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#451 2021-01-03 14:33:16

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Alternate BFR (Big Falcon Rocket)

------
OK, so actually maybe a bit more serious.  I would not be so sure about a Super Heavy in orbit.  It wants to have a serious need.  Not really so confident about that.
Now the Whoopie Cussion is pneumatic after all.
I have resisted double guessing SpaceX on their Super Heavy hang it notions.   But I will make some ventures.  Fools rush in after all....
It seems like they are moving towards a robotic, active launch tower.   So, from my view, it has the advantage of resources, which the Super Heavy may lack.
As far as reaction times, I might suppose it would have a very powerful computer system which would be well protected from RUD's and explosions.   I think that if birds of prey can do what they do, a powerful computer system might have that ability if equiped with sensory equipment.
I am very intersted in the notion that the Super Heavy will hang by it's grid panel structure.  Seems like they will have to be stout.  I don't know if it will rest on it's bottom prior to launch.
Speculation has it that it will have shock absorbers in the catcher arms, and then they will set it down on it's bottom.  No real information exists that I am aware of.
While it would be amusing to cover the launch tower with whoopie cushions to protect it, smile, I guess I would go with thrusters in the launch tower, to keep the Super Heavy from a collision.
Again this is a case where a ground device might have far more resources than a device that dangles against gravity in the air.
So, in my fantasy world, the launch tower has abilities to keep the Super Heavy at a proper Horizontal distance.  And presumably the catcher arms have shock absorbers.
So, then what about vertical control?
You have raptors that are not active, raptors that are active, and the engine bell itself, as somthing(s) that ground thrusters could fire against, to provide verticle cushion.
I can see where raptors that are firing might get really crabby about that.
So, I might suggest a "Cup" of air thrusters array.  That is they would be canted a bit, so as to present a upward thrusting cup of fluids, that the raptor exhaust could enter into, with the hopes that this process would not overpressure them.
This in addition might serve as a vertical flame diverter.
Here again, the ground device(s) would have the potential to have far more resources than a landing Super Heavy.
------
If you are squirting stuff at the Super Heavy, it could either be Oxydizing or not.  I guess I would prefer to try for the flame suppressing variety, that are not Oxydizing.
So perhaps this thing could be built to inhibit fires and subsequent potential explosions.
We would have the option of Nitrogen, which might be cool, or Steam which would be hot, or jet engine exhaust which would also be hot.
Hot methods might stress the metal structure over time.  But maybe not so much that it matters.  Don't know.
-----
Then some day in the very far future do you assist launch with these methods?  Maybe, but a long time off, I think.
Done.


Done.

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#452 2021-01-04 07:22:50

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Alternate BFR (Big Falcon Rocket)

Well, looking things over.....
-It turns out I discovered that Super Heavy can hover.   Falcon 9 can't actually hover, has to do a hover slam.  So, perhaps the notion of catching Super Heavy is somewhat supported by that.  I would imagine that Starship can also "Hover".
-I remember that they are going to use sea platforms, at least for the Super Heavy / Starship combination.

However, I am guessing that "Catching" Super Heavy will come far down the line, if they decide to do it.  Legs before that I presume.

One thing I have been wondering is if the $10.00 per Kilogram target is that important at first.  Or, in the same way if it is so very important to lift ~100 tons to LEO vs perhaps ~50 tons.   I wonder how the price is affected in that situation.  Not that I think that is the near future.  Maybe they lift ~80 tons, maybe ~90 tons.  I wonder how much that matters?

And to lift 100 people to LEO?  How much does that matter in reality?

How about 50 people to LEO, or maybe 16 people to LEO?

In any case still way ahead of where things are now.

I guess I will stop speculating so much and let the real wizards perform what they can do, and I can be a happy spectator, to think it is very good!

smile

Done.............

Last edited by Void (2021-01-04 07:27:31)


Done.

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#453 2021-02-02 13:45:45

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Alternate BFR (Big Falcon Rocket)

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BackPack Starship:
I have been posting along with others on two topics, and along the way though I might see something that "Could" be of value.  Not gauranteed.  I like to have the liberty to examine strange things, and so prefer a permissive discussion environment.
It also happens that Calliban and others have a much more firm notion of what they want to try to formulate, on one of the topics.   That is just fine, in fact very good.   But I am a different kind of cook, and they are presently busy in that kitchen.  Will love to see what they come up with. They are currently working in this one: "Index» Interplanetary transportation» Ballistic Delivery of Supplies to Mars".
I am going to let this one go quiet, at least from my posts, for a while: "Index» Planetary transportation» Void's Mars Starship Belly Flop Cargo Drop".
I will offer some strange ways to offload things while in flight, either in orbit or in an atmosphere.  Some of these are related to the two topics I have mentioned in this post previously.
First off, if you have a "Starship" without a nose cabin/cargo compartment, then that is all propulsion related materials, and propellants would fill most of it.   You would load a "Backpack" on the leward side.
This would have at least two negitive effects:
1) Off center load, and that could be serious, I am not saying it would not be a challenge.
2) More drag on assent to orbit.  For Earth this could be important.  Not so much for Mars, and not at all for the moon.
The original reason I started down this path, is that I felt that a "Backpack" would be a "Cargo".   My first intent was to use the Starships heat shield and navigation abilitys to get the "Backpack" into a "Drop Zone".   The backpack would be separated to travel a seperate fate from the Starship.   However, I also see a way that the Starship might drop the backpack, and then go back to orbit, presuming it had the propellants to do that.
You can go to the two topics for intentions for the Backpack, and later on this topic I may bring them up again.
However......If you could solve the Off Center problem, I also now see other potential advantages.
1) You might not detach the "Backpack" in flight.  You might land it.   Then you might have an unload method to drop the backpack and it's contents to the surface of the Moon or Mars.   This would then allow you to take the Starship itself back up to orbit.   The backpack would be housing, and the contents of it consumable or usable materials.   Either the Starship would have a hinge down near the engine bell, and you would use some motor/cable combination to detach the top, and then lowing it to the ground, or you would have a machine that could drive up to it and take it off.   Of course having an off center load removed, could induce toppling problems.  Those would need to be handled.
2) A potential safety feature may be available.   At some point during launch from the Earth to LEO, the "Backpack" might be dumped.  Here are some of the options:
a) It only holds cargo, and you are over water, your Starship is in trouble, you hope to save the Starship.
b) Nice passengers and crew are in it, you are over water, and you have a parachute(s).  In this case, you would be trying to get the passengers and crew away from a failing Starship.
c) You got annoyed with the Newmars people and wanted them off the ship.  No parachute.
Note: 'c' could apply to launching from any planet or moon. smile
3) Now, your backpack can be a "Shipping Crate".   Bring many of them to LEO, and ship them to Mars by way of a more efficient propulsion device.  Nuclear, Solar, Plasma Bubble?   Use ballistic capture to get them to Martian orbit, and then use a local "Backpack Starship" to bring them where you want them.  Mars/Phobos/Demos/A space station?
4) For the Moon and Mars, the "Backpack" might be permanently attached, particularly if carrying people.   In that case when you landed you would have the bottom of the Backpack relatively close to the ground.   This would simplify the offloading of certain things like people and some other items.   For big items, refer to item #1.
5) In a failing Starship situation, if the backpack only contains hardware and such, it could be ejected in some points in a landing process, to lighten the load.   In fact there may be situations where you would do so purposly, if you can recover the materials of the backpack in a useful way to your economy.
------
I may return in particular to #5, per recovery of useful materials later.   Similar to the other two topics I mentioned above in this post.
------
A little conversation about Dry Mass in this situation.
It occured to me that there might be a dry mass penalty, for having a backpack container.  However, if you don't have a nose cabin/cargo hold, much of that is compensated for.
------
I do see that SpaceX found the Falcon Super Heavy to be a lot of trouble for having three boosters connected, and for having to drop 2 of them on the way up.   Still they did it.   And as I see it, the backpack would not have rocket thrusters, (Usually), so part of that problem is done away with, and also they seem to be able to get the side boosters to drop away without collision.  So, they have a lot of the skills need for a "Backpack" already.
Done.


Done.

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#454 2021-02-03 14:05:16

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Alternate BFR (Big Falcon Rocket)

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Here is a picture, perhaps it will help.
Xj4Kquf.png
Mini-Starship is comming quite a bit from Dr. Robert Zubrin.
Here are some videos about Mini Starship and Starship alternatives.
https://www.bing.com/videos/search?q=St … ORM=VRDGAR
https://www.bing.com/videos/search?q=th … &FORM=VIRE
-----
My new thinking will of course involve thoughts from others:
The creators of Vulcan.  (I don't think my version will eat their lunch).
SpaceX/Elon Musk.
Dr. Robert Zubrin.
Members at www.newmars.com  Forums.   See pervious posts to topic references.
They are currently working in this one:

"Index» Interplanetary transportation» Ballistic Delivery of Supplies to Mars".
I am going to let this one go quiet, at least from my posts, for a while: "Index» Planetary transportation» Void's Mars Starship Belly Flop Cargo Drop".

Robert Dyck, "Index» Interplanetary transportation» Large scale colonization ship", or something along those lines.
Others.
------
What I am after is a way to deliver materials to Mars on the cheep.   You may consult the reference topics, in order to sort of understand that some of us think that their can be defined 3 classes or types of such.
------
How this would be related to Vulcan:
Vulcan I believe expends the propellant tanks, sends a higher stage to orbit, and trys to save the engines and avionics.  While they just drop the expended tanks, to burn and plunge into the ocean, my desire is to crash land the tankage of a Starship somewhere on Mars, with reasonable accuracy and precision.  However in that crash, I do not want to include the engines, avionics, and other valuable parts.
Those would be removed in LEO, and returned to Earth by the best means possible.
------
So, the Mini will cause the accuracy and precision if possible, since the Shield Starship will upon Earth Departure be not much more than tankage, Heat Shield, and Propellants.
As in the issustration, the relationship between the Mini and the Maxi Starship configurable.
To head off to Mars, the Mini, draws from the tankage of the Maxi remnant Shield Starship.
So, if we use Korolav Crater as an example impact and landing area.  I hope that the Martian entry configuration will allow Mini and other items to hide behind the Shield Starship.  I would prefer not to have flaps on the Shield Ship, it would be best if the Mini could orient the whole assembly into the atmosphere, and through into an ~Terminal Velocity of 940 mph.
At that point you eject the other objects, which may or may not have parachutes, and may possibly in some cases have their own landing engines of some sort.   Even with landing engines, these "Other" objects would likely not try too hard for a soft landing.
In many cases the prerence might be to drop them on the interior of a crater rim, particularly in the winter when their may be CO2 Snow/Frost.  This may allow for an inclined impact.
The mini-then very well filled with propellant, "Drops" the Shield Ship to a full 940 mph impact with the central ice of the Korolav crater.  It will shatter.
The Mini Starship then does a powered and controlled landing.
------
Where Dr. Zubrin and others feel that the Mini can escort people back to Earth, I would think that it would be ideal for use on Mars both as a hopper, and to get to Phobos and Demos.
Down the line I would expect a cycling spaceship, or some large scale spaceship for returning people to Earth.
Maybe something along these lines.
Robert Dyck, "Index» Interplanetary transportation» Large scale colonization ship", or something along those lines.
------
The Sheld Ship on impact will shred, and I think that robots with metal detectors and digging abilities may be good to retrieve the scrap.
The other impactors will impact at speeds of 0-1000 mph, in many cases 200 mph.  Similar retrieval methods may apply.
The Mini-Starship, it is hoped will land very well and be of much futher use.
------
SpaceX has a lot on their plate.  I am quite sure they do not want to make Mini-Starship at this time.   So, I suggest that they think about licencing some of their Starship technology to some other entity that has Hydrolox and Metholox engines, or will have.  Mini-Starship would be a good deal for the Moon, where Hydrolox propulsion may be prefered.
------
This system could be agumented by other orbital propulsion systems.  Nuclear, Solar, Plasma Bubble, maybe.  Maybe other things like magnetic reconection propulsion if that ever becomes real.
------
Well, that's it for now.
Done.

Wrong!!!!!

Added just a bit later:
Actually I forgot to include in the "Others" not just things previously discussed in the two other topics, but:
-Ping Pong Balls, Beach Balls, etc.
Hollow spring like balls, that can also release energy by popping, and rebounding.   Copper?, Aluminum?, Stainless Steel? Plastics?.  For plastics it is likely that even on the leeward side they will have to need greater protection from heat during entry to the Martian atmosphere.
-Chains
Chains was one of my original concepts.  The fun of it is that each link drags the other to a similar location of impact and may restrict rebound scattering, and if impacting a volitile substance may melt or vaporize it.  Further, if you dropped them into a sand dune, I expect the dune material to fluidize (Particle fluidization).   The impact may be prolonged over time, as you have not a single object impacting at once.
-Frizbees/aluminum parachutes/gliding objects?
Well I think you get the idea.
Done.

Last edited by Void (2021-02-03 14:25:40)


Done.

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#455 2021-07-18 21:54:35

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Alternate BFR (Big Falcon Rocket)

I suppose I should be a bit ashamed of 90% of what is in this topic.  Still, if
you don't try, you don't ever get anywhere.

I have been thinking of "One-Time" Starships.

I know that the whole SpaceX thing is re-usability, but on occassion they do
expend a Falcon 9 or could max out a Super Heavy to accomplish a task.

Here I am thinking about that notion that SpaceX is getting ready to build Starships
at a fast rate for a good price.

I am thinking about a Starship for Mars, that would not have more than one use.
Launch from Earth, Load up, go to Mars, and stay there.

So, if that would be the case, you could go ahead and use Falcon 9 like legs for
one time use and use an ablative heat shield for a one time use.

This vehicle could have a nuclear reactor(s) in it.  Perhaps they could even help to
propell the Starship more efficiently to Mars using electric propulsion.  Perhaps...

So, you land this thing somewhere, and you have electric power in it, and you can
manufacture Oxygen and CO automatically.  Of course you could mine ice and make
Methane, but why not reconsider lugging Hydrogen along with the ship?  Maybe not
easy.  Of course keeping liquids cold will be a problem.  However, if you have this
kind of a ship, you then have a setup for a basecamp, and then might dare to land some
cargo ships, and if they don't crash, you can then land a crewed ship.  Somehow along
the way perhaps landing pads could be constructed before landing the later ships. 
Constructed by automation I would hope.

Then if you have a source of water, you can start including that in the propellants
production.

Done.


Done.

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#456 2021-08-16 19:08:41

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Alternate BFR (Big Falcon Rocket)

Here is my doodle pad again.  Others have provided things.  I feel like I might have gotten to something.  We will see.

Carbon Monoxide in the Lunar polar deposit's.

Sky Surfing the Earth and maybe later Mars.

Well, if you don't try some stuff, then there is nothing.  I would rather have something than nothing.

Research.....


Done.

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#457 2021-08-16 19:15:05

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Alternate BFR (Big Falcon Rocket)

OK, if this is true, it is a quite big thing.

Quote from #12 of "Terraformation/World rings".

Quote:

Almost as much Carbon Monoxide at the Lunar poles as water.
https://www.technologyreview.com/2012/0 … to%20Earth

I missed this when I scanned the document earlier about the Soviet missions:
Quote:

Crott goes on to detail a number of other fascinating efforts to find water on the moon, including the famous impact experiment in which NASA slammed an empty rocket stage into one of these shadowy craters to see what the ejecta plume would look like. Sure enough, it contained plenty of water but lots of other stuff too including almost as much carbon monoxide as water.

So the bold line might help to say why NASA picked the Lunar Starship.

Done

Dark Star next.....


Done.

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#458 2021-08-16 19:29:38

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Alternate BFR (Big Falcon Rocket)

Dark Star:
https://en.wikipedia.org/wiki/Dark_Star_%28film%29
So, in an attempt to blow up an unstable planet, a bomb gets stuck in the ship?
Well, if I remember, this guy tried to claim he did not belong on this ship, as he was a surfer, and somehow mistakenly got
aboard.  They had an alien which they discoverd that looked like a beach ball and made no sense.  They would rather blow
up unstable planets than search for anymore aliens smile
Surfing:
https://www.bing.com/videos/search?q=da … ORM=WRVORC

I really do think that it might be possible to surf the upper atmosphere with a SpaceX Starship inspired surfboard.

Not done at all....


Done.

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#459 2021-08-16 19:41:02

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Alternate BFR (Big Falcon Rocket)

Ya, I have been uncomfortable about the distinction between the Earth<>Mars aerodynamic Starship and the Lunar(Deep Space) Starship.

Since it appears that propellants can be made from Lunar polar ices, as there is apparently H20 and CO, and other things, this could be a pathfinder for Mars.

I don't like the fact that we do not like to land heatshields and flaps onto the Moon.  It would be wasteful.  But without those, no use of the Earth's atmosphere if the Starship would return.  But what if there could be a surfboard that the Lunar Starship could ride into the upper atmosphere?  It most likely would be presented up into orbit by some means.  Would travel to Moon proximity by some means, and then enable the Lunar Starship to aeroburn into orbit.

Maybe even propellants from to Moon to LEO.

Maybe.

Lots of details and options not discussed yet.

Me tired. 

Nite Nite.

Done.

Last edited by Void (2021-08-16 19:45:12)


Done.

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#460 2021-08-17 02:06:41

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Alternate BFR (Big Falcon Rocket)

Got some sleep at least, not enough, but maybe can get some more if I get some stuff
out of my head.

I have not yet wanted to define the "Surf Board", as there will be so many options.
Some may test to actuality better than others.

To review it, the basic plan would be to try to have a two part assembly that would,
for the case of the Moon, allow travel LEO<>Moon orbit.  From there the Lunar, or
Deep Space Starship would leave the surf board shield in orbit, and then land on the
Moon without the Surfboard.  It would later take off and reaquire the "Surf Board",
and launch deeper into the Earth's gravity well, to aerobrake into LEO or some
approximation of LEO.  As it stands with refueling from Earth, you would perhaps
only go to a high elliptical orbet.

The "Surf Board" concept would start with the SpaceX main body shield, and four flaps
with motors and electrical systems.  However since it's main function would not be
to get the assembly deep into the atmosphere or to the surface, modifications of value
to it's purpose could be invented to improve it's effectiveness to air brake in the
Earth's upper atmosphere, and so to do that for the Lunar Starship as well.

A variation of the scheme might allow the Lunar Starship to actually land and bring
the shield down to Earth on some occasions, but I think that that would be the wrong
path.

Instead it might be possible to increase the "Footprint" of the shield.  That, and
staying at higher altitude, might allow the Heat Shield to be made of different materials.
I am thinking Stainless steel  But maybe somehow titanium scales (Titanium is hard
to work with, I read).

But as I have said, at this point I do not want to rule out ceramic tiles either.
Whatever works.

I am also thinking that Silocone Oil might be used for evaporative cooling.  That might
eventually be manufactured on the Moon.  I am not sure, but I think that as long as
it is not overheated to chemical decomposition, it may not clog transpiration channels.

https://en.wikipedia.org/wiki/Silicone_oil

High temp boiling???  At what temperature does it gel???
https://www.sigmaaldrich.com/US/en/product/sigma/m9389

Various kinds.  I guess I won't obcess about it.  I did say that there may be quite
a few different methods.  Don't want someone to come along and scuttle the whole concept
on one option just to satisfy their ego.

------

So going to another option....Shield gets itself and Lunar Starship into a lower Earth
Orbit, they separate, the Starship does whatever it is to do at that orbit, and returns
only itself to Lunar orbit/Land on the Moon.

The Shield has a power supply, and Ion engines (Argon from the Moon?), and flys itself back
to a nearer Lunar location so that the next Lunar Starship could be linked up to it for
it to do it again.

There could be more shields than Lunar Starships, so that a slow Ion drive will suit this
concept.

I guess that's plenty.  I will see if I can sleep.

Done.


Done.

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#461 2021-08-18 17:10:21

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Alternate BFR (Big Falcon Rocket)

I am going to take another run at SSTO.  I have learned things from members of this board.  I think I know where the probable limits of value of it may be, but I think that as SpaceX improves the engines, and also reduces the "Dry Mass", some special cases of it can be proposed for consideration.

I will intend to do that.

Not Done......

OK, Go.....

OK, presuming you could get a Starship without a heat shield, and without legs to orbit,
based on previous posting ideas, I can see that the best use for it could be on "airless"
worlds, such as the Moon.  So, they could be of value in those cases, as shelters, and
maybe as parts for Starships that need replacements, and for the metals of the Starships.

Looking at how many things the Starship would likely open up in space, I anticipate that
Spaceports will be congested.  And going SSTO could save money, as you either have
expensive insurance, or you have to pay damages if you blow something up.  If you blow up
your own SuperHeavy along with a Starship, then you have those losses as well.  And the
noise....Launching a SSTO Starship will be much more tollerated than a full stack of
Starship on Superheavy.

In another location I have had the Skysurfer idea.  I think that could work out nicely for
this.  I currently intend a two part robotic ship for vacuum which I think could transport
the SSTO Starships to the Moon, and perhaps Phobos and Demos, or some asteroids.  It may
consist of a sky surfer, and a Moon lander.  The two may facilitate the efficient transfer
of Starships to the Lunar surface.

The propulsive options likely to be present in this two part assembly would be aerobrake,
chemical fuel, likely Methane and Oxygen, and electric propulsion, likely Argon in use.
The materials should be available both in LEO, and from the Moon.


Insert CO in Moon ice here:
Quote from "Terraformation/World Rings/ #14:

Almost as much Carbon Monoxide at the Lunar poles as water.
https://www.technologyreview.com/2012/0 … to%20Earth

I missed this when I scanned the document earlier about the Soviet missions:
Quote:

Crott goes on to detail a number of other fascinating efforts to find water on the moon, including the famous impact experiment in which NASA slammed an empty rocket stage into one of these shadowy craters to see what the ejecta plume would look like. Sure enough, it contained plenty of water but lots of other stuff too including almost as much carbon monoxide as water.

So the bold line might help to say why NASA picked the Lunar Starship.

Done


I suppose a careful use of Nuclear, not too near the Earth might also be considered.

So, as I said, "To the future" has  mentioned that Starships could be landed
on the Moon, and then tipped over with a crane.  This unfortunately requires a crane, and
risk, and landing legs on the Starship.  To go SSTO we want neither landing legs, or
a heat shield.

So, imagine that the two part robotic delivery system was connected together, and had been
re-supplied as necessary on the Moon.  Then the lander part launches up to Lunar orbit, and
collects the Surf Board.  Then it launces to Earth, by some combination of Electric, chemical,
and maybe Nuclear propulsions.

It surfs itself down to a lower orbit once it can contact the Earth's atmosphere.  Then Lunar
lander then goes to get the SSTO Starship from whatever orbit it has assumed.  It is likely
that the SSTO Starship will have been at least partially taken on more propellants.  Oxygen,
Methane, and Argon.  The Moon lander tows the Starship up to get the Surfboard. Then the
whole assembly makes for a Lunar orbit.

The Surfboard stays in Lunar orbit.  The Lunar lander brings the Starship down.  The Starship
has no legs and may well tip over, so it will be delivered horizontal to the Lunar surface,
eliminating the need for legs, and the concerns of toppling.  The need for Crane(s) is greatly
reduced.  The Surfboard has the Electric Ion drive.  The Lunar lander has a broad base, and
has a large collection of chemical engines that will not dig a crater in the Regolith.

The Lunar lander can be very odd in shape, as it will not travel through atmosphere except
that it would be shielded by the Surf Board.  The Moon ship leaves the Starship behind, and
is loaded with propellants.

The Starship left on the surface can have wheels attached to it, and it can be towed across the
surface to the desired location.

-----

For other objects such as Phobos/Demos/Asteroids, some variations would be developed.

Done.

I lied.....

The Starship engines.  You would not need the small Lunar Starship engines on
the Starship, unless they were to be used on the Lunar Lander.

The Raptors could be taken out in LEO, and brought back down for re-use, or
it is possible that Starships near the Moon or Mars, would need replacement parts,
or possibly the metals of the engines would be reused.

I think that is about it....

Done.

Well I suppose to make the "Surfboard" more presentable to the public to understand, it could be called a "Sky Skipper".  Everyone is likely to have skipped
a stone or two off of water some time in their life.

Done for sure.

Last edited by Void (2021-08-18 17:53:46)


Done.

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#462 2021-08-19 15:19:23

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Alternate BFR (Big Falcon Rocket)

If it is possible to have a heat shield of the kind I recently spoke of in this topic, then it may be possible for the leeward side of the shield to shed heat by radiation.

If there is a robot with rocket thrusters hunkered down in there, it may be able to
endure the heat for a time.

Done.


Done.

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#463 2021-08-19 15:20:58

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

One thing I have an eye on for Starship would be to launch two of them up to orbit,
and remove the engines, and weld their skirts together.  Then baton spin it as per the thought of GW, and do synthetic gravity tests.  The might be possible to do before orbital refueling is developed.

I guess this machine could built on the cheep.  GW has cautioned that such a tin can will be subject to dangers from impactors, thermal cycling, and radiation.

However, I suggest that most of the volume would be devoted to experiments, biological and otherwise.  So, a relatively short time duration.

Perhaps 2 or 3 crew with a shelter for radiation, perhaps water jacketed.
In LEO, to reduce the radiation concern. 

The shelter for the humans could also be a separate pressure compartment.

My greatest interest would be at the 1/6 and 1/3 g forces.  Obviously for the Moon and Mars.  But I estimate that the two together might reach ~1 g at the nose tips.

I am hoping there would be no gyroscopic tumble involved with this notion.

Anyway if it were and could be done, then we could soon make comparisons between how things work on the Moon and against simulated Moon gravity.

We would also have the simulated Mars gravity of course.

I suppose something like this in the future would be useful to adapt humans to
different simulated gravity fields.

Done.

Last edited by Void (2021-08-19 15:28:10)


Done.

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#464 2021-08-25 19:43:43

Void
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Posts: 6,976

Re: Alternate BFR (Big Falcon Rocket)

I am currently wondering about propellants supplied to LEO from the Moon or NEO's.

I don't have a strong opinion or much talent to crunch the numbers and wonder about the technology or business aspects.

However I note that it would be very good if Starships could arrive to orbit without landing propellants, and pick what they need up at a depot filled from the Moon or
NEO's.

Another far away option may be to capture Oxygen from the Earth's atmosphere.

Curious matter, I don't think the so called Greenhouse/Climate change will get so
far out of control that we might chose to mine the Earth's atmosphere to cool the Earth off, but this would be one way in the far future to deal with a warming sun.

Humans can live at high elevations so, actually the Earth's atmosphere could be
reduced by a substantial amount to cool the planet.  I certainly do not contemplate
it in out lifetime.  I am sure other methods will do.

But still, "You seed dit first here".  smile

The board was too quiet anyway.

Done

Last edited by Void (2021-08-25 19:44:13)


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#465 2021-09-16 10:54:50

Void
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Re: Alternate BFR (Big Falcon Rocket)

I like this.  I suppose it deserves to be in a better topic than this.  That can be
up to others:

https://www.bing.com/videos/search?q=Wh … &FORM=VIRE

Not Done......  I am trying to be nice and not clog up the board with new topics, or posts that might interfere with other members objectives.

I am going to view this again, and then make some comments, if I can.

Pretty sure I can. 

Not done...../


Done.

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#466 2021-09-16 19:31:48

Void
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Re: Alternate BFR (Big Falcon Rocket)

Two solid things I think I see, are the Lunar Starship, or as an OF might say "Deep Space Starship", will air brake with the Earth's atmosphere several times to get to LEO, where it will need a small burn to be completed into an LEO desired.

And that LEO will be the lowest one sustainable.  That implies that the depot ship will have to thrust often to keep it from decaying into the atmosphere.  That suggests using the boil off to maintain thrust.

I don't say I am completely correct, rather this is my impression.

It makes fair sense, as what I think I know about Starship is that it is hoped to be
able to fly it 3 times a day, which would be maybe 2 days???? until the depot is filled???  Not too silly, if that can be done.

It is not surprising that humans will not occupy the Lunar Starship while it is making repeated burns into the Earth's atmosphere.

However that leaves me to wonder how people then transfer from Earth<>Moon???We know that the gateway specifies a interaction with the Orion capsule, so I guess that is a start at least.

Just a little hint that the propellants might not necessarily come from Earth.  I am sure that at first they will, but when we consider that the Moon contains so much Oxygen, and that Starships propellants are about 79% Oxygen, things come to mind.  Not sure that a good deal could be had.  But maybe yes.

At this point I am less inclined to speculate on Starship, more interested in getting evidence/facts/truth.

This works for me.

Done.

Last edited by Void (2021-09-16 19:45:58)


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#467 2021-09-27 00:57:27

Void
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Re: Alternate BFR (Big Falcon Rocket)

I will speculate on the Starship(s) now.

Just now my interests are on:
-Staging starships
-Lunar propellants
-Landing legs

If it was planned or not the Stainless Steel structure for the Lunar Starship is
brilliant.

There is quite a lot of reason to believe that Oxygen can be gotten from the Moon,
lesser amounts of Methane will be available, if I am to believe that there is
almost as much CO ice in the Lunar deposits as there is H2O.

So, it is not unreasonable at all to expect the Lunar Starship could be loaded
with propellants on the Lunar surface, and then bring them to orbit(s).

It could then do repeated burns into the Earth's atmosphere.  That practice
would likely cause a lot of boil off, and so be impracticle.

A Lunar Starship without a propellant load in the main tanks, could do the
Aerobraking without such a worry.

However where propellants were to be delivered to some location like LEO, a
device will be needed to add to the Lunar Starship.  A "Surfboard".  I believe
I have mentioned this before.  It would serve as a sunshade, to reduce boil off.
And then also as a "Surfboard" for the Lunar Starship to do repeated atmospheric
burns to bring the propellants to LEO.  The device might I suppose also be a
solar concentrating mirror, or may also include solar cells that would likely
need protection from the heating.  Maybe.  But the two first mentioned functions
would be the most important.

The tanker from the Moon notion might change to only Methane from the Moon, if
it becomes possible to mine the Earth's upper atmosphere for Oxygen.  Skyhooks
come to mind for that.

The Surfboard could have a larger "Footprint" than the Lunar Starship itself.
During an Aeroburn, this Surfboard has to not exceed the tollerance of Stainless
Steel, presuming it would be made of Stainless Steel.

The Surfboard would have standoffs connecting it to the Lunar Starship. It could
get hot enough to glow on both sides, which I consider an advantage as it would
dissapate heat better than the ship's walls.  But of course this will contiribute
to boil off.

My notion of how to handle boil off is to draw down the vapors in the tanks, and
consume it for power and propulsion. Get the most out of it, don't expect to be
able to deliver it all.  This is also how to chill the fluids to be cold enough
to be used by Raptor engines.

I have considered an internal combustion engine to power that process.  In the
case of Starship the output is likely to be a mix of CO2 and H20 vapors.  This
then can be heated by some process.  Solar energy?  Microwaves?  Heated to
a very high temperature and ported to thrusters to serve as thrust.

So Lunar Starship would have power from solar cells and also from a motor-generator
set.  It would have the ability to ramp up its power levels from time to time as
might be needed.

Centrifugal force of a forced fluid rotation would provide for separation of fluids
from gasses.  Once the "Hot Gass" thrusters fired, it is likely that would further
help to separate the two.

Once the Lunar Starhip was into the Earth orbit desired, it could transer propellants,
if that is desired.  It could be possible that Surface<>LEO Starships would not have
to have brought landing propellants to orbit, but could recieve them from the Lunar
Starship. Doing this allows for more cargo to be brought to LEO.

An alternative would be to stage two Starships for a mission.  The Lunar Starship
could serve as a 1st stage for another Starship.  This could increase capabilitys
quite a lot.  Of course the Lunar Starship would require a reserve of propellants
to get back towards the Moon.  So, there is some complexity there.  Refuel it in
Lunar orbit?  However if this version of a Lunar Starship were to be intended to
land, then it should likely leave it's surfboard in orbit to retrive in the next
cycle.

In thinking about it, I wonder if it would make sense to have a version of the
Starship which is not intended to land anwhere except a large Asteroid perhaps.
So, smaller and less engines.  But that has to be a distance off.

I have preveiously mentioned disposable landing legs for Lunar Starship. I have
started to think that may be an option for a Mars laning in some cases.

The reason would be where you did not have a good landing pad, and where you
had a need to protect passengers, incase you might have to land on a rough surface.

In the case of a Lunar Starship, a new set of legs could be attached in LEO.
The Starhip would land, and then when taking off could leave the legs behind.
This should not be a waste, as the legs should be recycled into things needed
on the Moon.

For Mars, of course it would be much harder.  However it was structured, the
legs would have to be folded up on the leward side of the Starship and would
have to unfold to go under the lip of the skirt, but not into the rocket plume.
I am not thinking of motors so much. Maybe a spring powered unfolding with
the use of explosive bolts.  Here again the Starhip sould be able to leave
the legs behind.  They should not be needed to land on Earth, and they likely
could be recycled to be of use on Mars.

Anyway lots of speculation.

Done.


Done.

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#468 2021-10-01 11:31:34

Void
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Posts: 6,976

Re: Alternate BFR (Big Falcon Rocket)

OK, for now I will continue.

I see two interesting quests.

1) Multi-layered heat shields
2) Multi-joined propulsion methods.

Per a speculated list of methods, these two might impinge on each other, in my
opinion.

I am often looking for methods not yet brought to valid production.  I have a
fealing that their may be something here.  I think it is worth taking the chance
for shame to look into this.

What I feel at this time is the potential of a complex sets of options.  Proper
analysis of practicality then would need to follow for each instance of trying things.

So, don't expect me to stick to one vision only, rather the feel of several
combinations to consider.

First of all a two layer heat shield interests me.  This might not be so different
than the method considered for bringing down parts of the Vulcan 1st stage, exept
that we do not want a one time primary heat shield.  We want one that is reusable.
We also do not intend to land anything on the surface of a planet.  We want capture
to orbit using friction of atmosphere, and curiously the heat of the friction of
atmosphere.

I guess that one concern about having a Stainless Steel primary heat shield in front
of a device such as a "Lunar Starship", would be center of gravity issues.  Impacting
the atmosphere, we need to keep the thing from rotating to present the rocket first
and the primary heat sheild second.  We might think to borrow from Virgin Galactic?
That is feathers following behind.  Rather to say portions of the heatshield behind
the rocket.  However information from GW has indicated to me that we cannot have
anything on either the primary heat shield, or the rocket itself being impinged on
by the flow of plasma or air from the primary heat shield.

Rather the primary heat shield must encompass to some degree the rocket.  However we
would want to allow the radiation of photons out to space from the leaward side
of the primary heat shield.  So center of gravity has to accomodated with success.

As for a Stainless Steel primary heat sheild held away from the rocket itself by
standoff structures, I don't know what the propper thickness might be.  I do think
from what I think I know that we would not want it to rise above ~700 degC.

The Rocket concerned might be Methalox or Hydrolox, or even with aviation fuel and
Oxygen.  I choose not to rule any of these out.

A method of thrust during aeroburn could involve a heat exchanger on the primary
heat shield.  Oxygen would be a big problem for use in such a function, so for
now I rule it out.  I think it will be less likely to employ this if you have
humans on board, as failure would likely lead to loss of life.  I understand that
complexity will also be a risk and a dry mass accumulation not desired, per Elon Musk,
"The best part is no part".  So, when incorporating complexity, value of the produced
result will need to be balanced against risk, and added dry mass.

A possibility would be the engine exhaust from a power conversion device.  We might
consider fuel cells, an internal combustion engine(s), or turbine.  Each to produce
electricy and/or mechanical energy.

It is quite hard to speak of all the optional methods, without leaving something
of worth behind.  I will try to be complete, but there may be a need for further
explainations to follow.

I believe I understand why SpaceX intends to use chilled propellants.  It keeps the
dry mass down, and avoids cavitation in the Raptor engines.  This is needed in order
to punch up through the Earths Gravity well and Atmosphere.  Probably true for Mars
as well, I would expect.

However, for a aeroburn that does not intend to lead to a landing, at least on 1st
pass, it could be considered to have a combination method of adjusting the speed
of the space vehicle.

The burning of boil off, in an engine that might produce electricity and mechanical
energy is of interest, and perhaps also even just burning the gasses in thrusters.

For an output exhaust from an engine, this might be further heated in the primary
heat shield as suggested in this post to ~700 degC.  (Optimally), this would then
cool the heat shield, and also capture some of the heat of atmospheric entry.

I am thinking then to send that to a Microwave engine, to heat it more, and then
to eject plasma.  This engine might also be useful to handle boil off during transet
to a objective target.

The reason to want thrust during an aeroburn would be to fine tune it, and also
delay the skip event, so as to keep the machine in interaction with the atmosphere
for as long as possible, while not destroying the primary heat shield.

-------

While I have described potential more complex space devices, I am interested in
contemplating a collection of methods that would also optimize the utility of various
tricks such as the Obirth effect, and gravitational assists to accomplish utility in
space.

I am sure that I don't have all of the potential covered but I consider it to be a
good start.

I don't mind commente or questions, but I think that this material(s) desirve some
patience, I can try to explain better if someone desires.  Just now I think I have
exceeded my concentration limits on this presentation.

No spelling checks, I need to rest on this material(s).

Done for now.


Done.

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#469 2021-10-14 18:32:29

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Alternate BFR (Big Falcon Rocket)

I could have started a new topic, but I can leave that to others, if they wish.

MINI STARSHIP(S)?  (It would be an alternate BFR, (Starship)). smile
These are a few months old, I don't know if these have been featured on this site.
Search:
"Terran-R mini starship"
https://www.bing.com/search?q=Terran-R+ … 41&pc=U531

Felix: (The first link might segway to this, it did for me)
https://www.bing.com/videos/search?q=Te … ORM=VDQVAP

I am guessing that Elon/SpaceX, will compete/Cooperate, here and there.

His objective is a City on Mars.  Unless it is a threat to SpaceX, I am guessing he will favor other Starships.  A merging
of technologies might even make sense eventually.

But all speculation, of course.

It is my thinking that a Mini Starship will have more drag in proportion to Starship on assent through the Earth's atmosphere,
but that it will have an advantage in the effort to decelerate in the Earth's atmosphere for the same reason.  At least that is what
I believe for now.  The notion is more surface area for mass and internal volume for Mini-Starship.  However by 3D printing
my impression is that Mini-Starship will minimize dry mass to a degree, in that it can supposedly build only to needed
strengths in various parts of the rockets.  Of course, the bigger the tanks, the less dry mass proportional to propellant
mass??? (I think).

Done.


Done.

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#470 2021-10-24 08:24:31

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Alternate BFR (Big Falcon Rocket)

This morning I have been thinking about Dream Chaser, and Mini-Starship, Vulcan,
Falcon 9, and Terran-R.

Dream Chaser is supposed to be able to launch on Vulcan.  Vulcan needs engines from Blue Origin.

So, I have read that Falcon 9 has potential to launch Dream Chaser.

Terran-R is supposed to have two stages fully recoverable, I think, so sort of a
Mini-Starship.  It is supposed to be as good or better than Falcon 9, so I speculate
that it might be able to launch Dream Chaser as well.

I don't see that Dream Chaser will be of much use beyond LEO.  That's OK.

Terran-R is a Methane and Oxygen engine.  That could indicate that a SpaceX Starship might refuel in in LEO, in maybe one or two tanker launches?  Hopefully
just one.

Even more, I anticipate that a aerodynamic Starship might serve as a booster for
Terran-R, mini-starship, and might simply loop up to push Mini-Starship and then
follow a path to intercept the Earth's atmosphere.  Or, the Starship, SpaceX could
loop around the Moon and back to Earth.

With such potential assistance from SpaceX, I wonder what missions the Terran-R
ship could achieve?  If a Starship as 1st stage, (Above LEO), did push a Mini-Starship up to loop around the Moon, could the Mini-Starship use the Oberth Effect?  https://en.wikipedia.org/wiki/Oberth_effect

Since the ship would have accelerated by falling into the Moon's gravity well.

I am not necessarily indicating crew on the Mini-Starship.  But not ruling it out.

Anyway, Robert Zubrin has suggested that crew returning from Mars might do
OK with a Mini-Starship.  Therefore not loading down the propellant production
On Mars.

So, then one trick would be to send the Mini to Mars as a robot, and bring the humans to Mars on the regular Starship which would give itself as cargo as
habitation and scrap metal.

Radiation then becomes a greater problem for the return trip.  But some advantages could be had.  If you had a pair of Mini's, it might be more practical
to tie them together to give artificial gravity on the return trip.  You might have to
have water on board for better shielding, or also perhaps use magnetic field as
assistive to the protection method.

Later on with propellant production increased, it might be possible to refuel ships in Martian orbit, or give them a boost with a Starship or Mini-Starship.  I am not sure what the utility would be for that, but some missions will be probes to other
places.

And back to Dream Chaser, my understanding is that it will be a more gentle re-entry to Earth, and that it could land on almost any airport runway.  That could
matter, as Starships will have to launch from special places, and land near where it would re-launch.  Congestion might be a problem, so Dream Chaser might likely have it's special uses.

I am sure that there will be other vehicles, to show up, but just now it if sort of fun to speculate on a Symbiotic relationship between SpaceX and Relativity Space, and Dream Chaser.

https://www.relativityspace.com/rockets

https://www.rocket.com/space/human-expl … eam-chaser

Done.

Last edited by Void (2021-10-24 08:47:20)


Done.

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#471 2021-12-11 08:24:29

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Alternate BFR (Big Falcon Rocket)

I think that this is of a greater quality than most materials I put in this topic.  It is not actually only for "BFR", (Starship).  Could include other ships.

I need to do some spelling work, and I will try to make some simple drawings as well later.

-------

So, I was up later last night as this thing came to me and of course unless I put
it into some sort of record, I would not be so likely to sleep.

I have been watching the work of others, and have for a time been thinking of what
might be done with a "Collection" of Starships on route to Mars.

I do favor Ballistic Capture at this time, as it allows for more windows of launch
than the Hohmann transfer does.  However, as I think this is a young idea, I do
anticipate that the return method for the ships will be Hohmann transfer,
Mars>Earth.

Ballistic capture has some negitive factors.  It takes longer, and so, radiation
concerns, gravity health concerns, and wear on the machenery in flight are
concerns.

I believe, however that what I will propose provides greater radiation protection
and some synthetic gravity, while providing "Safety in numbers" as factors.

Also, using Ballistic Capture may well reduce the stresses of aerobraking into
the Martian atmosphere.

Although it could be done with two Starships as a minimum, I would prefer four
Starships as the minimum.

Also, I want to include a joining hub, which likely will include solar panels,
and/or fission reactors.  The hub itself may well have it's own propulsive
method(s).

As a test, in LEO, the radiation problems being lower than in flight to Mars,
perhaps just 2 ships and a hub.

The Ballistic Capture method for going to Mars from Earth/Moon, more easily
conserves the value of the "Hub", than the return trip Mars to Earth/Moon.

I think it may be true, that an aero-break in the atmosphere of Mars from
Ballistic capture for the ships would possibly be easier than a direct Hohmann
injection, by a ration of 4.0/6.5 for stress.  Only  an estimate.

Going back to the 2 ship LEO space station, (2 Starship and 1 hub), we can
test health maintenance for humans and test animals, and determine, what is
the minimum amount that will deliver humans to Mars.  For early arrivals,
maybe more is needed so that they will be strong.  For later arrivals less
should be required.  We might hope to use Lunar Gravitational Simulation, as
we will be able to draw experimental data from Lunar efforts as well as from
LEO binary space stations.

I am anticipating that the hub will remain in orbit in the case of the test
space station, and then two Starships will periodically hook to it and then
generate a spin situation.

It would be nice if the hub included methods to travel from one ship to
another while spinning.

Having a solar powered hub in LEO, would not mandate that you had to do
a spin, if you wanted to do microgravity work.  However having it in orbit
would then create a situation where you did not have to bring all of your
life support for a Starship up and down all the time. Solar panels could
be included, and perhaps eventually even an automated greenhouse to deal
with CO2 and provide some O2 and greens.  It might also have emergency
materials to print repair parts for the Starships.  Perhaps heat shield
materials, tools, or just ship and hub parts.

So, this may take care of the gravity problem for prolonged exposure to
a space environment.

I have mentioned why to try 1/6th g.  I think that increasingly space
medicine will provide the rest of what is needed per muscle and bone
and blood pooling issues.  I understand that there is now an effort to
try to create suction pants that could be worn at night, that they
think will help unload the blood pooling in the head/brain/eyes. So,
I hope that .38 g is not required for transit to Mars.  1/6th g should
be sufficient for plumbing, so that you don't have to breath poo, pee,
and vomit as much.  Sneezes also.  Remediation of all of the more
disgusting potentials.

So, then we have the issues of space radiations.
-Solar Storms
-GCR.

Keep in mind that I have been learning from the other members.

My thinking for Solar Storms is to put a cargo ship in frot of a
passenger ship.  So then you would have two passenger ships, and
two cargo ships attached to the hub, or if you desired you could
have four pairs or six pairs instead of the two pairs I just
mentioned.

More people are expected to go to Mars than come back. We also
prefer those going to Mars to have their health more augmented.
Humans coming back from Mars, may have access to rehabilitation
services on the Earth or possibly in space near the Earth/Moon.

Additional methods for radiation also could include standard
notions of protection.  Storm shelters surrounded by useful
masses such as water, food and sewage.  These might also be
the sleeping areas as well.

-------

The Hub, helping to escort the collection to Mars, may be left
in orbit, or put on a moon such as Phobos/Deimos, or might be
broken apart and brought down to the Martian surface.

In the case of an active nuclear reactor on the hub, then that
most likely goes to a Martian moon base where it could be put
inside of a radiation shield of materials local to the three
worlds of Mars.

But it could also be that the hubs would return towards Earth,
in a collective Hohmann transfer method and most likely would
expended and not re-used.  They would have only a limited
lifetime anyway.

I will try to provide some rudimentary drawings next.

Done.

------

I got an unusually good sleep last night, so I guess it worked out.

Done.

Last edited by Void (2021-12-11 11:24:53)


Done.

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#472 2021-12-11 08:36:25

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Alternate BFR (Big Falcon Rocket)

OK, for anyone who may want to investigate "Ballistic Capture" to Mars.

https://www.scientificamerican.com/arti … ry%20orbit.

While Hohmann transfer may work for most deliveries of materials, transporting people safely is somewhat better served by what I presented in the previous post.

Quote:

Now new research lays out a smoother, safer way to achieve Martian orbit without being restricted by launch windows or busting the bank. Called ballistic capture, it could help open the Martian frontier for more robotic missions, future manned expeditions and even colonization efforts. "It's an eye-opener," says James Green, director of NASA's Planetary Science Division. "It could be a pretty big step for us and really save us resources and capability, which is always what we're looking for."

The whole article is worth reading, in my opinion:
Quote:

Ballistic capture therefore offers many advantages over current approaches for heading to Mars. Beyond avoiding the fuel-guzzling of a Hohmann transfer, for instance, it reduces danger to the craft because the vessel no longer must decelerate on a dime in a tight window near Mars, risking over- or undershooting its mark. The approach also drops fuel needs for the overall journey by 25 percent, Belbruno says, in a rough estimate. That reduction could be used to save money but it could also, instead, allow for bigger payloads at comparable prices. Delivering more mass to Martian orbit can then mean getting more robotic rovers, supplies or what have you to the surface. "What we want to do is leverage [ballistic capture] to put more mass on the ground," Green says. "That's the dream."

Avoiding the need to send the rocket up during rare launch windows would also be a big deal because launch delays are notoriously frequent. Missing a window can mean grounding a Mars mission for two years, plus wasted launch prep costs.

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Ballistic capture does come with plenty of caveats, of course. A straight shot with abrupt braking at Mars takes about six months whereas a trip relying on ballistic capture would take an additional several months. The burn-free, capture altitude is also quite high—some 20,000 kilometers above Mars, far beyond where science satellites set up shop to scrutinize the planet up close. But taking along just a little extra fuel can then gently lower a ballistically captured spacecraft into scientifically valuable, standard orbits of around 100 to 200 kilometers like those achieved with Hohmann transfers—or even onward to the Martian surface for a landing.

For manned missions, ballistic transfer would be a mixed blessing. On one hand, its longer journeys would add to the challenges of ferrying people to Mars. We're already worried about Mars-bound explorers driving each other crazy stuck in a tin can for six months, not to mention soaking up unacceptably high space radiation doses. For that reason, robotic missions look to be the first potential beneficiaries of Belbruno and Topputo's new low-energy transfers.

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On the other hand, because the need for launch windows would go away, ballistic capture could maintain a steady stream of supplies to the planet. Any extended Mars habitation effort would probably depend on Earth for materiel, at least until the establishment of self-sufficient farming and manufacturing. "Ballistic capture would be a good way to send supplies to Mars in advance of a manned mission," Belbruno says, "or as part of one."

NASA's Green agrees. "This [ballistic capture technique] could not only apply here to the robotic end of it but also the human exploration end," he says. Accordingly, Green arranged for Belbruno to speak with the agency’s Johnson Space Center staff back in October about how manned missions might exploit the concept.

Even further down the road, ballistic capture would be perfect, Belbruno says, for placing satellites into "areostationary" orbits—the same as geostationary, except at Mars (aka Ares). The upshot: Martian Internet and cell phone networks, anyone? If the new low-energy transfer works at Mars, it could, in theory, also be extended to deliver matter in bulk to any world in the solar system.

This potential breakthrough research is admittedly still in an early, theoretical phase. Ongoing work includes reworking the calculations of the physics by factoring in smaller influences on a Mars-bound spacecraft than the pull of gravity from Mars itself, such as Jupiter’s gravitational pull. NASA's Green said he envisions the agency wanting to test ballistic capture transfers at Mars in the 2020s.

Belbruno has his fingers crossed. "The route to the moon I found in 1991 was thought to be perhaps the only application of my theory," he says. "I am very excited about this Mars result."

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My understanding is that you can avoid immediate injection into aerobraking, and that potentially you can aerobrake from Low Martian Orbit, provided you have a means to modify your obit to Low Martian Orbit.

The savings in fuel may require Ion or other thrust, but I am not locked into a firm belief about that.  A major value is that rather than a sort of 2 year launch pattern, there are many more windows for launch.

Further, by not jumping from interplanetary orbit to aerobrake, you have the option to visit a Martian moon(s).  In some cases it might be possible to pick up useful materials before landing.  It is unlikely to have a special mineral of value, but if there were a base on Phobos for instance you might pick up Oxygen for landing, maybe even Methane.  In that case most likely Hydrogen would come from Mars or another source.

Where Elon Musk has tossed out the number, 1 million humans to Mars, it could be 1/10th that or 10 times that, and may continue for decades or even centuries, so, I am not wrong to think of bases on Martian moons.  As per Oxygen, eventually, Starships headed to Earth or Ceres, could get propellants from those Moons, or there may even be propellant depots in orbit such is planned for launches, Earth>Mars.

We need to consider "First missions/abilities" and then "Later missions/abilities".

Done.

Last edited by Void (2021-12-11 08:48:12)


Done.

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#473 2021-12-11 14:04:38

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Alternate BFR (Big Falcon Rocket)

OK, I think for space relations purposes, as I might understand them, I will
give some labels.

SUN> means from the sun.
SUN| might indicate the polar opposite of SUN>  What is beyond a spaceship,
planet, or space station.  The outer solar systems direction which of course
is actually in a direction away from the sun and in every direction.

For now, maybe that will do.

I have been thinking about how to use collections of Starships or other
ships for some time, in the hopes of discovering safety and practicality
factors that are aided by collections of objects.

These links will do I guess, but Imgur use to can them so that they would display as pictures without a double click.  Guess I have to learn something more now.
"L" version:
https://imgur.com/a/9k6P5lK
"Pancake" version:
https://imgur.com/a/cak1bPy

So, at this time since Ballistic Capture seems to be an option to get into the orbits of Mars, I consider those two basic diagrams to depict possible methods that are not Hohmann Transfer dependent.

While I did say that freight rockets might be sent Hohmann method, why do that, if you can use them to shield a passenger ship from some radiation.  There is usually no hurry for materials, but with exceptions then use Hohmann, if you can get a useful launch window.

So really you might even pancake 3 ships, to protect the least sunward one Sun| from some radiation.

For the "L" version one ship protects the nose of the other from radiation.  Perhaps.  Secondary radiation has to be looked at.

The block diagrams indicate the the hub could be very large.  In reality it could be a relatively flat plane of solar panels.  Probably with some tensile cables to attach the starships to.

Solar is rather predictable for orbital situations, unlike the surface of Mars.

If you don't like the attenuation that happens as you orbit away from the sun, then  make a reflector of "Tin Foil".

You could include starships without heat shields, particularly if they were going to be dropped off at Phobos, for it's base.  Of course it would not need legs then either.

I do not rule out having the hub very large, and having a propulsion method of it's own.  Electric, perhaps if it is to fly back to Earth.

As for Starship engines, perhaps the engine section could do a "Vulcan", and simply drop off in LEO, to be left behind.  That will be OK, as long as you have Starships at Mars that can work, their way into and out of the atmosphere of Mars to land people and cargo on the surface, and lift them to orbit also.

Done.

Last edited by Void (2021-12-11 14:28:50)


Done.

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#474 2021-12-11 15:11:27

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,750

Re: Alternate BFR (Big Falcon Rocket)

Dream chaser needs a payload fairing or shroud and a payload adapter to make it possible for it to be launched by any rocket manufacturer.
If it needs more than that then the rocket never had what it would take to launch its mass with the small adaptation required.

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#475 2021-12-11 16:25:58

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Alternate BFR (Big Falcon Rocket)

Not sure where you are going, but OK, I will deviate from what my last posts were about, for a bit.

You did stimulate me to think about Starship itself as a first stage.  I am often likely to test the limits.  Perhaps with things foolish, but lets go there.

A Sub-Orbital Starship, (No Super Heavy), 2nd stage inside, could perhaps be Dream Chaser?

If Starship were Sup-Orbital, then it could be very powerful, say compared to Falcon 9, 1st stage, or Neutron 1st stage.

I would like to decrease the amount of Heat Shield for the Starship, ideally only Stainless Steel.  Not sure how high, and how fast down it could tolerate for heating.

The question of how you get the 2nd stage out, I suppose is dependent on the air speed and density where you try to do it.  Perhaps you could do it at the "Ballistic Peak".  At that point it is almost zero g, I think????

You would open the fairings.

OK, for heating tolerances, the tools might start like Falcon 9.  I believe it has heat shielding in the engine compartment, and can use rocket exhaust at some points to make it possible for the ship to survive.  I think Neutron will do this as well.

I have had this additional thinking about active cooling.  What if you put channels around the skirt, and flowed either water or Methane through that?  The exhaust that into the engine bay.  With a tail descent, could that buy you a bit more mercy?

The skirt may support active cooling better, I think as it is likely thicker than the tanks skins.

And so could the modified Starship get away with that and have no ceramic heat shield tiles?  If the ship is not trying to achiever an SSTO, then might you have extra Methane or a water tank to accommodate such a method?

You may also have more propellants in your budget so that you might not bother with the skydiver mode, in order to reduce the terminal velocity. And that would allow you to dispose of the dry mass of the flaps and motors for the flaps.

But I don't know.  Perhaps you would want to do the tail entry first with active cooling, and then the belly flop sky dive, then the pendulum, and engine fire to attain the surface of the planet safely.

Dream Chaser's best attribute as far as I can see is in method of bringing people back down to the surface of Earth.

But maybe Rocket Lab could team up with SpaceX to put some 2nd stage of there talents inside of Starship as 1st stage.  (6 engines or 9 engines???)

So, I do this stuff.  I not trying to annoy rocket people.  I stay on the sidelines if I think I should.

Done.

Last edited by Void (2021-12-11 16:42:15)


Done.

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