What are your ultimate commercial rocket designs?

[RocketmanUS]

Soft cryogenics are space-storable (passively). It's hydrogen you've got to be worried about, and even that can be reduced to very low boil-off.

Just accept that SEP tankers need the same protection as depots.  A 10% increase in the solar panels will give you lots of electricity for things like refrigeration equipment.  There is also plenty of room for sun shields, possibly attached to the solar arrays.

Added mass.
Either make a larger SEP , increased time to destination, or decrease payload. So don't use hydrogen, it take up to much volume anyway.

Or Atlas V and F9 would be good for delivering propellants to LEO. Hydrogen gets good ISP with high thrust with LOX but need very large tanks plus special cooling and handling.

[go4mars]

Well you've got to remember Go4Mars' strategy and mine on HLVs are quite different.  He loves the idea of a monolithic HLV, while I've hedged my bets on a modular approach.

I like modular too, but on a bigger scale. 

Can fly 1,2,3, or 5 1st stage cores per launch.  5 would be shaped like 8o8
Fully reusable, always crossfeeds when more than 1 core. 

[Hyperion5]

Well you've got to remember Go4Mars' strategy and mine on HLVs are quite different.  He loves the idea of a monolithic HLV, while I've hedged my bets on a modular approach.

I like modular too, but on a bigger scale. 

Can fly 1,2,3, or 5 1st stage cores per launch.  5 would be shaped like 8o8
Fully reusable, always crossfeeds when more than 1 core. 

Yes, it's modular, but how often could you possibly ever need to fling 2000+ tonnes of payload at a time into LEO?  I'm sure that despite what some say you could make a fairly substantial LV commercially viable if you charged a low enough price per kg, but surely there's a limit.  My guess is you could at most make something pushing 120 mt viable if you got the costs down, but above that you're running out of payloads.  To develop a payload that even a Saturn V couldn't launch is neither cheap nor a run-of-the-mill engineering exercise.  I suppose we all better hope that Bigelow Aerospace starts getting some orders for its massive BA-2100 space station modules.  The problem is, just one of those has roughly double the interior volume of the ISS, so supplying such large space stations would be a feat.  Though at least ULA, Orbital, Spacex, Arianespace, Khrunichev or RSC Energia would not be complaining about the new demand. 

[Robotbeat]

Besides, the acoustic energy (etc) means you may need to build a new launch pad every time you launch the 2000 mT monster.

[oldAtlas_Eguy]

My ultimate rocket is driven by what would be needed to make SPS commercially viable. A LEO cost rate of <$500/kg (1/4 of that of FH) and a payload capacity of 400-600mt. This would be a triple core MCT like rocket (single core able to do 130-200mt). Some reusability would be used in order to get flight rates up to 25-50 per year, giving a new vehicle build rate of 2-5/yr. Flight hardware retired after 10-20 flights. Full reusability could get the LEO cost rates much lower, but anything less than $500/kg will do (BTW that’s a per launch price of <($200M for the smaller capacity or $300M for the larger capacity) per launch, a revenue from launches of $5B-$15B/yr. Smaller vehicles will not work because in order to support such large scale SPS you would need 200-2500 launches/yr of either a 50mt or 13mt fully reusable vehicle.

The triple core configuration would be cargo only but the single core could be used for personnel transport of as many as 100 persons per launch. In this configuration the US and personnel transport could be an integrated vehicle. Depends on what will work out for safety and cost.

If you are to believe SpaceX such vehicles will be available in 10 years, but using hindsight such a large triple core 400-600mt vehicle would not be available until 2028 with the single or 130-200mt class by 2023.

[Hyperion5]

My ultimate rocket is driven by what would be needed to make SPS commercially viable. A LEO cost rate of <$500/kg (1/4 of that of FH) and a payload capacity of 400-600mt. This would be a triple core MCT like rocket (single core able to do 130-200mt). Some reusability would be used in order to get flight rates up to 25-50 per year, giving a new vehicle build rate of 2-5/yr. Flight hardware retired after 10-20 flights. Full reusability could get the LEO cost rates much lower, but anything less than $500/kg will do (BTW that’s a per launch price of <($200M for the smaller capacity or $300M for the larger capacity) per launch, a revenue from launches of $5B-$15B/yr. Smaller vehicles will not work because in order to support such large scale SPS you would need 200-2500 launches/yr of either a 50mt or 13mt fully reusable vehicle.

The triple core configuration would be cargo only but the single core could be used for personnel transport of as many as 100 persons per launch. In this configuration the US and personnel transport could be an integrated vehicle. Depends on what will work out for safety and cost.

If you are to believe SpaceX such vehicles will be available in 10 years, but using hindsight such a large triple core 400-600mt vehicle would not be available until 2028 with the single or 130-200mt class by 2023.

Would your MCT-equivalent core be using existing engines like the F-1A or a totally new design?  Any ideas on core size and engine count? 

[oldAtlas_Eguy]

My ultimate rocket is driven by what would be needed to make SPS commercially viable. A LEO cost rate of <$500/kg (1/4 of that of FH) and a payload capacity of 400-600mt. This would be a triple core MCT like rocket (single core able to do 130-200mt). Some reusability would be used in order to get flight rates up to 25-50 per year, giving a new vehicle build rate of 2-5/yr. Flight hardware retired after 10-20 flights. Full reusability could get the LEO cost rates much lower, but anything less than $500/kg will do (BTW that’s a per launch price of <($200M for the smaller capacity or $300M for the larger capacity) per launch, a revenue from launches of $5B-$15B/yr. Smaller vehicles will not work because in order to support such large scale SPS you would need 200-2500 launches/yr of either a 50mt or 13mt fully reusable vehicle.

The triple core configuration would be cargo only but the single core could be used for personnel transport of as many as 100 persons per launch. In this configuration the US and personnel transport could be an integrated vehicle. Depends on what will work out for safety and cost.

If you are to believe SpaceX such vehicles will be available in 10 years, but using hindsight such a large triple core 400-600mt vehicle would not be available until 2028 with the single or 130-200mt class by 2023.

Would your MCT-equivalent core be using existing engines like the F-1A or a totally new design?  Any ideas on core size and engine count? 

See the SpaceX MCT thread for some of my thoughts on the engines and cores.

Basiclly a new 1.7mlbf methane engine used in a configuration of 6 on a single core giving ~150mt LEO capability and in a triple core configuration 600mt with crossfeed. Tank diameters of 8-10m. More likely 10m since anlthing over 3.6m requires use of barges so going to 10m vs 5m does not cost any more to transport. Plus a non-hamerhead single core 10m faring is appealing and its height is also manageble for use with methane prop.

[go4mars]

Yes, it's modular, but how often could you possibly ever need to fling 2000+ tonnes of payload at a time into LEO? 

Depends.   Does your cycler need a pusher plate?   Do your transport ships to the Mars colonies each house 30?  Or 150 people?   How much methane and oxygen do you expect to need for your successful mining/solar smelting operation?  Does the BA-21,000 go up with all it's water/shielding inside, or does that go on subsequent flights?  How much do you expect the lead-vortex General Fusion ultimate ISP solution to mass (needs a certain minimum size)?     And perhaps most importantly, how many people do you plan to have in the cabin segment of your hypersonic terrestrial transportation modules? 

[savuporo]

It would be one of these
http://www.scorpius.com/products.htm

Sprite, with 1000 lbs to LEO, more specifically.

Small enough parts to be transportable, assembly line manufacturing, with established mass production quality control methods, 95% reliable, only good for launching bulk materials with low payload value.

[Hyperion5]

It would be one of these
http://www.scorpius.com/products.htm

Sprite, with 1000 lbs to LEO, more specifically.

Small enough parts to be transportable, assembly line manufacturing, with established mass production quality control methods, 95% reliable, only good for launching bulk materials with low payload value.

Technically even the 5 meter core on an Ariane 5 or Delta IV is "transportable", they just need water transport to get to their pads.  Now I realize you're gunning for the Sprite, but those other rockets I see on offer, beginning with the Liberty, seem a lot more promising commercially.  They offer bigger payload fairings and more mass to LEO.  Given the most oft-launched launcher in history is considerably more capable than the Sprite (see R-7 family), wouldn't it make sense to up the scale and recommend something like the Exodus (19,700 lbs to LEO) or Space Freighter (33,700 lbs to LEO)? 

--------------

Since we're advocating rockets, here's what that Neptune V I envisioned looked like in its early simulations.  The design since these simulations has grown from 5.21 meters in diameter to 5.79 meters to improve the engine expansion ratios but has seen its length trimmed to just under 58 meters.  We also hedged in more margin with higher dry masses for both stages and cut down the combustion efficiency from 98 to 96%.  Yet despite all that I am fairly confident it should still out-lift an Angara 5 to LEO despite weighing less all while losing an engine at T+0.1 on both stages.  If you could get the engines and avionics quality up, this thing should crush many rockets in reliability given its engine-out margins. 

[Hyperion5]

Baldusi has been talking up this RD-162 engine so many times that I think it's high time we flung it onto a rocket geared for this thread.  So I dual-chambered it into a theoretical equivalent of the RD-180, added on a quartet of RL-10 equivalents, and the all-Russian counterpart to the Atlas V looked like this:


Novgorod 1
2 or 3-stage methalox/hydrolox rocket
Gross mass w/2 stages: 326.4 tonnes
SI gross mass: 281.4 tonnes
SII gross mass: 45 tonnes
Liftoff thrust: 407.8 tonnes
Diameter: 3.8 meters
Standard PLF: 4.1 meters
SI Engine: RD-163 dual-chamber fuel-rich SC methalox engine
SII Engines: quartet of RD-0146 hydrolox engines
Optional 3rd stage: Fregat SB or KVTK w/RD-0146D engine

Payload to LEO: 14,500 kg (estimate)
Payload to GTO: 6,500 kg (estimate)

Novgorod 3 (3 core)
Payload to LEO: 37,500 kg (estimate)
Payload to GTO: 16,000 kg (estimate)

Novgorod 5 (5 core)
Payload to LEO: 67,500 kg (estimate)
Payload to GTO: 28,000 kg (estimate)

I think this design might actually be more promising the the Angaras, because it could also replace the Soyuz & Zenit families in its single-core variant.  You also wouldn't need a unique core to get more than 35 mt of LEO capability.  It should also be quite reliable thanks to that upper stage setup.  Too bad the Russians aren't building something like it, because it looks really promising. 

[Falcon H]

My ultimate rocket design is a falcon heavy, but with seven cores instead of three, the cores could be recovered useing parachutes, and this beast would need a larger upper stage and fairing, maybe 5 meters wide.  

[Falcon H]

My ultimate rocket design is a falcon heavy, but with seven cores instead of three, the cores could be recovered useing parachutes, and this beast would need a larger upper stage and fairing, maybe 5 meters wide.  

Here is a sketch I made.

[Hyperion5]

My ultimate rocket design is a falcon heavy, but with seven cores instead of three, the cores could be recovered useing parachutes, and this beast would need a larger upper stage and fairing, maybe 5 meters wide.  

First off, I'm pretty sure that structurally the Falcon 9 is not built to handle six booster cores strapped to it, and even it if it is, that is an otherworldly 63 rocket engines.  I know Lobo thinks he can get up to six Falcon Heavy boosters strapped to the SLS and make it work, but I'm skeptical.  I know Lobo's a smart guy with an education in engineering to back that up, but I've yet to see people in the aerospace engineering field like Strangequark or Jim embrace using FH boosters in that quantity.  I know Ed Kyle is openly skeptical of just the 27 engines on the Falcon Heavy, so you can imagine his reaction to your proposal. 

Recovery of the cores is likely to be done via propulsive landings on terra firma, following the Grasshopper model.  I forgot to mention that Elon's already granted that last wish of yours.  The standard fairing on both the Falcon 9 & Falcon Heavy is 5.2 meters. 

[gin455res]

How about a falcon 1, with an xcor designed upperstage to open up the smallsat market?

[strangequark]

I know Lobo's a smart guy with an education in engineering to back that up, but I've yet to see people in the aerospace engineering field like Strangequark or Jim embrace using FH boosters in that quantity.  I know Ed Kyle is openly skeptical of just the 27 engines on the Falcon Heavy, so you can imagine his reaction to your proposal. 

So, yeah, that's a crazy number of boosters. However, I have 5 years of experience in this industry, and have been corrected and educated many times on this forum by "non-experts". Jim has 30-ish years experience, and an encyclopedic knowledge of spaceflight practice and history. I do not belong anywhere near that particular pedestal.

[Hyperion5]

I know Lobo's a smart guy with an education in engineering to back that up, but I've yet to see people in the aerospace engineering field like Strangequark or Jim embrace using FH boosters in that quantity.  I know Ed Kyle is openly skeptical of just the 27 engines on the Falcon Heavy, so you can imagine his reaction to your proposal. 

So, yeah, that's a crazy number of boosters. However, I have 5 years of experience in this industry, and have been corrected and educated many times on this forum by "non-experts". Jim has 30-ish years experience, and an encyclopedic knowledge of spaceflight practice and history. I do not belong anywhere near that particular pedestal.

I don't put Jim on a pedestal; FYI I'm just using you and Jim as examples of aerospace guys I know who aren't exactly jumping up and down saying "63 engines firing at once?  Let's do this!"  I mean, let's just say Falcon H is your boss, and he comes to you with this plan to mount not two but six Falcon Heavy boosters around the Falcon 9 core.  What kind of issues would you point out with this approach? 

I would bet you would have almost immediate reservations about this proposed vehicle, and not only because of there being some 63 rocket engines firing at once.  Just think about the payload masses we start being able to lift with this amount of liftoff thrust.  Supposing you could get past the booster issues, that still leaves you with an absurdly underpowered second stage.  The fairing sizes you could mount would also be inadequate for most 100 mt payloads.  Finally, the structural loads placed on the central core by the boosters and huge payloads would probably force engineers to reinforce the core a lot, which in turn would curb the payload mass you could launch.  Then there's the launchpad for a monster like this; the only ones I can think of that might handle it would be the old Shuttle/Saturn pads.  That means either higher operating costs or hundreds of millions or more for an all-new pad. 

[ClaytonBirchenough]

My ultimate commercial rocket design is not really a design, it's a philosophy; mass production, flying a rocket a day, no matter if payload is available. The rocket would be two stages, have the simplest engines burning LOX/RP-1. One engine in each stage. Rocket could probably launch 10 MT into LEO. If no payload is available everyday, launch extra propellant to a propellant depot. Once a week, you launch a similar rocket, but human-rated carrying a Dragon like capsule.

Payload delivered to LEO: 3650 MT (Excluding manned rocket)
Passengers delivered to LEO: ~364

MASS PRODUCTION MY FRIENDS

[Elmar Moelzer]

My ultimate commercial rocket design would be something designed by Gary Hudson, if someone just came and finally gave the man the funding he deserves.
I don't know exactly what Gary would make it look like with his increased experience and new materials and other options available these days, but I would guess it would be somewhat resembling the Aerospike Test Vehicle, the DC-X and/or the Phoenix VTOL.
I know, I can dream, alright. Not much else I can do anyway.

[QuantumG]

My ultimate commercial rocket design would be something designed by Gary Hudson, if someone just came and finally gave the man the funding he deserves.
I don't know exactly what Gary would make it look like with his increased experience and new materials and other options available these days, but I would guess it would be somewhat resembling the Aerospike Test Vehicle, the DC-X and/or the Phoenix VTOL.
I know, I can dream, alright. Not much else I can do anyway.

Good answer!