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#276 2019-03-05 16:06:29

Void
Member
Registered: 2011-12-29
Posts: 2,954

Re: Alternate BFR (Big Falcon Rocket)

Very entertaining materials.

I notice a cluster of (SpaceX)Dragon,(Bigelow)a habitat known as the B330,and (ULA)Atlas.  A frenemies group I guess.

……

I was also introduced to the "Wet Lab" concept, where space boosters might be repurposed in orbit.  (Had a similar idea recently, but, by far, not before the Wet Lab people from the 1960's).

It is nice to have a distinct phrase as an object to contain the concept in.

https://www.starposts.space/
Quote(s):

Our First Outpost will be INDEPENDENCE-1
made by re-purposing a spent upper stage in orbit.

WHAT'S AN OUTPOST?
Outposts are the pillars of exploration, and we're setting up camp in the solar system. We'll start in low-Earth orbit, where NanoRacks continues to bring customers to market. We'll expand from there, following the market - and following our customers. Whether a hub for satellite deployment or for a luxurious hotel stay - your outpost is ready to launch.

HOW IT'S MADE

WET LAB
In November 2017, NanoRacks, along with SSL, a Maxar Technologies Company, Altius Space, and Space Adventures, proved to NASA that it is technically feasible to repurpose a spent second stage of a rocket while in space. This concept is known as a "Wet Lab," and was originally a concept from NASA's Marshall Spaceflight Center in the 1960s.
America's first outpost, Skylab, was made from a spent Saturn V fuel tank. It was manufactured on the ground, but an important stepping stone for re-using spent upper stages.

So, I believe I read that they want to launch hardware into LEO, and want to be able to rely on "Dragon" for passenger and crew flights.

It is not clear to me if they will intend to recycle parts of the upper stage boosters down to Earth for re-use, will simply ignore them, or might shred them to become recycled materials in orbit.

But I can see some of the logic for the "Wet Lab" method.  It spares you from having to bring down a gigantic "Starship" through burn-in and landing.

But I bet they might contract with the SpaceX for the starship for some activities.

So if they make it, I guess it could be a close partnership relationship.

I really ponder if SpaceX will ever dispose of the dragon.  Maybe a continuous upgrade, and a entirely new 1st stage some day.  Starship will be grand, but I am thinking there may be many times you just want to work with 1-7 crew & passengers.  Perhaps some day that path leads to Lunar and Mars landers as well.  Maybe.

Done.

Last edited by Void (2019-03-05 16:22:28)


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#277 2019-03-19 11:14:56

Void
Member
Registered: 2011-12-29
Posts: 2,954

Re: Alternate BFR (Big Falcon Rocket)

I am going to really goof with stuff in this post, so, be warned.  I see SpaceX's toys, and want to play with them.  In this case "Test-Hopper" has my attention now.

https://www.msn.com/en-us/news/technolo … ar-BBUSJYX

If you look at the picture of it, it sure looks iffy as a space vehicle.  But of course they are saving costs, to get the data they need on the cheep.  I respect that.

Now though imagine child of "Test-Hopper".Question #1, is it possible to get the child to orbit?  I think you would need to add a nose fairing for assent though the troposphere.  You also need sufficient additional engines, and propellant capacity for that.

Should you want to bring it back to the Earths surface, what is the method?  I don't think about the proposed Starship method.  Rather, I am thinking heat shield on the blunt top end of the device, and on the leading edges of the landing leg fins.

The device sufficiently filled with propellants, might use greater than normal propulsive deceleration methods while in the vacuum of orbit.  Then like a bit like a Shuttlecock use aerobraking in the atmosphere.
https://en.wikipedia.org/wiki/Shuttlecock
Some type of roll-over propulsive landing.
Why land it?  Well for maintenance, and to put a new fairing on it to bring up to orbit.

So, a bit like Vulcan, but instead of disposing of the fuel tanks, and landing the engines and avionics, you recover the fuel tanks, engines, and avionics to the surface.  You also leave a fairing in orbit to do a "WetLab" method with.  That fairing can be regarded as a crate, or a child of "Skylab", which was a form of "WetLabing" according to things I read about Wetlabing.  If it is for habitat of humans, or some mineral processing device, you might build it in full on the surface of the Earth, and then add it to some assembly in orbit or on the Moon or an asteroid.  If it is a simple crate, then you may have freight inside it.  After removal of the freight, the crate would be repurposed in orbit or on some object such as the Moon.

So, if I am not too far off from reality, then we have a method Earth<>LEO.  But what about using the child of test hopper as a tug, and Moon lander, and even more?

Some of these proposed uses could be in conflict with heat shield methods, unless transformer type methods are included.  That is being able to apply heat shields to the device when appropriate, and being able to get them out of the way, if you want to attach something to the tug/lander.  Hopefully a reversible method.  Something like putting cloths on such as a coat, and taking them off when appropriate.

If it is to be an orbital tug, chances are you simply have a method to attach a load to the device.  If you can attach multiple loads, then attach them between the legs, in a load balanced fashion.  Else, then you must be able to attach to the stubby "Nose" of the tug.  You then do really need to be able to juggle the heat shield mode for that.

OK, for Moon landings, I suppose you might land with the fairing, if you have a crane method to get that wetlab object off.

Or, else you may get rid of the fairing in LEO or elsewhere not the Moon, and then add a space capsule to the assembly.  Traditional visualization imagines that the capsule will be on top of the stubby nose.  But that of course interferes with heat shielding desires.  That is not impossible, but it is the Moon, or an asteroid???, so you might put the capsule between two of the legs, and have balancing loads in the two other vacancies between the legs.  Not traditional, but it saves your crew having to climb down from high elevations, and also, you then may use cargo's in the two other vacancies.  Of course if you consume those cargo's, and still want to climb back to lunar orbit, and ultimately return to Earth, you must either ballast the two other vacancies with cargo from the Moon, or hope that your device has the capability to deal with an unbalanced load.

I guess the return is either to LEO or to Earth surface or a combination of both.  The propulsive tug may be able to aeroburn and land.  The capsule should be able to do likewise.  But any cargo from the Moon, most likely has greater value in orbit than on the surface of the Earth unless it is a metal such as Rare Metals, and precious metals.

As for Mars, I have trouble seeing how to directly use such a Tug.  But an indirect method is to use it to assist a starship to high Earth orbit before it departs, and so I might hope based on some of my readings, improve the conditions for the starship or other ship to execute a trip from Earth vicinity to Mars.


I think that covers it.

Done.

Last edited by Void (2019-03-19 11:48:28)


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#278 2019-03-27 11:16:54

Void
Member
Registered: 2011-12-29
Posts: 2,954

Re: Alternate BFR (Big Falcon Rocket)

I posted this in Starship is a Go, a bit ago, but here I am going to take all the permissions that are allowed to express my speculations.

Quote Me:

Hay Louis, this is also interesting:
https://www.bing.com/videos/search?q=sp … &FORM=VIRE
I agree that SpaceX has big things to do with the Moon.  If they can get a good share of that activity, it will benefit the Starship/Superheavy program, which of course will benefit the Mars program.
Out of respect, I will put my wild speculations on these issues in another topic, "Alternate BFR" I think.

Not Done.


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#279 2019-03-27 11:18:09

Void
Member
Registered: 2011-12-29
Posts: 2,954

Re: Alternate BFR (Big Falcon Rocket)

I posted this in Starship is a Go, a bit ago, but here I am going to take all the permissions that are allowed to express my speculations.

Quote Me:

Hey Louis, this is also interesting:
https://www.bing.com/videos/search?q=Sp … &FORM=VIRE  I agree that SpaceX has big things to do with the Moon.  If they can get a good share of that activity, it will benefit the Starship/Superheavy program, which of course will benefit the Mars program.
Out of respect, I will put my wild speculations on these issues in another topic, "Alternate BFR" I think.

So, now to speculate.   This is just how I think about what I see now.  It doesn't make it the best notions, but is what I think at this point.

I think that Superheavy, Starship, Child of Starhopper, and Dragon can all be involved, in a very flexible system, which in particular will facilitate the Moon, Mars, and perhaps Asteroid works.

In learning from GW, I have come to understand that the first stage of such a system will not require full fledged heat shield capability.

All others will need much more serious attention to heat shield concerns.  This can be accomplished with ablation, for a price.  It seems that for Starship, Elon Musk and SpaceX want that price to be small per maintenance, and they will try to include active cooling to reduce maintenance price for heat shield on the Starship.

Elon has stated that for SuperHeavy, it is intended to start with a lesser number of engines, to sort of limit losses, if first attempts are not optimal.  So, rather than them testing it with Starship on it, I would also expect them to put a fairing on it for such tests.  I presume sub-orbital tests.

For Starship, Elon has stated, that Starship can go into orbit without SuperHeavy.  It just doesn't normally makes sense because it cannot then deliver useful cargo.  But if you want to test out Starships heatshield incrementally, then you make a "Starship Light".  Only include what is necessary to test the heat shield, to reduce weight.  Also only include the instrumentation useful to analyze the Starships performance.  So, you could start it with hops, and then go ballistic, and then to orbits, perhaps more and more aggressive, until, you have tested the heatshield and properly modified it, and have reached the limits of what Starship can do without SuperHeavy.

And what about Starhopper?  I suggest that if it's offspring could be modified to the extent that it could be used as a second stage for a third stage, it might have a future.  There are other systems in planning which have both a two stage mode and a three stage mode.  I would be looking at the possible production of a three stage mode.  While two stages makes quite a lot of sense going Earth<>Mars, three stages might make a lot of sense for the Moon, and orbital activities.

……

So for instance what if you stacked "Child of Starhopper" on top of SuperHeavy, and put a fairing on top of that.  You might have some interesting options.  Quite a few actually.

In effect you would break Starship into two pieces.  The fairing is a crate, which may or may not have it's own propulsion systems.  The "Child of Starhopper" is the propulsion system of Starship, which you might use as a tug in orbit, or even as a lander on the Moon.  You may be able to recover it to Earth's surface by a combination of retro-propulsion and heat shield methods.  I think its fins could be simple, not with hydraulics.  K.I.S.S. can be good.  You just might have to be prepared to put sufficient heat shield on the blunt cone, and the leading edges of the fins.  Probably even heat shield on the fins themselves.

As for the fairing/crate.  You could bring cargo up.  That might include a Dragon or maybe more.  As for the crate, maybe it can be habitat in orbit, or on the Moon.  The fairing might be big enough that you could put a LEM type propulsion system under a Dragon to allow it to land on the Moon and get off of the Moon.

But that is not to say that Starship itself could not visit the Moons surface as well.

Asteroid missions?  Well, if the fairing could be a supply and fuel depot, you could connect a bunch of them to a Starship perhaps, then go do it.

Ya, that's about it for now.

Done.

Last edited by Void (2019-03-27 11:58:44)


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#280 2019-04-01 12:31:27

Void
Member
Registered: 2011-12-29
Posts: 2,954

Re: Alternate BFR (Big Falcon Rocket)

Well, to be polite, I guess I will hang out here on the bottoms of reality.
https://www.teslarati.com/spacex-starsh … stem-tour/

Kind of like it.  Looks like Elon Musk is doing his own talk about alternate Starships.

Interesting.  I expect Kilopower to merge with expendable Starships.  Seems sensible.  It might get some stuff done that helps.

Kind of luke warm about activity here on the site just now.  Need a pause I think.  Lets hope.

Done smile


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#281 2019-04-14 09:12:54

Void
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Registered: 2011-12-29
Posts: 2,954

Re: Alternate BFR (Big Falcon Rocket)

Well, I took this material from:
Index
» Interplanetary transportation
» Space X - another successful mission...

(Post #45)

Quote:

This is a very good read that may be liked.

https://www.nextbigfuture.com/2019/02/e … con-9.html

I will just say that it indicates some very important information.
-The intent is to build 1000 Starships / Super Heavy's.
-Eventually the cost per set???, may be less than to build a Falcon 9.
-The will be building 30,000 raptor engines a year supposedly.
-The cost for weight of mass to orbit is expected to drop by a factor of 10 (At least).

I will directly quote one thing:
Quote:

Elon Musk

@elonmusk
Starship & Super Heavy will press tanks autogenously even in version 1. Very important, as helium costs more than oxygen on Falcon, even though liquid oxygen is 2/3 vehicle mass & helium weighs basically nothing.

The highlight shows a very important factor.  If Oxygen and other consumables can come from above surface sources for a better price, then it makes all the sense in the world(s)  to utilize that for the overall plan(s).
Viewed in this manner, a narrow focus on Mars only is probably not the way to go.
I am going to copy this and put it under "Alternate BFR", as I have a desire not to muddy up every thread with wild speculations.  I will do wild speculation there.

Done
Quote Louis:

Thanks Void - an interesting sketch of how the future might unfold with Starship testing.
If they are going to get humans to Mars by 2024 (!) they will likely need something like 48 launches (6 Mars craft and 42 fuelling launches)  - based on previous discussions.  There will of course be lots of proving flights before that, so maybe add in another 24. 72 launches over say a four year period.  I'm thinking they might need a fleet of about 20 Starships to accomplish the mission with pre-testing and orbital fuelling. I am presuming it takes several weeks to refurbish a Starship/Super Heavy, so you can't just have one Starship doing all the fuelling and the launch windows are quite narrow.  Taking everthing into consideration, 20 seems like a reasonable estimate. So if production of the first operational model begins in 2020, that would mean about 4 to 5 being produced per annum. Seems reasonable.


Well, that was exhausting just transferring the materials over.

There appear to be 3 methods suitable to SpaceX machines.
(1) The restricted timing method so far what Elon Musk/SpaceX have proposed to use.  Included in that is a treacherous Hohmann Transfer, with a nasty Aero-Burn.
(2) Ballistic Capture to Mars, Aero-Burn optional.  Timing of missions much more permissive than for #1.  I think this one is very suitable to un-crewed vessels.
(3) High orbit departure from Earth, possible travel time 30-40 days.  I am not sure what the reception methods are.  But to keep a crew healthy and ready to work on Mars, I think this could be attractive.  I need to learn more about it.

The source material for #3, is not at my fingertips, but I think it may be possible to re-access it.  But for now if not pressed about it I won't.  I think it is logical that it could be done.  We often hear about alternate propulsive methods that could because of their power, do short missions like that.  However they are not ready to go at this time.  However a Starship fully filled with propellants in high Earth orbit, suggests to me that it could actually be a possible method.  And to me it makes perfect sense to expend the  cost to reduce mission risks.  A healthier crew at Mars.  We would not send people to Mars unless they were intended to be productive.  If they are sick that would reduce productivity.  Everything has a cost.  You pay for propellants, or you pay for loss of productivity and safety.

…...

In the beginning, everything would be sourced from the surface of the Earth.  Over time, I would expect expanding extra-terrestrial resources to be used to continue the Mars efforts, and other space efforts. 


I propose something I would call a Starship-Depot-Wetlab.

If the article link posted is true, then Elon Musk thinks there is a path possible for the new endeavor to produce Super Heavy / Starship for less than they produce a Falcon 9 now.

So, at that cost, the question of expendable can be reviewed.  SpaceX will expend a Falcon 9 when the purpose justifies the machinery cost.  So, it is not out of the question to do so with Starship of some kind.  In fact they already intend to use Starships as initial shelters on Mars, so it is not out of the question.  I have a feeling that if a Starship has been used on Mars for years, it may be to costly to get it maintained back to bein a traveling Starship again.  Not sure, but maybe that is true.

So, of course SpaceX will do what they want if they can.  However to show just how much potential I think there could be, I suggest that they or someone else might build a type of Starship which would be dedicated to Starship>Depot>Wetlab.  Per OF, it comes to mind that it should be possible to send such a depot to Mars orbit, to assist in return to Earth of Crew, where that would be desired.  In general, though I expect SpaceX and Elon Musk want them to stay at Mars.

But Depots could serve to be made into shelters for the Moon, Mars, and perhaps Phobos and Demos.  It is to a large degree work with stainless steel.  So metal working methods, to convert permanently the used depots. 

Just to illustrate the power of this, imagine that a crewed ship, also has a Depot attached to it, and both are fully filled with propellant in high Earth orbit.  If you could do a 30-40 day trip then artificial gravity should not matter that much.  However you might implement it.  Arriving at Mars, I suppose both ships detach, and the Depot becomes habitat on the Martian surface.  If you have so much propellant, then is it certain that aero-burn methods will be used however?  Maybe the Depot could simply use propulsion to to to Phobos or Demos.  And of course a Wet-Lab Depot, could simply boost a crewed starship to a quick journey to Mars, and then itself land on the Moon to be Wet-Lab habitat there.


I think that the reason to do thins like this at first would be to facilitate Crew wellness and productivity.  But later if Oxygen and Water can be sourced from the Moon, and perhaps Carbon and Methane from Mars/Demos/Phobos/NEO objects, then perhaps zero propellant eventually coming up from the surface of Earth.  If it is true that 2/3 of the weight of Starship is Oxygen, if I read that correctly, then the Moon is very much a big part of the picture as time goes by.

Kind of tired.  Need to eat.

There will be lots of wrinkles to all of this over time.  I don't even think that Elon Musk or SpaceX or others even realize what methods they are going to use.  I certainly don't have anything except a dim view of possibilities.  But what I can see, suggests that we are on to some really vast potentials.

Done.

Last edited by Void (2019-04-14 10:08:23)


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#282 2019-04-15 05:27:47

tahanson43206
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Registered: 2018-04-27
Posts: 577

Re: Alternate BFR (Big Falcon Rocket)

For void #281

Thank you for quoting Elon Musk, about his mention of autogenous pressurization as an alternative to using helium because of the cost of helium.

I was curious about this, and found a discussion on Stack Exchange:
https://space.stackexchange.com/questio … propellant

The answer appears to be using heat from the engines to produce gas from the propellant used for cooling.  The gas is then fed back to the tank to maintain pressure there.

(th)

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#283 2019-04-15 07:38:52

Void
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Registered: 2011-12-29
Posts: 2,954

Re: Alternate BFR (Big Falcon Rocket)

Yes.  I am still sketchy about how they pressurize the tanks with heated vapors, and do not run into major conflict with the super chilled propellants.  At this time, I am imagining that the warmer injected gas is typically not in direct contact with the super chilled liquid, that there may be an intermediate layer of cool vapors between them.  But I am not saying that is the answer of how it can work, it is just the best I have until someone who might know can update my thinking.

But the big issue is that SpaceX(Elon Musk), are looking for ways to get "Starship I" capable of swings around the Moon, while reducing it's cost.  "Starship II" will then evolve with greater capabilities such as traveling to Mars to land safely.  At least that is the desire.

They do seem to have their eye on the Moon, and it is possible that Lunar Oxygen is a reason for that.

Done.

Last edited by Void (2019-04-15 07:40:27)


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#284 2019-04-15 12:14:54

Void
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Registered: 2011-12-29
Posts: 2,954

Re: Alternate BFR (Big Falcon Rocket)

Well Elon Musk is pranking (Sort Of), about adding dragon wings to Starship.  What he is up to, if a change to the structure, I don't know.

I guess I will step back awhile away from this one, as I fear I might get burned.

He seems to be thinking of a ring of fire.

Done.


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#285 2019-04-16 04:47:08

elderflower
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Registered: 2016-06-19
Posts: 1,087

Re: Alternate BFR (Big Falcon Rocket)

There has to be a heat exchanger, maybe just a coil like in a hot water indirect tank. You can't inject gas into the LOX tank directly as it will contain water vapour which will freeze and block valves and instrument taps.

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#286 2019-04-16 16:34:14

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 15,058

Re: Alternate BFR (Big Falcon Rocket)

Coils of gas not so much for cooling a nozzle would need to ensure that metal eat through would not occur as the piping for the exchanger would not be as thick so as to keep mass down as it must run the total length of the tank from the engines where the heat for expansion is being generated. Even the length of the tank should be enough to cool the gas a bit with in it to still be in an expanding mode when it enters the top of the tank but if it needs more cooling we could add coils around the tank as well. The gas that enters each tank must be the one that supplied it so as to not mix them.

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#287 2019-05-06 19:53:01

Void
Member
Registered: 2011-12-29
Posts: 2,954

Re: Alternate BFR (Big Falcon Rocket)

Umm... I should know better, but if I were working with Visual Basic for this spam, I would write a program that uses:

Split on the text file that can be extracted from the spam.  I would use the return character to split the lines into an array contained in a variable.

https://www.bing.com/search?q=Visual+Ba … d77dbb7962

Quote:

Code sample
Dim TestString As String = "Look at these!"
' Returns an array containing "Look", "at", and "these!".
Dim TestArray() As String = Split(TestString)

Well it is about like the above.  Been a while.  I think you would want to specifically call out the Ascii character for line return.

Then after that you could loop through the elements of the array, and test each line for phrases, using Instr()  (In String).  Umm...I think Instr() can be used for other things as well.  I just remember using it to count or to change operations depending on the presence of a text phrase.  Been a long time. I think it has to be encased in other structures as well.

Then you would have it count how many matches there were.  A number would be the result, and then I presume a save of the message could be blocked for new members if the count is too high.

I know that "Real" programmers typically frown on Visual basic, but I am guessing any programming language has the equivalent.

When I was working, I got tricked into becoming to a greater responsibility as a programmer than I wanted.  Lots of stress.  FDA audits.  Been away for 6 years.  Not very warm about it at all.  I always did like the puzzling part of it though.

Done.

Last edited by Void (2019-05-06 20:02:58)


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#288 2019-05-06 21:04:36

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 15,058

Re: Alternate BFR (Big Falcon Rocket)

The key word traps and other such failed as these idiots keep trying. All the more reason to limit the cotent to near text only so as to limit coding from getting into the forum.

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#289 2019-05-14 18:30:32

Void
Member
Registered: 2011-12-29
Posts: 2,954

Re: Alternate BFR (Big Falcon Rocket)

This post relates to my post #164 in "Index
» Human missions
» Lunar economics etc".

I feel I am being polite, to put this greater speculation here, and to let the other members stick to more established notions of what can be done with BFR(Super Heavy/Starship).

In post #164, I speculated on retiring old starships to the Moons south pole.
-Preparing a landing pad.
-Landing the elderly starship.
-Piling regolith around the base or lower half of the ship.  Radiation protection, impactor protection, stabilizer against toppling.
-Putting a rotating curtain like solar array suspended from a crossbeam mounted on a bearing, which bearing would be mounted on the nose of the starship.

I believe that some amount of sun is often available, in some locations.  It can be as good as only 10 hours of dark a month in the best case.
The curtain would only have to do a rotation once a month.  It may fully rotate in a complete circular fashion, or might have a stop at some point and then reset to a starting position on the opposite side of the stop.  If it is full rotation, you will need rings and brushes for the electrical power to be conveyed into the ship.  Else, if you have an almost 360 degrees rotation with a stop, then you may use a cable system to conduct electricity into the ship.

Supposing that you had an air lock 1/2 way up the ships side and the regolith berm reached there, you could have a berm ramp to access the surface.  Else, when you set up the landing pad, perhaps you would have a tunnel of material upon which the berm would be piled and you would somehow have an egress out of the base of the ship.

So, then the retired ship should have different pressurization zones, the bottom half, and the top half.  This will allow an impactor to vent the upper half without venting the more protected lower half.

I also thing that radiation protection can be more greatly achieved, if bricks in large proportion made of regolith, could be piled on a floor/ceiling between the top and bottom half's.  Such a pile of bricks will also add compressive strength to help allow pressurization of the lower half.  Similarly the berm about the lower half will also assist in offering counterpressure for the sides.

So, now what is new?

I think I would like to propose a starship never intended to land on any world but the Moon.  No heat shield, no need to endure aero braking.  This will lighten it up a bit.  Lower grade steels perhaps, may lower it's price.

Good chances it does not need to use a Super Heavy to get to orbit.  It is not a cargo carrier, it itself is the cargo.

I have been lead to believe that Starship can achieve orbit, but with ~0-20 tons of cargo.  Not entirely at all sure it can do ~20 tons.

But you would not incur the expense of using a Super Heavy.  You also would not put the Super Heavy at risk of loss in a failed launch.

Engines recycling could be an issue.  However there are a couple of options there.  You use old engines about to be retired and/or you have a LEO space station which can extract some of the engines to achieve orbit, and then have them returned to Earth's surface.

Such a station would have a tube flange the same size as Starships aft end, and capable of mating with it.  Either to provide a non-pressurized enclosure, or maybe even a pressurized enclosure.  I suspect a human in a suit is needed in that chamber in either case.  non-pressurized, of course requires a pressure suit (On a tethered life support method), pressurized risks noxious gasses, so you still should have a suit.  So, you have that person(s) pull most of the engines, and box them up for shipment back to Earth.

You then fly the thing to the Moon, and a empty starship receives the boxed up engines into it's cargo hold and moves them down to Earth again.

So, then what do you eventually have on the Lunar south pole?  100?, 1000?, 10,000? Starship habitats???  Once you reach a critical mass of energy procurement, and a necessary volume of pressurized protected interiors, in a 1/6 g environment, I anticipate the ability somewhere to actually have a functional industrial economy on the Moon.

To me that is an item worth seeking.

Done.

Last edited by Void (2019-05-14 18:53:39)


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#290 2019-05-14 19:43:26

SpaceNut
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Re: Alternate BFR (Big Falcon Rocket)

Expendable designed for one way lunar lander hotel never to return goes against the reuseable cost lowering that Space x has targeted but then again its not completely without merit in thats a used vehicle that should have already owned its keep for making a profit.

Does the BFR have an air lock for making them useful on the lunar surface?

So how do we get man there if we do not reuse bfr's and make returnable cargo ships as well?

Then there are the risk mitigations for man staying long term which will still need lots of work
Whats the science target that man needs to forfill?

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#291 2019-05-14 19:56:09

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Re: Alternate BFR (Big Falcon Rocket)

Good query SpaceNut, I will try to be rational in my answers.

Actually I think Elon has already speculated on the value of a Starship as a Moon base beginning.  So, that would make it re-purposed instead of strictly speaking reusable.  But it is then reused, and under optimal circumstances continually used.  So then in that case, we first validate that the technique is plausible, then we must asset the benefit cost balance on the situation.  As I see it in any case, reusability for boosters, then expands the envelope of choices.  In the case of Falcon 9, if the case merits it they can expend the Falcon 9 for a payload delivery of exceptional weight and merit.  And as GW has explained elsewhere he estimates the Falcon 9 will have perhaps 10 lives.  (Meow).

So then Starship, the first hope to have a reusable 2nd stage, can also be a choice per objective item.  As you seem to have agreed, retiring old propellent refuel Starships to the Moon, could be a reasonable objective.  They would have been good workhorses, and then rather than junking them on Earth, perhaps they could be repurposed to continue humankinds space progress at places like the Moon, and perhaps for some of them Mars.

The situation where you might build a intentional type of Starship for first time repurpose, would be where merit is identified for it's placement on the Moon.  I think the technical ability is rational to contemplate.  Of course we are not going to push it unless there is ultimately a pay off.

But from a technical standpoint I think it is possible.  The possibility of not having to use Super Heavy to get it to LEO, is attractive.  Every time Starship is stacked on top of Super Heavy, extra costs will appear, and extra risks.  But it has to be done, if your starship is intended to move mass other than itself to LEO.  But if the mass it will move to LEO is itself, and it can be reconfigured (Reduce engines in LEO), and refilled with propellants to go to the Moon, then you have another animal.  Question is as you have stated, what is important to do on the Moon?  What would help make it worthwhile?

As for the Airlock question, either the newborn Starship/Moon hab would be given the flanging for one, or some cutting torch action and welding on the Moon should give options.  Granted, it has to be a metal that can be worked those ways.

So then the objectives on the Moon.  As I see it the South Pole of the Moon, is about the most mercy you are going to get from the universe that we have discovered so far.  Mars does have an atmosphere, tenuous, with useful substances such as Carbon, but otherwise is not nearly as friendly.  The Moon is relatively proximate to Earth.  The South pole has a much more constant flux of solar energy available, and it is very much though that water at least is available.  So that begins utility.

Our first use is medical.  You expose humans and test animals to 1/6 g and see how that compares to 1 g (Earth), and microgravity (ISS).
Then you have three points on a curve.  You might guesstimate what Mars will do to human health.  I am not suggesting that we would hold back SpaceX for this reason, rather that we would have an accumulation of data for the Moon over time, and that then would likely be compared to that of Mars also.  It may be that Mars would have to be abandoned as a permanent inhabitation, and so then synthetic gravity machines in orbit of Mars.  But I think it more likely that we will decide to tolerate the gravitational conditions of Mars.  But Moon data will help to decide that question.  It will also help to decide what g force to try for if we build O'Neill cylinders, and Stanford Torus's. Why build for more if you can tolerate less.  So that is a first use of the Moon.

There are several continuing sequences of buildup of the Moon, which I feel would be very useful for the Mars effort in the long run, and also for NEO's.

But I will say that yes some Starships can land on the Moon with personal, and then leave to go back to Earth.  They will be handicapped for not having the makings of Methane on the Moon.  Blue Moon like landers, may at first be just fine to exchange and contribute people to the Moon.  It will depend what the population of the Moon becomes.  If it becomes large, then Starship the reusable transport vehicle could be come a big thing for the Moon.

Still Blue Moon uses Hydrogen and Oxygen which are available on the Moon.  Even so though, if NEO's are accessed, then Methane for Starship can come from them.  Or even Carbon itself could be delivered from the Earth to the Moon.  Starship actually could drop it before landing.  Carbon should survive rather well for a relatively low velocity impact on the surface of the Moon.

So now you may have means to supply Starship with Water, Methane, and Oxygen somewhat from the Moon.  And perhaps this could be done in some cases.

But of all of these I suggest that Oxygen come from the Moon, and at first Methane from the Earth, to give Starship powers to go to Mars and to NEO's.  If you can mine NEO's, or perhaps even the moons of Mars, then you may have a source of Water, Methane, Oxygen, Platinum group metals, Gold, and rare Earth metals.

And then a Moon base on the south pole will be convenient to launch robotic probes to various locations of the Moon using something like Blue Moon, to drop off probes, and to collect samples.  Just General Science, which has a value in calibrating our understanding of reality.

Understanding reality more correctly is a thing of great value.

Done.


Quote:

Expendable designed for one way lunar lander hotel never to return goes against the reuseable cost lowering that Space x has targeted but then again its not completely without merit in thats a used vehicle that should have already owned its keep for making a profit.
Does the BFR have an air lock for making them useful on the lunar surface?
So how do we get man there if we do not reuse bfr's and make returnable cargo ships as well?
Then there are the risk mitigations for man staying long term which will still need lots of work
Whats the science target that man needs to forfill?

Last edited by Void (2019-05-14 20:24:34)


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#292 2019-05-15 06:31:44

Void
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Registered: 2011-12-29
Posts: 2,954

Re: Alternate BFR (Big Falcon Rocket)

I thought I would add a bit more thinking to the just previous post.

Starship Canards: Don't need them if you are going to park it on the Moon permanently.  Cost saving, weight saving, and drag saving when going up through the troposphere.

Two hydraulic actuating fins:  Don't need them if you are going to park on the Moon permanently.  Cost saving.  Some weight saving.  You should not need such a powerful type of hydraulics equipment included.

And I already said no need for a heat shield.

And as far as what would have been the windward re-entry belly, it does not need to be so strong.  Weight saving perhaps.

So, factoring those things, it becomes more likely that such a stripped down starship could get to orbit without the Super Heavy, and perhaps with less engines.  More cost savings.

Done.


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#293 2019-05-15 06:59:25

Void
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Registered: 2011-12-29
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Re: Alternate BFR (Big Falcon Rocket)

Per posts #289-292

A berm of regolith outside the ship/house will help with radiation.

Bricks of regolith on the inside may help as well, especially for GCR from above.

But if water is available, it should be possible to have a pool of it above the ceiling of the compartments where humans could live.

It also could serve as an aquatic garden as well.  Artificial LED lighting I expect.

As for metal corrosion, Stainless should last for a while, and it should also be possible to include a waterproof liner of some type of plastic film for the pond bottom and sides.

And then Magnetic shielding for radiation can be considered.

Done.

Last edited by Void (2019-05-15 07:03:06)


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#294 2019-05-15 11:10:16

Void
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Re: Alternate BFR (Big Falcon Rocket)

Per posts #289-293

I have had further thoughts on this.

Raptor engines, getting old, are part of this speculation.  And interesting read here to start with:
https://space.stackexchange.com/questio … or-the-bfr

So, ~31 raptor engines, ~7 on most Starships, and a maximum of ~24 on the Super Heavy?  No matter, each redesign seems to shift this around a bit, and Elon Musk has indicated that Super Heavy may begin testing with a lesser amount of engines.  On top of that they are starting with a compromise engine, and will if possible then specialize over to sea level and vacuum engines.

So, I have already speculated on what to do with elderly Starships, was thinking send them to the Moon for Housing.  But I am now thinking that they could go to Mars instead for Housing, since they may have chances of one more atmospheric entry.  Not sure if they should carry a load up from Earth, using Super Heavy.  Maybe they would grunt themselves to LEO one final time, and get refueled, and depart for Mars.
So then that can account for what to do with the 6-7 aging Starship engines which would go to Mars.  But you are going to have an abundance of aging engines due to the large number involved in Super Heavy.  Those then I would think could point to the Moon.

So, then the old Starships go to Mars, as robots, and land with a full complement of old engines, on a pre-built landing pad.  You do similar as for the Moon.  You heap regolith perhaps 1/2 way up the sides, use cutting torches, and welding to make airlocks where you want them, and then if possible put a water pond overhead, higher inside the retired rocket.  Methods to reduce corrosion recommended.  The pond most likely is illuminated with LED's.  Similar to the Moon, you put a bearing on top of the nose, you most likely remove the canards, and hydraulics.  You put a solar drape beam on top.  You could drape solar panels from it almost down to the ground.  You may put reflective foil on top of the berm pseudo cone that you surrounded the base of the retired Starship with.  This then will have some tendency to reflect up to the draped solar panels.  You may in the case of Mars, consider extending the solar panels upward from the beam.  If you really want to get fancy, then allow the panels to be balanced in weight above and below the beam, then you can tilt as well, to catch the maximum sunlight.

But when you start adding complications, you might want to review the K.I.S.S. principals.

As for the old engines, could you pull them before you lay in the berm of regolith?  Before you scrap them might they serve one more use?
I am thinking that if you built circular mirrors on a heliostat carriage, you might then use the engines to intercept the focus, and heat a fluid.  So far I am thinking an alcohol of some type, maybe an Ammonia Water mix.  So that would be a way to collect concentrated heat for a process.  In this case I am thinking a feed to a turbine.  But for that to generate electricity, you must have a condensation side.  I am thinking radiators inside of an ice covered reservoir.  Maybe some other uses could be employed.  And then eventually the engines become scrap metal, which may have utility to  build something.

Now back to the Moon, in order to use aging raptor engines to send housing to the Moon, I think that after all, you build a new ship for a one time voyage to the Moon, and then a repurposing as housing on the Moon per my previous posts.

Think Liberty Ships in Space.
https://en.wikipedia.org/wiki/Liberty_ship

A very simplified ship, no intention to land anywhere with an atmosphere, specifically most likely, to land on the Moon's South Pole.

For the Moon, I see less utility in using the old engines as solar collectors in a Heliostat.  I guess they may become valuable scrap metal.

Prior to landing the Liberty Starship smile, some engines needed to reach LEO could be removed, and returned to Earths surface to launch more of these simplified Starships to the Moon.  Or all of the compliment of 6-7 engines could be delivered to the Moon with the Starship, and recycled as desired.

I think that this scheme would greatly accelerate both the Mars campaign and that for the Moon, and lead us to a position much earlier where other objectives could be on the agenda.

Done.

Last edited by Void (2019-05-15 11:40:39)


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#295 2019-05-15 18:50:09

SpaceNut
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Posts: 15,058

Re: Alternate BFR (Big Falcon Rocket)

We have started to see that the version which musk will end up with is not going to be one size or configuration fits all or most as the ship is evolving its features for the destinations.
Sure would be nice to have a shipyard on orbit to work ships configurations, make repairs and even to build up new stronger ships but that is another wish list item it would seem.

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#296 2019-05-15 21:29:37

Void
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Registered: 2011-12-29
Posts: 2,954

Re: Alternate BFR (Big Falcon Rocket)

Right again SpaceNut.  More wishes, but I think very good ones.

We are basing our wishes on a current view, which is based on what we think Elon Musk/SpaceX and Jeff Bezos/Blue Origin are telling us, but they are plucking dreams out of the ether themselves.  Hard to say what the future reality can be.  But that is good.  We have possibility.

Yes I think a space service center in LEO, is going to be a major desire.  A staging point where a ship which had to get from surface to LEO, can be reconfigured as you indicated for it's destination, and the rigors of it's passage to that destination.

While it may be possible to make a vacuum garage which allows a ship to be serviced by a tethered space suited crew, I also see that these Starships can in fact be our first possibility of synthetic gravity machines.  Per GW Johnson, two linked together could generate .5 g on a spin.  I would prefer to test ~.38 g, and if we are not on the Moon to test it, then ~1/6 g as well.  But really I think the real Moon is the test for ~1/6 g, and then of course if SpaceX tests people on Mars, then that, but how will we know what is the most economical g force to generate in a synthetic gravity machine until we test it on animals and humans?  Why spend excess effort to generate 1 g, if it turns out that ~.38 or ~1/6 g can be sufficient for at least extended periods in space?

Imagine linking multiple of these shells together to a hub.  You may also link them serially, if you want to achieve the g force with a slower spin.  This could all be done in LEO.  And if you have synthetic gravity machines in LEO at ~.38 g, then you can do quite a few experiments which will help the pioneers that might by then be on Mars.  The people on Mars will be far too busy just making it to be doing general science on the subject of dealing with ~.38 g.  So, I think this plan is wise.  I really think that entities like SpaceX could launch some of these devices to LEO, and yes, I think that a garage can be created for Starships to be reconfigured in LEO.  It does not need to be pressurized.  Just a buffered environment.  Thermally buffered.  Suitable lighting, and tethered life support.  Barriers to loosing crescent wrenches and nuts and bolts to orbit to be space junk.

Maybe later some additional radiation protection with Moon materials and/or magnetic shielding.

These are things worth striving towards.

Quote:

We have started to see that the version which musk will end up with is not going to be one size or configuration fits all or most as the ship is evolving its features for the destinations.
Sure would be nice to have a shipyard on orbit to work ships configurations, make repairs and even to build up new stronger ships but that is another wish list item it would seem.
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Last edited by Void (2019-05-15 21:39:42)


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#297 2019-05-24 21:07:19

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Re: Alternate BFR (Big Falcon Rocket)

I am not the only voice in the peanut gallery.

A bit of a tough read for me.  Still I like the SpaceTug notion, and also to make bases and space stations with it.

https://www.reddit.com/r/spacex/comment … _think_so/

Its a read, that's all.

Done


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#298 2019-05-24 22:01:18

SpaceNut
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Registered: 2004-07-22
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Re: Alternate BFR (Big Falcon Rocket)

Well here is something more to wet your whistle.... SpaceX Super Heavy Starship Will Also Be Space Tugs and Cycler

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#299 2019-05-25 09:04:20

Void
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Registered: 2011-12-29
Posts: 2,954

Re: Alternate BFR (Big Falcon Rocket)

Well, that is wonderful, and so complex.

I am very encouraged.  I think that our future in space can be both intelligent, and very muscle bound.  Which is a good thing.  It is like a cascade of potential good fortune.  And so we should make all efforts to facilitate this.

Done.


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#300 2019-05-25 09:07:51

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Re: Alternate BFR (Big Falcon Rocket)

I have a notion for heat shield, which I do not intend to invalidate other more established notions.  My purpose here is to introduce it for others to ponder as well, and justifiably to criticize if needed, support if possible, and perhaps think of possible applications.

This is more of a notion, I don't have a specific application.  I recall that Josh at one point indicated that for stainless steel rocket booster balloons, it is helpful to keep them inflated to maintain a pressure within.  I also recall that GW has supported that for a reentry device.  GW has indicated that heat sinking is another notion that can be explored.

In the near future say 10 to 50 years, we can likely hope to get materials for this notion from the Earth, Moon, NEO's?, maybe Mars/Phobos/Demos.

What I want is a phase change device.  Ice>liquid>gas>venting, this to sink heat of reentry activities, for landing on planets with atmospheres, perhaps even later on for aero-capture endeavors.

The early wish is to have from the Moon ideally a frozen reservoir of materials.  My wish is a two layer block of ice.  Oxygen ice in the interior, and water ice in the exterior of the reservoir.  We hope from an extra terrestrial source.

For now, I will imagine that this is a uncrewed device.  Later on if proven, then we might consider interior protected spaces where a crew will not be exposed to live hot steam.

Many places in space provide cold, a lack of vibration, so that a ship prior to reentry could be "Primed" for reentry.

So, you would have a double layered freeze pop into which you could sink heat of reentry.  To the degree necessary you would have the option to vent hot steams of water, Oxygen, or Methane derived by converting liquids to gas, and ideally solids to liquids prior to that.

The steam of water in particular, but perhaps even that of Methane, could serve to inflate the body of the balloon during the stresses of reentry.  Oxygen is a fussy baby, I would dread to provide an explosion or combustion in the process of dealing with Oxygen steam.  So, Oxygen while available from the Moon in quantity, will need to be in constraints in order to not dance with the devil.

I actually do not propose to want to thin the walls of something like Starship, I am just citing the most vulnerable possible instance of the method.

I see no reason to not also incorporate other means of heat shielding like pica, and active cooling, or disposable heat shield material from the Moon, if that is convenient, and I expect that depending on the situation, you would.  Maybe down the line even magnetic shielding.  I have no intention to dispute the value of these methods.

So the basic idea is to have cryogenic solids and liquids to sink heat into, and in the process to perhaps inflate the "balloon" during reentry.

Ideally these would come from economic advantaged sources.  Extra-terrestrial, or even the Earth.

If you are using water vapor to inflate the balloon, and cooling it with the processes of ices of materials on board, and perhaps as useful by venting excess of the water vapor and even Oxygen or Methane, this seems to me a potential method of handling the buildup of heat during reentry.  Inflating the balloon, is a way to stiffen the balloon while under stress.

Ideally these masses would be dumped overboard prior to landing to lighten the ship, and reduce rocket thruster braking necessities. I presume we would want to calculate this so that these materials could be dumped overboard, after the peak heating is well over.

So we would be dealing with a complex situation, I think.  Fluids of vapors and liquids, and solid icy materials.  Natural convection will play a role, particularly in the case of vapors.  The windward side heating the vapors the most, and g forces causing convection of hotter vapors to the leeward side. 

This does not exclude the use of pumping devices to modify the fluid flows.

I have a notion for heat shield, which I do not intend to invalidate other more established notions.  My purpose here is to introduce it for others to ponder as well, and justifiably to criticize if needed, support if possible, and perhaps think of possible applications.

This is more of a notion, I don't have a specific application.  I recall that Josh at one point indicated that for stainless steel rocket booster balloons, it is helpful to keep them inflated to maintain a pressure within.  I also recall that GW has supported that for a reentry device.  GW has indicated that heat sinking is another notion that can be explored.

In the near future say 10 to 50 years, we can likely hope to get materials for this notion from the Earth, Moon, NEO's?, maybe Mars/Phobos/Demos.

What I want is a phase change device.  Ice>liquid>gas>venting, this to sink heat of reentry activities, for landing on planets with atmospheres, perhaps even later on for aero-capture endeavors.

The early wish is to have from the Moon ideally a frozen reservoir of materials.  My wish is a two layer block of ice.  Oxygen ice in the interior, and water ice in the exterior of the reservoir.  We hope from an extra terrestrial source.

For now, I will imagine that this is a uncrewed device.  Later on if proven, then we might consider interior protected spaces where a crew will not be exposed to live hot steam.

Many places in space provide cold, a lack of vibration, so that a ship prior to reentry could be "Primed" for reentry.

So, you would have a double layered freeze pop into which you could sink heat of reentry.  To the degree necessary you would have the option to vent hot steams of water, Oxygen, or Methane derived by converting liquids to gas, and ideally solids to liquids prior to that.

The steam of water in particular, but perhaps even that of Methane, could serve to inflate the body of the balloon during the stresses of reentry.  Oxygen is a fussy baby, I would dread to provide an explosion or combustion in the process of dealing with Oxygen steam.  So, Oxygen while available from the Moon in quantity, will need to be in constraints in order to not dance with the devil.

I actually do not propose to want to thin the walls of something like Starship, I am just citing the most vulnerable possible instance of the method.

I see no reason to not also incorporate other means of heat shielding like pica, and active cooling, or disposable heat shield material from the Moon, if that is convenient, and I expect that depending on the situation, you would.  Maybe down the line even magnetic shielding.  I have no intention to dispute the value of these methods.

So the basic idea is to have cryogenic solids and liquids to sink heat into, and in the process to perhaps inflate the "balloon" during reentry.

Ideally these would come from economic advantaged sources.  Extra-terrestrial, or even the Earth.

If you are using water vapor to inflate the balloon, and cooling it with the processes of ices of materials on board, and perhaps as useful by venting excess of the water vapor and even Oxygen or Methane, this seems to me a potential method of handling the buildup of heat during reentry.  Inflating the balloon, is a way to stiffen the balloon while under stress.

Ideally these masses would be dumped overboard prior to landing to lighten the ship, and reduce rocket thruster braking necessities. I presume we would want to calculate this so that these materials could be dumped overboard, after the peak heating is well over.

So we would be dealing with a complex situation, I think.  Fluids of vapors and liquids, and solid icy materials.  Natural convection will play a role, particularly in the case of vapors.  The windward side heating the vapors the most, and g forces causing convection of hotter vapors to the leeward side. 

This does not exclude the use of pumping devices to modify the flow of these fluids, if it would provide benefit to protect the ship.

It may be possible to pressurize the steam and push it out on the windward side as an active cooling method for the hottest locations on the windward side.  It perhaps can also be possible to vent the vapors on the leeward side.

There is even a possibility, perhaps remote, that vented steam could be directly used as a thrust mechanism.  I leave that for discovery of possible benefit, a bit questionable but something to ponder I think.

……

A balloon of pure water steam, may be unstable.  Not sure.  So perhaps a damper gas could be included.  Something that is not too reactive.  Nitrogen, Argon, something else?  I just suspect that you could modify the process to make it less bumpy.  I think life steam reacting with cold ice, might be blustery???  On and off?

Just some thinking.

Anyway, I guess the applications for this at least at first would be for reentry to Earth or Mars.

That's about it for now.

Just a possibility that might work in concert with other methods.

Oh, yes, if you had crew quarters, they would be isolated from the fluids of this process.

Done.

Last edited by Void (2019-05-25 09:58:13)


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