Alternate BFR (Big Falcon Rocket)

SpaceNut · 2018-11-07 18:01:30

Thanks for the twitter post void as that is very interesting.

Once built it does allow for the testing of all functions in real time use from start of launch, to refueling, and to returning home.

I did a comparison of the current falcon heavy to the bfr and its about 5 times the size of the heavy to get to a bfr.

1,100t (propellant) + 150t (payload) + 85t (vehicle) = 1,335t (total mass with max payload)

So a scale model of the bfr sizing for the heavy means that the second stage would have 220 t of propellant for a new mini flight test vehicle.

SpaceNut · 2018-11-07 18:25:08

This is the payload recovery option which allows for it to land just as the first stage does.
The end of the second stage looks like a modified dragon capsule super draco engine design.

GW had worked out the engine design for moon and mars landing and it should be very simular but will need more fuel to make it possible.

First stage recovery needed 1/4 of the full fuel tank to make a landing possible.

This sure beats trying to catch them in a speed boat net....

Void · 2018-11-15 13:07:07

OK, I have not been banned yet. Intend to behave. Had some thoughts further on this topic. It is hard to resist more silliness on my part.

Per Spacenuts post #202, I see, a picture depiction of a nose down vehicle, with perhaps two "Aerobreak" structures, not quite wings.

I have been thinking about both Mini-BFS and the real BFS. The configuration suggested in the post #202, finally lead me to the idea of a foldable umbrella which would serve as heat shield and some other things.

First of all, for any "Unpowered" recovery of such vehicles, I would be extremely shy about involving crew or passengers. Not until an extreme time in the future if it were really well proven.

Elon Musk for giggles, I suspect has spoken of recovering the 2nd stage of the Falcon 9 with a party balloon, and a bouncy house.

Since then it has been re-enforced that the Falcon 9 is to be retired, and the BFR/BFS to eventually take up all activities. And yet they persist in trying to recover the fairings. So apparently they have a fetish for discovering handling methods, as relatively pure research.

And so I do understand any Mini-Bfr to be almost entirely a research device, to discover methods for BFR/BFS. I really don't expect them to be very serious about recovering the first few. But they may rehearse methods of unpowered recovery.

So, I will give my current ideas on a direction to try. Not that they will not likely do it their own way, rather that I think the possibility may remotely exist.

I also want to include the possibility of very low orbit achievement, since this system as a BFR/BFS might deploy a payload which may have it's own third method of propulsion to achieve a desired orbit. So then ultimately I am thinking of a satellite type deployment from a BFS. So a payload into the very upper Earths atmosphere, and then it's deployment under it's own power to the orbit of desire. The BFS to experience orbital decay, and return to Earth, perhaps without retro-propulsion, lowering fuel requirements for the BFS.

But we also have work from Europe, on air breathing electric rockets, so maybe that fits in somewhere, if you want to dwell in very low Earth orbit. Here is an article:
https://alien-ufo-sightings.com/2018/11 … athes-air/

I have seen a spec of about 100 miles up for it.

Back to the umbrella, and it's possible multiple uses. I have seen articles for a ballute:
https://en.wikipedia.org/wiki/Ballute
I guess this is the best guess for Elon's "Party Balloon". But employing a ballute adds weight I am sure.

I have seen articles for centrifugally deployed "Umbrella" heat shields.
https://www.sciencedirect.com/science/a … 6518303850

I currently lean towards an umbrella, but not necessarily spinning. I would rather have solid vanes and also flexible membranes between those solid vanes. On the outside, a heat shield, but also a device to reduce terminal velocity of the assembly.

We would not want the assembly to hit the "Bouncy House" at a speed as fast as human terminal velocity I would think. It is way to fast.
https://www.reference.com/science/termi … be601c861e

But if the landing 2nd stage or BFS(Special), was heading down nose first with a trailing umbrella skirt, and it had purges all of it's propellants, perhaps it could fall at a lower velocity.

But I have more games to play with the Umbrella/Skirt/Kilt while in low orbit. Solar panels on the insides of the hard parts, if you need solar energy for some purpose, such as an air breathing electric rocket. On the insides of the soft parts of the Umbrella/Skirt/Kilt, a reflective coating. So for solar electric, a method. Not sure how it fits in, maybe, maybe not.

And using the skirt, maybe to be able to modify orbit by atmospheric skimming/deflection. Changing an elliptical orbit from that to more circular by atmospheric skipping. The configuration of the Umbrella/Skirt/Kilt being changeable. The soft webs following the angle forced on the hard parts. Requiring hydraulics then I suppose. Electric power useful for that as well perhaps.

So, you do an entrance to the atmosphere when you are done in the decaying orbit, Umbrella/Skirt/Kilt perhaps surrounding the engine(s) for additional protection of it. As speed decreases you reduce speed, you deploy the Umbrella/Skirt/Kilt outwards to increase atmospheric drag. Hopefully purging any remaining propellants. Steering by selective of perhaps four hard vanes, to aim for the bouncy house.

Kind of like a badminton shuttlecock but with a steerable Umbrella/Skirt/Kilt.
http://newmars.com/forums/edit.php?id=152342

Probably no intention of recovering cargo this way, or propellants, making the device to recover as light as possible. And I am hoping that this thing would be highly steerable to the "Bouncy House". One possible way to power the hydraulics during descent through the troposphere would be wind vanes, but I don't know where they would be deployed. Just a thought. Maybe something else.

So, then the "Bouncy House".

I have thought of it being deployed at sea. Salt water and waves and weather being obnoxious to it I would think.

I have thought of it being a floating device, lighter than air. Expensive I would think and hard to connect to utilities like an upward air spray.

I think a semi land impact. A balloon like a giant inner tube, with a taper narrowing towards the hole in the middle. It floating in a fresh water impoundment/pond. The impoundment/pond being just deep enough, and yet not too deep for utilities such as pressurized air to squirt upward at the impacting device, to be included.

So then the first thing the impactor encounters before impact is an upward flow of highly pressurized air, to serve as an initial braking process. Then impact with the "Bouncy House".

Then the "Bouncy House" pushes down on the water it is floating on, and this is a hydraulic breaking. Waves should emanate from it's periphery, bleeding off impact energy that way. Also if required, pressure relief valves should drain some of the energy of compression within the "Bouncy House".

……

Is that how they will do it? Probably not, I am guessing. But from the sketchy information it is my best approximation for now.

Would it recover the hardware sufficiently well to justify the costs? I don't know. Maybe it comes close.

……

For the "Big Falcon Rocket" stage, perhaps the Umbrella/Skirt/Kilt would surround it partially, before the BFS separated. The soft parts and solar cells being on the insides, protected by the hard vanes. That then asks how the interior would react to BFS engines firing. Could turn it to toast.

Anyway I had fun.

Don't think I will participate elsewhere for a while.

Criticism is OK. Complete dismissal, not perhaps quite so welcome until good reasons given. And anyway, we will see what SpaceX really does.

Done.

Last edited by Void (2018-11-15 14:17:57)

SpaceNut · 2018-11-15 21:01:28

Its ok....

The wings are the payload shroud opening to allow the satelite to be launched from with in the structure. Once its gone they close so that the shroud is return via propulsive landings on earth in the same way that the first stage does.

Notice that the stage has the same design as the red mars capsule in that its got the super draco engines canted at the base to provide the escape velocity if there is an issue and if they are not used they can then be used in the retro pulsive mode.

Void · 2018-11-16 11:18:52

Very good of you to respond at all.

OK, for a moment, going onto more solid grounds, that nose down depiction, with;
1) Falcon 9 Fully Reusable Second Stage.
2) Payload Bay with Retractable Fairings.
3) Heat Shield for Reentry.
4) ??? Super Draco Engine(s)
"12 engines in 3x4 configuration.

My Comments:
A) That item which actually after all has a heat shield on it's bottom, does not depict how the Draco Engines pop out, and also how landing gear would pop out. That is not to say that they could not. My interpretation has some trouble seeing how the Draco engines could be used before aeroburn, so I don't see engines to finish orbit.

B) After all there does not appear to be any engines to finish orbit, or I have missed something important. It does appear that this is a 1, 2, 3 setup. My best interpretation is that the Falcon 9 (1) pushes the Falcon 9 (2) mostly above atmosphere, then the Payload Bay with Retractable Fairings, pops open, and deploys the payload. Without the Falcon 9 (2) having propulsion at that point, then I have to presume that the Falcon Payload (3) will have its own rather small propulsion device to finish to a stable orbit. Or an orbital ship has to do a very dangerous snatch of the payload from tenuous upper atmosphere.

C) If my interpretation could be close, I would think this could be rather clever. It would deliver the Falcon 9 (2) to a fast decay orbit. I am thinking it might even be ballistic.

D) I see that there are 5 devices depicted in the image you provided. As I see, it the two on the far left, and the one on the farthest right, are not directly related to the 2nd one from the right. But the one in the middle seems to be related to the " Falcon 9 Fully Reusable Second Stage". Having you make me take a second look, then I could see the intent for a propulsive landing. Hopefully I have not deviated to much elsewhere in my understanding of their intentions. No guarantees.

…..

From here, however I have to begin to draw on other "Only Possible" considerations.

If this Falcon 9 (2) is to enter atmosphere in a much more brutal fashion than the Falcon 9 (1), I presume that the "Payload Bay with Retractable Fairings" will close in the first phases of reentry. If there is no Falcon 9 (3) (Payload), then it will be bottom heavy for sure, and that should work nice, kind of like an arrow falling from Orbit? Sub-Orbital?

But then after the most brutal phase of re-entry, do you open the retractable Fairings again, to add added resistance to atmospheric fall? Something like the latest depiction of BFS.

…..

From here, I have to get even more weird again, drawing on several hints seen on the internet. And I fully understand that I could be way off track.

Something that Elon Musk said itself
https://techcrunch.com/2018/04/16/elon- … nce-house/
Quote:

Elon Musk
✔
@elonmusk
· Apr 15, 2018
Replying to @elonmusk
SpaceX will try to bring rocket upper stage back from orbital velocity using a giant party balloon
Elon Musk
✔
@elonmusk
And then land on a bouncy house
72.9K
7:02 PM - Apr 15, 2018

So, maybe he is just goofing on us. He seldom does not have strange intentions when he does this sort of thing. Look at the Boring Company.

Elon Musk has directly said that the Mini-BFR will not land with propulsion. I think his verbalization of his thinking is ambiguous, and changeable over time, which is a good thing.

However others say that the Falcon 9 (1), (2), (3?) is to be reusable. Actually if my interpretation of Falcon 9 (3) is correct, then it comprises a payload and a small propulsion device. Those would go to orbit, and I suppose, so method might be considered to recycle the propulsion device of a presumed Falcon 9 (3?). Perhaps captured into a standard BFS and brought down. Debatable how economic that might be.

Not landing the BFS Mini (Falcon 9 (2)), at all would make sense, at least at first. It has been described as a research vehicle. As such at least the first editions of it will indeed likely be at best hope only partial successes, to the purposes desired. Injection into Orbit or Sub-Orbit, reentry, navigation through various layers of the atmosphere. Likely crash.

I would be inclined to think that they will never land a Falcon 9 (2), but they are so obsessive about recovering the payload fairings, that that demonstrates that they adore playing games with there hardware, seeing what they can or cannot do.

The boats with nets to try to catch Fairings, does suggest a precursor to a "Bouncy House" for an unpowered landing for a Falcon 9 (2), or perhaps some day, a payload delivering version of BFS. That would have to be one humungous "Bouncy House".

……

I am still confused by the "Giant Party Balloon". Most people interpret it to be an inflatable heat shield.
https://www.newscientist.com/article/dn … irst-time/

I have problems with this as it would add mass to the Falcon 9 (2). But maybe this will be tolerated by SpaceX.

But then there is this: (Flexible umbrella heat shield deployed by centrifugal force).

And that leads me down some strange rabbit holes.

……

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

The Fairings if more than two more likely might just be able to spin the whole craft with auto-rotation, to convert downward momentum into autorotation. I don't think they would make particularly good blades though. And I don't see how to precisely steer that spacecraft arrow to a landing pad for retro-propulsive landing, or a "Bouncy House".

……

What I can imagine however is to do a cross between the centrifugal umbrella and using the fairings to reduce terminal velocity.

Like an upside down Umbrella/Skirt/Kilt. Some parts hard, some soft of a durable flexible fabric. The soft flexible parts having been kept internal to the closed fairings, somehow after deploying the payload. Entry to atmosphere, most brutal part of aeroburn done with fairings closed. Thereafter opening the upside down Umbrella.

This would be my substitute for a "Giant Party Balloon".

It could be highly steerable within a "Cone of Falling", perhaps if there were at least 3 Fairings instead of 2. I presume that the fairings could be extended individually but in concert as desired to deflect the "Arrow" to a pad or "Bouncy House" within a "Fall Cone".

As for spinning it, I don't think so.

To do this of course will require hydraulics I would suppose, and the soft parts of the Umbrella would also be additional weight. I guess it can be tried to get a cheep lunch, but maybe not so much a free lunch.

……

Quite a few of you here will blush to see me put such notions on this board. I guess I have little or no shame

As I have said we will eventually see what they really do.

Done.

Last edited by Void (2018-11-16 12:32:05)

Void · 2018-11-16 15:38:58

Well, I have a part II for this. A catchers Mitt new and improved.

For giggles I will call this "Mary Poppins & The Wizard of OZ".

If we called the falling spacecraft with the "Umbrella/Skirt/Kilt" "Mary Poppins", then I am rather apprehensive about Mary Poppins terminal velocity through the atmosphere. The catchers mitt I so far mentioned very likely is not good enough.

But what if we could make a catchers mitt composed of an upwelling vortex of warm to hot gasses?

It is a little bit of a cheat, because we would be using modified rocket engines to do the landing/make the vortex.

I will be aggressive and cite modified Raptor engines, but it could be other engines.

So, we might as well more or less keep the existing catchers mitt, a "Bouncy House" of a giant innertube floating on an impoundment of water / pond.

But lets consider putting an array of engines around the pond. Those being ground based, and modified. Unless we want to incinerate Mary Poppins, we have to tone down the heat a bit. Mix in Nitrogen or CO2 perhaps. So, indeed the engines must be modified to be a new device really.

So, the array of engines will have throttle capability, and aiming capability, to control with precision the nature and the updraft of the vortex, catchers mitt.

The few cases where a human has survived a skydive without a parachute could have involved an updraft, and falling on an incline, or bushes. They end up with major injuries anyway.

We should want to do better than that.

The vortex should not have to fire for an extremely long time, and being ground based engines, I have fair faith that it could be done.

Generate a hurricane force updraft, or more, with a centering relatively calm spot in the middle.

Mary Poppins job is to dive into this precisely. The Wizard of OZ needs to make this catchers mitt available appropriately.

It is not inconceivable that the spacecraft encased in this vortex could actually levitate instead of flinging headlong into the hard catchers mitt. And then the vortex would be throttled down appropriately to lower the device to the inner tube receiver landing pad socket.

I think it could be made to work.

……

Obviously I am thinking of an Earth based operation. Not previously Mars. The terminal velocity for Mars would be horrific. Still you could make a catchers mitt to some degree in a like manner.

Done

Last edited by Void (2018-11-16 15:56:49)

Void · 2018-11-16 16:39:45

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

We have then to keep the temperature of the "Ring of Fire" tolerable I guess.

Done.

Void · 2018-11-16 21:42:49

OK, some afterthoughts.

#1 and a really big one is that I did not account for where the engines for Falcon 9 (2) would be. You cannot put them on the heat shield or that messes up the heat shield. The other end inside the payload fairings, is for the payload, but perhaps you could put some small engines on each of at least 3 payload fairings. Maybe you could get away with that.

That also leaves open the questionable option to use the engines to spin the umbrella, or if you elected to have the fairings act like rotary rocket blades, that maybe also. Not putting a lot of weight on that. If you did, then it would be a power assisted landing, so a bit of a cheat as well.
https://en.wikipedia.org/wiki/Rotary_Rocket

I would rather the landing device be purged of inflammable propellants prior to landing.

#2 I mentioned Nitrogen or CO2 as a quenching fluid to cool the exhaust to a tolerable temperature for "Mary Poppins". Liquid water might work as well.

Exhaust of a mixture of Burned Natural Gas, and Oxygen, and water vapor perhaps? I think "Mary Poppins could tolerate a few seconds of a high temperature mix.

The landing burn time on a Falcon 9 (1) is rather short I believe as well.

Yes, I am goofing around, but I really like that landing scenario. It's Hot! No it's cool! It might work.

I enjoy things like this. It is really cool to be very precise about known methods, but that can blind you to other dreams. Try not to fall for that.

I really want to see what SpaceX will really do. Probably dismay/amaze me, and that's just OK-Good-Fine.

Done.

Last edited by Void (2018-11-16 21:48:48)

Void · 2018-11-17 12:42:28

Alright, I guess I will go farther with this stuff, will now allow a special type of parachute. Don't have to be corralled in by what might have been the architecture which seemed to be mandated. Will break out a bit.

For Earth landings, I see no reason to preclude a parachute when landing in a "Ring of Fire". Parachutes can be annoying for navigation. Winds and such would make it harder to land with precision with standard parachutes. However if you had a smaller one which deploys explosively just before encountering an updraft from a "Ring of fire" landing method, perhaps that could be useful.

The ring of fire would be ground based engines in a circle I think firing upwards to create an updraft convenient to break the final fall of a returning spacecraft. As I have spoken before, I think it would not only be using Natural Gas and LOX, but have a thermal damping component mixed in before discharge, to reduce temperature, and to also bulk up the swirling updraft. I have mentioned Nitrogen, CO2, and water. I think Water is now my best starter. Cheep, and I presume effective to both cool the discharge sufficiently and to also provide a lighter than air updraft. A speculated value of discharge of several hundred degrees being a place to start. Likely survivable by the descending craft and perhaps if used, a parachute. Or and actuated Umbrella/Skirt/Kilt. A stream of mostly water vapor discharged by such engines say at several hundred degrees would really, I think create quite an updraft.

……

Now I will attempt to adapt it in some way to Mars. In preparation of that I must explain what I think about the nurturing of a human start on the planet.

We would like to do as much as we can do "In-situ". And yes, where and when possible than do that. But it is reptilian level nurturing. Maybe even more basic than that. We could have a space program where we splat human zygotes onto the surface of Mars, as some types of aquatic creatures procreate. We could not expect that to work out at all, I have to believe. Darn weaklings! Why won't they adapt and grow?

Well that's stupid. So, then the BFS. Then we could hope to nurture humans with necessary tools, to do In-situ. It make fair sense.

I think I can presume from previous dialog that there are members that understand that along the line we at first at least have to provide bulk materials from the Earth, and perhaps Earth + Moon + Asteroids (Maybe). I am not sure that the BFS is the best way to deliver bulk materials to Mars such as various special materials. Special materials would be those not immediately or conveniently available In-Situ on Mars, at least not in the beginning.

I do not think that it will be reasonable to try to assist the landing of a BFS type spaceship with a "Ring of Fire" method. Not for a very long time at least.

I do think that speculative investigation of a method to deliver special materials to Mars could be justified.

I propose a Sky Crane, Chain delivery into a ring of fire with a late deployed parachute as a first speculation. This would be intended to deliver special materials to the surface to feed people food, and also to provide feedstock for 3D printers, and presses and such that could manufacture needed structure.

I will avoid innovation as far as initial entry to the atmosphere I will stick with tried and true, maybe later innovations could occur for that.

For now, then I am imaging a Viking probe type entry, with a saucer aero shell for aero burn. Maybe a hypersonic parachute. The lower shell cast off after it's use, and the hypersonic parachute also cast off appropriately. That does not signify that these parts could not later be retrieved and recycled somehow.

I like a chain payload delivered with a skycrane. In this case the skycrane should only ultimately have to land itself, but not the payload. Not exactly.

At some point during descent, the chain is released in a planed fashion to dangle under the sky crane. We don't really want the chain to snap, so careful deployment is required, and also, we plan the chain to have stronger links at the top and the weaker links at the bottom.

So strong metal alloy materials as the more upper links, and weaker materials in a progression of strength down lower. The weaker links perhaps to be of plastics for 3D printers and extruders. Even further down perhaps, links composed of some type of food item. Some type of strong digestible material. Maybe it has to be soaked in water before being prepared as a food.

So, then you have this sky crane with a chain below it, guiding this assembly to a "Ring of Fire" receiver. As may be appropriate, as it enters into the ring of fire receiver, it may deploy explosively a parachute.

The chain encounters the ground. This could be padded in some way, to reduce impact shock. Also it must be considered that the chain may rebound upward, and impact the sky crane. We would want to avoid that.

So, the sky crane may be assisted in a slowed impact by the upstream from the "Ring of Fire" receiver both by its own encounter to the updraft, but also perhaps by the proposed parachute above it.

As the chain impacts the receiver, it no longer is a burden to the spacecraft, as it is no longer suspended. Just before the sky crane lands, perhaps explosive bolts release the top end of the chain, and now the sky crane and parachute have only to land themselves, with the assistance of the updraft from the "Ring of Fire".

And so then you have landed needed raw materials in what I think may be a rather effective and efficient way.

This then is a way you could deliver bulk materials to Mars, until they are replaced by In situ methods. This may accelerate the development of the society we would hope to start on Mars.

As for the sky crane, and second parachute: Recycle the parachute, maybe even use it again. The sky crane might be repurposed into a vehicle to hop about on the surface of Mars. Or I suppose if you wanted to bring it back up to orbit, maybe it could be used again. I would rather it become a surface vehicle.

Done.

Last edited by Void (2018-11-17 13:40:57)

Void · 2018-11-17 16:57:10

Foiled Again!
https://www.businessinsider.com/elon-mu … gn-2018-11
Quote:

Elon Musk says a 'radical change' is coming to SpaceX's monster Mars rocket design
Benjamin Goggin and Dave Mosher 0m
AP
In a tweet, Musk revealed that "radical change" was coming to the design of the Big Falcon Rocket (BFR), which is meant to go to Mars.
The tweet appeared to indicate that the second stage of the Falcon 9 will now be used for component tests for the BFR, and that the company is abandoning plans to make the second stage of Falcon 9 reusable.
Musk has said that his "aspirational" goal is to launch an unmanned cargo mission to Mars by 2022.
In a tweet, Saturday, SpaceX founder Elon Musk announced that "radical change" was coming to the design of the Big Falcon Rocket (BFR), that is being made in an attempt to go to Mars.
Musk left out any specifics of his plan, simply announcing that "SpaceX is no longer planning to upgrade Falcon 9 second stage for reusability" and would be "Accelerating BFR instead." Musk called the new design "very exciting" and "delightfully counter-intuitive."
Earlier in November, Musk announced that "Falcon 9 second stage will be upgraded to be like a mini-BFR Ship," to test components for the BFR. His latest tweet indicates that the company is fully leaning into this plan, and is abandoning previously reported plans to upgrade the Falcon 9 second stage so that it could be re-used.
In September, Musk announced that Yusaku Maezawa, a Japanese billionaire and art collector would be the first passenger of the BFR. Along with eight artists, Maezaqa intends to complete a week-long mission called "#dearMoon."
The mission would kick off the larger plan for BFR, which is to eventually make it to Mars and assist in its colonization. Musk says he wants to launch an unmanned mission to Mars by 2022, and a manned mission by 2024.
Previously, designs for the BFR included a 180-feet tall spaceship atop of a 230-foot-tall rocket booster that promised to lift up to 150 tons of cargo and ferry as many as 100 passengers to Mars. It's unclear how much of this is set to change under Musk's reported redesign.
The news is consistent with previous reports that many SpaceX resources would be re-allocated towards the BFR by the end of 2019.
SEE ALSO: Elon Musk just revealed the 'final iteration' of SpaceX's biggest and most powerful rocket ship — take a look

But I do love them. Where else are you going to get this kind of entertainment?

Done.

Void · 2018-11-18 16:00:58

Since I think SpaceX is out on a fantastic dream. I might as well play my game one more time. I don't think we will be privy to their newest plan for a bit.

I am still into "Ground Engines"/"Ring of Fire".

Applying the K.I.S.S. notion, then I will simplify to Natural Gas as the fuel for them, nothing special, just natural gas. And then perhaps Air as the Oxidizer. I feared Air, but if sufficient amounts of the Oxygen in it were combusted, then it would become relatively less dangerous to the received craft. I still think a damper component is needed such as water.

I do understand that we do not have an engine for that at this time. I think one should be built. By the way, this is not too far from a fire fighting method I once envisioned for tall buildings. Burn off the Oxygen, cool the output, and inject it into a burning building. Snuff the fire that way. Of course it might very well snuff who is in that building. That would not be good. But then you must have a contingency to save them. And if they were going to die in flames and smoke anyway, I guess then you have to make a choice.

In a distant dream I also wonder if partially purified components could be generated in this process, a salable product. If you compress air in large cylinders, and then flash off part of it, then it seems a possible goal to see if you can retain a fraction of it as a product.. However this would be a sideline, not intended to shackle the first intended objective of catching a falling payload.

As I see it for non-crewed recovery of hardware the method above might have merit. The recovery of valuable hardware being the objective. The inclusion of a payload back from orbit to Earth being a less important notion.

I see that falling object to catch as being as spoken before. Perhaps resembling a nose down falling squid or Octopus. I am imagining multiple fairings at the top opened up. It might spin to do a helicopter maneuver to reduce terminal velocity, or it may have a complete webbing between the fairings to just do simple air resistance. Or perhaps it would explosively deploy a rather small parachute at an appropriate proximity to the catcher.

Again I am imagining the catcher primarily composed of an serious updraft, perhaps a funnel resembling a tornado or dust devil. A vortex but one traveling upwards. An object inserted into it properly may remain centered and levitated as may be desired, then by advanced AI control of the process to be lowered down to a relatively solid appropriately constructed receiver pad.

It is not certain to me where the engines would be placed. That is an open canvas. Would the engines be used at all in landing? That is an open canvas. Would then thing insert into a socket, maybe robot arms finally stabilizing it from the ground? Or would the Fairings be able to descend downward to create a spider like geometry where they become landing legs.

I don't care to over define it for the reasons that testing and imagination have a place before choices are made.

Done.

Last edited by Void (2018-11-18 16:29:12)

Void · 2018-11-20 13:00:28

Well, I am going to go again. This time it will be even more speculative. I am not in a competition with anyone. I will list the concerns for what I mention as I go. I think that these are things that could be considered. After all this is just talk at this point.

I will refer to Spacenuts post #202 as a visual aid, to just approximately suggest the first part of what I will suggest.
The middle two depictions to be specific. Not the left two, nor the rightmost one.

A question is, "How many ways could the retractable fairings benefit the delivery of payloads to orbit, the retrieval of valuable launch hardware, the retrieval of returning payloads, and safety margins.

If you can really have retractable fairings, then I suggest at least three, perhaps five or six. Not two.

I am going to refer the currently canceled Mini-BFS of Falcon 9, and vaguely to something like the previously named BFR/BFS, but really not them either, just some proposed notions which could be partially derived from them.

And in this discussion I will note some concerns.

Anyway to begin with SpaceX seems to declare with certainty that a 1st stage is needed to get any second stage up high enough to serve a useful purpose in the Earth's gravity well. Not needed for any worlds smaller than the Earth. I have no reason to believe that they do not know what they are talking about. I take it as gospel.

OK if I can assume, (And make an A** out of me perhaps), that the nose of the 2nd stage could be composed of 3, 5 or 6 "Petals" of a fairing, that is where I start.

So, then what could be inside the Fairing assembly? I think now that perhaps that could include engines pointed up, payload further down from the engines, and solar panels.

I had wished the solar panels could be directly bonded to the inside of the petals, but I think the environment would be too hostile to them. So I think now that they would be deployable and retractable from the lower payload bay, and then back into it.

A major concern to note at this point is that if your 2nd stage has its engines pointed up out of the fairings, then how do you disconnect the 2nd stage from the 1st stage safely, and what do you do if the 1st stage malfunctions? I have some poorly conceived notions, but for now lets suppose that you don't have crew or passengers on board, and this is a machine to deploy hardware to orbit, or propellants.

Just so I have given some concept, then I will initially suggest that the 1st stage might have small deployable parachutes that emerge from it to slow it down, and that some spring loaded catapult ejects the 2nd stage. The 2nd stage then must reorient itself to put the engines downward. Maybe not possible without catastrophic disassembly. But for now humor me. Those may be things to fix or not in the future. For now please give me permission to suppose that somehow it will be possible.

So, you get your engines pointed downward, and you open the fairings to fire them or the ship explodes. Your choice

So if my folly does not guarantee an exploded 2nd stage, then you have a 2nd rocket bell composed of 2, 5 or 6 fairing petals, and I presume that this is likely to be run hydraulically. It is deformable as to symmetry and size of aperture. For my current thinking this may allow for steering of the 2nd stage, and also adjustment to atmospheric pressure.

As a secondary bell surround, it would likely do two things other than steering and adjusting to atmospheric pressure.
1) Possibly some exhaust may reflect off of it.
2) It seems definite that some radiant energy would reflect off of it from the engine flames.

These could be good or bad effects. On the one hand it may annoy the propulsion system so it would be likely that you would prefer to hope to angle the "Petals" so that they reflect energy towards the flames themselves and not the engines. If you could pull this off, you would be getting an additional energy supply to heat up the exhaust gasses further.

.....

I continue, hoping that I have not made a fatal error that cannot be overcome.

Where are you going?

I think if you are delivering propellants, or payload which does not have it's own propulsion, then you have to get up to a decent orbit.

If you are delivering payloads with their own propulsion method, then maybe you only go up to a decaying orbit sufficiently stable to get the out and off on their own.

The advantages of a decaying orbit are that you obviously don't have to expend as much fuel to lift to orbit, and you may be allowed to scrimp on retro-propulsion to start back down. Also, there is less of a problem of generating long term space junk.

Concern, you might rain down space junk where you don't want to. But then you would not be generating longer term space junk in orbit.

If you do go to orbit and need solar electric power, then you can orient the "Flower" of petals to a sunward pointing, and if you brought along solar panels you can deploy them between the "Petals". So then the fairings can serve as reflectors to add reflected energy towards each solar panel.

So, you then do your business, and it is time to try to get home. In the case of being in a decaying orbit, it is possible that it is flexible how much retro-propulsion you use to modify your path. In the case where you are in a prolonged orbit, you would need to initiate retro-propulsion.

Then you are intending to do a nasty aero-brake. From what I have learned from a Rocket Man (A real one), it would be very bad to have the petals of the fairings deployed into the spill during this phase. I expect they would be ripped to pieces, so the fairings should likely need to be closed up again. The brunt of the hardest part of the aero burn would be taken by the "Nose", likely a replaceable heat shield needed on the nose. Ablative I presume.

When possible, when the speed has reasonably drained off, you might dare to open the fairing petals again hesitantly. They might help to lower the speed, and as they would be individually and collectively openable, then you might also get some navigating out of them.
So, this could be another use for the fairings, as auxiliary speed abatement and also as navigation downward.

......

A next maybe function of the fairings may be some kind of autorotate to slow speed. I have already precluded crew and passengers, but I do say that there might be an emergency rescue method involving this, if there were no other way to get them to the ground safely. That is presuming that there might be crew and/or passengers on board. If it is just the machine, then autorotation may have a place in normal use. Not sure.

......

Landing.....

I see three possible modes. All could benefit from the use of a "Wizard of Oz" type ground engine assistance. In some cases they might dispense with it.

A) The one most capable of dispensing of it would use retro-propulsive landing. You would have to turn the thing over to point the engines to the ground and land, using the fairings as landing legs. If you were to have crew and/or passengers on board, then this would be the one to use, at least until in the far future other methods were mastered.

But for "A" when crew and/or passengers were not involved then "Wizard of Oz" type assistance from ground engines may be considered.

It will be a determiner of how much propellant you must carry with you, to orbit and back. If you can get away with less, then that could be more, as far as cost is determined.

This landing would be rather artistically pleasing from an Sci-Fi perspective.

B) The next and perhaps more propellant frugal mode would be a nose down return, into a catchers mitt. I have previously suggested something for this. You might use autorotation, and a very, very powerful assistance from ground engines. And the fairings would be deployed very far out for the reception into the catchers mitt. At the bottom may be a giant innertube floating on a pool of reasonably clean water. The ground engines might even be able to catch the falling object and levitate it with it's co-operation. AI controlled I presume. Then it would be lowered to the inner tube, if necessary, pressure relief valves would be active to release overpressure in the receiving inner tube. Upon impact with the inner tube, the innertube would depress down on the pool of water and create a wave of water outward from the perimeter of the inner tube. In this case the nose heat shield might be badly affected, but I presume that it is an item to replace each mission. In this case the fairings would not be landing legs, but might be sort of perpendicular to rest on top of the inner tube to stabilize this landing ship.

It might not be ruled out to deploy explosively parachutes from each fairing to assist in the reception to the "Catchers Mitt". Extra weight and extra complexity, but so what? Just do it if it benefits the process. If not, then don't do it.

C) The next mode I like the least. Spider mode. That is nose down, and fairings down also. Again parachutes from each fairing permitted.
Maybe even landing engines on each fairing. With or without assistance from a "Wizard of Oz" ground engine method, with or without an inner tube and such. I like it the least.

......

Oops! Before I do that, I will speak about saving a type "A" landing perhaps with crew/passengers on board with a type "B" landing.

If such a mission is incapable of performing a type "A" landing due to detected propulsion systems problems, then to save the lives, you might attempt a crewed/passenger rescue with this method. It would not be pretty for the humans, but perhaps they would survive. Of course a "Catchers Mitt" landing pad would have to be on standby/ready, and the ship would have to be able to reach it.
......

Done, but I am about to post something equally weird, or maybe weirder.

Last edited by Void (2018-11-20 14:37:30)

Void · 2018-11-20 14:38:33

OK, so if you do have a "Wizard of Oz" landing pad, can you use it to help catapult a mission to orbit?

Nasty possibilities of failure embedded in this. I don't know how happy such a stack would be about being bombarded with an upward ferocious stream of exhaust. With current designs, I would say no people whatsoever for those strange experiments. Lots of thoughts about it also required!

Thermal stresses a big issue. How happy would the stack be about such a hot bombardment of its structure while it is essentially cryogenic inside? Current designs not so much I expect.

But I seem to recall that the Saturn Five had a catapult. If I am not confabulating a memory, it seems to me it was required to get the thing started, as it burned so much propellant just getting the first few feet.

Anyway, we also launch(ed) jets from aircraft carriers??, With steam catapults also, so maybe it should not be dismissed without a try or two.

A Concern: While such a stream of vapors might even melt off ice, and ignoring the fact that it might thermally and otherwise stress the "Stack", might it also improperly used add ice to the stack. Don't want that.

But if you tried this then you might have a few effects that if you can tolerate them, they might assist in a launch.
-You might reduce the ice load.
-You might have a hot air lift. How would you chose to deal with that?
-You might have an impinging air flow, upward. How might you use that? Would you have temporary structures to catch the wind? Structures that then detached when there utility expired?

This is pretty green, and I don't have a problem with that. There are chances. Chances for value chances for failure.

......

SpaceX has apparently for now elected not to experiment with the Mini-BFR. OK, but if they then make some kind of new "Super Heavy Lift / Starship, and eventually outdate the Falcon 9 (1) + (2), then before they junk it maybe they would consider some experiments with the hardware. Later on.

Done.

Last edited by Void (2018-11-20 14:54:12)

Void · 2018-11-20 14:55:11

Food for the imagination of the young perhaps.

Void · 2018-11-20 19:59:30

Once again I suppose.

In previous posts, I see that I may have allowed or promoted some confusion about "Nose".

In some cases the nose might be the fairing apex, in others the heat shield end per the pictures in Spacenuts post #202.

I think you can sort that out.

……

Per post #212, referring to a spider mode of landing, "C":

I think that if you wanted to you could invert the assembly of the 2nd stage, and have the fairings chomp around the 1st stage of the super heavy lifter or falcon 9.

They would then not be capable of completely closing, and in this case then the heat shield of #202 post would be pointing up. But then you would be acting in a more traditional mode, where the 2nd stage engines would point down as is perhaps less concerning per separation of the 2nd stage from the 1st stage.

The fairings then may still be able to perform the things I have mentioned for them, more or less.

This might also be done for modes "A" and "B" of landing method.

But for "C", could we consider the appropriate use of parachutes between the pedals of the "Fairings". Somehow. And then perhaps a type "C' spider mode landing. It would then rest on the 3, 5, or 6, maybe 4 fairings as legs in the end. The nose heat shield which I consider to be most likely expendable/replaceable would or would not end up also on the ground, as support.

I think with the deployment of such parachutes, the likelihood of guiding the device to a ground engine is diminished, so it would be on it's own. A lot of weight for fairings and parachutes to break the fall of. So, maybe a no-go. Still, and interesting question.

I am hoping that I will not have a follow up here for this.

Really looking forward to what SpaceX proposes next. I am hoping to be wowed, as I don't take myself as serious as you might think.

Just a lot of fluffy wishes, and some strange ponderings. This is after all a discussion board, not mission control in action.

Done.

Last edited by Void (2018-11-20 20:10:50)

Void · 2018-12-02 09:56:09

I am posting this here. I am not aware that it is already posted. I will not be offended in the least if the moderators want to move it.

I have to double check that it is the one I just watched, but it seems to be a conference of real space industry type people, and the main topic seems to be about under what conditions they should throw in with SpaceX, the Super Heavy Booster / Starship.

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

Things that interest me are that it is remotely possible that "Starship" will be able to go single stage to orbit. It is not certain that it would then have propellants to land.

How this interests me, is in using it as a workhorse to get revenues.

Information I have seen that might support this is that Elon seems to have said that SpaceX has made several materials breakthroughs. So maybe if so, then the "Starship" will have enhanced performance over what was previously believed.

I really think that when possible, it may be that single stage would be preferred over 2 stage launches, unless you have to really get performance. I think the cost and risk levels will definitely rise, if the Super Heavy Booster is involved. Greater risk to the whole assembly, and also greater risk to the launch pad.

……

I suppose that here is where I might make a greater fool of myself, but so what. I imagine two possibilities for single stage use, so far as getting hardware to orbit.

1) Send starship sub-orbital, and somehow deploy the hardware from the cargo holds, and then of course those items will need their own propulsion method. I think that carries dangers through, possibilities of the cargo exploding.

2) In orbit propellants. SpaceX is certainly considering propellant depots at least to some day to beyond Mars. Personally if it were me sending a Starship to Mars, I would bring a propellant depot on the mission anyway. More radiation shielding, and why land with empty tanks anyway, until you have the Mars surface propellant plant and depot highly established?

But to refuel a single stage operation in orbit their may be some interesting options down the line. Oxygen from the Moon for instance in a LEO propellant depot. Maybe eventually propellants from asteroids. And maybe some time way down the line, Oxygen from the Earth's upper atmosphere.

And I am going to speculate that if a standard Starship could achieve orbit, but not land unassisted, a refueling Starship may be able to go to orbit and land. Maybe there could be the launch of two Starships, a standard one and a refueling one which would assist the standard one to refuel enough to land.

I am not saying that I am so sure that this is a route that SpaceX will take, rather I just enjoy looking into the flexibility that this emerging hardware may have.

……

I am also interested in Starship being a temporary orbital space station. One that can be taken down periodically for servicing. It might make obsolete methods like the ISS. And after all if they had the market for that purpose they could make more of them and gang them together in orbit, if that served a good purpose. For instance, if there were some process of manufacturing of a value in micro-gravity, then you send the whole setup to orbit, you process your materials into manufactured items, and then you land. Perhaps greatly simplifying the materials handling. You might not even need spacesuits, and robot arms to manipulate the hardware and materials.

Obviously the above might be the way to go for experiments in manufacturing also.

Done.

Last edited by Void (2018-12-02 11:07:26)

Void · 2018-12-02 11:48:49

Per post #216 the one just before this, I am thinking that a LEO tug could make a lot of sense. Something that is a hybrid between a chemical rocket system and a electric rocket system. Therefore with significant amounts of solar panels.

I am guessing that xenon will be too expensive, so something else. Possibly at first the thing would have to be refueled periodically using a full Super Heavy Lifter assembly and a Refueling Starship. However eventually perhaps it would be capable of using very high atmosphere air for it's electric propulsion mode.

Maybe someday this:
https://en.wikipedia.org/wiki/Air-breat … propulsion

So, if you could go single stage to orbit, you could leave out the solar panels for that Starship. It would link up with the tug, and tap electrical power from it.

Then several possibilities might exist.

The tug might pull it to a higher orbit, and then back down again at some point.

The tug might be able to donate propellant to the Starship, so that it could land.

The tug might just help keep it in a very low orbit long enough for micro-gravity manufacturing from on board materials could be completed.

And at some point propellants might come from the Moon in part or asteroids.

…..

So it would be sort of an backwards method. Instead of lofting the 2nd stage up with a 1st stage, the single stage to orbit would have a boosting assistant to help it in LEO, and also decaying orbits.

…..

But even with the solar panels eliminated I don't know how much useful mass it could bring to very low orbit beyond itself.

Done

Last edited by Void (2018-12-02 11:56:10)

Void · 2018-12-02 13:04:42

I have thought about it a bit more, per posts #216 & #217.

If a "Starship" could be stripped of solar panels, and probably life support and could be made a reliably automated micro-gravity factory, and if it could have help from a LEO/atmospheric tug, I think it might work. I still don't know what the mass margins are however.

On the other hand such a tug might also be useful if you send up a whole stack with a heavy load. That is a Super Heavy Lifter + Starship.
It could hand off it's payload to the tug, in a very low orbit perhaps, and so in some cases allow a bit more mass to be lifted. Not saying it is a guaranteed payoff, but I think perhaps technologically possible. Again you might be able to leave out the solar panels on the Starship, to make more room for payload mass.

……

About the Tug. It would actually have three types of propulsion. Aerobraking, Chemical, and electric ion. I think the three could work together rather well. The solar panels could be maneuvered for aerobraking when it was desired to drop lower in orbit. But if you drop too low then the electric ion thrusters are not enough, so you would want the chemical thrusters to get you to a higher orbit quickly. I think that makes fair sense.

……

As for the tug being reusable, I suppose it might be possible to bring it down inside a landing Starship with enough propellants and an appropriate cargo bay. However it will be an item that would deteriorate over time, so maybe some items would be burned up in the atmosphere, and perhaps some other items would be recovered, depending on reuse potentials.

Done.

Last edited by Void (2018-12-02 13:13:25)

Void · 2018-12-02 16:46:55

I have thought about it a bit more, per posts #216 & #217 & #218.

What I like about this "Sky Snatch" method is it seems like it could be scaled over time.

A resource it does require is propellants. But at the start, the BFR total propellant system providing those, over time that would be able to shift over to "Earth Orbital In Situ". Materials from the Moon, NEO's, and from the Earths upper atmosphere perhaps, maybe even from Mars I guess although I have some doubts about that, Argon and CO2 might be targets.

……

The most ambitious "Eagle Grab" that I can imagine would be to dive down, and grab a ballistic spacecraft being contemplated for space tourism. To do that I am sure hefty heat shields and a real bundle of propellants would be needed. I am inclined to think it goes a bit too far.
But I wanted to imagine a further bound for the idea. Then I would be less ambitious, at least for the first 50 years I would think.

……

So being less ambitious then solar panels formable (At least some of the time), into some kind of air frame that would be useful in very thin atmosphere. It would be desired to avoid heating the device more than a few hundred degrees at most I would think, by aerobraking.

So, not diving too deep. Needing very capable AI, to accomplish the hookup, and chemical propulsion to do the primary lift. Thereafter a combination of electric rocket, chemical through the Van Allen Belts, and then electric rocket again could be contemplated. But mostly I think the thing would work in LEO and then dip into the atmosphere to make another grab, or to escort an object down again.

Done.

Last edited by Void (2018-12-02 17:01:18)

Mark Friedenbach · 2018-12-02 18:49:44

Void wrote:

Done.

You keep using that word. I do not think it means what you think it means.

Void · 2018-12-02 19:20:50

Yes, don't be worried. That is for a particular member who sometimes interrupts me.

Would you like me to go away? I could for awhile for perhaps entirely. This is not my place. I have other places to be, maybe. Do you exclude me? I can accept that I am not appropriate. Then for me that could be easy. I will relent if you want it.

I will take another formation then. Not entirely a disappointment really maybe what I want

So then what?

Terraformer · 2018-12-03 08:45:23

Mark Friedenbach wrote:

Void wrote:
Done.
You keep using that word. I do not think it means what you think it means.

Inconceivable!

Mark Friedenbach · 2018-12-03 11:31:43

No Void, I don’t want you to go away. I just found some humor in the situation. Keep being weird!

Void · 2018-12-03 17:51:19

Quote:

No Void, I don’t want you to go away. I just found some humor in the situation. Keep being weird!

OK thanks, I do resemble that.

SpaceNut · 2018-12-03 19:28:21

Not Done... whoops dammed submit button...

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