Large scale colonization ship

elderflower · 2019-09-17 14:42:23

There's only one way the question can be resolved. Some scientifically trained people go there and identify it! That mean geologists, chemists, mineralogists, biologists.
There is no chance of either planet being pristine as we have been swapping rocks for 4 billion years (applies to all major inner solar system bodies), so the planetary protection lobby must have a different agenda that they aren't talking about.

SpaceNut · 2019-09-17 16:43:07

We have already carriered with each probe life that did not die from being processed so lets move on as there is nothing to see here.

Since Nasa is going to the moon we will be probabvly 15yr to 20 before they are serious to going to mars.

Space x BFR while it could be a decade I wouls not think that they will try all that much sooner as there is no other paying customer for going any where other than LEO and the moon at this time....

RobertDyck · 2019-09-29 13:48:26

I mentioned the window for "economy cabins" on the outside hull would have a window, and that would could be the TV. I said this because I repair laptop computers, I have taken apart an LCD display. It's a very thin transparent glass over a flat panel back light. The Liquid Crystal Display works with a layer of glass polarized in one direction, and a pixel is formed by an AC current through a small liquid pocket causing the liquid to become polarized 90° to the glass. With 2 filters polarized 90° to each other, they block light becoming black. Obviously they have red, green, and blue pixels. The point is when the LCD is removed from the back light, it's actually as transparent as glass and very thin. Actually too thin, it's easy to break. The display is taped to the back light, and the back light provides structural support.

So could we design a TV to be transparent when turned off? Here's a transparent TV that can be purchased. It's intended for store windows with advertising on the TV and merchandise displayed behind the TV. This video shows an enthusiast trying to game on it. (Click image for YouTube video.)

You can install "electronic tint window" behind it. This window is a big LCD that blocks light. With the window behind the TV blocked, you get a clear TV picture.

SpaceNut · 2020-06-28 17:55:20

bump talk of pebble reactors

not to mention slow glass...

Calliban · 2020-06-28 18:13:13

Not sure about a Mars built pebble bed NTR for an interplanetary ship. It could work, but it would have quite a large critical diameter, making it quite massive. Also, to avoid an overly burdensome neutron loss due to absorption in the hydrogen coolant, the coolant density in the pebble bed would need to be constrained (I.e low engine pressure) which puts a limit on thrust-weight ratio and peak acceleration. I haven't run the numbers, but my hunch is that it would work much better with some low enriched uranium. The advantage of a Mars built NTR would appear to be that nuclear material doesn't need to be launched from Earth.

Phobos could provide a colony ship with reaction mass. This could make a mass driver type engine a desirable option.

Last edited by Calliban (2020-06-28 18:17:30)

RobertDyck · 2020-06-28 18:48:59

Here's a rough hand drawing by me. A wheel with one deck as the living quarters of the large scale colonization ship. Central hub is a zero-G chamber used as reception for settlers arriving. During transit to Mars, this can be used as zero-G gymnasium. The reception chamber has spokes to the wheel, with ladders down. Be careful, near the hub it's zero-G, but the farther down you go the more gravity. Aft the hub chamber is a zero-G cargo hold. Aft of that is porpellant tanks, and the very back has the main rocket engine.

There may be 4 spokes instead of 3.

1,000 settlers on the ship each transit to Mars. SpaceX Starship used to deliver settlers from Earth surface to the ship in Earth orbit. 100 settlers at a time. If you look at proposed floor plan for Starship, there's plenty of room for twice that number for a short trip to Earth orbit. Shown is Starship approaching the hub.

Last edited by RobertDyck (2020-08-18 11:42:15)

tahanson43206 · 2020-06-28 20:00:20

For RobertDyck re #106

First, ** nice sketch ** !!! I'm trying to inspire void to give it a try!

Question about sketch ... you've got the AG covered, but how are you dealing with solar flares?

Second, out of curiosity, I clicked on your "website" button and found this:

Next monthly meeting:
Thursday, June 28, 2018, at 7:00pm
Millennium Library downtown. In a tutorial room. Ask at the desk on the second floor.

It could be a Canadian thing << grin >> In any case, how'd the meeting go? We're all doing virtuals these days (Twitch or Zoom).

(th)

RobertDyck · 2020-06-28 20:23:52

tahanson43206 wrote:

Second, out of curiosity, I clicked on your "website" button and found this:
Next monthly meeting:
Thursday, June 28, 2018, at 7:00pm
Millennium Library downtown. In a tutorial room. Ask at the desk on the second floor.
It could be a Canadian thing << grin >> In any case, how'd the meeting go? We're all doing virtuals these days (Twitch or Zoom).

Sigh! My job interfered with meetings. We haven't met in a long time. The mayor has armed guards check everyone's bag when entering the Millennium library. Excuse is drugs, but he just doesn't want poor people using the library. We chose to halt all meetings until that practice stops. It may require a new mayor.

tahanson43206 · 2020-06-28 20:45:32

For RobertDyck re #108

Today is June 28th of 2020. All I saw was Thursday and June 28th, and missed the 2018 entirely.

Two years is a long stretch ... any chance your members would be interested in trying again in virtual mode?

The results of the change to virtual have been quite interesting to observe locally ... The local computer society has been re-energized, with all the monthly meetings back in operation with more attendees than in the drive-to-library days, and the Dot Net group is thriving, with speakers from around the country and 43 attendees at the last event, which would have packed the usual meeting room.

Twitch is better for a host>>audience configuration. Zoom is better for a smaller group with a lot of interaction, but a presentation is possible.

You do need decent bandwidth for either mode. That is not a problem in a large city (or at least most large cities) but it might not be a as feasible everywhere.

(th)

RobertDyck · 2020-06-28 22:25:30

tahanson43206 wrote:

Question about sketch ... you've got the AG covered, but how are you dealing with solar flares?

Water wall, tank of water 4" deep on the aft side of the ring. Windows in that wall filled with mineral oil to same depth.

RobertDyck · 2020-06-28 22:39:26

tahanson43206 wrote:

Today is June 28th of 2020.

And the province already started phase 3 of re-opening. A lot of us believe the government shouldn't open the border to the US yet. Sorry, but number of cases in the US are bad. Decision to allow movie production crews to claim they have self-isolated for 2 weeks where they came from before entering our province? Not a good idea! We keep getting close to zero cases, but a one or two new cases from people entering our province. Friday there were 2 new cases, bringing the total case count to 11. No one in hospital, and no one has died in this province since May 5. Phase 3 of re-opening came into effect June 21, which increased the size of groups that may meet indoors from 10 to 50. So we could meet now, but it's recent. Most members also belong to the local science fiction club, their venue still isn't even answering phone calls.

tahanson43206 · 2020-06-29 07:16:16

For RobertDyck #110

I like the sound of the water wall. Just to be clear ... by "aft" end, I presume you mean "Sun pointing" end, and the navigator will set up the gyroscopic effect by insuring the vehicle is aligned properly before beginning rotation. After that, unless precession occurs, the alignment should remain stable. According to a quick check with Google, precession is likely, but in a vehicle that size it may be small, and perhaps even only noticeable to instruments.

Re #111 ... Congratulations on the progress (or at least holding the fort). I don't think anyone can be proud of the demonstration of magic thinking on the part of millions of Americans. However, I watched an hour long interview with an historian discussing the invention of the Polio vaccine, and how the public reacted. The vast majority of Americans apparently were on board with the risks vs reward proposition, but there were still millions who were not.

Re #109 ... OK ... but even for science fiction enthusiasts, there might be some openness to using Zoom or Twitch. Perhaps the technical capability is an issue for this population. I concede that my observations are based upon two highly computer literate (and equipped) populations.

Finally, .... you may very well have been too busy to note the recent work by GW Johnson ... he's been thinking about a Mars expedition and the various elements that would be needed for some time ... Recently he briefly tossed out an idea for an expedition ship that would not land, but instead would orbit Mars or perhaps even orbit Phobos. Your vision of a large vessel with artificial gravity and a reasonable level of solar flare protection should appeal to him. If you have time to review his work, you'll find that he wrote up a description (actually several versions) of landers that would be supplied with fuel/oxidizer from the expedition ship, and NOT be dependent upon in situ resources.

That doesn't mean in situ resources should not be developed and used if possible. It simply means that the expedition is NOT fatally dependent upon in situ resources.

GW Johnson has also be thinking about orbits. He's offered a version of the Aldin cycle which would be designed to return reliably to Earth in two years from launch, if the expedition cannot stop at Mars for some reason. His design appears to deliver astronauts to Mars slightly more rapidly than the Aldrin design.

A distinction is that GW Johnson's design (as I understand it) expects to stop at Mars. The design of the orbit has two attractive features: It is faster than the minimum energy Hohmann orbit, and it returns reliably to Earth if necessary.

Your design appears (to me at least) to be a candidate to be merged with GW Johnson's ideas.

(th)

Last edited by tahanson43206 (2020-06-29 07:17:02)

RobertDyck · 2020-06-29 10:56:11

tahanson43206 wrote:

I like the sound of the water wall. Just to be clear ... by "aft" end, I presume you mean "Sun pointing" end, and the navigator will set up the gyroscopic effect by insuring the vehicle is aligned properly before beginning rotation.

I said aft, because I intend the aft end of the ship to point toward the Sun during transit. The hub could be used as a zero-G gymnasium during transit. Aft of the hub would be zero-G cargo, aft of that would be propellant tanks, and finally aft most would be the main engine. This keeps propellant tanks between the main engine and zero-G hub, so if a nuclear engine is used, propellant acts as radiation shield. Those same propellant tanks also shield the hub against solar radiation.

For the ring, the aft window wall would point toward the Sun during transit. You want to keep radiation shield small to reduce mass. There would be 4 rows of cabins, the narrow side of the cabin would be the window wall. Only cabins with an aft window would need radiation shielding; inside and forward cabins would be in the shadow of aft cabins. Inside cabins would have a large screen TV instead of a window.

The ship would have to steer. The forward face of the wheel would be covered by a fabric heat shield for aerocapture and aerobraking. A fabric door in that heat shield would open for docking. Edges of the heat shield would fold back to expose forward cabin windows during transit, but fold down for protection during aerobraking. The ship would have numerous video cameras; smartphone cameras are very high def now, they're incredibly small so the ship could afford several. Inside cabins could set their TV to any one of the outside cameras, effectively getting the same view as an outside cabin. Forward cabins would have to do that as well during aerobraking, since the fabric heat shield would cover their window.

This thread started when Elon Musk announced that Starship version 2 would be much larger. He said twice as long and twice diameter, so 8 times interior volume. I started by saying you could build this instead, just slightly more volume than Elon's Starship version 2. And artificial gravity during transit would be highly beneficial.

tahanson43206 · 2020-06-29 11:18:07

For RobertDyck re #113

Thanks for your clarification. Since the word "aft" itself has absolutely NO relationship to the Sun (or anywhere else than the bow) your clarification is helpful.

Is there any chance of collaboration between the somewhat similar visions of GW Johnson and RobertDyck?

It seems to me as though we have two (space) ships passing in the (void) night right now.

Pun not intended, Sir Void!

(th)

Last edited by tahanson43206 (2020-06-29 11:19:10)

RobertDyck · 2020-06-30 17:26:19

Bump. Read the beginning of the thread.

GW Johnson · 2020-07-03 08:31:31

Are you still looking at aerocapture at both ends of the journey? That at Mars is very likely to be too highly variable in effect. You will need at least standby propulsion if the density just happens to be factor 2 too low. Otherwise, you bounce off instead of capturing.

GW

tahanson43206 · 2020-07-03 12:29:35

For RobertDyck re #115 .... Fair enough! I'll schedule time to read the entire topic.

For GW Johnson re #116 .... I am hoping the discussion between the two of you will lead to something solid ...

The idea of depending upon aerocapture or deceleration using atmospheric drag at Mars seems worth setting aside, in favor of those whose vision is limited.

Elsewhere in the forum, not long ago, I ran across something posted years ago that deserves to be brought forward ... It is possible to start out from Earth with a load of pure water in the propellant tanks, and electrolyze it on the journey, if sufficient solar panel acreage is built into the large ship design.

If there is NOT sufficient fuel and oxidizer manufactured en voyage, when the ship reaches Mars, then perform the Wave-Off and return safely in another 18 months or so.

If there ** IS ** enough fuel and oxidizer stored for a successful docking (with Phobos or just LMO) then the expedition can slow to match Mars, carry out the mission as you have outlined it multiple times in your blog and in this forum, AND return safely to Earth at the next Hohmann return window.

I hope the collaboration between the two of you will continue to gather International contributors! It is ** already ** International.

There is no reason (that I can think of) to stop at just two countries.

(th)

SpaceNut · 2020-07-03 16:12:44

The water is from the radiation shadow shield and is a separate tank. We could make use of that water at the end of the trip if we have the through put and energy to run the electrolysis units. But as we had to solve in the balloon tank topic the hydrogen and oxygen needs to be liquified before the engines can use it.

Scale of a ship to hold 100 or more people have not been constructed in orbit and while we have the ISS with a crew of less than a dozen max at any given time we are looking to have a ship that is nearly 10 times as large but its more than that as its about power for all to make use of and supplies of food , water and so many more support systems to keep all safe. Its those things for the wish list that makes the ship even larger.

tahanson43206 · 2020-07-03 17:22:40

SpaceNut re #118 ...

No, on this one we are not talking about the same thing. You are ** certainly ** right that there needs to be water set up for use as a radiation shield. That water could be used for cooking and similar needs during the voyage, and returned to other tanks in a condition in need of renewal, but still perfectly effective as radiation shield.

I am talking about a ** completely ** separate set of tanks, which are loaded with pure water (to facilitate electrolysis) for processing during the outbound voyage. The electrolysis could yield gas which is pumped into expandable/elastic containers until just before it is needed as a fuel and oxidizer. At that point, the gas could be liquefied and stored for use in maneuvers to bring the entire complex into orbit around Mars.

The designers (at this point) do NOT need to be nickel-dime'ing this process. Artificial limitations are not needed. Real limitations are going to be challenge enough.

I'm looking forward to reading the entire topic from the top, as RobertDyck suggested.

(th)

GW Johnson · 2020-07-03 17:52:18

I'm finding RobertDyck's large scale colonization ship idea very intriguing. Up to now, I have always considered the old Project Orion nuclear explosion drive the best way to do that job. I still have yet to see anything better, but I remain an open-minded skeptic.

GW

RobertDyck · 2020-07-03 18:35:28

tahanson43206, out-of-the-box thinking is always good. However, I would suggest using liquid hydrogen propellant, with active refrigeration to prevent boil-off. In fact, a small "flash" tank to capture hydrogen boil-off, and refrigeration to re-liquefy and put back in the main tank. The open-cycle gas core nuclear thermal rocket uses LH2 as propellant, not LOX. And oxygen is much heavier. LOX is a great oxidizer for chemical rockets, but any sort of nuclear thermal works best with pure LH2.

That said, nuclear thermal can work with pure distilled water. It would have to be pure because any solute would precipitate out where water boils. Don't want to clog the engine with hard water scale. Water is heavier than LH2, so lower exhaust velocity and that determines specific impulse. However, water is much more dense so smaller propellant tank. Water is something to consider for applications where tank size is an issue.

RobertDyck · 2020-07-03 18:42:46

GW Johnson wrote:

I have always considered the old Project Orion nuclear explosion drive the best way to do that job.

I realize there are advantages. Specific impulse of a nuclear explosion is truly impressive. Even though most of the force is wasted, does not push the concussion plate, it's still very impressive. However, you are highly dependant on that concussion plate not rupturing and blowing up the ship. Each detonation provides a hard kick, even with shock absorbers between concussion plate and ship. But more importantly, the Outer Space Treaty does not allow it. The treaty prohibits any form of nuclear bomb in space. And Starfish Prime demonstrated what happens when you detonate a nuclear bomb in low Earth orbit, so you couldn't use such a drive system for Earth orbit departure.

Void · 2020-07-03 20:22:38

Just a quick question about Orion, for now ignoring legal issues.

If Starship works out, I am thinking that it would be possible to bring water up to orbit, put it into bags to freeze.

If you put such onto the pusher plate, how might that change performance? Obviously a big steam explosion, and perhaps a bit of cushion?

That is when they conceived of the device, I don't think they anticipated lower cost lift to orbit. Of course Starship has to actually work.

If you have an answer, fine, otherwise no problem.

tahanson43206 · 2020-07-04 06:51:28

2020/07/04 Review of RobertDyck's topic: Large Space Transport Vehicle >> Post 1 of planned 3

This post includes citations for the first 50 posts of RobertDyck's Large scale colonization ship topic

(th)

tahanson43206 · 2020-07-04 11:09:34

2020/07/04 Continuing review of RobertDyck's Large scale colonization ship topic:

Post 2 of planned 3

#051 http://newmars.com/forums/viewtopic.php … 30#p159830 GW Johnson Added Ceres work sheet (nuke bang or nuke ion)
#052 http://newmars.com/forums/viewtopic.php … 34#p159834 tahanson43206 Uranium in Solar System
#053 http://newmars.com/forums/viewtopic.php … 36#p159836 RobertDyck Nuclear thermal
#054 http://newmars.com/forums/viewtopic.php … 39#p159839 GW Johnson Yes, looked at Nuclear thermal plus treaty issues
#055 http://newmars.com/forums/viewtopic.php … 41#p159841 RobertDyck India Thorium development plus ion engines vs thermal
#056 http://newmars.com/forums/viewtopic.php … 45#p159845 tahanson43206 Manage nuclear forces safely (need to)
#057 http://newmars.com/forums/viewtopic.php … 46#p159846 RobertDyck Nuclear pulse illegal - suggest drop idea
#058 http://newmars.com/forums/viewtopic.php … 48#p159848 SpaceNut reminder of RTG's in space and new kilowatt reactor
#059 http://newmars.com/forums/viewtopic.php … 50#p159850 tahanson43206 Suggest dropping nuclear power for this topic?
#060 http://newmars.com/forums/viewtopic.php … 57#p159857 GW Johnson Reminder topic is about very large ships
#061 http://newmars.com/forums/viewtopic.php … 59#p159859 SpaceNut Attributes for colonial sized ship
#062 http://newmars.com/forums/viewtopic.php … 61#p159861 RobertDyck More detail of ship design with images
#063 http://newmars.com/forums/viewtopic.php … 62#p159862 RobertDyck More detail of ship design with images
#064 http://newmars.com/forums/viewtopic.php … 64#p159864 Calliban First post by Calliban - in favor of nuclear
#065 http://newmars.com/forums/viewtopic.php … 65#p159865 Terraformer Reminder of beamed power and work of Hop (member)
#066 http://newmars.com/forums/viewtopic.php … 66#p159866 Calliban Considering tether options
#067 http://newmars.com/forums/viewtopic.php … 67#p159867 Terraformer More on tethers vs rotating skyhooks
#068 http://newmars.com/forums/viewtopic.php … 72#p159872 tahanson43206 Momentum recovery when using tethers
#069 http://newmars.com/forums/viewtopic.php … 75#p159875 Terraformer Ion thrusters to recover momentum
#070 http://newmars.com/forums/viewtopic.php … 90#p159890 RobertDyck More on ship cabin design >> toward mass estimate
#071 http://newmars.com/forums/viewtopic.php … 13#p159913 Calliban Details of Thorium reactor design pro's/con's
#072 http://newmars.com/forums/viewtopic.php … 14#p159914 RobertDyck Link to article on Indian Kaiga 1 plant 962 days
#073 http://newmars.com/forums/viewtopic.php … 15#p159915 elderflower - CANDU reactors
#074 http://newmars.com/forums/viewtopic.php … 27#p159927 kbd512 Thorium - plenty of Uranium (on Earth)
#075 http://newmars.com/forums/viewtopic.php … 46#p159946 GW Johnson Closer look at nuclear thermal plus hint ferry

Post 2 of planned 3

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Re: Large scale colonization ship

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