existing standards; this has already been tackled with airplanes and the ULD https://en.wikipedia.org/wiki/Unit_load_device.

The size is primarily determined by the aircraft family and is small enough that they can by transferred to flatbed trucks for road transport. 5' width compared to an intermodal 8' width.

The upshot being they are not directly compatible with intermodal containers but it doesn't matter. By the time you are loading your goods into a container you know where they are going and how they are going to get there. You or your shipper will know the container that the majority of the journey will be taken in.

So for Mars we need a unit size small enough that it could be carried on a flatbed truck. It would then stack into the MCT airframe, which could just be a single large volume. Very large items are not going to be common I think because of the handling limitations on rocket and on Mars.

Offline lamontagne

  • Full Member
  • ****
  • Posts: 1032
  • Liked: 1427
  • Likes Given: 232
Re: Standardized container cargo system for Cargo MCT
« Reply #81 on: 06/14/2016 10:32 PM »
Here is a field of 10 containers and connectors, compared to a Bigelow 330 and a 2100.
Don't really know how much a container would mass, but they suffer a bit in comparaison, I find.

I think containers can be useful only if the MCT has an unpressurized cargo area.  Otherwise, wouldn't it be almost as easy to pack smaller containers into a cargo hold in the ship, since a spaceship is even more 'fragile' than a sea ship, and maximum care must be taken in mass distribution and anchoring to resist severe acceleration stresses?

Why pack a rigid container, when you can pack an inflatable habitat, if the main purpose, in the long run, of the container is to act as an habitat?

And is an unpressurized cargo hold a good idea in a spaceship that is essentially a large balloon, that probably gets a significant amount of it's structural resistance from internal pressure?

So perhaps the best container for MCT is in fact a small and light carbon fibre box, not necessarily airtight, that packs well, can be reused for other purposes and fits in existing transportation modes?  It might be designed to be easily recycled on Mars.  Cardboard boxes are probably not strong enough for the need, so a nice carbon fiber shell with a lot of tie down points.  Might as well use high quality materials, so perhaps even lithium aluminium alloys?

Any simple ways of recycling carbon fiber?








« Last Edit: 06/14/2016 10:39 PM by lamontagne »

Offline RonM

  • Senior Member
  • *****
  • Posts: 2126
  • Atlanta, Georgia USA
  • Liked: 998
  • Likes Given: 777
Re: Standardized container cargo system for Cargo MCT
« Reply #82 on: 06/14/2016 11:51 PM »
Any simple ways of recycling carbon fiber?

Instead of recycling the carbon fiber, the boxes can be made out of carbon fiber panels and supports that can be disassembled and reassembled into other shapes. The panels can be used to build tables, chairs, interior walls, etc.

Offline docmordrid

  • Senior Member
  • *****
  • Posts: 4287
  • Michigan
  • Liked: 1439
  • Likes Given: 1
Re: Standardized container cargo system for Cargo MCT
« Reply #83 on: 06/15/2016 12:20 AM »
Build a Bigelow tech dome and attach a rigid floor. When folded (thinking deflated Jiffy Pop) stack them like pallets in the hold, perhaps 2-4 per vehicle. Remove, inflate, connect.
DM

Offline lamontagne

  • Full Member
  • ****
  • Posts: 1032
  • Liked: 1427
  • Likes Given: 232
Re: Standardized container cargo system for Cargo MCT
« Reply #84 on: 06/15/2016 12:29 AM »
Any simple ways of recycling carbon fiber?

Instead of recycling the carbon fiber, the boxes can be made out of carbon fiber panels and supports that can be disassembled and reassembled into other shapes. The panels can be used to build tables, chairs, interior walls, etc.

If it's anything like fiberglass, then it's harder to rework than one would want.  But there are probably some good lessons to be learned at Ikea... and I remember milk bottle plastic crates used to find 1000 uses.  Perhaps a form of re usable plastic would be better, at that.  Mulch it up after use and run it through a 3D printer...

Offline Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8621
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 5370
  • Likes Given: 3555
Re: Standardized container cargo system for Cargo MCT
« Reply #85 on: 06/15/2016 01:29 AM »
I can hear it now... "Container pieces are not LEGO elements"

.. well, why not? I'm all about reuse. I was earlier saying that it should be possible to strip a passenger carrier of 3/4 of its fittings if they were properly enginnered, and hey presto, you have prewired walls and panels to use inside habitats...

Why not design these containers to be made of components that can be assembled different ways? Especially if they're not pressurised (for reference, boats made of LEGO elements are not watertight...)
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline biosehnsucht

  • Full Member
  • *
  • Posts: 181
  • Liked: 44
  • Likes Given: 52
Re: Standardized container cargo system for Cargo MCT
« Reply #86 on: 06/15/2016 06:17 AM »
The 5' size of ULD may not be large enough, but the idea isn't bad. Flip it 90 degrees and you can optimize space usage of a vertical round cargo hold better (ULD being of course for aircraft which are 90 degree from a rocket in terms of which way the round part is pointing). You can probably grow the overall size a meter or more in either/both width and length easily this way, though your largest single object doesn't get bigger necessarily, you can put more in each container and make more use of space. If you combine ULD shaped (rectangular box with a corner cut off) with regular rectangular containers (those not around the periphery) you can probably get the best of both worlds.

I like the idea about putting the MCT containers inside ISO containers for road transport to the launch site / cargo integration area, so you don't have to move things from container to container, but that may not be feasible depending on what size you want those MCT containers to be. Still the idea has merit, you could just design ISO-y oversized road transport containers if needed that the MCT containers go in, unless the MCT containers are so big as to make that infeasible (i.e. if they were 5m wide, they're gonna be really hard to road transport at all, probably need to ship contents to cargo integration site then pack them in MCT containers).

As for the argument about whether these are even needed and if instead should just have everything stored on smaller pallets or whatever tied down somewhere, while most goods / supplies don't need large containers to move them, when setting up a colony there will be plenty of large items that need to be transported such as construction equipment or general purpose rovers (both of which could be made to fit a 5' dimension but it might be better not to), power storage / generation and ECLSS type utility equipment, and (possibly expandable) hab modules to name a few.

Especially if you are trying to offload 100t of cargo and get the MCT refuelled and sent back on the same synod, doing so by hand with 1-to-2 person portable sized cargo elements will require too much labor and time, especially for early ~10-person crews. If you can offload large containers (of whatever dimension) you can get the offloading done rapidly, and spend the rest of the time after MCT has departed with the specific items in the containers as needed.

Offline darkenfast

  • Member
  • Full Member
  • ****
  • Posts: 735
  • Liked: 370
  • Likes Given: 719
Re: Standardized container cargo system for Cargo MCT
« Reply #87 on: 06/15/2016 08:01 AM »
I personally don't see the need for a standardized cargo container for some time.   Pallets and various sized boxes?  Yes.  Large equipment carried outside the pressure hull?  Maybe.  Intermodal containers came about because it was more economical to ship goods from factories to consumers in other countries in such containers.  The ships involved can carry the extra weight of thousands of these containers and then they are shuffled around in container yards and moved about on trucks and trains.  None of this will be necessary off-planet for a very long time.  Space and weight on the MCTs will be too limited, and there won't be enough long-distance shipping on Mars to justify it.  Think of it like a base in Antarctica that only got C-17 flights in every 26 months.  Every synod, a few ships will come in.  Everyone will turn out to unload, unpack, sort out and load up return cargo.   Standardized shipping containers would just make things harder at the scale we are looking at.  Most stuff can go in boxes and bags, perhaps attached to pallets.

Online Doesitfloat

  • Full Member
  • **
  • Posts: 220
  • Detroit MI
  • Liked: 310
  • Likes Given: 126
Re: Standardized container cargo system for Cargo MCT
« Reply #88 on: 06/15/2016 02:09 PM »
I agree with darkenfast.  Standardized containers will not be part of the first generation of colonies.
I was thinking of a thin pallet with a net on the top but with the reduced gravity only the net is needed.

Offline lamontagne

  • Full Member
  • ****
  • Posts: 1032
  • Liked: 1427
  • Likes Given: 232
Re: Standardized container cargo system for Cargo MCT
« Reply #89 on: 06/15/2016 02:45 PM »
I agree with darkenfast.  Standardized containers will not be part of the first generation of colonies.
I was thinking of a thin pallet with a net on the top but with the reduced gravity only the net is needed.
Musn't forget launch acceleration and vibration, as well as some possible reverse acceleration during atmospheric re-entry as the ship changes attitude radically.
We all know what a single bracket failure can do to attached elements is a space vehicle...

« Last Edit: 06/15/2016 02:47 PM by lamontagne »

Offline biosehnsucht

  • Full Member
  • *
  • Posts: 181
  • Liked: 44
  • Likes Given: 52
Re: Standardized container cargo system for Cargo MCT
« Reply #90 on: 06/15/2016 05:16 PM »
You have to unload 100t of cargo (possibly multiple 100t's of cargo, if many cargo MCT have arrived prior to your arrival). If not containerized, are you going to do this with a pallet jack / manual labor? That is a waste of time and human energy, and time and human energy will be at a premium.

Standardized containers for MCT are about being able to unload and deploy things in a timely manner. They allow for various tools such as an onboard crane / hoist with spreader bar or similar method to move the container outside of the vehicle onto the ground, and some other asset (itself also deployed in a similar fashion) to then move the container from there.

Not everything will be literally in a container necessarily (i.e. if all it would contain is a large rover or construction vehicle, it may just have a frame around it with the attachment points on the frame, no sides), but containers allow for tighter packing and better use of space as well vs open pallets (because contents can be attached to walls/ceiling as well as floor allowing greater use of space).

Online guckyfan

  • Senior Member
  • *****
  • Posts: 6384
  • Germany
  • Liked: 1608
  • Likes Given: 1415
Re: Standardized container cargo system for Cargo MCT
« Reply #91 on: 06/15/2016 05:58 PM »
You have to unload 100t of cargo (possibly multiple 100t's of cargo, if many cargo MCT have arrived prior to your arrival). If not containerized, are you going to do this with a pallet jack / manual labor? That is a waste of time and human energy, and time and human energy will be at a premium.

I expect the whole cargo hold to be taken off and the propulsion unit returning to earth without it.

Offline Burninate

  • Full Member
  • ****
  • Posts: 1129
  • Liked: 343
  • Likes Given: 72
Re: Standardized container cargo system for Cargo MCT
« Reply #92 on: 06/15/2016 06:20 PM »
You have to unload 100t of cargo (possibly multiple 100t's of cargo, if many cargo MCT have arrived prior to your arrival). If not containerized, are you going to do this with a pallet jack / manual labor? That is a waste of time and human energy, and time and human energy will be at a premium.

I expect the whole cargo hold to be taken off and the propulsion unit returning to earth without it.

I've been trying to work this out, and it would be very useful, but...

How?  The ability to drop 15m-diameter cargoes would seem to require engines canted so far to the side that they'd pick up quite a lot of cosine loss in effective specific impulse, and-or engine bells so shrunken that they'd pick up quite a lot of underexpansion loss in direct specific impulse.  We already don't understand how the vehicle could achieve the needed amounts of delta V at 380s Isp.
« Last Edit: 06/15/2016 06:22 PM by Burninate »

Online envy887

  • Senior Member
  • *****
  • Posts: 2707
  • Liked: 1248
  • Likes Given: 780
Re: Standardized container cargo system for Cargo MCT
« Reply #93 on: 06/15/2016 06:36 PM »
The engine nozzles have to cant around a 15m heatshield, there is no way they will survive interplanetary re-entry velocity if they are sitting in the plasma flow. Why not cant around the cargo hold too?

Offline Burninate

  • Full Member
  • ****
  • Posts: 1129
  • Liked: 343
  • Likes Given: 72
Re: Standardized container cargo system for Cargo MCT
« Reply #94 on: 06/15/2016 06:45 PM »
The engine nozzles have to cant around a 15m heatshield, there is no way they will survive interplanetary re-entry velocity if they are sitting in the plasma flow. Why not cant around the cargo hold too?

Depends on whether the spacecraft performs top-first or bottom-first reentry.  A blunt sphere-cone reentry with a rigid heatshield does not seem to permit sufficient deceleration for Mars before impacting the surface - it shifts too much dV requirement to the engines.  The options seem to be some sort of expandable decelerator (inflatable or actuated), a magnetoshell, and-or gliding reentry.  Largely propulsive reentry is feasible, but seemingly not in combination with fast transits, and it may require high-orbit prop depots as well.
« Last Edit: 06/15/2016 06:48 PM by Burninate »

Offline biosehnsucht

  • Full Member
  • *
  • Posts: 181
  • Liked: 44
  • Likes Given: 52
Re: Standardized container cargo system for Cargo MCT
« Reply #95 on: 06/15/2016 09:11 PM »
I'm not so sure the engines can't be protruding through a heatshield (more or less like a Falcon 9 first stage), assuming they have sufficient propellent to run at least some of the engines with enough power to use the supersonic retropropulsion effect to push the shock wave far enough out to reduce aero heating. For Mars decent that is probably easier since the atmosphere is thinner in the first place (less need for a heat shield), for Earth this may be more difficult.

Even if you cant the engines around the heatshield (more like Crew Dragon than Falcon 9 first stage), if you drop off the cargo as one giant module, you still have a problem, since you just dropped your (Mars) heat shield you need a second, more massive (at least you could save mass on the Martian one) Earth heat shield, which is above your engine nacelles. Alternatively you might put your engines far up the side of the vehicle to be above the Earth return heat shield, but now you need to shield the sides of the cargo from the engine exhaust and so on.

Online guckyfan

  • Senior Member
  • *****
  • Posts: 6384
  • Germany
  • Liked: 1608
  • Likes Given: 1415
Re: Standardized container cargo system for Cargo MCT
« Reply #96 on: 06/15/2016 09:30 PM »
I expect the whole cargo hold to be taken off and the propulsion unit returning to earth without it.

I've been trying to work this out, and it would be very useful, but...

How?

I expect the main cargo hold at the top. I know it will require some capable equipment to do. But I expect some capable equipment to be part of building the colony anyway. Removing the top will expose a fresh heatshield for earth return.

I expect the part that returns to earth to be almost exactly a tanker as used on earth to carry fuel to LEO.

Offline Impaler

  • Full Member
  • ****
  • Posts: 1283
  • South Hill, Virgina
  • Liked: 362
  • Likes Given: 0
Re: Standardized container cargo system for Cargo MCT
« Reply #97 on: 06/15/2016 09:37 PM »
You have to unload 100t of cargo (possibly multiple 100t's of cargo, if many cargo MCT have arrived prior to your arrival). If not containerized, are you going to do this with a pallet jack / manual labor? That is a waste of time and human energy, and time and human energy will be at a premium.

Standardized containers for MCT are about being able to unload and deploy things in a timely manner. They allow for various tools such as an onboard crane / hoist with spreader bar or similar method to move the container outside of the vehicle onto the ground, and some other asset (itself also deployed in a similar fashion) to then move the container from there.

Not everything will be literally in a container necessarily (i.e. if all it would contain is a large rover or construction vehicle, it may just have a frame around it with the attachment points on the frame, no sides), but containers allow for tighter packing and better use of space as well vs open pallets (because contents can be attached to walls/ceiling as well as floor allowing greater use of space).

Finally someone else gets it.  I see between 9 and 12 TEU containers in MCT and an integrated gantry crane lowers them onto waiting trucks.  The whole process would take a few hours and then the vehicle can be made ready to launch again.

Online envy887

  • Senior Member
  • *****
  • Posts: 2707
  • Liked: 1248
  • Likes Given: 780
Re: Standardized container cargo system for Cargo MCT
« Reply #98 on: 06/16/2016 02:20 PM »
I'm not so sure the engines can't be protruding through a heatshield (more or less like a Falcon 9 first stage), assuming they have sufficient propellent to run at least some of the engines with enough power to use the supersonic retropropulsion effect to push the shock wave far enough out to reduce aero heating. For Mars decent that is probably easier since the atmosphere is thinner in the first place (less need for a heat shield), for Earth this may be more difficult.

Even if you cant the engines around the heatshield (more like Crew Dragon than Falcon 9 first stage), if you drop off the cargo as one giant module, you still have a problem, since you just dropped your (Mars) heat shield you need a second, more massive (at least you could save mass on the Martian one) Earth heat shield, which is above your engine nacelles. Alternatively you might put your engines far up the side of the vehicle to be above the Earth return heat shield, but now you need to shield the sides of the cargo from the engine exhaust and so on.

Further discussion of this is certainly merited, but it belongs in the MCT speculation thread: http://forum.nasaspaceflight.com/index.php?topic=37808.2320

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo MCT
« Reply #99 on: 06/16/2016 03:44 PM »
I'm not so sure the engines can't be protruding through a heatshield (more or less like a Falcon 9 first stage), assuming they have sufficient propellent to run at least some of the engines with enough power to use the supersonic retropropulsion effect to push the shock wave far enough out to reduce aero heating. For Mars decent that is probably easier since the atmosphere is thinner in the first place (less need for a heat shield), for Earth this may be more difficult.

Even if you cant the engines around the heatshield (more like Crew Dragon than Falcon 9 first stage), if you drop off the cargo as one giant module, you still have a problem, since you just dropped your (Mars) heat shield you need a second, more massive (at least you could save mass on the Martian one) Earth heat shield, which is above your engine nacelles. Alternatively you might put your engines far up the side of the vehicle to be above the Earth return heat shield, but now you need to shield the sides of the cargo from the engine exhaust and so on.

Further discussion of this is certainly merited, but it belongs in the MCT speculation thread: http://forum.nasaspaceflight.com/index.php?topic=37808.2320
Yes, forward the payload handling issues into the MCT design thread as another MCT design consideration but please only mention MCT designs in passing when they directly affect the container/payload issues.

Online envy887

  • Senior Member
  • *****
  • Posts: 2707
  • Liked: 1248
  • Likes Given: 780
Re: Standardized container cargo system for Cargo MCT
« Reply #100 on: 06/16/2016 05:30 PM »
Assuming actual steel TEU containers aren't going to be launched to Mars:

What level of compatibility with TEU standards is necessary to simplify shipping and handling before launch?
Would a 2.5x2.5x6m container with a non-launched spreader beam/adapter to fit standard truck and rail interfaces work?
Would a 2x2.5x6m container that would fit nicely inside a standard 20-foot container work better?

Offline Impaler

  • Full Member
  • ****
  • Posts: 1283
  • South Hill, Virgina
  • Liked: 362
  • Likes Given: 0
Re: Standardized container cargo system for Cargo MCT
« Reply #101 on: 06/16/2016 08:36 PM »
Again TEU standards have nothing to do with the material the container is made of, only it's shape and load bearing capabilities.  You would have to be intentionally obtuse to believe the TEU standard implies steel construction or that I was in favor of steel containers, but just make such a impossible (cause I know how much people love to intentionally misunderstand), I EXPLICITLY said aluminum and carbon-fiber construction for containers and yet we STILL have people talking about steel, it's like their is no defense possible.

Online envy887

  • Senior Member
  • *****
  • Posts: 2707
  • Liked: 1248
  • Likes Given: 780
Re: Standardized container cargo system for Cargo MCT
« Reply #102 on: 06/16/2016 10:12 PM »
Well aware of all that. But, all existing containers ARE steel, so new ones would have to be designed and built... so why not optimize dimensions as well as materials for the Mars transport system?

Online guckyfan

  • Senior Member
  • *****
  • Posts: 6384
  • Germany
  • Liked: 1608
  • Likes Given: 1415
Re: Standardized container cargo system for Cargo MCT
« Reply #103 on: 06/17/2016 06:23 AM »
Well aware of all that. But, all existing containers ARE steel, so new ones would have to be designed and built... so why not optimize dimensions as well as materials for the Mars transport system?

I don't have a firm opinion. However I believe that the BFS cargo hold will be so big that size and waste of volume may be of minor concern. Unless they want the containers to be pressurized they could as well use earth standard container sizes. Unlike planes that have containers designed to make best use of the available volume and size of the particular airframe.

Offline biosehnsucht

  • Full Member
  • *
  • Posts: 181
  • Liked: 44
  • Likes Given: 52
Re: Standardized container cargo system for Cargo MCT
« Reply #104 on: 06/17/2016 08:10 PM »
I don't have a firm opinion. However I believe that the BFS cargo hold will be so big that size and waste of volume may be of minor concern.

Just for fun, see how many TEU containers you can fit into a 14m or 13m diameter circle (basically 15m outer diameter, then allowing for interior wall depth + door opening area + etc), without stacking. Not that many...

You can stack, put more than 2 layers seems unlikely (I will be surprised if there's even one layer of stacking)

To be fair though, it's not hard to hit 100t of payload with the volume of even 4-6 TEU.

So the constraint may first be (depending on payload) the density of the payload hitting the 100t limit, before the size of the containers no longer fit. This is partially why I don't expect to see more than 2 layers of containers, and likely only one layer. Clever packaging (not wasting space within the TEU) should allow for getting ~100t out of 4-6 TEU nearly every time.

Offline Impaler

  • Full Member
  • ****
  • Posts: 1283
  • South Hill, Virgina
  • Liked: 362
  • Likes Given: 0
Re: Standardized container cargo system for Cargo MCT
« Reply #105 on: 06/17/2016 09:27 PM »
Cargo density is usually very low, I think 9-12 TEU is a reasonable target with ~10 mt of cargo each, when higher density cargo is being carried then the container count goes down but the vehicle needs to be voluminous enough to carry low density cargo efficiently.  So containers absolutely will be stacked minimum of 2 high and more likely 3 high.

Online guckyfan

  • Senior Member
  • *****
  • Posts: 6384
  • Germany
  • Liked: 1608
  • Likes Given: 1415
Re: Standardized container cargo system for Cargo MCT
« Reply #106 on: 06/18/2016 06:36 AM »
Cargo density is usually very low, I think 9-12 TEU is a reasonable target with ~10 mt of cargo each, when higher density cargo is being carried then the container count goes down but the vehicle needs to be voluminous enough to carry low density cargo efficiently.  So containers absolutely will be stacked minimum of 2 high and more likely 3 high.

With low overall density and lowest density on top that should not be a problem. Especially with lightweight containers.

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo MCT
« Reply #107 on: 06/18/2016 04:15 PM »
The ultimate point of the container system is to eventually support the transfer of hundreds of containers per synod. This would likely be done not by individual MCTs but by a large in-space only L2 to Demos and back spacecraft that can hold (actually have hundreds of containers attached to its structure) so that the dry weight per 100mt of transferred cargo for this portion of the journey is not up to 100mt for the dry empty weight of the MCT but only 10mt for the open light weight in-space structures, solar arrays that never have to be stowed and less engines and bigger tanks. Now add in the purchase of methalox at these two locations L2 and Demos (at Demos the methalox may still be brought up from the Mars surface in tanker flights) at a cost of just a few $100/kg. This relegates the MCT into a local only usage where just a few MCTs being reused a 100 times in one synod can then transfer > 10,000mt of cargo per synod. If a manned craft is done similar then number of persons transferred becomes a possible > 10,000 per synod as well. Large standardized containers makes such in-space transfers possible optimizing the transfer of cargo and people for costs. Costs for transfer of 100mt of cargo drops to possibly <$100M per 100mt of cargo (<$1,000/kg).

Offline Impaler

  • Full Member
  • ****
  • Posts: 1283
  • South Hill, Virgina
  • Liked: 362
  • Likes Given: 0
Re: Standardized container cargo system for Cargo MCT
« Reply #108 on: 06/18/2016 11:35 PM »
If your going to make open frame freight vessels like that they would be SEP, not methan-Lox powered as that would allow for the propellant to be just a small fraction of the departure mass rather then the overwhelming majority.  SEP propellants like Argon can be acquired at mars and brought to orbit just as methane and Lox would be.

Personnel transport might be a completely different vehicle and it might rely on chemical engines to provide greater speed, but it would also likely be an in-space-only vessel with the nominal BFS (now not very big after the introduction of this 'space liner' being used as a rapid-cycle lander, I can a fleet of these BFS unloading cargo from freighters and then once a passenger ship arrives (which is once every 780 days) they switch over to ferrying them down and because the trip is only minutes long the passengers can be packed in at coach airliner densities of ~2 m^3 each, each BFS can easily 100 passengers at a time by simply bolting some pressurized passengers modules (which have been brought on the liner or from the surface where they are stored when not in use) into the cargo-hold.

In just a few trips thousands of people would be disembarked and anyone returning to Earth would be brought too the passenger liner which can now return to Earth promptly, the BFS fleet can then return to bringing freight down from orbit so their is no wasted downtime of a passenger only vehicle.

Offline JamesH65

  • Full Member
  • ****
  • Posts: 626
  • Liked: 364
  • Likes Given: 8
Re: Standardized container cargo system for Cargo MCT
« Reply #109 on: 06/19/2016 10:27 AM »
Well aware of all that. But, all existing containers ARE steel, so new ones would have to be designed and built... so why not optimize dimensions as well as materials for the Mars transport system?

Exactly. There is no point at all in using the existing size. It's a size optimised for Earth transport.  The 'space version' will never be used on earth in the same way as existing containers (not strong enough), so there is no need to be a compatible size.

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo MCT
« Reply #110 on: 06/19/2016 01:00 PM »
This is my atempt at defining the requirements that the design of the container must meet.

Container requirements:
 - Cost CHEAP. Primary optimization is for low costs in the complete life cycle and to reduce costs generally for the end to end costs of transporting, packing, unpacking, movement, and reuse/repurpose.
 - Withstand abrasive and corrosive dust.
 - Deep space environment of vacuum and sunlight and shadow thermal transitions.
 - Multiple G axial acceleration (~5g).
 - 0g handling and acceleration and torque in any direction.
 - 1 atmosphere external pressure to 0 atmosphere external pressure.
 - Ease of handling in from 1g to 0g gravity
 - Compliance with planetary protection protocols. But this will not go away just morph into a biological control process to keep from transporting harmful biological active organisms to the fragile (at first) Mars colony environment.

These requirements in certain combinations cover the specific environment regimes:
 - Earth surface
 - Earth launch
 - Deep space
 - Mars EDL
 - Mars surface
 - Mars launch
 - Earth EDL
and possibly it will cover these as well
 - Lunar surface
 - Other planetary bodies surfaces: asteroids, moons of Jupiter and Saturn.

The standards will cover the solar system.


Offline mfck

  • Office Plankton Representative
  • Full Member
  • ****
  • Posts: 525
  • Israel
  • Liked: 236
  • Likes Given: 109
Re: Standardized container cargo system for Cargo MCT
« Reply #111 on: 06/22/2016 07:39 AM »
Cheap, robust, versatile - choose two?

Offline chalz

  • Full Member
  • *
  • Posts: 168
  • Austrangia
  • Liked: 77
  • Likes Given: 999
Re: Standardized container cargo system for Cargo MCT
« Reply #112 on: 06/22/2016 05:30 PM »
Anything wrong with wooden crates? Choose a slow grown, tight grain hardwood and it can be reused multiple times after unpacking. Contaminants would be present so it would be after organic matter is allowed.

Also could we have a modular system of crates in several sizes and shapes. A 3d analogue to A series paper sizes.

Offline The Amazing Catstronaut

  • Full Member
  • ****
  • Posts: 1071
  • Arsia Mons, Mars, Sol IV, Inner Solar Solar System, Sol system.
  • Liked: 755
  • Likes Given: 628
Re: Standardized container cargo system for Cargo MCT
« Reply #113 on: 06/22/2016 09:25 PM »
Cheap, robust, versatile - choose two?

It's a container. It's the least difficult to engineer major compartment of the entire spacecraft.

Choose three.
Resident feline spaceflight expert. Knows nothing of value about human spaceflight.

Offline lamontagne

  • Full Member
  • ****
  • Posts: 1032
  • Liked: 1427
  • Likes Given: 232
Re: Standardized container cargo system for Cargo MCT
« Reply #114 on: 08/09/2016 01:25 AM »
Space container suggestion
With Orbital transfer vehicle to suit.

Low to high orbit, about 200 tonnes of cargo.

« Last Edit: 08/09/2016 01:26 AM by lamontagne »

Offline Lobo

  • Senior Member
  • *****
  • Posts: 6674
  • Spokane, WA
  • Liked: 518
  • Likes Given: 313
Re: Standardized container cargo system for Cargo MCT
« Reply #115 on: 08/16/2016 06:16 PM »

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).

A more mass efficient means (cylindrical) of building a pressurized container within a rectangular shipping frame isn't a deal breaker, see attached.  More elegant construction methods are very doable.

Yea, I think this idea is a good one.  All will have the same square or rectangular outer dimensions, and thus whatever machinery is transported to Mars to unload, transport, and place these containers will be common to all of them.  Unpressurized square/rectangular containers are placed on the ground and opened and unloaded.  They could even be put back on MCT and sent back to Earth to be reused, if they don't have an immediate use for them on the surface.
Pressurized units will be plugged into the base, and either used themselves as expansion modules, or used to unload pressurized cargo (food, consumables, anything used inside the base) and then could also be sent back to Earth and be reused if they don't make colony modules out of them.  They may prefer to use pre-fabbed building modules for that, and more of a MPLM type pressurized cargo module just for transportation.  Then they don't need to be designed with all of the power and ventilation and other hookups that an actual habitat module would need.  And thus could be a lot lighter.
Since MCT is supposedly going to be designed for 25mt of return cargo mass, that could be returning empty containers or returning crew, or both.

Just depends which way SpaceX decides to go.


Offline Lobo

  • Senior Member
  • *****
  • Posts: 6674
  • Spokane, WA
  • Liked: 518
  • Likes Given: 313
Re: Standardized container cargo system for Cargo MCT
« Reply #116 on: 08/16/2016 06:24 PM »

People are literally the only things that will travel pressurized, the pressurized containers will be different but they are not part of this topic because this is a topic about CARGO CONTAINERS.

So far no one has articulated a single type of cargo that actually NEEDS pressure, just a nebulous 'need' unsupported by any reasoning, or at best reflexive copying of ISS methodology.  The gap between the logistical paradigm need to do colonization and most commenters suggestions is huge.  We are not talking about an initial landing here were talking about logistics to support hundreds of thousands of tons of cargo a year.

Atlas Guy points to logistics of moving into and out of airlocks, but this ignores the fact that connecting a large pressurized container to a habitat is a very slow process, it takes hours in zero-g.

The kind of air-lock I'm suggesting would naturally be the size of a shipping container (cause it probably is a specialty container similar to the tank posted earlier) and hold nearly it's entire contents.  Dust is controlled by having a large tented garage like space covering the whole 'yard' where the containers being unloaded sit, containers enter the yard by truck through a dust trap, robots unload pallets and place them in the air-locks.  Or if we can send a large enough airlock (perhaps inflatable) then the whole container can go into it directly off the transport truck.

Empty containers are going to be accumulating on Mars clearly, but their are a million uses for them other then trying to LIVE in them, which is incredibly shortsighted because habitation on Mars is not just having a pressure vessel, it's having several tons of life-support equipment too.  Uses for disassembled containers would include using them as foundation slabs, roofing to support regolith over real habitats, melting down the aluminum and making simple rods and spare parts for virtually every other piece of machinery.  Their is literally no end of things you would do BEFORE trying to live inside a cargo container.

Now naturally their WILL be pre-fabricated living units sent to Mars and these could be in the shape of a container, but it's more likely to be an expandable Bigelow type habitat folded up inside the container.  Again that's a topic for another thread.

Cargo that need to be pressurised and possibly heated (unpressurised means no heating)? Few things off the top of my head.

People
Basic Electronics (unless hardened)
Food stuffs (unless you really really ensure there are no air pockets in the packets)
Anything with mechanical bearings for surface use (can get round this)
Some plastics. In fact anything that cannot withstand very very low temperatures.

Sure there are lots more.

More than just people.

Most everything that goes up to the ISS inside of Dragon instead of in the trunk would/should be pressurized, and with some form of temperature control.

Food, electronics (that aren't designed to operate in the vacuum of space or on the surface of Mars), personal items, etc.

There's a reason cargo going inside the ISS are transported pressurized.  It would be the same way for things being transported to a Mars colony that would be going indoors.

Pressurized cargo containers may or may not be designed to be integrated into the colony has a hab module, or just for transportation only.

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo MCT
« Reply #117 on: 10/23/2016 06:23 PM »
This bump is to document several items.

That pressurized cargo will be within the ITS habitat and not need a larger pressurized container. At least not initially in the all in one Cargo/Crew ITS specified.

That unpressurized containers would be ~ 3X3X5 m pie shaped so that they will fit in a 12m diameter ITS and also fit through the small side opening for loading and unloading these containers. ~11 containers would fit in the ITS per cargo level.

Although these containers may not be very large compared to the ITS they should be large enough to pack fully assembled items like large (compared to current rovers on Mars) rovers/construction robots.  Each container would have ~22.5m^3 of volume. If the unpreasurrized containers are stored on 2 levels with 22 of them total to house 150-200mt of cargo then each would hold 6-9mt which would be about the right weight for a large rover/construction robot. A container full of solar arrays to deploy on the surface at 20kg/m^2 would be an array of 300m^2 that would produce a max output of ~7.5KW+. Possible array would look like a flower with petals. With each petal being 3m wide at the edge and ~5m long.


Offline Llian Rhydderch

  • Full Member
  • ****
  • Posts: 855
  • Terran Anglosphere
  • Liked: 547
  • Likes Given: 5288
Re: Standardized container cargo system for Cargo MCT
« Reply #118 on: 10/23/2016 09:57 PM »
Thanks for the bump.

Looking forward to seeing sketches and orthogonal images of some container design ideas that fit within the "constraints" that the revealed Interplanetary Spaceship would have.

Might it be profitable here to first develop a detailed list of those constraints, as we understand that which Musk released as to design on 27 Sep?
Re arguments from authority on NSF:  "no one is exempt from error, and errors of authority are usually the worst kind.  Taking your word for things without question is no different than a bracket design not being tested because the designer was an old hand."
"You would actually save yourself time and effort if you were to use evidence and logic to make your points instead of wrapping yourself in the royal mantle of authority.  The approach only works on sheep, not inquisitive, intelligent people."

Offline Space Ghost 1962

  • Senior Member
  • *****
  • Posts: 2419
  • Whatcha gonna do when the Ghost zaps you?
  • Liked: 2305
  • Likes Given: 1674
Re: Standardized container cargo system for Cargo MCT
« Reply #119 on: 10/23/2016 10:08 PM »
Suggest F9 existing fairing sized loads.

Makes for an easy transition between one LV family and the next. For likely both will overlap in operation, so if ITS or ICT isn't operational, then the payloads go up "the old fashioned way" ;)

Keep in mind that ITS/ICT will gradually come online over years, and likely will be autonomous for a hundred missions before flown with crew. Wouldn't take much to "kick" payloads out the side hatch with a "revolver" mechanism, ejecting them like spent shell casings.

Offline mfck

  • Office Plankton Representative
  • Full Member
  • ****
  • Posts: 525
  • Israel
  • Liked: 236
  • Likes Given: 109
Re: Standardized container cargo system for Cargo MCT
« Reply #120 on: 10/24/2016 02:42 AM »
How many F9 PLF volumes could one place in radial layers inside the BFS volume? Could someone kindly sketch that in a CAD program?

Offline TripD

  • Full Member
  • ****
  • Posts: 530
  • E. Clampus Launchus
  • Liked: 399
  • Likes Given: 266
Re: Standardized container cargo system for Cargo MCT
« Reply #121 on: 10/24/2016 03:11 AM »
I did a quick compare using the scale reference provided by Dante80. 

Offline biosehnsucht

  • Full Member
  • *
  • Posts: 181
  • Liked: 44
  • Likes Given: 52
Re: Standardized container cargo system for Cargo MCT
« Reply #122 on: 10/24/2016 03:44 AM »
So, 3 PLF worth (plus some extra room) if you actually still have a propulsion section, right?

Offline mfck

  • Office Plankton Representative
  • Full Member
  • ****
  • Posts: 525
  • Israel
  • Liked: 236
  • Likes Given: 109
Re: Standardized container cargo system for Cargo MCT
« Reply #123 on: 10/24/2016 10:34 AM »
So, 3 PLF worth (plus some extra room) if you actually still have a propulsion section, right?

Yep, too little too bother, I guess.

If you rotated them horizontally, you'd get, what, six,  maybe nine, but you'd had too much of a "hammerhead"?

I did a quick compare using the scale reference provided by Dante80.

Thanks, exactly what I had in mind. (No likes on Tapatalk :( )
« Last Edit: 10/24/2016 10:37 AM by mfck »

Offline biosehnsucht

  • Full Member
  • *
  • Posts: 181
  • Liked: 44
  • Likes Given: 52
Re: Standardized container cargo system for Cargo MCT
« Reply #124 on: 10/24/2016 04:55 PM »
So, 3 PLF worth (plus some extra room) if you actually still have a propulsion section, right?

Yep, too little too bother, I guess.

If you rotated them horizontally, you'd get, what, six,  maybe nine, but you'd had too much of a "hammerhead"?

I did a quick compare using the scale reference provided by Dante80.

Thanks, exactly what I had in mind. (No likes on Tapatalk :( )

Well, it would still have a potential use. Though it sounds like Elon isn't interested in using ITS to launch payloads other than the tankers / spaceships. If they did built one which was a propulsion section plus some kind of retractable fairing mechanism, it could launch pretty much anything up to and including B330 or similar sized space station modules, couldn't it? You could possibly even launch 3 regular payloads though accounting for the change in CoM would be tricky after releasing each payload if you have to do any burns to get from one payload's intended orbit to the next.

Offline Space Ghost 1962

  • Senior Member
  • *****
  • Posts: 2419
  • Whatcha gonna do when the Ghost zaps you?
  • Liked: 2305
  • Likes Given: 1674
Re: Standardized container cargo system for Cargo MCT
« Reply #125 on: 10/24/2016 07:55 PM »
Keep in mind that the volume of the PLF and the volume of the payload inside the PLF are different.

The difference in volume is in part a function of how the PLF separates. If you don't have an actual PLF.

So you model the internal payload adapter and per payload outlines, which are smaller, with mechanism relevant buffer between - much smaller.

Your largest payload would be adjacent to the "door". It would open, tilt over the adapter and extend to allow the  same separation plane (ON THE SIDE), follow the same separation sequence as before, retract the mechanism, rotate next payload into position, and repeat (following orbital vehicle adjustments).

Hardest part of this would be the payload adapter's power/signal/other requirements, as well as any payload isolation requirements. Estimate 15-10 large, 10-20 medium, and 50+ small payloads per flight in this manner.

Other issues with this would be planning the flight profile for such to reach desirable orbits. Most likely to reach non adjacent, highly different inclination/phase/apsides, multiple lunar encounters and weeks of flight would be required, which would not be zero cost or low radiation exposure (many transits through the Van Allens).

Offline Impaler

  • Full Member
  • ****
  • Posts: 1283
  • South Hill, Virgina
  • Liked: 362
  • Likes Given: 0
Re: Standardized container cargo system for Cargo MCT
« Reply #126 on: 10/24/2016 11:08 PM »
This bump is to document several items.

That pressurized cargo will be within the ITS habitat and not need a larger pressurized container. At least not initially in the all in one Cargo/Crew ITS specified.

That unpressurized containers would be ~ 3X3X5 m pie shaped so that they will fit in a 12m diameter ITS and also fit through the small side opening for loading and unloading these containers. ~11 containers would fit in the ITS per cargo level.

Although these containers may not be very large compared to the ITS they should be large enough to pack fully assembled items like large (compared to current rovers on Mars) rovers/construction robots.  Each container would have ~22.5m^3 of volume. If the unpreasurrized containers are stored on 2 levels with 22 of them total to house 150-200mt of cargo then each would hold 6-9mt which would be about the right weight for a large rover/construction robot. A container full of solar arrays to deploy on the surface at 20kg/m^2 would be an array of 300m^2 that would produce a max output of ~7.5KW+. Possible array would look like a flower with petals. With each petal being 3m wide at the edge and ~5m long.

This would make for a very badly volume constrained system, your looking at interior volume in each container only twice the size of a Dragon capsule but trying to put MANY times more useful mass into it then has ever been done.  Space cargo is just much lower density then most people realize and that's why Dragon has only flown with about 2 tons inside it.  A density of around 200 kg/m^2 is a more reasonable density to aim for rather then the 350-400 your calculations project.

Offline biosehnsucht

  • Full Member
  • *
  • Posts: 181
  • Liked: 44
  • Likes Given: 52
Re: Standardized container cargo system for Cargo MCT
« Reply #127 on: 10/24/2016 11:16 PM »

Other issues with this would be planning the flight profile for such to reach desirable orbits. Most likely to reach non adjacent, highly different inclination/phase/apsides, multiple lunar encounters and weeks of flight would be required, which would not be zero cost or low radiation exposure (many transits through the Van Allens).

If you have enough payloads, if you sent up a tanker to refuel the payload deploying spacecraft, you then would have tons of prop to make lots of orbit changes, right? if nothing else, could you deploy multiple GEO sats directly into their final orbital slots, then moving on to the next one's slot (by lowering/raising the orbit etc). The question is whether this is still at all economical or not ...

Offline Space Ghost 1962

  • Senior Member
  • *****
  • Posts: 2419
  • Whatcha gonna do when the Ghost zaps you?
  • Liked: 2305
  • Likes Given: 1674
Re: Standardized container cargo system for Cargo MCT
« Reply #128 on: 10/24/2016 11:35 PM »

Other issues with this would be planning the flight profile for such to reach desirable orbits. Most likely to reach non adjacent, highly different inclination/phase/apsides, multiple lunar encounters and weeks of flight would be required, which would not be zero cost or low radiation exposure (many transits through the Van Allens).

If you have enough payloads, if you sent up a tanker to refuel the payload deploying spacecraft, you then would have tons of prop to make lots of orbit changes, right?

Not quite - there are orbits that you can't possibly reach from other orbits. And there are ones that are cost/ delta-v prohibitive. Handling multiple payloads is far from easy.

Quote
... if nothing else, could you deploy multiple GEO sats directly into their final orbital slots, then moving on to the next one's slot (by lowering/raising the orbit etc).

Sure, but then there's the launch scheduling problem - not all geostats are ready at the same time, to be delivered all at once. Or the ones going to SSO, or various other arrangements. And, there's an economic incentive to not waiting - being on orbit is when a sat starts paying back its significant costs.

Quote
The question is whether this is still at all economical or not ...

Yes. If parts of this do become economic, then still more services that aren't now ... might.

Like when you're out seeding new geosats, you might be able to retrieve ... marginal ones. To begin with, not worthwhile. But if you corner the market consistently, then piggybacking on a similar mission, might allow you some room for "business development" of space satellite market futures.

Online envy887

  • Senior Member
  • *****
  • Posts: 2707
  • Liked: 1248
  • Likes Given: 780
Re: Standardized container cargo system for Cargo MCT
« Reply #129 on: 10/25/2016 12:44 PM »

Other issues with this would be planning the flight profile for such to reach desirable orbits. Most likely to reach non adjacent, highly different inclination/phase/apsides, multiple lunar encounters and weeks of flight would be required, which would not be zero cost or low radiation exposure (many transits through the Van Allens).
...
It's not really that difficult for a lot of payloads. Just launch different flights to reach common inclinations and apogees: a large majority of commercial launches would be to a few general inclinations: SSO, ISS, GTO.

It's relatively easy to reach any GSO slot from the same original GTO by timing perigee raise. It's also relatively easy to put a group of LEO birds in one constellation plane and migrate them to other planes as needed.

Edit: fixed quotes.
« Last Edit: 10/25/2016 08:46 PM by envy887 »

Offline biosehnsucht

  • Full Member
  • *
  • Posts: 181
  • Liked: 44
  • Likes Given: 52
Re: Standardized container cargo system for Cargo MCT
« Reply #130 on: 10/25/2016 07:55 PM »
If you have enough payloads, if you sent up a tanker to refuel the payload deploying spacecraft, you then would have tons of prop to make lots of orbit changes, right?

Not quite - there are orbits that you can't possibly reach from other orbits. And there are ones that are cost/ delta-v prohibitive. Handling multiple payloads is far from easy.
Well I meant in similar orbits, i.e., all in the same / similar plane so your not making plane changes, just adjusting your orbit between deployments enough to Hohmann transfer or similar to the next payload's location. But as you said ...
Quote
... if nothing else, could you deploy multiple GEO sats directly into their final orbital slots, then moving on to the next one's slot (by lowering/raising the orbit etc).

Sure, but then there's the launch scheduling problem - not all geostats are ready at the same time, to be delivered all at once. Or the ones going to SSO, or various other arrangements. And, there's an economic incentive to not waiting - being on orbit is when a sat starts paying back its significant costs.
Fair point, even Arianespace has enough trouble getting two payloads to get together, I'm sure three is even more (and non-linearly) difficult to coordinate.

Quote
The question is whether this is still at all economical or not ...

Yes. If parts of this do become economic, then still more services that aren't now ... might.

Like when you're out seeding new geosats, you might be able to retrieve ... marginal ones. To begin with, not worthwhile. But if you corner the market consistently, then piggybacking on a similar mission, might allow you some room for "business development" of space satellite market futures.

Probably would need those sats designed for retrieval, since it's unlikely they can fold up their solar arrays. Though with a few manipulator arms and such you might be able to install upgrades or swap failed hardware on a satellite bus that was built with such repair / upgrades in mind... and those might be something they need to design for moving cargo between BFS to get a whole 450t of payload onto one craft.

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3136
  • Florida
  • Liked: 1539
  • Likes Given: 123
Re: Standardized container cargo system for Cargo ITS
« Reply #131 on: 06/17/2017 07:12 PM »
Bump since this topic has been in discussion in other topics.
« Last Edit: 06/17/2017 07:13 PM by oldAtlas_Eguy »

Tags: