ALLGO, Inflatable Moon Crane (IMC), 16 42 inch inflatable tubes

Last crawled date: 1 year, 11 months ago

Inflatable Moon Crane (IMC) that can lift the highest loads (11000kg) with the biggest diameters (8 meter). With 2 meter headspace under the load! Structurally sound, all forces are calculated and accounted for!

This is my design it can be packed in the smallest NASA module designed to go to the moon: the 8.4 meter USA.

The capsule also packs 2 big containers, one battery and one air tank with a volume of 9383 liter. If the air tank is pressurized to 250 bar that would come down to 2.345 ML or 2,873 kg of air. All the inflatables need only need 714,061 Liter (or 0.71ML) to fully inflate, so that is some extra air for the crane.

I ran the program (PressArchAnalysis) that was used in the "Feasibility of a Self-Erecting Shelter with an Inflatable-Fabric-ArchSupported Roof and Rigid Walls" file mentioned in the comments by Kevin Kempton. The calculations showed that one 42 inch inflatable arch of 22 meters wide, reinforced with 100mm wide 10mm high straps, could hold 0.8 times the weight of 11 Metric Ton on the moon. So lifting 11 Metric Ton on the moon could be done with 2 arches, but that would be in a static situation. When its moving all sorts of dynamic forces would also act on the inflatables. And id better fill up as much cargo capacity as i can because wasting space is a real big shame when it costs so much to lift things into space, especially when i has to go to the moon. So 16 beams in total. That should hold itself. 8300 lb/in was used as fabric strength in the calculations with the program.

Also the 8 meter diameter as mentioned in this link: https://www.herox.com/LunarDelivery , was something i wanted to design around. So using all the cargo space (on the floor) wasnt such a bad idea.

The arches are tied with cables so there wont be any forces trying to push the arches outwards. That is a big concern when using arches, so that is why i think my design is pretty solid. There are 2 tie arches that go on both sides of the wheels, that way the wheels wont be pulled inward or outward. Ensuring the crane will stay on its feet.

There is a platform with a crane in the middle of the arches. The arches are connected to the carts and platform through the use of bulkheads and clevises. "Review of Habitable Softgoods Inflatable Design, Analysis, Testings, and Potential Space Applications, page 8."

The crane can move 1.8 meter to each side by a trolley on a track. 3.6 meter total movement. It is based on a tower crane. So it should have enough lifting capacity. The hoist is in the top of the IMC, and not at the bottom, so you dont have to put two times the load on the structure. One load, the load, and one load, the pull, that makes twice the load on a structure. That is why tower cranes have the hoist on top, and not at the bottom of the crane.

The communications is in the GHz range, ive seen NASA uses 3.380GHz, 7.185GHz, 14.295GHz, 21.395GHz, and 28.65GHz. With that small a wavelength that makes using a dipole as antenna to small and antenna, that is why there is an antenna array on every corner of the IMC. Also i added a dish antenna on top of the IMC. Its calculated that with the 1.5 feet it has, there is a 22.75dBi amprification, and 12.09 degree 3- dB beam angle. "ARRL satellite antenna handbook, page 10-18". I was inspired by the first moon lander and rover its dish antenna. The larger the dish the smaller the beam angle. So a dish array could be something to look for if there is a station set up on the moon.

The bladder of the inflatable is urethane coated nylon fiber "Review of Habitable Softgoods Inflatable Design, Analysis, Testings, and Potential Space Applications, page 8". The outer layer is Vectran, coated in urethane (unlike what is mentioned in the literature) . It is believed that the lunar dust can cause abrasion in between the fibers and can cause failure of the Vectran membrane, or cause a leak of the bladder. The inflatable members are kept at 49psi (25% ultimate tensile strength as mentioned in the literature provided). The restraint layer is the MMOD layer.

The wheels have a deployed and undeployed state, it saves in cargo space and gives extra height for under the IMCs crane. The moving element is protected by a sleeve. It is believed that if you can have an inflatable crane on the moon, you can have a sleeve around the suspension. There was no other good option for a suspension that could coupe with the 25cm and still would be able to lift the heavy loads. Even though it is said in the description hydraulics are a no no. There are 12 couples of wheels, so 24 wheels in total.

There are solar panels on the roof of the IMC, and there are deployable solar panel fabric solar panels on the sides of the IMC. In the undeployed state they are rolled up on top of the IMC, in the deployed state they are brought in position by reels on the carts (yes, some names where used wrongly on the parts, but he the IMC is there).

There is a winged door on the bottom of every cart that holds a connection for the IMC to connect to an external battery. The carts hold extra batteries and extra compressed air for the inflatable arches.

The top of the crane and the carts have whipple shields as an MMOD protection layer to protect them from high velocity debris.

The inflatable members are folded double and rolled up like a flattened candy roll. "Review of Inflatable Booms for Deployable Space Structures Packing and Rigidization, page 4".

There is a hatch that you can open under the carts that holds the connector for the battery.

The cables are placed in the buckets designed for them, so they can deploy without intertwining and being thrown all over the capsule during launch.

The weight, well i cannot say much about the weight of the rest of the structure, because the parts are not designed for the forces they need to handle. But the inflatables will weigh between 168 to 335 pounds each (a 558.43 sq ft surface area). So 134 to 268 cubic feet in total. ("the inflatable material was about 0.3 to 0.6 pounds per square foot of surface area and when tightly packaged for shipping the density was about 20 pounds per cubic foot."). With 489.34 cu ft on each side of the carts left, there should be enough space to fit the 4 x 16.75(cu ft per inflatable packed)= 67 cubic feet per side. So the cargo should fit with 3657 cubic feet left to spare in the capsules cone. So that should leave some room for extra attributes if the weight of the launcher permits it.

Some calculations (For all calculations see the pictures, the entire crane has been statically checked with math. It will stay up): lets say the load on the crane is 11000kg, and the crane and roof weighs 2000kg. ((11000+2000)*1.62)= 21060 Newton, 21060/8=2632.5N. 8 symmetrical pieces seen from the top of the crane. 2418.35/2907.89=0.8317. Distances from the inner and outer legs to the middle of the crane, seen from the top. 2632.5*(1/(1+0.8317))=1437.23N for the inner leg. 2632.5*(1/(1+0.8317))=1195.27N for the outer leg. 1195.27+1437.23=2632.5N (so that should be enough proof that its the load divided right for the legs). The loads on earth would have a weight of 1437.23*9.81=146.51kg, and 1195.27*9.81=121.84kg on earth for the inner and outer arches. So if tested on earth only load with (146.51+121.84)*8= 2146.8kg. The heaviest loading possible for an arch with an asymmetrical loading caused by the crane to move 1.8 meter is 2646.45N, or 269.77kg on earth, when loaded with 13 tons on the moon. The maximum forces on the wheels (due to the cranes out of center position) are 3807.34N.

The IMCs brakes need to be on when the crane has an asymmetrical load, otherwise it will start moving into the direction of the load. If the brakes opposite of the load brake the load will be applied to those arches, if they both brake the load is divided over the arches, if the side of the load brakes the arches on that side will carry an extra load. Some thought in making the outer layer should be given, while the asymmetrical loading may give some extra strain sides of the arches. This could be done by putting in some extra heavy wires in the vectran fabric.

All in all i believe the IMC (Inflatable Moon Crane), is the best answer to the question: how would NASA pack the biggest crane in the smallest NASA moon capsule as possible.

Also: When not in use its big solar arrays can produce a lot of electricity. The big battery capacity will ensure long service time before needing a recharge. The rig can be used for heavy mining operations in the future too!

I added some inspiration pictures that really helped me to design this IMC gantry crane.

Design is uploaded in IGES (its STEP now, while that did seem to work) for the final assembly and the payload assembly.

If there are any questions about my design, email!

Greetings,

A B

p.s.

If people want i can provide all the parts and assemblies. Do leave a comment! I like criticism! The STEP files show a really clear picture. I can actually say im proud of this design! This thing can lift tons!!