Author Topic: Zubrin's New Falcon Heavy Architecture - Moon Direct  (Read 64066 times)

Offline DougSpace

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Re: Zubrin's New Falcon Heavy Architecture - Moon Direct
« Reply #140 on: 04/11/2018 05:59 am »
SpaceX doesn't like Hydrogen, modifying their pad to support LH2 is just a distraction that has no return.

The return would be right away.  If part of a NASA-funded Lunar COTS program, SpaceX would be paid once they installed the LH lines as a milestone payment.  Also, SpaceX might get a block buy of FHs whereas now they have relatively few customers for their FHs.  That block buy money would go towards BFR engineering work.  But also, there’s another option.  SpaceX launched all but the LH.  ULA launches LH tanks, they dock and fire.  I spoke with a recent executive of ULA and he said they’d jump at the chance to get their XEUS/ACES Lander development pays for by NASA, would use that money to develop the Vulcan (competitor launcher) and would be happy to be launched on FH if NASA shows the money.  Don’t kid yourself — “money speaks” and and makes interesting bedfellows.

Offline DougSpace

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Re: Zubrin's New Falcon Heavy Architecture - Moon Direct
« Reply #141 on: 04/11/2018 06:12 am »
If you follow Zubrin's plan. Then you need to developed a lander, an ascend vehicle and a habitat module in parallel. Called it a wash in time required to developed the Zubrin vehicles and modules in comparison to the BFS. However the payload delivered to the Lunar surface by Zubrin's plan is a small fraction of what the BFS is capable of depending on how much refueling of the BFS is done.

Zubrin’s lander could be the Centaur-derived XEUS.  Since it would only be a modification if the highly-flown Centaur, it could be developed quickly and cost-effectively.  If we do my approach instead of Zubrin’s then the XEUS serves as the ascent vehicle so no new vehicle there.  The Moon and Mars need habitats separate from the landers.  Long-term crew need to have their habitat covered with regolith to protect against GCRs.  Water-derived lunar propellant goes a long ways towards not requiring a SHLV for (even large-scale) development.  Think about it.  If you don’t have to launch descent or ascent propellant, water for drinking, sanitation, oxygen, & food, and the organically in the ice can be used for plant CO2 & plastics, you’s drastically reduced the amount that needs to be launched each time.  A larger percentage of payload becomes crew/settlers.
« Last Edit: 04/11/2018 06:13 am by DougSpace »

Offline DougSpace

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Re: Zubrin's New Falcon Heavy Architecture - Moon Direct
« Reply #142 on: 04/11/2018 06:29 am »
Zubrin’s Lunar Direct plan is only viable if the BFR & BFS service introductions is drastically delay.

Definitions: BFB = the booster; BFR = BFB + BFS.

People really need to stop and think about what it’s going to take to get a BFR proven to a level that we can start abandoning alternate approaches.  Starting with the BFS, an empty Grasshopper version is needed and doing a series of increasing hops.  If one goes “boom” (as did the Grasshopper) then that’s a delay.  The BFS needs to go further than the Grasshopper by going to space.  Any landing crash (of which SpaceX is very experienced) then that’s a delay.  Elon wants the BFS to be SSTO!  And re-entry failure (of which SpaceX has experience) then that’s a delay.  After re-entry at LEO speeds, the BFS has to land.  Any landing failures (...)...  Get the idea?  But even a SSTO BFS is not sufficient to abandon alternate vehicles because the BFS has to re-enter at lunar if not Martian speeds.  And for that we need the BFB.  And finally you can start developing the BFS life support systems and such.  So, basically, you need the entire BFR before assuming that we’ve got the “two birds in the bush”.

Offline hkultala

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Re: Zubrin's New Falcon Heavy Architecture - Moon Direct
« Reply #143 on: 04/11/2018 06:34 am »
[oftopic]

Why are all threads polluted with this BFS SSTO nonsense?

Elon wants the BFS to be SSTO!

Only on Mars, not on earth. Elon knows BFS-SSTO is worthless on earth.

Quote
  And re-entry failure (of which SpaceX has experience) then that’s a delay.  After re-entry at LEO speeds, the BFS has to land.  Any landing failures (...)...  Get the idea?  But even a SSTO BFS is not sufficient to abandon alternate vehicles because the BFS has to re-enter at lunar if not Martian speeds.  And for that we need the BFB.

No, where you need BFR to get any to any meaningful orbit where you want to go. Barely reaching 185km orbit in the native inclination of your launch site is practically worthelss if your paylaod is going to 500 km orbit on 55 degrees different inclunation.

[/quote]
« Last Edit: 04/11/2018 06:36 am by hkultala »

Offline sanman

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Re: Zubrin's New Falcon Heavy Architecture - Moon Direct
« Reply #144 on: 04/13/2018 10:16 pm »
Elon wants the BFS to be SSTO!

Only on Mars, not on earth. Elon knows BFS-SSTO is worthless on earth.

Musk has simply remarked that BFS would be capable of traveling from Earth to LEO on its own, not that this would be a nominal mission profile.
On the Moon or Mars of course, the BFS could achieve full escape velocity for return to Earth.

For the Moon specifically, Musk has said BFR could travel to the Moon and back - so that's BFB+BFS for Earth-to-Moon, and then just BFS can return from Moon-to-Earth without even requiring any refueling. That last fact would enable the BFR/BFS to bootstrap a lunar architecture even faster than Zubrin's FalconHeavy-based model. But of course, FalconHeavy exists today, while BFR/BFS is still in early development.

How many Zubrin-type FalconHeavy missions to the Moon could be performed pending the emergence of BFR/BFS?

Offline speedevil

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Re: Zubrin's New Falcon Heavy Architecture - Moon Direct
« Reply #145 on: 04/13/2018 11:40 pm »
How many Zubrin-type FalconHeavy missions to the Moon could be performed pending the emergence of BFR/BFS?
How long is a piece of string?
Or more relevantly, the number of zeros on that string.

Neglecting and assuming stuff, you could probably get 20 FH flights a year, if you paid $2.5B in 2019, and maybe more in 2020.

Once you start getting to 2020, you get into the realm where BFS might be flying alone, if someone is actually paying for it, consideration might be given to SSTO driven moon missions, where a sub 5M cost launch gets you a ton on the moon. (with a _lot_ of refuelling).

I can't see - even if you found a magic money tree funder, that anything FH based other than stuff to stage in orbit (for example, tanks of kerosene and oxygen) could happen within a couple of years as you'll be developing stuff to fly.

Prepositioning a couple of thousand tons of fuel could of course have very interesting consequences.


Offline DistantTemple

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Re: Zubrin's New Falcon Heavy Architecture - Moon Direct
« Reply #146 on: 04/14/2018 02:37 am »
EM promised drastic reductions in launch price. Well he delivered  one tranche. To bring the F9 class launch to $62M. He has forced everyone else to drastically rush round in circles trying to reduce theirs. But once he started reusing stage 1s, he didn't do as many expected, and cut prices again. He seems to have given small discounts, and kept the extra profit "towards the development costs".

EM has several aims. (in my words) 1. Mars.... why are we not there? 2. Launch cost and 3. Appropriate vehicles 4. Stimulate everyone to get excited about space, and start making progress again.

He doesn't particularly want to destroy other launch providers. He wants NASA to be more effective, but not undermined. And since it looks like he's on his own going to mars, he needs to make a profit. So he won't be dropping his prices to $10M for a BFR launch, to outside customers any time soon, unless maybe they are cooperating on his project. He also has to make a profit now before BO manages to reuse their rocket, and prices really drop. It'd be bad business to waste his head start.

I think if anyone asks him to cooperate on moon projects, he will view it largely as a distraction. And the only way for it not to slow him down will be if its fully funded, and he gets something out of it. Even if he's paid to develop technology, its still taking his engineers off of the Mars project.

So lets think how much he will charge for a BFS to the moon with two tanker support trips; he won't be charging internal prices... he'll be making real money ($200M profit) so he can send more BFSs to Mars... or to build launching platforms. There is no reason to throw money away! And he'll probably just sell services like transport and fuel, and not get too involved. And by charging proper prices he'll allow others to stay in business too.
We can always grow new new dendrites. Reach out and make connections and your world will burst with new insights. Then repose in consciousness.

Offline DougSpace

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Re: Zubrin's New Falcon Heavy Architecture - Moon Direct
« Reply #147 on: 04/17/2018 07:24 pm »
> How many Zubrin-type FalconHeavy missions to the Moon could be performed pending the emergence of BFR/BFS?

That depends upon how many setbacks (e.g. crashes) occur during the BFR development and SpaceX funding.  It also depends upon when XEUS development gets funded.

But, assuming XEUS funding within a year, and say two setbacks during BFS development and two setbacks with BFB-BFS testing with a six-month delay for each setback, I’d say that uncrewed XEUS missions could start in three years and reach a launch rate of one every other month. 

Say BFS hops starts mid 2019 and intraatmosphere hops take 12 months.  Adding the full engines and poking into suborbital space takes six more months.  One crash sets back 6 months.  Let’s assume that either BFS doesn’t achieve SSTO or that it has difficulties (landing crash) necessitating the development of the BFB in order to prove out the BFS for orbit & successful landing. 

Let’s guess that it takes 12 months to build and test the BFR with its engines and a 6-month hop testing with one six-month set-back.  Then combined BFB-BFS test with a second six-month set-back with a landing crash of either the BFB or BFR.  Let’s assume no fueling or other unexpected set-back.  By my estimates, that means that a workable, uncrewed BFB-BFS becomes available at the beginning of 2026.  Here’s that timeline.

19.5 - Hops start
20.5 - Hops done
21.0 - Recovery from setback
21.5 - Full BFS pokes out atmosphere
22.0 - Atempting orbit when setback
22.5 - Recovered from setback
23.5 - Done building BFB
24.0 - BFB hops done
24.5 - Recovered from setback
25.0 - Combined test w/ accident
26.0 - Recovered from setback

If there’s questions about four setbacks, count how many setbacks SpaceX has had until now.  It’s much
more than four.  So, I’m being kind to SpaceX.

So, the FH-XEUS would be 3.5 years ahead of the BFR.  At 6 FH-XEUS launches per year this would come to 21 lunar missions which, by my count would complete and populate the initial habitat (crew of eight) and be 13 missions into the International Crew Lunar Exploration Phase (crew = 98).

I know, lots of educated guessing to come to an answer.  But transparent educated guessing is better than pure opinion or failing to consider the factors.
« Last Edit: 04/17/2018 07:29 pm by DougSpace »

Offline Steven Pietrobon

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Re: Zubrin's New Falcon Heavy Architecture - Moon Direct
« Reply #148 on: 04/18/2018 07:36 am »
He doesn't particularly want to destroy other launch providers.

I disagree with that. SpaceX went out of their way to have the RD-180 banned, the engine for ULA's cheapest launch vehicle, the Atlas V. Elon also ridiculed Blue Origin's attempt at getting access to LC-39A.
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline speedevil

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Re: Zubrin's New Falcon Heavy Architecture - Moon Direct
« Reply #149 on: 04/18/2018 09:23 am »
Elon also ridiculed Blue Origin's attempt at getting access to LC-39A.
Musk:
Quote
“[Blue Origin] “If they do somehow show up in the next  5 years with a vehicle qualified to NASA’s human rating standards that can dock with the Space Station, which is what Pad 39A is meant to do, we will gladly accommodate their needs. Frankly, I think we are more likely to discover unicorns dancing in the flame duct.”

At some point, it becomes less ridicule, and more fair commentary.

Blue having anything flyable and qualified to fly in September of this year (five years) would almost be more surprising than the unicorns.

Offline envy887

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Re: Zubrin's New Falcon Heavy Architecture - Moon Direct
« Reply #150 on: 04/18/2018 07:43 pm »
He doesn't particularly want to destroy other launch providers.

I disagree with that. SpaceX went out of their way to have the RD-180 banned, the engine for ULA's cheapest launch vehicle, the Atlas V. Elon also ridiculed Blue Origin's attempt at getting access to LC-39A.

Pointing out the stupidity of relying on a hostile foreign power for a critical national security need is not the same as going out of his way to get the engine banned.

Musk wants to see all launch providers pursue reuse and refueling, even the Russians. If they don't want to do that, I'm sure he's willing to see them die off.

He tweeted today:
Quote
Russia has great rocket technology & talent. Much respect. Would encourage focus on reusability. Single-use rockets cannot be competitive any more than single-use aircraft.

https://twitter.com/elonmusk/status/986641687081398272


Offline DougSpace

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Re: Zubrin's New Falcon Heavy Architecture - Moon Direct
« Reply #151 on: 05/31/2018 03:36 am »
Robert Zubrin recently presented at the NSS - ISDC Conference about his Moon Direct concept.  The video of his presentation is here:


Offline TrevorMonty

Re: Zubrin's New Falcon Heavy Architecture - Moon Direct
« Reply #152 on: 05/31/2018 03:07 pm »
Zubrin made a good case for 6kms DV lander. It allows for 4 different options.
1) Surface exploration sorties as he pointed out. From base or LOP-G
2) Round trip from LOP-G to lunar base.
3) Most of round trip from LEO to LOP-G
4) 1 way between LEO and lunar base.

In case of LOP-G there will need to be a fuel depot so lander can be refuelled.

Fuel boiloff shouldn't be issue for 4 days which is LEO - lunar trip and enough for short duration sorties. With sorties of week or more it will be limiting factor. In case if 2) fuel will need to be removed from lander and kept cold using cyrocoolers at base.

Options 1 and 4 rely on ISRU fuel while 2 and 3 can use earth supplied fuel. I still think LOP-G is good idea especially for early missions. Once ISRU fuel is available then LOP-G can be bypassed, doesn't mean it will be obsolete as there will always be still a need for space stations.
« Last Edit: 05/31/2018 03:07 pm by TrevorMonty »

Offline QuantumG

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Re: Zubrin's New Falcon Heavy Architecture - Moon Direct
« Reply #153 on: 05/31/2018 11:51 pm »
A critical part of this presentation is that Zubrin is describing two different landers: crew and cargo. The crew vehicle is to be LH2/LOX and fully reusable, 6 km/s delta-v or better, 8 tons wet mass. The cargo lander is expendable and can use whatever propellant combination is desired by the provider. For someone like SpaceX, I imagine it might just be the second stage of the Falcon Heavy doing some fancy landing.. he doesn't really specify. The idea is that if the cargo lander can put 8 tons or more on the surface then it can put a fully fuelled crew vehicle on the surface. Crew can then make the one-way trip in another crew vehicle, land, do surface operations, get back in the fully fuelled crew vehicle and come back to LEO. That process can be repeated as many times as necessary to setup propellant production on the Moon - and none of the crew vehicles will be expended. It's an efficient and conservative design decision. There's lots of improvements that could be made at a later date: reusable cargo vehicles, aerobraking back into LEO, etc.

Human spaceflight is basically just LARPing now.

Offline DougSpace

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Re: Zubrin's New Falcon Heavy Architecture - Moon Direct
« Reply #154 on: 06/01/2018 02:28 pm »
In case of LOP-G there will need to be a fuel depot so lander can be refuelled.

Could LOP-G simply be replaced with “rendezvous point”  (eg EML1) where a payload (propellant, cargo, or crew) rendezvouses with a reusable lunar lander and simply hands over the payload?

Given the few days involved with cislunar transport, it simply becomes a matter of scheduling — no need for long-term in-space storage of propellant.  Whenever propellant production starts on the lunar surface, then the lunar surface becomes the depot with propellant storage accomplishes using the ambient temperatures of small, permanently-shadowed craters or tanks shadowed via a ring wall of reflective Mylar.

Standardized payload modules means that payloads would be handed off from incoming craft to the reusable lander on a one-to-one bases — no need for a Gateway to accumulate propellant, cargo, or crew.

Offline DougSpace

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Re: Zubrin's New Falcon Heavy Architecture - Moon Direct
« Reply #155 on: 06/01/2018 02:35 pm »
A critical part of this presentation is that Zubrin is describing two different landers: crew and cargo.

When Zubrin spoke on The Space Show about Moon Direct, he seemed to be unaware of the ULA - XEUS or ACES lander concepts.  When he spoke at ISDC he still made no mention of it.  The XEUS / ACES concept could start with modifying a Centaur upper stage to be a reusable lander.  The Centaur masses just below 2 tonnes.  The concepts involve one lander but with either a propellant, cargo, or crew module attached to it.  The nice thing is that flights (and reflights) of the cargo version can give the lander experience leading to human-rating of the lander.  No need to develop an entirely new crew lander.

Offline TrevorMonty

Re: Zubrin's New Falcon Heavy Architecture - Moon Direct
« Reply #156 on: 06/01/2018 09:58 pm »
In case of LOP-G there will need to be a fuel depot so lander can be refuelled.

Could LOP-G simply be replaced with “rendezvous point”  (eg EML1) where a payload (propellant, cargo, or crew) rendezvouses with a reusable lunar lander and simply hands over the payload?

Given the few days involved with cislunar transport, it simply becomes a matter of scheduling — no need for long-term in-space storage of propellant.  Whenever propellant production starts on the lunar surface, then the lunar surface becomes the depot with propellant storage accomplishes using the ambient temperatures of small, permanently-shadowed craters or tanks shadowed via a ring wall of reflective Mylar.

Standardized payload modules means that payloads would be handed off from incoming craft to the reusable lander on a one-to-one bases — no need for a Gateway to accumulate propellant, cargo, or crew.
If you can refuel on surface then just fly direct between LEO surface. Without ISRU the lander will need to refuel in orbit, whether that is LOP-G or fuel depot or tanker. The advantage of LOP-G is if something goes wrong during fuel transfer crew has save haven until rescued.

I'd fly crew from LEO-LOP-G on lander, offload crew and send lander to nearby depot/tanker for topup then pickup crew for lunar landing. Repeat for return trip.

I like idea of returning lander to LEO for servicing, lot cheaper to do in LEO than LOP-G. Might even be able to use large pressured hangar to allow crew to work in short sleeve enviroment. If lander is LH/ LOX there shouldn't be any nasty chemicals to deal with.

Even with ISRU fuel in place, there still a case for having rescue lander stationed at unmanned LOP-G. A 6kms lander at LOP-G can rescue crew from anywhere in cislunar space and deliver them to LEO, Lunar surface or LOP-G.

Alternatively lander in transit can divert to LOP-G, eg enter LLO detect fault that would endanger landing or return to LEO so divert to LOP-G.

For cargo missions use expendable landers flying direct from earth until ISRU is in place.
« Last Edit: 06/01/2018 10:05 pm by TrevorMonty »

Offline A_M_Swallow

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Re: Zubrin's New Falcon Heavy Architecture - Moon Direct
« Reply #157 on: 06/02/2018 12:57 am »
In case of LOP-G there will need to be a fuel depot so lander can be refuelled.

Could LOP-G simply be replaced with “rendezvous point”  (eg EML1) where a payload (propellant, cargo, or crew) rendezvouses with a reusable lunar lander and simply hands over the payload?

Given the few days involved with cislunar transport, it simply becomes a matter of scheduling — no need for long-term in-space storage of propellant.  Whenever propellant production starts on the lunar surface, then the lunar surface becomes the depot with propellant storage accomplishes using the ambient temperatures of small, permanently-shadowed craters or tanks shadowed via a ring wall of reflective Mylar.

Standardized payload modules means that payloads would be handed off from incoming craft to the reusable lander on a one-to-one bases — no need for a Gateway to accumulate propellant, cargo, or crew.

During the Napoleonic Wars the Royal Navy perfected resupplying ships at sea. Suitably modified those techniques could permit the construction and supply of cargo and people to the Moon.

Construction and operation of a Moon base using a “rendezvous point” needs the lunar lander, propellant tanker(s), cargo carrier and Earth reentry vehicle to all meet at the same place. Anything is possible but needs cost justifying. Also what do we do with the lunar lander between missions? Also how and where is the reusable lander repaired?

Due to the difficulties of landing heavy cargoes I suspect that we will have a space station at least 10 years before we have a fully equipped lunar base.

How sophisticated does the spacestation need to be?
Could we for instance get away with a homing beacon and 5 IDS docking ports?

Offline QuantumG

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Re: Zubrin's New Falcon Heavy Architecture - Moon Direct
« Reply #158 on: 06/02/2018 05:27 am »
When Zubrin spoke on The Space Show about Moon Direct, he seemed to be unaware of the ULA - XEUS or ACES lander concepts.  When he spoke at ISDC he still made no mention of it.

Yeah, because who cares about the expendable cargo lander. The commercial provider can do whatever they want. It's their problem to solve.

Quote from: DougSpace
No need to develop an entirely new crew lander.

For Zubrin's plan? Yeah there is. You need a *fully reusable* crew vehicle. That's the whole point.

Human spaceflight is basically just LARPing now.

Offline Oli

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Re: Zubrin's New Falcon Heavy Architecture - Moon Direct
« Reply #159 on: 06/03/2018 06:03 am »
I like Moon Direct as a concept, but Zubrin's mass assumptions are ridiculous as always. 2t dry mass for a vehicle that can fly astronauts from LEO to the lunar surface and back.  ::)

Let's be generous and assume the crew module is ~5t and the tankage/landing gear dry mass fraction is 10%. That's a ~29t vehicle with an ISP of 450s. Note since a cargo version would have no return payload, it could return to LEO with little fuel, ~6.5t instead of ~21.5t.
« Last Edit: 06/03/2018 06:20 am by Oli »

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