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For SpaceNut .... re Post #25
I set this up as a competition.
In post #25, you said it is NOT a competition.
Is there a reason you prefer it NOT be a competition?
If you do not want competition between forum members, I'll have to modify the topic.
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What is the actual competition?
The designs are different and that makes it not a competition persay, granted they are both just large ships to carry people to mars and back.
Its like the difference between the RFP for the moon in which Bezo built designs based on stated requirements versus you take what we design for you an like it.
Both have propulsion but one is more common to current than the megabeam drivers that mean a new level of technology.
About all that is happen so far is content that should be kbd512's topic is here instead.
I can always change my post if I can understand
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SpaceNut,
I will post all relevant engineering details in my large ship concept thread after I have made the required calculations for working loads and anticipated duty cycle.
tahanson43206,
You're asking for quite a bit of someone using a hand calculator, the relevant equations, and an eleven year old MacBook Pro with a failing display that can barely run a web browser. I hope you know that.
Since they're so commonly used here on Earth and the concept of hydraulic or fluid bearings seems so foreign, I may opt to use ball or roller or wire based slew ring bearings, accepting a more limited service life and higher installed weight. Fluid bearings would be ideal, though.
Fluid bearings are used in marine propulsion applications because the loads are so high, asymmetric in nature, and ball or roller bearings would fail in operation too frequently. That said, the linear speed of a 6m diameter slew ring bearing operating at 5.37rpm is only 1.687m/s, which falls within the continuous operation capability of large / heavy duty slew ring ball and roller bearings subjected to the types of loads that they'll be subjected to here. Examples where such heavy duty slew ring bearings are used on Earth include cranes, tunnel boring machines, excavators, industrial turn tables, radars, and wind turbines.
Linear Velocity = (2π/60) * radius * revolutions per minute
V = (6.2832/60) * 3 * 5.37 (to provide 1g with the specified 25m torus radius from my thread)
V = 1.687m/s or 3.774mph (happens to fall comfortably within the linear velocity limits of the slew ring bearings I had in mind)
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For SpaceNut ... your participation and support are critical to the success of this initiative.
The fact that I have clearly failed to set up this topic as a competition between two talented individuals is disappointing.
I'll keep trying to see if there is a way to give a highly competitive member of the forum an opportunity to run in his own lane, while a non-competitive member keeps slowly, methodically, incrementally building his vision.
What we do NOT need is a highly competitive member backed up behind a slow, methodical, painstaking member.
I became aware of the problem I am addressing when we opened the Zoom sessions. All of a sudden, in the rapid fire exchange of voice and image communication, it became VERY clear that our slow, methodical, painstaking member was NOT moving fast enough or in the right direction to please our highly competitive member.
So, I understand your question to a certain extent ... one of the two people is NOT competitive. The other IS highly competitive.
This is not a good combination. I **am** highly competitive, but I'm a very slow burn, so anyone watching over the short term would not realize I am competing.
We (Mars Society) have an opportunity to make a good showing to the National Space Society. I was a member of the L5 Society before it merged with the National Space Institute. I was a (very minor) officer in the L5 Society, but my position was sufficient to earn a place at the table at one of the national L5 Space Conferences in San Francisco, where Dr. Jerry Pournelle (*) faced off against the less warlike members of the Board to try to take over the group to support the Star Wars enterprise that was active at the time.
I want to make sure that the Mars Society presentation on March 12th looks as good as possible.
We have an excellent subject. We have a capable presenter.
The Zoom sessions revealed a mismatch between the support that is needed to build to the presentation, and the personalities engaged in the sessions.
The "Practical" topic (kindly created by kbd512) is a place where ideas incompatible with the Large Ship topic of RobertDyck can be developed.
So it is possible you are not aware (or rather, have not been aware) of competitive currents at the individual level or at the group level.
(*) Bob Heinlein was alive at the time, and present as an observer at the board meeting where the fireworks took place. Larry Niven was also present at the conference. I'm not sure if this was before or after "Ring World" but he was already famous in the science fiction field.
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The two existing Large Ship designs are in development by RobertDyck and kbd512, respectively.
Today, after taking a couple of days to think about how it might work in practice, I've decided to launch the Large Football Ship concept.
An American football has evolved to fly smoothly through the air on Earth, ** and ** do do so with minimal wobble about the Z axis.
The mass of the American football is almost entirely in the shell of the object. There is air inside, and it ** does ** have mass, but that mass is negligible compared to the rubber of the bladder, and the material comprising the outer coating.
It is possible to imagine a version of Large Ship with a shape identical to that of the American football.
The diameter would be identical to that of the Large Ship as designed by RobertDyck.
However, the length would be identical to that of the American football, extended in proportion to match the diameter.
Management of mass inside this rotating object would require instantaneous adjustment as smaller masses move about inside the vessel.
For every step by a passenger or crew person, there would be an instantaneous and exactly equal movement on the opposite side of the vessel. The instantaneous response would be managed at the speed of light (in optical fiber), so that the momentum of the rotation would be preserved at all times.
Likewise, all movements of mass within the vessel, such as liquids, would be correspondingly instantaneously matched on the far side of the vessel.
Passengers and crew would be aware of the need for compensating momentum transfers on the opposite side of the vessel, and everyone would be expected to plan movements and to confirm success of the compensating momentum adjustments tied to their movements.
The freedom of movement erroneously depicted in Science Fiction Movies would be bound by the immutable laws of physics.
SearchTerm:football shape for Large Ship (type) passenger vessel
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Basically a modified version of a doughnut with a center hole in the football shape to park and lock the starship into its center. You then disembark to the habitat area leaving the ship to gain control via the remote station once the power and other umbilical cables are hooked up from the habitat to the starship.
Since we are going to have at least 1 cargo ships we can make it so that the second ship enters from the opposite side. Which means you have the ships contents for the legs of the journey to go to mars and the return journey home. The other cargo ship can go on ahead to land on Mars before the crew arrives.
That means that the crew starship lands and only requires a much smaller amount of fuel created on mars to go back to orbit with food stocks grown on mars to get the return trip home started.
I think GW could figure out the fuel required to re-dock on orbit with the football habitat plus second cargo ship as being some where in the 300mT or less for a crewed starship return.
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For SpaceNut re #31
Thanks for picking up on the Football Shape concept for a passenger vessel...
To add to the development of this concept, please look for foot ball images that would help to explain to forum readers what this would look like. The introduction of a doughnut hole certainly adds interest value!
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Not quite what I had in mind but you get the idea
Ships would enter into the tip of the football shape and stop just shy of the tail fins of the starship.
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For SpaceNut re images of foootballs and doughnuts!
Perfect! It will be fun to see how your thinking evolves in this specific arena!
You've certainly set the stage!
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This is similar shaped as well
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For SpaceNut re #35
Thank you for this image, which not only illustrates the shape of interest with respect to the football design, but ** also ** (and importantly) illustrates the mass symmetry that is designed and then built into those blades. They are (or will be when constructed) perfectly symmetrical from prow to stern. They are (or will be when constructed) perfectly balanced just as your earlier illustration of a rotating automobile is perfectly balanced.
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For SpaceNut re #35
Your image of the American football with all-American doughnuts inspired me to ask if there might be Blender files for the American football....
Google came up with quite a list!
Blender American Football Models | TurboSquid
https://www.turbosquid.com › american+football › blend
Blender 3D american football models for download, files in blend with low poly, animated, rigged, game, and VR options.Animated Blender Football Models | TurboSquid
https://www.turbosquid.com › Search › football › blendAnimated Blender 3D football models for download, files in blend with free format conversions, royalty-free license, and extended usage rights.
American Football Free 3D Models Blender - .blend download
https://free3d.com › 3d-models › blender-american-foo...
Free 3D American Football Models. 1 found. Blender (1)FBX (0)Cinema 4D (0)3ds Max (0)Maya (0)obj (2). Animated (0)3D Printable (0)Rigged (0)Lowpoly (1).Football Free 3D Models Blender - .blend download - Free3D
https://free3d.com › 3d-models › blender-football10 Free Football 3d models found for Blender. ... Holiday Beach Cartoon Scene 3d model ... FREE 32,392. american football 3d model · american football.
Blender Football Model - Blender 2.8 Modeling Tutorial
https://www.youtube.com › watch
Preview
36:28
In this Blender Football Model Tutorial, you will learn how to model an American Football, apply an image ...
YouTube · W3 Productions · Aug 24, 2019
Missing: files | Must include: filesModel Download: American Football - BlenderNation
https://www.blendernation.com › Art › Models & Rigs
Oct 28, 2012 — I have a LONG history with Blender - I wrote some of the earliest Blender tutorials, worked for Not a Number and helped run the crowdfunding ...American-football-ball 3d models - 3dMdb
https://3dmdb.com › 3d-models › American-Football-ball
81626 American-Football-Ball 3d models are waiting for you. ... ...cartoon american football turbosquid made in blender 2.78, 3d cartoon american football ...american football 3d - STLFinder
https://www.stlfinder.com › ... › ? american football 3d
l➤ american football 3d ✓. 3d model of the American football. The file is created in Blender 2.79 and can be opened in any compatible packages.American-football 3D models - Sketchfab
https://sketchfab.com › tags › american-football
Available on Store. American football ball. 969 Views 0 Comment. 6Like. Download 3D model · Chiefs helmet. 2k Views 0 Comment. 48Like. Animated.
Missing: blender | Must include: blenderFootball 3D Models | CGTrader
https://www.cgtrader.com › ... › Football 3D models
4,090 3D Football models available for download. 3D Football models are ready for animation, games and VR / AR projects. Use filters to find rigged, ...
The ones that do animation are of interest.
The ones that do animation with the ** Physics ** engine are of ** particular ** interest.
The hypothesis I am pursuing in the current series is that instanteous matching of momentum on both sides of the rotating vessel is required to maintain stability.
If there is an animation of an American football that obeys the laws of physics (via the Blender Physics Engine), then it should be possible to introduce an instance of a person walking around on the inside of the structure, to see how that disturbance affects the rotating model.
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For SpaceNut re structure of a spacecraft shaped like a football....
In history, there were very large vehicles constructed of aluminum to provide air transportation over several decades, from the late 1800's through the First World War and right up to World War II.
dirigible frame construction history
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About 732,000 results (0.49 seconds)Rigid airship - Wikipediahttps://en.wikipedia.org › wiki › Rigid_airship
Construction of USS Shenandoah (ZR-1), 1923, showing the framework of a rigid airship. A rigid airship is a type of airship (or dirigible) in which the envelope ...Construction and operation · History · Demise
Airship - Wikipediahttps://en.wikipedia.org › wiki › Airship
An airship or dirigible balloon is a type of aerostat or lighter-than-air aircraft that can ... A semi-rigid airship has some kind of supporting structure but the main ...
The engineering that went into design and construction of these large vehicles may prove relevant to design and construction of a football shaped version of Large Ship.
The components would (presumably) be fabricated on Earth and lifted to orbit, for assembly there by robots operated from Earth.
There would appear not to be a reason to enclose the frame in fabric, except for advertising purposes. Those might be great enough to justify a very thin film of material stretched around the frame to carry the name of the builder, the company, and the vessel itself.
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This post is intended to hold links to (possible) repositories of information about design and construction of a large dirigible (in this case, Shenandoah)
About 163,000 results (0.64 seconds)
Collection: Jerome C. Hunsaker papers | MIT ArchivesSpacehttps://archivesspace.mit.edu › repositories › resources
... construction, and procurement, and documentation of this work includes ... by Hunsaker, and the dirigible Shenandoah, whose design he supervised.ZR-1 U.S.S. Shenandoah | Airships.nethttps://www.airships.net › us-navy-rigid-airships › uss-s...
Construction of ZR-1 took place during 1922 and 1923; parts were fabricated at the Naval Aircraft Factory in Philadelphia, and the ship was assembled at the ...
Missing: repository plansCorrespondence on Rigid Airship Construction, 1919-1920 | Naval ...https://usnwcarchives.org › repositories › archival_objects
Correspondence on Rigid Airship Construction, 1919-1920 · Naval Historical Collection · Thomas G. Miller papers (MSC) · Correspondence on Rigid Airship ...S-575-D Construction crew of USS Shenandoah (ZR-1)https://www.history.navy.mil › nhhc › nhhc-series › s-file
Description: Construction crew of USS Shenandoah (ZR-1) during the airship's construction at Lakehurst, NJ, January 12, 1923. Shenandoah's structure is ...
Missing: repository | Must include: repositoryFrom the Mailbag - Navy Lakehurst Historical Societyhttps://www.nlhs.com › from-the-mailbag
Oct 30, 2019 — Lakehurst Hangar #1 is rather unique in layout/appearance (a British-influenced design for a two-bay rigid airship construction/operation ...USS Shenandoah diagrams (airships.net) - Pinteresthttps://br.pinterest.com › Vehicles › Aircraft
USS Shenandoah diagrams (airships.net) by kitchener.lord, via Flickr Steampunk ... Zeppelin · Deck Plans ... Zeppelin L32 pictured under construction.Shenandoah Crash Sites (U.S. National Park Service)https://www.nps.gov › articles › shenandoah-crash-sites
Sep 3, 2017 — The Navy soon began to plan construction of several of its own rigid airships. These rigid airships possessed a rigid framework or hull that ...
Missing: repository | Must include: repositoryZR-1 Shenandoah | Library of Congresshttps://www.loc.gov › item
... interior view of the USS Shenandoah under construction at the Naval Air Station, ... Subject Headings: - Shenandoah (Airship): - Airships--American--New ...
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Much like the other ships the design needs to account for a total number of people that will be onboard the ship. Once you have that number it needs to have a duration for the ships use to solve other numbers such as for water, food, oxygen and more. Sure we can recycle the oxygen from co2 scrubbing and sabatier reaction of unclean water to keep making new clean water and getting rid of the carbon.
Of course there are the decisions to feed the crew with fresh means a greenhouse growth put into place with a given set of footage required and a base level of water to be used for that purpose.
The design needs to have a plan of how things are distributed around the area that is to be used. Of course this is part of the construction phase which mean you are starting to estimate cost for materials. You are also at the point to chose if its and inflatable or pieces constructed on orbit or some combination that will get the shape achieved.
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For SpaceNut re #40
Thanks for your reminder of the issues that must be addressed as the design teams proceed!
****
Below is a contact form submission I just entered into the ALCOA corporate web site.
Hopefully the person whose duty it is to read inputs from the entire world will find it mildly amusing. I think it is highly unlikely there will be even an acknowledgement, let alone a response.
Hello!
I'll be astonished if this inquiry receives a reply, but duty requires me to write.
***
The Mars Society has many activities. The NewMars forum is one of them. I am a moderator.Two gents are thinking (and writing) about what it will take to create, provision and deploy a passenger ship for the Mars/Earth trade. While the range of options is large, the leader of this thought study decided to set a couple of parameters for design. These include:
1) Artificial gravity of Mars equivalent (about .4 of Earth standard)
2) Rotation rate of 3 RPM (20 seconds per revolution).
3) The laws of Physics dictate the resulting size of the human habitat section.
4) Passengers: 1000 Crew: 1000 <<== this was a typo! It should have read 60 (of course)With these specifications in place, imaginations are hard at work.
I am writing you (company in general and my reader here in particular) to note that Aluminum is very likely to be a major component of the metal of which such a vessel will be made.
The shape that I find particularly interesting is the American football (NFL standard). The reason for this is the stability of the shape that has evolved as passers requested more and more stable shapes to fly accurately through the air. A happy consequence of the demand for longitudinal stability in flight is that the resulting shape appears to be suitable for a unitary vessel configuration. Thus, it should be possible to calculate the amount of Aluminum that would be needed to build a vessel, using the airship Shenandoah as a model.
If Alcoa is interested in supporting the work of the Mars Society, or this aspect of the work, Mars Society is a fully vetted non-profit corporation of the United States. It recently received a grant on the order of $1`,000,000 from the Blue Origin foundation.
The amount that is estimated to build and fly a model space passenger vessel, with the shape of an American NFL football, is (about) $2,000,000. I am hoping that the unique shape of the proposed test article would capture the favorable attention of millions of young people around the United States and (hopefully) around the world.
If (by any chance) there is interest in pursuing this (typically Mars Society) idea, we have a contact point at newmarsmember @ gmail.com.
The Executive Director of the Mars Society is Mr. James Burk. He will be familiar with the activities of the forum, but he does not track closely, so please give him time to research the proposal if you decide to contact him.
Thanks!
Here goes a "Hail Mary!" pass !!!
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Here is a toy that resembles the concept
The current version of starship does have an entry problem for parking the rocket into the center of the football design that would need to be compensated for and that is the forward fins which I think are only required for an Earth or Mars landing bully flop maneuver.
here is some of the other art work but?
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This is a follow up to Post #41
I was surprised to receive a reply at all, so even a re-direction is helpful.
Hello,
It looks like you intended to contact Howmet Aerospace, which is now a separate company.
Please see press release below.
https://www.howmet.com/press-release/20 … e-company/
Please resubmit your request to Howmet Fastening Systems at the link below:
https://www.howmet.com/global/en/contac … p?rid=2433
Here is the link to Howmet Fasteners online catalog: http://catalog.howmetfasteners.com/Best Regards,
Alcoa Editor
For SpaceNut re #42 ... The question of how Starship will dock with ** any ** of the Large Ship designs is a good one. Hopefully RobertDyck will have noted your interest in this aspect of the design, and have an answer ready by March 12th.
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The standard space x design would have a cargo airlock to exit the vehicle at about the x on the deep space image. It is in that location for the lunar model as well.
The mars unit and earth have the forward winglets that would cause the ship to enter into a much larger inside the football diameter than the main body of the ship in the first image. That means that since only one hatch is present that there is no way to set it in the center without some modifications so as to attach the ship to the internals of the football shape. This same modification will be present for the opposite side of the football as well.
Depending on the number of cargo ships required to fill the football shaped ship that entry will need to happen multiple times to fill the ship with water, food and internal build of the design as well. I am thinking that the ship will dock to the football with a tunnel similar to the airline off ramp from a plane.
edit
For most rotating designs one would not be rotating to park a ship to it once its built. We start rotating once we do the main boost to get the ship to escape earth velocity and would cease it to allow for it to separate the rocket going to the surface as well at the destination.
The center where is larger we can get artificial gravity that is any value that we would want and towards the end we get a much smaller level.
F=(0.0011)W²R where F is centrifugal force in Earth gravity, W is spin rate in RPM, R is length of the spin arm in meters
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For SpaceNut re #44
Thanks for your several suggestions for features to think about for the football shape!
You are right (of course). When I started down this path, I was thinking primarily of stability of a rotating vessel in flight. A rotating space station will (probably) have to contend with wobble, but for a ship in flight, failure to maintain mass discipline will be a cause for concern.
The Large Ship design of RobertDyck (as I understand it) will maintain rotation at all stages of flight. The design of the center shaft is intended to facilitate docking of Starships, which would rotate to match the rotation of the ship as they approach. RobertDyck has an animation that shows what this would look like, early in his topic.
The Large (but smaller) Ship design of kbd512 is still in development, but I ** think ** the central shaft will NOT rotate, so docking with visiting vessels should be similar to docking with the ISS.
Your observations about Large Ship (football version) are leading me toward imagining that the ship is going to have to cease rotation when docking, unless an alternative docking method is imagined.
My expectation is for one end of the football shaped vessel to be dedicated to propulsion. The other end (the prow) might be designed for docking, and the model of RobertDyck's example might work.
Thanks again for giving the alternative design your attention!
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The shape is not all that important as you can make use of as much or as little of the overall length as one would desire. You might decide that a cylinder at a given diameter inside of the shape is all you would want. Even the AG gravity level is up for trials.
https://www.dimensions.com/element/american-football
short diameter of 6.68”-6.76” (16.9-17.2 cm) and length of 11”-11.25” (28-29 cm), resulting in circumferences of 21”-21.25” (53-54 cm) on the short axis and 28”-28.5” (71-72 cm) in the long.
NFL and other pro leagues is two 1-inch stripes located 3 to 3.25 inches from either end of the ball.
Each section of the cylinders have the inner to outer wall of the specified " 3 meters is an estimate for height."
The smaller diameter is just able to allow the winglets on the top to enter inside it with some clearance for alignment which might be 17 m for that to be achieved.
It is a rough football shape as we do not care about the curves of the football shape. With each cylinder getting larger but shorter than the one it has inside it.
So we are scaling up the overall shape between the stripes to approximate the length of the 2 sections of a starship that would be entering the center fro opposing sides.
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Here is the topic for a like kind vehicle to compete with the other 2 designs. So how would you build it in orbit, whats its estimated mass for the engines and fuel, whats the means to get to mars let alone fall into orbit, how about the 20 tesla field, billion volt electrostatic fields ect....
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