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The local chapter of the Royal Astronomical Society of Canada (RASC) gushes about software called "Starry Night". Not the painting by Vincent van Gogh. They use it to simulate the sky and aim their telescopes. However, it has a realistic planetarium display, runs on either Windows or Mac. Oh! SkySafari runs on iOS or Android. I don't know if it can rotate the entire sky at 3 rpm. Worth a look. (it has a free trial download)
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By the way, life support. Using solar panels for electricity, with direct sunlight powering chloroplast bags for oxygen generation, this ship has very long duration life support. With greenhouses to grow salad and vegetables, and grow special pea plants for replacement chloroplasts. The chloroplasts will produce starch as byproduct of oxygen generation, instead of toxic gasses. That starch can be used by the kitchen. One thing I have experimented with is mixing pure starch with water, adding a pinch of yeast nutrient (ammonium phosphate) and grow bread yeast. After 3 days, cook in a microwave oven. The result is white translucent with consistency of pudding. I had to experiment to get consistency right. If you don't get it right it goes from liquid to hard rubbery. But done right, it has the aroma and flavour of freshly baked bread. Starch is pure carbohydrate, but yeast produces a little protein, lipids, and complete vitamin B complex. Without B12, that requires a separate bacteria that grows like yeast. Haven't tried it so can't vouch for it's flavour. But traditional bread yeast tastes good. Starch pudding and veggies; may not be the greatest diet, but if free return leaves you stuck in space so long the stored food runs out, this should keep you alive until you get back to Earth.
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For RobertDyck re #375
Please draw a picture of the latest vision of how the spokes are mounted with respect to the central shaft of the vessel. I like the idea of setting the habitat in the middle (centre) of the shaft, but since this is a change from the original sketch, I'd like to be sure you are making that adjustment.
Regarding bulkheads ... they will be in compression at Mars gravity while in flight, but they will be in tension as Mars atmosphere inside the habitats tries to blow the roof out and away from the floor. When the habitat ring is at rest before acceleration to flight rotation, the walls will be entirely in tension mode, trying to prevent the roof from pulling away from the attachment points. Seals will be needed at any seams between walls that are not welded.
Pressure tests will be required before flight and during flight. The occupants of the International Space Station are chasing a pesky leak that appears to be happening in the sections of the station where the crew sequestered themselves in order to test the seals in the other segments. A leak on this order would be a serious concern for a vehicle intended to support life for two years, and this vehicle is quite a bit larger than the ISS.
We could use additional contributors to this topic. In particular, we need structural engineers who can assist with assigning numbers to the structural elements that are being imagined in the early stages of design.
(th)
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For RobertDyck re topic in general ...
Re "Starry Night" ... The enthusiasm about Starry Night by your associates is justified (in my opinion). I have an ancient copy of the product called 'Backyard Edition" and even with its age and limitations it does a good job of presenting the sky in a wide range of attitudes and times.
I had forgotten about the feature that allows the program to advance the sky at a rate specified by the operator. I've used that feature numerous times to follow the progress of an object of interest, but for those searches, I was using sidereal time and stepping by day, so the object's motion could be predicted over a period of weeks.
The computer where the program resides is mothballed. I'll take a look to see what it would take to put it back online. My expectation is that a full rotation of the sky every 20 seconds would not be a "natural" condition, but if people are stuck on a rotating space ship they might find ways to cope.
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Second Life is a candidate location to build a full scale model of the ship. It provides graphic tools and vista capabilities that allow for construction of large buildings and entire landscapes, such as a university complex.
There are Open Source versions of Second Life as well. In any case, some investment is required. Second Life provides for rental of server time and data storage, and an Open Source solution would require provisioning a server, online access and the detail of DNS services.
Building a model in Second Life would be ** much ** more feasible if the project had a sponsor with deep pockets.
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Spoke attachment. Rough image.
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There are a couple options. You asked for the spoke to not be structural, but making functional elements structural is something vehicle engineers have been doing for decades. So how many spokes? 2, 3, 4? With only 2, any torsion could twist the ring, treating the spokes as an axle to rip the spokes off the hub. 3 is stable. Cylindrical spokes give it strength. The spokes will be pressurized; the same pressure as the rest of the ship. Pressure adds stiffness, so is actually good for structural strength. A cylinder is a strong shape. This means the elevator will also be a cylinder, a round car that rides up and down the spoke. So the spoke is the elevator shaft. The spoke will be stronger than ring hull, because it's structural. Obviously the spoke will require thermal and micrometeoroid shielding. Do we want windows in the spoke, so people can see they are riding down to the hub? Probably not, just an elevator without windows like a normal elevator. That allows the spoke to be all structural, without windows.
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In post #228 I had calculated elevator size and shaft size. Based on an example cargo elevator, the largest elevator from the example website, I calculated car diameter of 2.42512m. Outside diameter of the shaft would be 3.19512m; this is floor space taken inside the ship. After adding thermal and micrometeor protection, I estimated spoke diameter of 3.25m.
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For RobertDyck re #380 ...
Thanks for the diagram ... it revealed that my mental map of what you were trying to say was poorly mapped ...
I now understand the spoke (cylindrical) would be centered in the 19 meter width of the Rim. It makes perfect sense, but I had thought you were talking about something else entirely.
C'est l'magique des images! [C'est la magie des images!] The first was accepted by Google translate but the second is it's recommendation.
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PS ... we need (desperately) to find you a qualified structural engineer. Your current design puts the entire thrust of the main engines on the thin walls of the passenger passage from the Rim to the Hub. That is a pressurized volume which should not be subjected to torsion of any kind.
I think you may have been the forum contributor who pointed out the weakness of the current configuration of ISS cylinders, which are mated via docking ports, and which can withstand only tiny twisting forces before breaking.
(th).
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True. I don't know if it's necessary for a diagonal brace between ring at the spoke attachment and point aft of the hub. Cargo hold? Propellant tank? And I don't know if buttress is necessary between spoke and ring. I am expecting attachment of the spoke to ring will not be simple sheet metal, but rather reinforcement within the ring. Integrating structural reinforcement with partition walls is the job of an architect.
And I we could use someone able to plot planetary trajectories. I posted some results that I found with Google, but we really need to refine it. And that includes calculating velocity upon Mars arrival.
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For SpaceNut re RobertDyck Post #384
There would appear to be an invitation there to recruit someone to combine forces with GW Johnson to address Celestial Navigation. It seems to me that GW Johnson has rather exhaustively studied navigation between Earth and Mars, but perhaps there are some refinements possible.
We have a hint that RobertDyck would be willing to consider structural design advice from a properly qualified person.
The Recruiting topic is a good place to thrash out text we might want to publish in various venues, to see if we can find the right person(s).
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For RobertDyck re Layout of Rim habitat with 248 cabins (economy)
Given 19 meters across, and 238 meters of circumference, the spreadsheet has 19 columns (corridors stretched) and 99 rows.
The spaces between rows of cabins are: 10 rows, 9 rows, 10 rows and 9 rows
The groups of cabins are 15 15 15 16 (for a total of 61)
I'll be interested to see how you decide to allocate the free space between the four clusters of cabins.
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I posted a link in "Mars round trip time", here: NASA Ames Research Center Trajectory Browser
Orbit Injection Injection Post- Total
SPK ID Name Size cond. Earth Destination Duration C3 Abs ΔV Inject. ΔV Route
code Departure Arrival (km2/s2) DLA (km/s) ΔV(km/s) (km/s)
499 Mars 6779 km 0 Nov-02-2024 Apr-27-2025 176 days 25.9 25° 4.34 2.44 6.78 EM
499 Mars 6779 km 0 Nov-18-2024 Apr-27-2025 160 days 46.1 25° 5.15 2.52 7.67 EM
499 Mars 6779 km 0 Nov-18-2024 Apr-11-2025 144 days 48.1 26° 5.23 3.49 8.72 EM
::Edit:: Hmm. This gives "Post-Injection ΔV" in km/s, but does not give arrival velocity or orbital parameters.
Using this orbital calculator, an orbit of about Mars with a period of 2 weeks and a periapsis of 3,427km will have periapsis velocity of 4.963km/s. Periapsis is measured from the centre of mass of the object, Mars has an equatorial radius of 3,397.2km, so this means 29.8km above the surface. That's deep enough for aerocapture. Trying to calculate G forces to aerocapture.
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That is dependant on the initial distance and mass at launch.
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ΔV is not dependand on mass. Acceleration (deceleration) during aerocapture is not either. Acceleration is dependant on ΔV and time to achieve it. The greater the change of velocity, the greater the acceleration required. The more time acceleration is applied, the lower the acceleration. Mass simply changes thrust required to achieve that acceleration.
Reading the user guide for the NASA orbital calculator... "Post-Injection ΔV" is that required to achieve orbit with periapsis just barely out of the atmosphere, and C3=0. That means minimum reduction of energy to just enter orbit. Pushing the calculator to the extreme, difference between highest periapsis velocity I can get to orbital period of 3 days changes periapsis velocity from 4.999 to 4.896 km/s. That's a change of just 0.103 km/s. So "Post-Injection ΔV" for Nov-02-2024 is 2.44 km/s. So add 0.103 to get 2.543 km/s. For a rough calculation, assume aerocapture occurs over 1/4 the circumference of Mars at the altitude of periapsis, so 5,383km. Velocity will initially be speed of periapsis plus ΔV, so 4.896 + 2.543 = 7.439 km/s. Using this calculator result is 2.91361 m/s² over 872.801 seconds (14 minutes, 32.801 seconds). Earth's surface gravity is 9.80665 m/s² so that's 0.2971 G.
The ship will be rotating with Mars gravity, so this will feel quite dramatic. Direction of "down" will change to 38° off vertical for 14½ minutes. Total magnitude of gravity (centrifugal plus deceleration) will be 0.48 G.
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For RobertDyck ... noting your excursion into celestial navigation ...
This post is about the design and operation of the Rim Habitat ...
In the United States old prison cells are usually about 6 by 8 feet in dimension which is 48 square feet (moreover however American Correctional Association standards call for a minimum of 70 square feet = 6,5 m2), with steel or brick walls and one solid or barred door that locks from the outside.
Prison cell - Wikipedia
The economy cabin planned for RobertDyck's Large Ship is 2.4 meters by 4 meters, or 9.6 square meters.
A feature of the Large Ship scenario is that the passenger can visit the rest of the rim not taken up by cabins.
Corridors are continuous around the entire circumference of the rim, so it is likely that running and walking will be popular pastimes.
It would seem reasonable to screen passengers for claustrophobia.
It would ** also ** seem (to me at least) reasonable to suppose that NASA screens for claustrophobia early in the Astronaut selection process.
(th)
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Yea, NASA does. I went to one symposium where I spoke to a former NASA flight surgeon. He claimed one flight of Shuttle had a French astronaut who turned out to have severe claustrophobia. He tried to exit through the airlock. Without a spacesuit. While in orbit. I haven't heard this story through any news release, just direct one-on-one conversation with a former flight surgeon. So I can't confirm the story. But according to this story, the other astronauts had to tackle him, prevent him from killing himself. So, uh, it is an issue.
This is a spacecraft. And it's a passenger transport, not a cruise ship. Designed for a 6 month transit, not a cruise. A lot more luxurious accommodations than other ships, but it isn't going to be comparable to a modern cruise ship. In fact, the economy cabin is based on 3rd class for a passenger steam ship in the first decade of the 20th century. Not as spartan as steerage. In fact, a 3rd class cabin on the Titanic or SS City of New York did not have a toilet or shower in the cabin. Here is a replica of a 3rd class cabin at the Titanic Museum.
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Ok, floor plans. Where a spoke attaches, there will be an elevator. The elevator is in the middle, so at minimum removes 4 inside cabins. An elevator is a good place for a cross corridor, to connect forward and aft circumferential corridors. Luxury cabins will have one central corridor. Elevators are good places for common spaces. So rather than corridors, just open space used for something practical. I was thinking the gym would be one big open space, to make it feel spacious. This is a gym in Winnipeg...
Modern cruise ships have multiple dining rooms. In 1900s (first decade), ships had one big dining room for first class, another for second class. Modern cruise ships have multiple smaller dining rooms. In post #44 I suggested 2 large rooms with lunch room/fast food/banquet room space to seat 100 at a time per room. Four themed diners for 50 people each. And for premium/luxury passengers, a fine dining restaurant that can accommodate 20 people. If seating is 10 sq.ft. per person, 15 sq.ft. for fine dining, that's 4,300 square feet.
Fine dining would have table waiter(s). Actually, floor area is that recommended for a full service restaurant, fine dining would normally be larger, but this is a ship. Dress it up to look nice. To reduce staff, most meals in "normal" dining rooms would be buffet.
::Edit:: To address the claustrophobia, you could organize the dining rooms as one to seat 300, with operable wall partitions so it can be divided. Then just 2 separate dining rooms for 50 people. Or just a single big one for 400. I just thought multiple dining rooms would make the ship feel larger. A very large dining room feels impersonal, smaller more intimate. And themed dining rooms give variety.
Found another resource. This website allows you to edit floor plans on the web. This starts with an example you can edit: Restaurant Seating Chart.
smartdraw
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For RobertDyck re 391 and 392
Thanks for the claustrophobia story! Good Grief!
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Thanks too, for the reminder of the placement of the spokes ... in my first attempt to show the floor plan, I divided by four to try to achieve some balance, and since 248 is divisible by four I forgot about the spokes.
I'll redraw the diagram with cabin sections divided into groups of 20/21/21 rows. If you were to decide to increase the cabin count to 256, then the sections could be 21 rows each, which would be better for balance.
The presence of the spokes will impact your planning for non-cabin areas.
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Elevators need to be designed for the emergency situation of loss of power .... A solution to consider is using an escalator concept for passengers to ascend on one side of the shaft using a chain of standing platforms (perhaps?) and descend on the other side using a similar concept.
Edit#1 ... the presence of the spokes would NOT (necessarily) impact the concept of using the corridors for running, since the tracks will be on the "floor" of the habitat, and the spokes will open in the "ceiling"
Runners were work up a sweat, so there would (presumably) be a run on shower water after each exercise period.
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In 1999 had a job in Miami, Florida. My girlfriend at the time worked for Royal Caribbean Cruise Line. They just completed construction of Voyager of the Seas; employees got a tour of the ship before the first passengers. She took me as her guest. Construction workers were still installing finishing touches like chandeliers. So I saw it. The web site lists dining rooms. Yea, it's way bigger than the ship I propose, when it was built it was the largest cruise ship in the world. There are even larger now, and that's a luxury cruise ship, not a passenger transport. But as an example...
Things To Do
Dining rooms: Chef's Table, Café Promenade, Izumi Sushi & Hot Rocks, Chops Grille, Giovanni's Table, Windjammer, Main Dining Room.
Bars & Lounges: Schooner Bar, Solarium Bar, English Pub, Pool Bar, Diamond Club, Suite Lounge, R Bar, Viking Crown Lounge.
So, separate dining rooms into themes. Just one bar, and food can be served there. If there's no room for a bar, dress one of the smaller dining rooms as a bar.
Standard tickets, both economy and single cabins, include all means served at regular dining rooms. Any meals in the fine dining room are extra. Luxury suites come with included meals in fine dining. Then there's booze.
We could set up a 'still to make vodka. I said the oxygen generator is a bag of chloroplasts. That produces starch as a byproduct. So as long as life support works, you could make an inexhaustible supply of vodka. Oh, wait. Starch is broken down by amylase, and the usual source is barley sprouts. Where would we get barley seeds? Gamma amylase comes from a mould that grows on something sugary, usually left over sugar cane pulp after all the juice to make sugar has been squeezed out. This is getting too complicated.
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For RobertDyck re #394
Thanks for the "visit" to "Voyager of the Seas" !!! It is as close as ** I ** will ever come to one of those regal vessels, but your word picture and links really help to bring it to life!
Here is a possibility that arises from the discussion you are leading ... It is possible to design an Earthly accommodation based upon the characteristics of the Rim Habitat you have been considering.
The link to the restaurant drawing web site is what suggested this as an option.
The complex based upon the Rim Habitat floor plan would be part of a theme park with Mars oriented exhibits and "rides".
A Mars habitat could be set up with your recommended mix of gases and pressure.
As a reminder ... Dr. Zubrin will be a guest on the space show 15 minutes from "now" (21:45) EST/US.
(th)
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Quickly went to thespaceshow.com, but it says "The Dr. Zubrin Program Will Now Be on Thursday evening, Oct. 1, 2020."
Your idea of a Mars theme park isn't new. In 2005 I was part of the Mars Homestead Project, phase 1, The Hillside Settlement. That was a project lead by Bruce Mackenzie to design the first permanent settlement on Mars. The idea was 12 settlers on a one-way trip. They arrive on Mars with nothing but rocks and sunlight and dirt, etc. What do they need to bring with them? What would the base/settlement look like? I think we did good work. Bruce is an alumni from M.I.T., he recruited several talented individuals. I as very honoured that he asked me to join his team. Our architect was a master student at M.I.T., our project was his thesis. He got his degree. After the project was finished, a couple team members got ambitious. They wanted to build a theme park with a full-size replica of the base/settlement. They got quite far. Unfortunately they had a falling-out with Bruce; the went their separate ways.
Wikipedia: 4Frontiers Corporation
I notice the 4Frontiers Corporation website hasn't been updated since 2017. The theme park wasn't built. Bruce lead more design studies, completed Phase 2, Plains Settlement. Was going to do a 3rd, but looks like that wasn't finished.
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for RobertDyck re #396
Thanks for the explanation !!! That explains why the Live Play button didn't work. I tried two OS and two different computers before giving up. Somehow I missed the reschedule announcement.
Thanks for the reminder of the theme park idea .... and thanks for the reminder of Bruce Mackenzie in that context!
Here is an update of the Rim Habitat layout with three sets of cabins and three spaces between for whatever you want to do with them.
I decided not to show the round shape of the spoke openings, because we are looking down on the "floor".
(th)
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For RobertDyck re Drawing Site you found ...
Here is an attempt to show a hotel floor plan offered as a sample ...
Surprise! It worked ... It shows a superior representation than the simple spreadsheet layout.
For one thing, the room numbers are shown. For another, the walls of the rooms are thicker, which helps to set them apart.
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Something like this...
Elevator where a spoke connects will have to be something like this. The elevator is in the centre of the rim. Stairs up to roof greenhouse and observation deck. Greenhouse could be one side of the spoke, observation deck the other. This transitions from 2 corridors for standard cabins to 1 corridor for luxury cabins. Luxury cabins are beside fine dining, and easy access to observation deck, and elevator to hub. Kitchen close to fine dining. Public washroom for dining room. Kitchen has water wall to provide radiation shield for infirmary and bridge. Kitchen storage is across corridor just because we need to do something useful with that space. This isn't the entire Kitchen; I said 2,100 sq.ft = 195.1m². Here kitchen is 71.3m² and storage is 3.4m², so 120.4m² more area for kitchen elsewhere.
Storage could extend under the stairs, and the wedge behind the elevator.
The 16 standard cabins closest to this spoke could be crew cabins.
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For RobertDyck re #399
Interesting thinking going on there.
For the time being, I'm assuming you will decide to preserve the corridors for two reasons ...
a) They are going to be a safety requirement. Any blockage to the corridor would cause a fire code citation.
b) They are going to be ** very ** popular!
Small decrease, but in competitive track and field, it's a big difference. And just for anyone still unimpressed, that time would translate to 10.6 meters per second, or an average of 23.7 miles per hour.Aug 9, 2013
How Fast Can A Human Run? - National Geographicwww.nationalgeographic.com › onward › 2013/08/09 › h...
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238 meters (circumference of Rim) divided by 20 seconds (time of one revolution) gives a velocity of 11.9 meters per second.
In the 1/3 gravity of the Rim Habitat, it should be possible to a human to achieve 11.9 meters per second, which would mean they would reduce their apparent weight to zero.
Running in the direction of the spin would allow them to build up simulated gravity, which would be good for muscle tone.
One corridor would (most likely) be set up spinward and the other the opposite, to avoid collisions in the (relatively) small space.
Please consider reworking your kitchen and other concepts to fit in the layout of Post #397.
Meanwhile, I'll attempt to improve the model in Post #397 by following the example of Post #398
I don't think you need to allocate space for any more cabins. The crew can reside in the 252 I had to use to obtain symmetry.
The 248 you started with did not provide a symmetrical configuration, but 252 does ... 21 rows of 4 cabins in 3 sets gives 252 cabins.
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