XpertKerbalKSP

Ideas for a fully re-usable launch vehicle?

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27 minutes ago, sevenperforce said:

There's a splendid blending of graceful awe and stunning complexity with a liquid-flyback-booster stack. Though I think the payload-to-dry-mass ratio is...not great.

How would you choose engines/body/fuel types/etc.?

This is Energia II, a reusable booster made by strapping wings and landing gear to the same type of booster that once launched Buran to it's only flight. Most of the engine hardware is the same as the standard Energia and Zenit boosters, just stuck on winged tanks.

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On 4/21/2017 at 9:56 AM, sevenperforce said:

While I have no argument with the rest of your analysis, I'm pretty sure this is incorrect. Falcon 9 v1.0 could only launch 4.5 tonnes to GTO, expendable. Falcon 9 FT sent SES-10 to GTO, with recovery, and that bird was over five tonnes.

From wiki, so take them with a grain of salt:
Falcon9 1.0: 333,400 kg
Falcon9 v1.1: 505,846 kg
Falcon9 FT: 549,054 kg
Falcon9 block 5: unknown (likely not much more than FT)

So there was some improvement in mass (and of course a less-than-fully-recoverable falcon heavy could provide heavier launches) even with recovery, but at significant R&D costs.  I've heard of plenty of other rockets pitched as re-usable (I'm certain I heard the claim that at least one Ariane was supposed to do the trick) but only the shuttle (and suborbitals: don't forget the X-15 in there with spaceship1 and new Sheperd) had managed it, and still couldn't do so profitably.

Edited by wumpus
shift-enter for singlespace: ctrl-enter for submit. Not a good system.

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57 minutes ago, shynung said:

This is Energia II, a reusable booster made by strapping wings and landing gear to the same type of booster that once launched Buran to it's only flight. Most of the engine hardware is the same as the standard Energia and Zenit boosters, just stuck on winged tanks.

Oh, I know; I was just wondering if DECQ was proposing an identical stack or if he has any suggested improvements.

48 minutes ago, wumpus said:

From wiki, so take them with a grain of salt:
Falcon9 1.0: 333,400 kg
Falcon9 v1.1: 505,846 kg
Falcon9 FT: 549,054 kg
Falcon9 block 5: unknown (likely not much more than FT)

So there was some improvement in mass (and of course a less-than-fully-recoverable falcon heavy could provide heavier launches) even with recovery, but at significant R&D costs.  I've heard of plenty of other rockets pitched as re-usable (I'm certain I heard the claim that at least one Ariane was supposed to do the trick) but only the shuttle (and suborbitals: don't forget the X-15 in there with spaceship1 and new Sheperd) had managed it, and still couldn't do so profitably.

That's GLOW for each version, not payload for each version. F9FT certainly is not putting 550 tonnes into LEO.

Edited by sevenperforce
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20 minutes ago, sevenperforce said:

That's GLOW for each version, not payload for each version. F9FT certainly is not putting 550 tonnes into LEO.

Obviously.  But it takes a much bigger rocket to launch a slightly larger payload and then land the booster (and I'm sure going from ~1.1 to at least 1.3 TWR helped a lot with gravity losses).  That's a lot of R&D to reuse a single rocket (so far.  And I'm not sure they will reuse anything else that isn't B5).

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5 hours ago, wumpus said:

Obviously.  But it takes a much bigger rocket to launch a slightly larger payload and then land the booster (and I'm sure going from ~1.1 to at least 1.3 TWR helped a lot with gravity losses).  That's a lot of R&D to reuse a single rocket (so far.  And I'm not sure they will reuse anything else that isn't B5).

They are using Thiacom-8 and one other (maybe CRS-9) as the side boosters for the inaugural Falcon Heavy flight. 

Any ideas for a drop-in recoverable second stage...for Falcon 9 or any other launch vehicle?

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6 hours ago, sevenperforce said:

Oh, I know; I was just wondering if DECQ was proposing an identical stack or if he has any suggested improvements.

Ah, I see. :rolleyes:

I would suggest an identical stack, though. The original Energia stack is already a powerful machine.

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OK, my revolutionary 100% reusable design is complete! What do I win?

58lNPnZ.png

 

(That was actually quite fun to make! :))

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13 hours ago, sevenperforce said:

There's a splendid blending of graceful awe and stunning complexity with a liquid-flyback-booster stack. Though I think the payload-to-dry-mass ratio is...not great.

How would you choose engines/body/fuel types/etc.?

Okey, here's a very crude example of a completely reusable media, let's combine the side load of the Energia rocket, the reusable style of Energia2, the first stage of the SSRB, and 4 engines SSME/RD0120.
It turned out such a monster, although it is quite damp but still the idea has the right to life.

10566980.jpg

10566979.jpg 

10566981.jpg

10566983.jpg

10566991.jpg

10566990.jpg

At the same time, the rocket should have its own engines "OMS", to them a separate installation where the engines and fuel are located, you can see its location although it does not look good.

10566994.jpg

One big defect is that this crap can not carry the shuttle unless the shuttle's wings can be folded at the time of going into orbit, all this garbage should be able to take out a cargo of about 55-70 tons, but the numbers are rough, so it's only Very rough sketch, but he has the right to his life.

P.S. Thanks for the question, you warmed up my interest in a completely reusable option of putting cargo into orbit, I spent about 2 hours doing this 3d sketch. :P

 

 

 

 

 

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Reusable rockets are not true.
3d-printed Manufactured with additive technologies and self-cannibalizing ones are.

Printing an aluminium can, solving and burning the tank together with the fuel while it works.

Edited by kerbiloid

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4 hours ago, DECQ said:

Okey, here's a very crude example of a completely reusable media, let's combine the side load of the Energia rocket, the reusable style of Energia2, the first stage of the SSRB, and 4 engines SSME/RD0120.
It turned out such a monster, although it is quite damp but still the idea has the right to life.

At the same time, the rocket should have its own engines "OMS", to them a separate installation where the engines and fuel are located, you can see its location although it does not look good.

One big defect is that this crap can not carry the shuttle unless the shuttle's wings can be folded at the time of going into orbit, all this garbage should be able to take out a cargo of about 55-70 tons, but the numbers are rough, so it's only Very rough sketch, but he has the right to his life.

P.S. Thanks for the question, you warmed up my interest in a completely reusable option of putting cargo into orbit, I spent about 2 hours doing this 3d sketch. :P

Hmm, very nice! Reminds me of SLS, but with wings added to the core and a side-slung payload. Does the core go all the way to orbit but simply not circularize? How much dV does the side-slung vehicle carry? What kind of staging/recovery are you thinking?

Another note is that with Falcon 9 and Falcon Heavy, we already have fully-reusable first stages. So all you need for a fully reusable launch system would be a fully-reusable drop-in replacement for the F9/H second stage.

Might be a probable test bed for Raptor and ITS. I know my concept from the first page could definitely be dropped-in on the Falcon Heavy.

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So I just ran some numbers, and if you dropped my 4-meter mini-ITS concept onto a single-stick Falcon 9 FT, it could handle every Falcon Heavy payload with full reuse and RTLS for the first stage.

EDIT: Specifically, the methalox fully-reusable upper stage could do 22.6 tonnes to LEO on a single-stick RTLS Falcon 9 FT, and 40 tonnes to LEO on a Falcon Heavy with RTLS of the boosters and droneship recovery of the core. Paradoxically, once you have a solid recovery mode, recovery penalty for the upper stage is not very high because you don't have to boostback and you don't have to burn through re-entry.

I see absolutely no reason why SpaceX would not do exactly this.

Edited by sevenperforce
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14 hours ago, sevenperforce said:

Here's some lineart of my proposed crewed-version upper stage:

crew_dragon_3_view_2.png

crew_Dragon_3.png

Yes, thought the same myself in that the nose cabin can be ejected. Nose will be far lighter than an dragon pod as it will not need much systems and no life support outside of some spare oxygen 
Is cargo pressurized here? Had probably better to make it unpressurized and you would install an module to get more pressurized volume or an air lock. 
I would add another hatch in the back of cabin, use the area with the escape rockets for pressurized cargo. the front wall of that cargo hold would be bottom of pod after an abort. 
 

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6 hours ago, magnemoe said:

Yes, thought the same myself in that the nose cabin can be ejected. Nose will be far lighter than an dragon pod as it will not need much systems and no life support outside of some spare oxygen 
Is cargo pressurized here? Had probably better to make it unpressurized and you would install an module to get more pressurized volume or an air lock. 
I would add another hatch in the back of cabin, use the area with the escape rockets for pressurized cargo. the front wall of that cargo hold would be bottom of pod after an abort. 

The Shuttle approach of doing manned crew alongside unpressed cargo is a poor one, I think. Much better use can be made of pressurized cargo; send unpressed cargo up on the primary variant, the one with the unpressed cargo bay.

The configuration can probably take a little bit of tweaking. The level of ECLSS in the nose cabin will depend somewhat on whether you want it to have lifeboat capability. In other words, if the back end of the vehicle is disabled by a micrometeoroid strike or some other major problem in orbit, you'd probably want the crew to be able to eject/decouple and be able to return to Earth safely. This means it may need to have, at the very minimum, a heating/cooling system, its own RCS/OMS, and CO2 scrubbers.

You could probably also build it with an optional airlock in the payload compartment.

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1 minute ago, sevenperforce said:

The Shuttle approach of doing manned crew alongside unpressed cargo is a poor one, I think. Much better use can be made of pressurized cargo; send unpressed cargo up on the primary variant, the one with the unpressed cargo bay.

The configuration can probably take a little bit of tweaking. The level of ECLSS in the nose cabin will depend somewhat on whether you want it to have lifeboat capability. In other words, if the back end of the vehicle is disabled by a micrometeoroid strike or some other major problem in orbit, you'd probably want the crew to be able to eject/decouple and be able to return to Earth safely. This means it may need to have, at the very minimum, a heating/cooling system, its own RCS/OMS, and CO2 scrubbers.

You could probably also build it with an optional airlock in the payload compartment.

Dragon has the trunk, i say its nice to have the option for unpressurized cargo, if you don't need it you can use it for secondary payloads.
And yes multiple variants is possible here, it don't change the basic design much except that I would make structure so it can handle an large hatch.
You would want the cargo version door on the cargo compartment anyway so you need an aerodynamic cover an also grab points for the arm.

One downside with this design is that you will have limited stay time in orbit because of cryogenic oxygen ch4. 

I would not make the crew module an separate capsule, its add too much weight.
For incident in orbit return to space station or launch an rescue mission. Two of this ships should be able to dock. 
Don't think you could abort an reentry well anyway leaving this as an launch abort or landing abort. 
One issue with landing abort is how well it would work during final part of landing,
However at this point the landing engines are running and they have redundancy, having one tiny solid engine who tip the ship up so you can eject upward for eject. 

 

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1 hour ago, magnemoe said:

I would not make the crew module an separate capsule, its add too much weight.
For incident in orbit return to space station or launch an rescue mission. Two of this ships should be able to dock. 
Don't think you could abort an reentry well anyway leaving this as an launch abort or landing abort. 
One issue with landing abort is how well it would work during final part of landing,
However at this point the landing engines are running and they have redundancy, having one tiny solid engine who tip the ship up so you can eject upward for eject. 

I factored in the extra dry mass for separate re-entry; you can use the same heat shield you'd be using anyway, and you need parachutes for the launch abort, so that's not a problem. There aren't really a lot of extra systems required. Columbia taught us that rescue missions aren't always possible; what if the vehicle is on an inclination other than the ISS?

For landing abort, you can have the lower escape engine triggered a split second before the upper one, so it tilts you upward.

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Given that Blue in the past has talked about biconic crew vehicles, you might redo the design with BE-4, BE-4U, etc...

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30 minutes ago, tater said:

Given that Blue in the past has talked about biconic crew vehicles, you might redo the design with BE-4, BE-4U, etc...

AFAIK, BO has no plans to do a second-stage-as-payload approach, and their biconic orbiter cannot very well be expanded to a tanks-and-engines profile.

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On 2.5.2017 at 8:53 PM, sevenperforce said:

AFAIK, BO has no plans to do a second-stage-as-payload approach, and their biconic orbiter cannot very well be expanded to a tanks-and-engines profile.

An integrated payload and second stage has some issues, you get space shuttle flexibility and might save some weight, downside is increased complexity and safety issues.
If will be simpler to have an separate upper stage who either use payload under fairing or an pod. 

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3 hours ago, magnemoe said:

An integrated payload and second stage has some issues, you get space shuttle flexibility and might save some weight, downside is increased complexity and safety issues.
If will be simpler to have an separate upper stage who either use payload under fairing or an pod. 

For LEO operations, using an integrated second stage crew vehicle is a bit of a tossup. Flexibility is actually a little more limited, because you cannot use (or reuse) the same stage or stage configuration for crewed launches and payload launches. This isn't necessarily a dealbreaker, though; as long as the tanks and engines have the same dimensions for manufacturing purposes, the supply-chain production side of things can benefit from economies of scale. The immediate advantage of an integrated reusable second stage vehicle is that you have only one orbital EDL to worry about.

Of course, the final advantage is disputable. Having a single vehicle to refurbish doesn't necessarily make everything easier, a point often missed by SSTO advocates. It may be cheaper to refurbish a capsule and an upper stage separately, as both are highly specialized. But it is definitely attractive to be able to use the large volume of the upper stage to help gently decelerate the crew capsule.

For BLEO operations, on the other hand, having refuelable, reusable upper stage integrated with the crew vehicle seems like a no-brainer. You've got to take tanks and engines with you for the transfer burn anyway, and high-velocity re-entries really benefit from the extra volume of an upper stage.

The ideal configuration, I suppose, would be an independently-recoverable upper stage and crew vehicle which can dock together and enter together. But that seems ridiculously complicated.

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1 hour ago, sevenperforce said:

The ideal configuration, I suppose, would be an independently-recoverable upper stage and crew vehicle which can dock together and enter together. But that seems ridiculously complicated.

Isn't that essentially the Apollo missions' configuration when going from Earth orbit to Lunar orbit? Rocket stage, lander, crew capsule? Not to say this isn't complicated. but it's not that complicated.

Though, I tend to agree with the idea that combining the upper stage and the payload/crew module, a la ITS, is a better configuration.

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6 minutes ago, shynung said:
1 hour ago, sevenperforce said:

The ideal configuration, I suppose, would be an independently-recoverable upper stage and crew vehicle which can dock together and enter together. But that seems ridiculously complicated.

Isn't that essentially the Apollo missions' configuration when going from Earth orbit to Lunar orbit? Rocket stage, lander, crew capsule? Not to say this isn't complicated. but it's not that complicated.

Though, I tend to agree with the idea that combining the upper stage and the payload/crew module, a la ITS, is a better configuration.

Not at all; they can dock together just fine, but they obviously can't re-enter together. That's the part I was highlighting.

The only issue with combining the upper stage and the crew cabin a la ITS is that launch abort is really unpleasant.

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2 minutes ago, sevenperforce said:

Not at all; they can dock together just fine, but they obviously can't re-enter together. That's the part I was highlighting.

I don't see much advantage in making them reenter together if the upper stage and crew vehicle can reenter independently.

9 minutes ago, sevenperforce said:

The only issue with combining the upper stage and the crew cabin a la ITS is that launch abort is really unpleasant.

The crew cabin can be designed to be detached from the upper stage for emergencies, then have a launch abort tower stuck on top.

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1 hour ago, shynung said:

I don't see much advantage in making them reenter together if the upper stage and crew vehicle can reenter independently.

The crew cabin can be designed to be detached from the upper stage for emergencies, then have a launch abort tower stuck on top.

For LEO, the main advantage is that a big fluffy re-entry vehicle is much safer and endures lower peak heating and lower gees than a smaller vehicle. That's true whether the crew vehicle is a capsule or a lifting body; the version which retains the stage will have an easier entry than the version which doesn't.

For BLEO, you pretty much have to have your capsule and your stage connected for EDL, since you can't re-integrate for relaunch. So that's an absolute requirement. You can get around it for the moon, since there is no atmosphere to make entry sticky, but it's automatically necessary for Mars. I mean, you can do a capsule on top of an MAV on top of a heat shield, but...egads.

If you're going to go the route of having the crew cabin detach from the upper stage, then you have to ask yourself whether the cabin is going to detach with or without ECLSS, the aeroshell, and so forth. If it detaches with ECLSS and aeroshell, then it is essentially a separate capsule that can serve as a lifeboat, and so you have to ask whether it makes sense to give it an independent emergency re-entry heat shield. And so forth.

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