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#1 2018-07-03 20:03:42

Void
Member
Registered: 2011-12-29
Posts: 3,011

Bigelow and evolving situations of reality.

If I am not mistaken this seems to have been missed.

I know that the Bigelow project was put in low gear, until new launch systems would be ready.  It seems like it is coming out of hibernation now.

*Note, I have been eating up my data, and may run out tonight, so I might get cut short.


https://en.wikipedia.org/wiki/Robert_Bigelow
http://www.businessinsider.com/private- … low-2018-2
http://www.bigelowaerospace.com/pages/news/
https://bigelowspaceops.com/
https://en.wikipedia.org/wiki/BA_2100

Quote:

BA 2100
From Wikipedia, the free encyclopedia

BA 2100

Model of the BA 2100
Station statistics
Crew
16[1]
Mission status
Proposed
Mass
65–70 tonnes (143,000–154,000 lb)[1][2]
Length
17.8 m (58.4 ft)[1]
Diameter
12.6 m (41.3 ft)[1]
Pressurised volume
2,250 m3 (79,000 cu ft)[3]
The BA 2100, or Olympus,[3] is a conceptual design for a larger, heavier, and more capable expandable space station module, or interplanetary human transport module,[2] by Bigelow Aerospace. The larger BA 2100 would extend the volume and capabilities of the BA 330 module, which is under development as part of the Bigelow Commercial Space Station.[4] As with the BA 330 module, the number in the name refers to the number of cubic meters of space offered by the module when fully expanded in space.[5]
The mass of the BA 2100 could be as low as 65 to 70 tonnes (143,000 to 154,000 lb),[1][2] but would more likely be "in the range of 100 metric tons".[6] It is substantially larger than the BA 330, with the docking ends of the module alone estimated at approximately 25 feet (7.6 m) in diameter.[2] The concept model showed the docking ports at both ends.[5] The BA 2100 would require the use of a super heavy-lift launch vehicle and would require an 8-meter (26 ft) fairing for launch, such as the Block II version of the Space Launch System, which would have a 130-tonne (290,000 lb) payload capacity;[6] or the satellite delivery version of the BFR, which would have a 150-tonne (330,000 lb) payload capacity in its reusable configuration or 250-tonne (550,000 lb) payload capacity in its expendable configuration.[7]
Pressurized volume of single BA 2100 module is 2,250 cubic metres (79,000 cu ft),[3] compared to 931 cubic metres (32,900 cu ft) volume of the whole International Space Station as of May 2016.

If it is true that SpaceX can deliver to orbit these items, then I might venture that the concerns about the Lunar Gateway or Lunar space stations can be reduced.

……

Another evolving situation of reality is that Mars has shown its venomous side, as if it were not already a massive challenge.  The global dust storms.

For this reason (Because Killopower was introduced to me by members here), my dream precursor mission to Mars would be uncrewed,
and would have these killopower reactors on it.  It would be based on BFS, but would power itself to Mars with ion power, and of course land with combustion.  It would land and then become an atmospheric processing plant.  Stockpiling liquid CO and O2, for an eventual crewed landing.  If there is some strange way to collect water either from the air, or from the duricrust, such as electrical processes which would cause positive water ions to flow from the atmosphere to the duricrust and from the duricrust into the ship, then that would be great.  Not holding my breath.  The crew upon landing would be able to hook up to the automated landers, and then have quite a lot of resources, consumables available to them immediately.


……

However, I don't believe that any human landing or the landing of such an unsterilized ship will be allowed any time soon.
Today I encountered an article indicating a move to tighten up the rules for planetary protection.  Things like thou shalt not put a red roadster into interplanetary orbit.

So, that fight will be coming.  I am not sure how it will come out, but I do believe the fight is emerging.  I think this whole thing was a setup to divert the American space program, and then stop it.  Probably fostered by international concerns working with concerns in this country which might find that suitable to their objectives.  Maybe a bit paranoid, but typically the objective is pork, and even better how to get the money for the pork to a non space related purpose.

Anyway, I hope SpaceX does it but they may very well be stopped by politics.

……

So what to do in that case?  Well the Moon,  Neo's/Nea's, Venus?  The good thing about Venus, is you could send an appropriate probe there to look for microbes in the clouds.  If it is designed well, it should give a fairly quick yes/no answer.

Another thing that could happen is an orbit to orbit mission to Mars to retrieve sample returns from the surface of Mars, and from the moons of Mars (Those moons should contain fragments from Mars, that are historical in nature).

We might hope that then it would be decided that Mars was dead/alive, but no, they could spin this alive/dead thing for a very long time.

Oh, just because we didn't find life here, does not mean that it isn't on Mars.  And on top of that they don't want to visit places that might be most probable to find life, because we might contaminate it with Earth life.

……

So my point is go with what is possible.  Be ready to deal with that.  That could be reality.

Done.

Last edited by Void (2018-07-03 20:28:45)


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#2 2018-07-03 20:53:20

Void
Member
Registered: 2011-12-29
Posts: 3,011

Re: Bigelow and evolving situations of reality.

Very interesting! (Void said)

This then, I do like, maybe do not happen, but maybe do.

"Lunar, Sooner: ULA and Bigelow Announce Lunar Depot Partnership "

https://www.ulalaunch.com/about/news/20 … unar+Orbit

I really want to see what the Vulcan will do!  A different approach to reducing costs.
https://en.wikipedia.org/wiki/Vulcan_%28rocket%29

Yes, I understand the "UnMarsy" VOID shall be burned in the seventh level of NewMars Hell.  :0  smile
Done.

Last edited by Void (2018-07-03 20:56:31)


I like people who criticize angels dancing on a pinhead.  I also like it when angels dance on my pinhead.

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#3 2018-07-03 20:58:28

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 17,333

Re: Bigelow and evolving situations of reality.

Bigelows pockets for developing are less than Space x but also he has no ability to get his product into orbit so he must wait for others to want what he can create.

Nasa currently has Beam in orbit attached to the ISS as a trial of what it is capable of.

Metal versus fabric has been found to give an approximate 30% reduction in mass over that of the current cans in use by Nasa.
The Beam is being explored for radiation protection to which it does not seem to be as good but we think that it could be modified such that it could be better.
Beam and even the current prototypes are only capable of 2 entrances but the metal cans can have many more to all for it to grow in different directions.
Bigelows inflateables are just the ticket for Venus cloud cities as this would be simular to a blimp for applicationbut would require the acid test before man should go.
Bigelows habitats for mars surface still needs testing in a dust sand blasting as mars would be for part of mans presence would see.

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#4 2018-07-04 08:37:01

GW Johnson
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From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 3,754
Website

Re: Bigelow and evolving situations of reality.

BEAM's shell is only about half a meter thick.  It was designed to give the same radiation protection as the metal modules of the ISS,  and seems to provide exactly that. 

B330's shell is about a meter thick,  and is intended to provide twice the radiation protection of an ISS module.  That's "good enough" for the slow drizzle of GCR,  but not enough for the blast of a major solar flare's radiation. 

I'm not yet familiar with the B2100.  But if you dock the right sort of stuff around any of these modules,  you can use that stuff as a shadow shield for a solar flare event.  Propellant comes to mind,  as well as water/wastewater tanks. 

Multiple modules docked end-to-end could be spun end-over-end for artificial gravity,  if the internal fitments were arranged for that.

GW

Last edited by GW Johnson (2018-07-04 08:41:56)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#5 2018-07-04 12:04:52

Void
Member
Registered: 2011-12-29
Posts: 3,011

Re: Bigelow and evolving situations of reality.

The picture to me looks good.  If you have a look at what the various public and private space entities are doing separately, there is some cause for concern that it does not make sense.  But if you look at them collectively, the potentials look rather good I think.

You have SpaceX, BRF/BFS which would have the methods to reduce lifting costs, by the methods we know of.

ULA Vulcan is different, and so most likely they will each find a niche market for what they can do.

Blue Origins is mysterious, but we have the Shepard, Glen, and Armstrong proposed, and the "Blue Moon".  I am not sure, but I get the impression that the 1st stage boosters for Blue Origins will have more of an aerodynamic flight capability than those of SpaceX.  They seem to be impressed with there proposed ability to land the boosters on a moving recovery ship.  Probably that will enable them to handle rougher seas I am guessing than for stationary barges.

Then you have the Bigelow inflatables, which may be compatible with each of those.

……

While BFS is supposedly intended to be able to land on the Moon, and probably will on occasion, I might think that on other occasions it would simply orbit the Moon, and "Blue Moon" might land the materials to the Moons surface.  Or alternately perhaps something like Blue Moon would do as Dr. Zubrin has suggested.

So, the configuration might be BFS as Command Module & Blue Moon as LEM, or;
Per Dr. Zubrin, similar, but the BFS (Command Module) parks in an Earth orbit of some type.

They might not directly work together, perhaps loads are parked at a space station to await handling by Blue Moon.

I don't know what the intention of reusability for the Blue Moon would be.  Would some vehicle bring it down to Earth periodically for servicing?  Perhaps it would be multi-use and then throw away.https://www.space.com/36369-blue-origin-will-make-lunar-deliveries.html
https://www.space.com/36369-blue-origin … eries.html
I think I saw at some time that it may be that Blue Moon will also be able to land people, but I don't know for sure, or how life support would be managed.

I think the idea is to originally land very automated equipment as precursor to human presence.

……

And then you have hints of ULA capabilities such as a refuellable orbital device, and Magnetic Radiation Shields.
http://spacenews.com/bigelow-and-ula-an … -facility/
Quote:

The companies said they are working together on a concept for a “lunar depot” using an expandable module provided by Bigelow and launched by a next-generation ULA rocket that could support both NASA and commercial uses as soon as 2022.
Under the concept, a ULA Vulcan 562 rocket would launch the Bigelow B330 module into low Earth orbit. The module would remain in Earth orbit for up to a year to undergo tests and be visited by crews.
ULA would then launch two more Vulcan rockets, each placing an Advanced Cryogenic Evolved Stage (ACES) upper stage in orbit. One of the ACES would refuel the other, which would then dock with the B330 and send the module into a low lunar orbit.
The announcement build upon existing work between the two companies to study launching B330 modules, originally on the Atlas 5, Bigelow Aerospace President Robert Bigelow said in an Oct. 17 interview. He said his company decided to shift to the Vulcan vehicle and then build upon its capabilities, such as the ACES upper stage that is intended to also serve as a refuelable space tug.
“There is synchronicity between what ULA has in the way of capabilities and what we’re doing,” Bigelow said. “We decided to collaborate and prepare a proposal that the White House and NASA could accept as part of an overall space plan.”


Quite a box full of tools.  Only question, is where might SLS fit in?  It does not matter I think.  If it has a real secret capability that is fine, or if it is just a Oink Oink, I guess I don't care as long as the other activities continue, and eventually intersect to a greater purpose.


Done.

Last edited by Void (2018-07-04 12:32:17)


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#6 2018-07-04 15:58:11

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 17,333

Re: Bigelow and evolving situations of reality.

Bigelow is not going to be paying for his product to be launched or at least not very much as he will be wanting others to pay for its useage as its just a hotel in space for many.

Refueling tugs, magnetic shielding, are in the paper study prototype design phases with some of it near possible and others not so much but it still comes down to big bucks to pay for it as the developer is not going to pay for it to be used that is what a customer is for but whom will be that customer?

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#7 2018-07-04 19:29:22

Void
Member
Registered: 2011-12-29
Posts: 3,011

Re: Bigelow and evolving situations of reality.

Its not dark yet, so I will try.

SpaceX has https://en.wikipedia.org/wiki/Starlink_ … tellation)

It will also claim to bring fuel for Satellite servicing to orbit the cheapest, but I think that Vulcan, New Glen, and New Armstrong are a question mark for that.  China says that it plans to build a reusable system, and I have to believe that Europe (Whatever that will be), will try to do the same.

I would imagine, that it will become internationally mandated that if you put something into certain orbits, you are responsible to dispose of it.  Perhaps you might even be charged criminally if you damage the function of someone else's equipment in space without just cause.

So, disposal and recycling will be a business I would imagine, not just launching satellites.  Maybe "Waste Management" has a future in orbit smile

https://en.wikipedia.org/wiki/Waste_man … _hierarchy

So, that is a basic economic base I would think.  I believe that ULA intends to be involved in Satellite servicing/refueling.  I would imagine others will also.
…..

So, an "In-orbit" market for materials may appear, along with some level of manufacturing from materials from Earth, and recycled materials.  After that the question arises, do you get materials from other sources to use in orbit?  The Moon, Neo/Nea, and also can you scoop gasses off the top of the Earth's atmosphere?

Three methods for mining the Earths atmosphere to orbit may be available.
1) The European air breathing ion rocket.
https://futurism.com/esa-ion-thruster-breathes-air/
https://en.wikipedia.org/wiki/Air-breat … propulsion
2) Skyhook.
https://en.wikipedia.org/wiki/Skyhook_%28structure%29
3) Space Tethers.
https://en.wikipedia.org/wiki/Space_tether

Perhaps a combination of the three, or two of the items above.

I myself am interested in CO2 and O2 which could be obtained, from the Moon or NEO/NEA's.  (For the CO2 from the Moon, I anticipate Carbon from the Earth or eventually NEO/NEA's, or Mars.  However I think the lunar ice deposits also have Carbon Monoxide or Carbon Monoxide.

Obviously if you can ion thrust the Earths atmosphere, you should be able to do the same for CO2 or O2.
There are other propulsive methods that could be used such as flinging them magnetically from a linear accelerator, or a Radio Wave / Microwave method.

But while you are dealing with the Moon, and NEO/NEA's then why not valuable building materials?  Although you might process Lunar materials on the Moon, I think rather to bring the Moon materials to LEO, and then extract the Oxygen using Carbon and CO, and then extracting the "Low Hanging Fruit" for materials, such as metals, then the remainder "Slag" goes into Mineral Wool.

Mineral Wool might make Fiber Wool (Fiber Glass), but you are going to want to not mess up LEO with fibers that could collide with equipment.  Maybe the processing should be in L1.

…..

Then when all this is developed, you can support interplanetary activities which may get financed for science, or if you make the prices low enough the building of "Land".

That is an update of O'neill Cylinders, or habitats on Planets.
https://en.wikipedia.org/wiki/O%27Neill_cylinder

Then of course there are nationalistic and internationalistic military/policing or chest pounding actions to pay for stuff also.

It is getting dark.

……

Methods for inhabiting planets are much like vegetation's propagation methods.
In favorable climates, seeds are a likely method.
In harsh climates, the deserts, Arctic, runners are the preferred method.
Between those two would be something like the Prickly Pear Cactus.  Break off a leaf, and put it on the ground and it might take hold like a seed.  Some other plants can do that as well.

So, to expand to Mars, you can do a seed and hope for the best.  In that case I recommend a automated planted pseudo BFS with Kilopower and atmospheric processing to precede habitation.  No guarantees of success, and the growth rate may be slower than with runners.

Otherwise it makes more sense to treat the space environment(s) as deserts of the dry & cold type.  Runners are the correct method.

Done

Last edited by Void (2018-07-04 20:02:05)


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#8 2018-07-04 21:39:59

kbd512
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Registered: 2015-01-02
Posts: 3,098

Re: Bigelow and evolving situations of reality.

Radiation Shielding
I want to see BEAM with a BNNT fabric liner.  It won't stop SPE's since it wasn't intended for that purpose, but the combination of fabric structure and liner should minimize GCR to the extent practical.  I originally intended for the ITV to use soft shell modules, but was willing to use Aluminum alloy construction and more assembly steps if that's what was required to get the job done.  If the masses are similar to or less than an Aluminum alloy modules, I think the packing volume efficiency and the ability to ship nearly complete ITV's is worth the added complexity.  Since additional fabric coverings (Kevlar or Spectra) are necessary to prevent or limit penetration of Aluminum alloy modules by debris, I think the mass per unit of pressurized volume will be less than an equivalent Aluminum alloy module.  There's no engineering reason that I can think of as to why inflatable structures can't withstand the loads applied by low thrust ion engines.

Core Module Design
I was thinking of a BA2100 core module with four radial spokes connected to a wheel when I thought up my ITV concept.  The core module would have several levels, but no solid center section.  The levels would be fabric floors and concentric radial rings (about the long axis of the module, in order to distribute consumables mass to balance the rotating assembly) connected to a fabric center section containing all electronics and life support equipment mounted to soft racks made rigid by the inflation of the module.  The food consumables storage would consist of fabric bags attached to soft mounts or tie-downs around the walls of each level of the module.  The fresh water would be stored in a series of multi-cell water plastic bags around the core, like small inflatable air mattresses containing water instead of air, each unit containing a fractional portion of the total fresh water supply.  The pumping system in the core will refill these crew transportable multi-cell water bags using recycled water from a grey tank in the bottom of the core module.  A crew member will attach one of the portable fresh water bags to a water pump/dispenser for rehydrating food, cooking, cleaning, showering (permissible because the rotation of the core flings water outwards), etc.  Basically, the crew work and exercise in the rotating wheel section, but congregate in the lower gravity core section for sleeping (so there's no need to wake people up to move them during SPE's), meals, cleaning, showering, and maintaining the life support equipment located there.  Most hours of the day are spent in 1g, with frequent brief transitions to the lower gravity core.

ITV Engineering Section Design
I've seen this flexible inflatable robotic arm produced by Festo that's called the "Octopus Gripper" that was designed to handle fragile materials using a series of inflatables segments to serve as the robot arm and a small segment containing suction cups as an end effector to grip soft objects like eggs, tomatoes, wine glasses, human hands, etc.  That would make an excellent prehensile tail for the ITV.  The flexible tail section would have the electric motor used to counter-rotate and gyroscopically stabilize the habitable section and engineering section at one end (the end that connects to the ITV core module) and the Iodine propellant cartridge and ion engine mounted to the other end (the end that produces axial thrust in the direction of travel).  This would preclude the requirement for heavy gyros or attachment of smaller thrusters to change the attitude of the vehicle.  The end with the electric motor also serves as the solar panel mount for the megawatt class thin film array.  Magnetic gearing independently manipulates the rotational rates of the habitable and engineering sections.  That is a real thing in use in some electric and hybrid vehicle transmissions to transfer torque from a motor or internal combustion engine to the tires, so look it up if you don't believe me.

Water and Electricity Don't Mix
The placement of electronics, batteries, and life support equipment in the center of the core module ensures that any water leaks are flung radially outwards and away from anything that might produce an electrical short if water contacted it.  Lighting will be achieved through the use of flexible light pipes.  Air circulation will be accomplished using a series of flexible air ducts.

ITV Emergencies and Effects Limiting Design Features
Each spoke of the artificial gravity wheel has a pair of airlocks to separate the spokes from the core module.  Each section of the wheel also has a pair of airlocks separating sections of the wheel from each other.  If any section is penetrated or otherwise leaks, then the occupants in the other sections have time to seal off the punctured section from rest of the assembly and effect repairs.  Hopefully the thick multi-layer construction prevents significant penetrations from occurring, but if it does then it won't kill everyone at the same time, provided that the crew exercises airlock discipline by closing hatches behind them.  Ocean going ships have water-tight doors for water-tight integrity, but the ITV has airlocks for air-tight integrity.  Each crew member in the wheel will carry a bottle containing a few minutes of oxygen for evacuation from affected wheel section.  If the core module is penetrated, then the crew must temporarily abandon the ITV, board the BFS-MP strapped to the nose of the ITV-E flying in formation with them, and effect repairs.  All systems aboard the ITV are remotely operable from BFS-MP or using mobile phones and tablets.

The light pipes will flash different colors to indicate specific classes of emergencies.  The light coloration will be white for normal operations, red for fire, blue for pressure loss, green for all other classes of emergencies, and amber indicates that it's time to suit up to abandon ship.  Audible and vibration alarms will transmit on all smart watches, phones, and tablets.  A flashing color means there's an emergency somewhere else in the ship.  A solid color means you're in the affected section and need to evacuate immediately.

Delivery and Outfitting of ITV's for Interplanetary Missions
It may be possible to send an entire ITV to ISS with a single BFS-C flight, but the food / water / life support (filter cartridges or bags) / medical supplies / propellant consumables must be transferred via CTB's with a subsequent BFS flight.  The ITV should be offloaded and inspected after each mission.  If the inflatables, solar panels, computers, communications, batteries, and life support are still in good condition, then crew consumables are replenished / loaded onto the ship and preparations are made for the next mission.  If there is any damage, then the damaged equipment is repaired or replaced.

Overall, I think this sort of setup provides the necessary systems redundancy, damage control capabilities, and backups to assure that the crew reach their destination alive and in good physical condition.

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#9 2019-09-03 21:18:57

SpaceNut
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Registered: 2004-07-22
Posts: 17,333

Re: Bigelow and evolving situations of reality.

Not a new topic to get people into space with the use of a Hotel....

Company Claims Orbital Hotel to Host 400 Space Tourists Will Be Operational By 2025

Thats a good use for the 100 passenger BFR if its flying by then.

Thats a feat that the space shuttle if it had been altered for could have done quite easily...

Maybe someone will do a shuttle once more but not so costly to operate....

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#10 2019-09-22 09:52:07

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 17,333

Re: Bigelow and evolving situations of reality.

Bigelow could supply such a habitat for the societies goals of testing under near mars conditions at the analog site.

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#11 2019-09-26 05:04:45

elderflower
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Posts: 1,149

Re: Bigelow and evolving situations of reality.

SSTO is being worked on. See Skylon on wikipaedia.

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#12 2019-09-26 22:49:39

GW Johnson
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From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 3,754
Website

Re: Bigelow and evolving situations of reality.

What I have seen regarding the SABRE engine is encouraging.  There is still a lot more testing to do before it could possibly fly.

I'm not too enthusiastic about the Skylon airframe designs I have seen.  With tip-mounted engines,  the shocks shed by the engine inlet spikes will impinge the wing leading edges.  Above about Mach 6,  there are no known materials but ablatives that might possibly survive this,  and any ablatives will have to be very thick and heavy,  and single-use,  if they can survive at all,  which I doubt.

Reentry starts at Mach 25.  I think the shocks will cut the wings off the bird during reentry. It may even have problems on ascent from about Mach 6 on up.  Depends upon how fast they are flying when they exceed about 200,000 feet altitude.

I say what I say about shock impingement heating,  because it amplified the already-horrific hypersonic heating by a factor of 7-ish,  on the X-15 flight that was severely damaged by this.  That was only Mach 6.7.

GW

Last edited by GW Johnson (2019-09-26 22:52:05)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#13 2019-09-27 03:51:53

elderflower
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Registered: 2016-06-19
Posts: 1,149

Re: Bigelow and evolving situations of reality.

I expect SABRE will fly fairly soon as a prototype missile engine. It will give us the power to use a very long range hypersonic missile. Money becomes much more freely available when used for development of devices for destruction and killing.

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#14 2019-09-27 12:06:29

GW Johnson
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From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 3,754
Website

Re: Bigelow and evolving situations of reality.

Sadly,  what you said about money for military applications is true enough. 

As I understood the publicity announcements,  SABRE is really a rocket that uses liquified scooped-up air for its oxidizer.  They operate in this mode up to Mach 5-ish,  accumulating liquid air on board,  because they scoop up and liquify more air than the rocket needs.  Then from Mach 5 at some unclear-to-me high altitude,  they operate as a straight rocket,  drawing liquid air from the on-board tanks.   

This kind of thing was first proposed in the late 1950's or early 1960's.  Back then,  nobody could demonstrate a rapid air liquifaction technology,  and also solve all the real-world heat exchanger icing problems.  Apparently,  the makers of SABRE have solved those issues. 

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#15 2019-09-28 22:35:36

GW Johnson
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From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 3,754
Website

Re: Bigelow and evolving situations of reality.

Does anyone have a good figure for the overall effective density of the fabric layers that Bigelow uses as the insulation / meteoroid protection / radiation shielding on things like their B-330 module,  and later designs,  for deep space?

I ask because the density times the thickness is essentially the shielding mass per unit area for radiation shielding purposes.  Using a wild guess of 20 g/cm^3,  and a thickness of 1 m (B-330),  that works out to 20 g/cm2 shielding.  If polymer-based fabrics,  that's mostly C and H atoms,  which are rather low atomic weight.  Not a lot different than water. 

20 g/cm^2 is not a bad shield for solar flare events.  It also has some effects upon galactic cosmic radiation,  which could act to reduce peak-year 60 REM/yr exposures to nearer 50 REM/yr.  And at lower atomic weights,  the secondary shower effect is minimized. 

If something like Kbd512's "BNNT" fibers could be made into a commercial product,  then incorporating them into such a shield is even better. 

Meanwhile,  we already have a feasible solution,  at least in Bigelow's inflatable designs. 

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#16 2020-01-02 19:13:31

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 17,333

Re: Bigelow and evolving situations of reality.

Beam is there and being tested but we are holding for what?
Lets either make a choice or call it a no go...

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#17 2020-01-02 20:06:04

louis
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From: UK
Registered: 2008-03-24
Posts: 5,310

Re: Bigelow and evolving situations of reality.

We know how to protect against radiation - ice/plastic/water/regolith.

How does Mars hab pressure compare with say propane vessel pressure. Am I right in thinking Mars pressure is about 20 x that of a propane holder on Earth?  If so, that is a sobering thought!

SpaceNut wrote:

Beam is there and being tested but we are holding for what?
Lets either make a choice or call it a no go...


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#18 2020-01-02 22:37:37

kbd512
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Registered: 2015-01-02
Posts: 3,098

Re: Bigelow and evolving situations of reality.

Louis,

The pressure that a prototypical propane tank is capable of withstanding, or at least the ASME-approved ones for use here in the US, equates to 250psi or 17 atmospheres or a 561 foot tall column of water.  US DoT requires 375psi.  The 250psi tanks are about 1/8 inch thick.  The DoT approved tanks are a bit thicker.

We do build specialty habitats capable of withstanding more pressure than that, in compression, by using thicker gauges of high-strength steels like HY-80 or HY-100.  We call them submarines.  I've never heard of one being launched into orbit, though.

As far as radiation is concerned, 1/8 steel wouldn't provide much protection and it may actually make things worse from secondary particle showers in the case of GCR's.

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