Author Topic: IAC 2017 -- BFR v0.2 - DISCUSSION THREAD 3 (Post Speech)  (Read 375188 times)

I wonder if Zubrin has considered even once that he could be wrong and tried to understand SpaceX's architecture financially in an objective way. I mean he's talking with a guy and a company that sure knows something about putting together actual hardware and the associated costs. Not to mention a company that sees reducing costs as priority and has actually demonstrated the capability of doing that in reality. I'm sure their design is way more likely to choose the right trade-offs than Zubrin's. 
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Offline speedevil

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Re: IAC 2017 -- BFR v0.2 - DISCUSSION THREAD 3 (Post Speech)
« Reply #1281 on: 02/20/2018 10:16 AM »
Graphites sublimation energy is equivalent to about 10km/s - that is it takes 10km/s of impact to impart enough energy to wholly vaporise it. Graphite powder is inexpensive.
A BFS can be loaded from four BFS  with graphite powder, refuelled by 5 or so BFS, make TLI, and then flip and go home.
Not sure where you're going with this. I mentioned carbonate rocks as a possible carbon source because they are used for iron production on Earth for this purpose. But for direct conversion to CH4 you might as well ship them (IE Graphite powder) as is.


I was idly wondering about the silly option of hard landing graphite powder on the moon, without a vehicle, , for use in later ISRU, when the bugs are pretty much worked out.

Mass transfer to the moon is quite inexpensive in comparison to if you actually land it properly.



Offline blasphemer

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Re: IAC 2017 -- BFR v0.2 - DISCUSSION THREAD 3 (Post Speech)
« Reply #1282 on: 02/20/2018 10:40 AM »
Ice on lunar poles may not be just water ice, but other volatiles such as carbon dioxide and maybe methane as well. In that case BFR could possibly be refueled there.

Offline john smith 19

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Re: IAC 2017 -- BFR v0.2 - DISCUSSION THREAD 3 (Post Speech)
« Reply #1283 on: 02/20/2018 06:38 PM »
I was idly wondering about the silly option of hard landing graphite powder on the moon, without a vehicle, , for use in later ISRU, when the bugs are pretty much worked out.

Mass transfer to the moon is quite inexpensive in comparison to if you actually land it properly.
True. The obvious being a heavy sphere loaded with 50lb sacks of graphite beads (used in the oil industry for drilling mud apparently). That would handle a very hard landing.
BFS. The worlds first Methane fueled FFORSC engined CFRP structured A380 sized aerospaceplane tail sitter capable of flying in Earth and Mars atmospheres. BFR. The worlds biggest Methane fueled FFORSC engined CFRP structured booster for BFS. First flight to Mars by end of 2022. Forward looking statements. T&C apply. Believe no one. Run your own numbers. So, you are going to Mars to start a better life? Picture it in your mind. Now say what it is out loud.

Offline dglow

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Re: IAC 2017 -- BFR v0.2 - DISCUSSION THREAD 3 (Post Speech)
« Reply #1284 on: 02/20/2018 07:03 PM »
I wonder if Zubrin has considered even once that he could be wrong and tried to understand SpaceX's architecture financially in an objective way. I mean he's talking with a guy and a company that sure knows something about putting together actual hardware and the associated costs. Not to mention a company that sees reducing costs as priority and has actually demonstrated the capability of doing that in reality. I'm sure their design is way more likely to choose the right trade-offs than Zubrin's.

Zubrin's in a hurry. He'd rather see Mars launches begin sooner, launching on Falcon Heavies (the Mars Society has baselined such plans), than wait for BFR.

Remember, his initial argument in the '90s was to bring back Saturn Vs and launch on those. He doesn't give a damn what kind of launcher is used, he just thinks it's lame that we haven't started any missions yet.

And... he's kinda right.
« Last Edit: 02/20/2018 07:04 PM by dglow »

Offline DigitalMan

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Re: IAC 2017 -- BFR v0.2 - DISCUSSION THREAD 3 (Post Speech)
« Reply #1285 on: 02/20/2018 07:16 PM »
I wonder if Zubrin has considered even once that he could be wrong and tried to understand SpaceX's architecture financially in an objective way. I mean he's talking with a guy and a company that sure knows something about putting together actual hardware and the associated costs. Not to mention a company that sees reducing costs as priority and has actually demonstrated the capability of doing that in reality. I'm sure their design is way more likely to choose the right trade-offs than Zubrin's.

Zubrin's in a hurry. He'd rather see Mars launches begin sooner, launching on Falcon Heavies (the Mars Society has baselined such plans), than wait for BFR.

Remember, his initial argument in the '90s was to bring back Saturn Vs and launch on those. He doesn't give a damn what kind of launcher is used, he just thinks it's lame that we haven't started any missions yet.

And... he's kinda right.

I think he's wrong.  It will take a lot of mass to mars and regular flights to enable an economically viable initial human outpost.  I don't think it would be feasible without a much lower cost of mass to Mars than FH.

Where is the money going to come from?

edit: I think an analogy is that he is anxious to get on any bus to a faraway place and doesn't care that the regular bus has 100 stops whereas the express is only a 30 minute wait.
« Last Edit: 02/20/2018 07:17 PM by DigitalMan »

Offline hkultala

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Re: IAC 2017 -- BFR v0.2 - DISCUSSION THREAD 3 (Post Speech)
« Reply #1286 on: 02/20/2018 07:22 PM »


I wonder if Zubrin has considered even once that he could be wrong and tried to understand SpaceX's architecture financially in an objective way. I mean he's talking with a guy and a company that sure knows something about putting together actual hardware and the associated costs. Not to mention a company that sees reducing costs as priority and has actually demonstrated the capability of doing that in reality. I'm sure their design is way more likely to choose the right trade-offs than Zubrin's.

Zubrin's in a hurry. He'd rather see Mars launches begin sooner, launching on Falcon Heavies (the Mars Society has baselined such plans), than wait for BFR.

Remember, his initial argument in the '90s was to bring back Saturn Vs and launch on those. He doesn't give a damn what kind of launcher is used, he just thinks it's lame that we haven't started any missions yet.

And... he's kinda right.

We know what happened to space funding after Apollo.

Zubrins plan has too high risk for the same thing happen again. "Been there, done that, mars is no longer interesting, lets use these money to build new hi-tech weapons instead".

Elon Musk has much better contingency plan. Go to mars on a craft that is not only capable of sending an exploration mission but also a colonization mission.

Offline speedevil

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Re: IAC 2017 -- BFR v0.2 - DISCUSSION THREAD 3 (Post Speech)
« Reply #1287 on: 02/20/2018 07:24 PM »
And... he's kinda right.

To a degree, but, well, 3 tons to mars, all stages recovered (apart from the second stage) per launch, versus 75 tons per launch, to TMI.

(four launches of 150t of cargo to LEO, cross-ship into one BFS, fill prop with another 4 BFS, TMI, drop ballistic cargo, return).

If FH is costing you $10M/ton through TMI, and BFS even at $10M per launch, $130K/ton, it pretty much becomes equally expensive somewhere before ten tons to Mars.

A billion either buys you a hundred tons to TMI, or eight thousand.





Offline john smith 19

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Re: IAC 2017 -- BFR v0.2 - DISCUSSION THREAD 3 (Post Speech)
« Reply #1288 on: 02/20/2018 08:18 PM »
I think he's wrong.  It will take a lot of mass to mars and regular flights to enable an economically viable initial human outpost.  I don't think it would be feasible without a much lower cost of mass to Mars than FH.

Where is the money going to come from?
I guess the obvious question is how do Zubrin's goals compare to Musks.

Musks is a long term, sustainable and (ultimately) self sufficient settlement on Mars. That suggests investing in a certain amount of time and effort to get a  certain level of capability.

How does this compare with Zubrins game plan? If his goals are more modest then a faster path to Mars would seem possible.
BFS. The worlds first Methane fueled FFORSC engined CFRP structured A380 sized aerospaceplane tail sitter capable of flying in Earth and Mars atmospheres. BFR. The worlds biggest Methane fueled FFORSC engined CFRP structured booster for BFS. First flight to Mars by end of 2022. Forward looking statements. T&C apply. Believe no one. Run your own numbers. So, you are going to Mars to start a better life? Picture it in your mind. Now say what it is out loud.

Offline Torbjorn Larsson, OM

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Re: IAC 2017 -- BFR v0.2 - DISCUSSION THREAD 3 (Post Speech)
« Reply #1289 on: 02/20/2018 09:02 PM »
I think he's wrong.  It will take a lot of mass to mars and regular flights to enable an economically viable initial human outpost.  I don't think it would be feasible without a much lower cost of mass to Mars than FH.

Where is the money going to come from?
I guess the obvious question is how do Zubrin's goals compare to Musks.

Musks is a long term, sustainable and (ultimately) self sufficient settlement on Mars. That suggests investing in a certain amount of time and effort to get a  certain level of capability.

How does this compare with Zubrins game plan? If his goals are more modest then a faster path to Mars would seem possible.

If it is faster and Zubrin started years (90's?) before Musk (00s?), how come he has nothing to show while Musk has both cut launch costs with a factor 10 and has developed a Mars capable launcher? That sounds like a viability constraint right there (aka "wrong" vs "right").

Edit: Clearer language.
« Last Edit: 02/20/2018 09:05 PM by Torbjorn Larsson, OM »

Online RonM

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Re: IAC 2017 -- BFR v0.2 - DISCUSSION THREAD 3 (Post Speech)
« Reply #1290 on: 02/20/2018 09:52 PM »
I think he's wrong.  It will take a lot of mass to mars and regular flights to enable an economically viable initial human outpost.  I don't think it would be feasible without a much lower cost of mass to Mars than FH.

Where is the money going to come from?
I guess the obvious question is how do Zubrin's goals compare to Musks.

Musks is a long term, sustainable and (ultimately) self sufficient settlement on Mars. That suggests investing in a certain amount of time and effort to get a  certain level of capability.

How does this compare with Zubrins game plan? If his goals are more modest then a faster path to Mars would seem possible.

If it is faster and Zubrin started years (90's?) before Musk (00s?), how come he has nothing to show while Musk has both cut launch costs with a factor 10 and has developed a Mars capable launcher? That sounds like a viability constraint right there (aka "wrong" vs "right").

Edit: Clearer language.

Zubrin influenced NASA planning. Ares V and SLS are pretty much what Zubrin had in mind. Of course, without money from Congress, any version of Mars Direct isn't happening. So, SpaceX steps in with their plan and funding.

Offline dglow

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Re: IAC 2017 -- BFR v0.2 - DISCUSSION THREAD 3 (Post Speech)
« Reply #1291 on: 02/22/2018 03:00 AM »
And... he's kinda right.

To a degree, but, well, 3 tons to mars, all stages recovered (apart from the second stage) per launch, versus 75 tons per launch, to TMI.

No, you misunderstood: "he's kinda right"... that we could (and should) be at Mars already.


I guess the obvious question is how do Zubrin's goals compare to Musks.

Musks is a long term, sustainable and (ultimately) self sufficient settlement on Mars. That suggests investing in a certain amount of time and effort to get a  certain level of capability.

How does this compare with Zubrins game plan? If his goals are more modest then a faster path to Mars would seem possible.

Zubrin wrote the book on going to Mars and staying there. Literally. Find a copy of The Case for Mars and scan the index.

Zubrin was thinking long-term well before Musk. His team originated ISRU-based mission profiles, which is the very foundation of BFR. It's why Mars Direct and the DRMs which followed were a complete inversion of SEI's 90-day Study.


His core argument is that we've always been able to do Mars, even with the launchers we had (or could derive from what we had) readily available. Simple vehicles driven by more launches off smaller rockets... vs giant rockets flying very, very complex vehicles.

Watch this – it's Zubrin speaking at Ames in 2014:




That said, I agree that he's on the wrong side of FH vs. BFR.
But he wasn't wrong 25 years ago, and that's why the man is impatient.
« Last Edit: 02/22/2018 03:02 AM by dglow »

Offline speedevil

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Re: IAC 2017 -- BFR v0.2 - DISCUSSION THREAD 3 (Post Speech)
« Reply #1292 on: 02/22/2018 04:15 AM »
That said, I agree that he's on the wrong side of FH vs. BFR.
But he wasn't wrong 25 years ago, and that's why the man is impatient.

I understand impatience.

ISRU and his contributions to pushing the agenda are valuable. I should reread the book - I have a couple of copies somewhere.

Without 'something' - be it sea dragon, OTRAG, or even FH  drastically lowering launch costs, it wasn't happening on anything other than Apollo funding, and what would have been possible on Apollo funding was quite a lot better than Apollo in some ways.
FH has improved this some, but it seems unlikely government is going to cough up any time soon.

(anytime soon in this context = before at least the possibility of largish streams of revenue from Starlink, or BFR comes online).

Even if you could develop hardware for FH, it's almost going to have to be so optimised for weight that it's both a dead end when BFR comes online, and many of the technical aspects - entry systems - are less relevant.

The most depressing outcome (well, ish) would be if BFR hits in 5 years, and works, but there is no meaningful payload for it.

Offline Lars-J

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Re: IAC 2017 -- BFR v0.2 - DISCUSSION THREAD 3 (Post Speech)
« Reply #1293 on: 02/22/2018 06:35 AM »
That said, I agree that he's on the wrong side of FH vs. BFR.
But he wasn't wrong 25 years ago, and that's why the man is impatient.

Was he? Or maybe I'm just biased... Zubrin is one of those speakers that seems to have a natural talent of turning people against him just by sheer force of (terrible) personality. He has is loyal supporters, but you would think that at some point the organization would realize that he is just burning bridges. What you call impatience I call obnoxiousness.

Which is sad, because his ideas aren't that bad.

Offline john smith 19

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Re: IAC 2017 -- BFR v0.2 - DISCUSSION THREAD 3 (Post Speech)
« Reply #1294 on: 02/22/2018 09:23 AM »
His core argument is that we've always been able to do Mars, even with the launchers we had (or could derive from what we had) readily available. Simple vehicles driven by more launches off smaller rockets... vs giant rockets flying very, very complex vehicles.
I think you have that backwards. Watching his presentation suggests more "viable (big) rockets regularly launching a minimal architecture with the least possible number of special units."
Quote from: dglow link
Watch this – it's Zubrin speaking at Ames in 2014:

That said, I agree that he's on the wrong side of FH vs. BFR.
But he wasn't wrong 25 years ago, and that's why the man is impatient.
A very interesting presentation in several ways.

Firstly note that the raw data for it was drawn from a study done in the early 90's just after the study that kicked off Ares.  So a 100Kw (that's a 134Hp) nuclear reactor is available (that never happened) but solar cells and batteries are not very efficient by modern standards.

Secondly note the emphasis all along on safety.  :) If engines fail at Mars the crew come back alive (and now I know free return trajectories are possible only with impulsive engine systems, not low constant thrust systems) Multiple landing sites with multiple habs and vehicles with enough range to get between them. Artificial gravity en route (if anything the accumulating results on the effects of micro gravity on the human body suggests this is even more relevant with "spaceflight participants" rather than full astronauts being most of the people on board).

The key single point of failure seemed to be the 100Kw nuclear reactor. Today Kilopwer promises much more "granular" units at 10Kw each (so no single point of failure) with a real shot at being built and flying.

The discussion on radiation exposure, and how the total dose would be same over 10 years for ISS crew as for a fully crewed Mars exploration programme (and how basically the same radiation levels from 2 different Mars probes "proved" both that crewed Mars transport was safe and  not safe) , was very interesting.
It's an exploration strategy, not a settlement strategy.
I especially liked his "insiders guide" to reading an exploration study. All studies are written by writers with a preference. The challenge is to recognize it and read their assumptions and weightings accordingly.

This presentation was made 2 years before Musk fleshed out what he meant by the initials "MCT" but the numbers (AFAIK)are from the early 90's study.

Obviously the PV efficiencies and battery storage capacities have moved on a lot since those numbers were generated. Likewise water recycling had not been demonstrated on the ISS (I think there are 2 or 3 different systems currently under test for this on ISS and they seem to be bearing out Zubrins expectations on reducing water up mass) And of course it's now looking like there are substantial, relatively easy to harvest, Methane deposits on the surface as well. ICE powered surface rovers (which would a lot easier to build and repair on Mars with in situ resources) are looking like quite a viable option.

TBH with the description of the BFR/BFS, initial flights using at least 2 BFS's at a time (with a goal to grow the fleet over time) and the possibility of Kilopower reactors going with them, I'd think Zubrin was feeling that Musk and SX are seeing things more his way. Big rockets with a few big payloads used repeatedly.  I could see him still being concerned about prioritizing short journey times over a fail-safe free return trajectory, but that could change before first flight.

I think what causes problems is Zubrins willingness to admit that that in fact NASA cannot have everything.". NASA has a finite budget and if you want to actually send people out (rather than talking about sending someone out) you have to make hard (and sometimes very hard) choices.  :(
That is a very uncomfortable message for a lot of people to hear.

Yes the NASA Administrator only "administers" but if you've got a President who expresses a direction (any direction) to go in (Mars, Moon, Martian Moons, whatever) then you should a)Provide them with options to get there b)Consider the political environment, and that includes the budget.

There is the Apollo "ideal," (IE 5% or more of the whole Federal budget, not the 0.9% NASA gets now) version, then there is the what-we-can-do-if-we-get-a-viable(but not easy)-budget-increase programme
and then there is the what-we-can-do-if-we-get-no-budget-and-have-to-do-it-within-the-current-level programme.

It appears NASA rarely (ever?) considers the last option, but IRL it seems the most plausible.  :(

However that's starting to move into space policy territory, and it's quite depressing. 

As BFS moves toward flight hardware I can see Zubrin starting to warm to its capabilities.
« Last Edit: 02/22/2018 09:41 AM by john smith 19 »
BFS. The worlds first Methane fueled FFORSC engined CFRP structured A380 sized aerospaceplane tail sitter capable of flying in Earth and Mars atmospheres. BFR. The worlds biggest Methane fueled FFORSC engined CFRP structured booster for BFS. First flight to Mars by end of 2022. Forward looking statements. T&C apply. Believe no one. Run your own numbers. So, you are going to Mars to start a better life? Picture it in your mind. Now say what it is out loud.

Offline Ludus

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Re: IAC 2017 -- BFR v0.2 - DISCUSSION THREAD 3 (Post Speech)
« Reply #1295 on: 02/22/2018 05:09 PM »
And... he's kinda right.

To a degree, but, well, 3 tons to mars, all stages recovered (apart from the second stage) per launch, versus 75 tons per launch, to TMI.

(four launches of 150t of cargo to LEO, cross-ship into one BFS, fill prop with another 4 BFS, TMI, drop ballistic cargo, return).

If FH is costing you $10M/ton through TMI, and BFS even at $10M per launch, $130K/ton, it pretty much becomes equally expensive somewhere before ten tons to Mars.

A billion either buys you a hundred tons to TMI, or eight thousand.

Zubrin along with most of the Space old guard just don’t take BFR/BFS seriously, it’s too outside the paradigm. What SpaceX says it’s doing is mass producing general purpose Spaceships the size of Jumbo airliners that cost about the same to build and operate. They don’t buy that.

The BFR/BFS approach doesn’t scale down to what would have seemed reasonable, starting with a few people and small specialized very expensive ships. If it works, it works by entirely transforming the scale and assumptions of the industry. Otherwise it just crashes and burns.


Offline AC in NC

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Re: IAC 2017 -- BFR v0.2 - DISCUSSION THREAD 3 (Post Speech)
« Reply #1296 on: 02/22/2018 05:44 PM »
One would think after 25 years, one might have a eureka moment where they realize the economics are a BF®™ Deal

Offline M.E.T.

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Re: IAC 2017 -- BFR v0.2 - DISCUSSION THREAD 3 (Post Speech)
« Reply #1297 on: 02/22/2018 07:39 PM »
I think Zubrin just wants to live to see boots on Mars. So anything that can go there NOW rather than in 10 years will have his support. Because he has seen too many of the 10 year estimates always remain 10 years away.

Anyway, I think he is wrong and Musk is clearly right. This time 10 years might really be just 10 years away.

Offline niwax

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Re: IAC 2017 -- BFR v0.2 - DISCUSSION THREAD 3 (Post Speech)
« Reply #1298 on: 02/22/2018 08:19 PM »
He isn't necessarily wrong on a few key points. If your mission profile is to refuel on Mars using the stuff you brought and fly home as soon as possible, then filling up a BFR will take you something comparable to that 20MW nuclear reactor he tweeted about recently. For a one-off mission something like he proposes will be more efficient. It's like suggesting to build an automated moon colony before launching Apollo when all you want is to plant a flag before the Russians. From the perspective of someone reliant on government funding and without a billionaire willing to finance it themselves, that one mission is all you're gonna get. By the time BFR actually flies, development on it will have spanned three to four presidencies. Apollo happened largely during Kennedy-Johnson and cold war pressure but was still canceled early. BFR-style colonization can and will only happen when your funding is large and unconditional.

I think we may see both. Musk goes ahead with his colonization plans and there is a more traditional government-funded mission, quite possibly using SpaceX to at least push stuff to LEO.

Offline Kansan52

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Re: IAC 2017 -- BFR v0.2 - DISCUSSION THREAD 3 (Post Speech)
« Reply #1299 on: 02/22/2018 08:27 PM »
I think Zubrin just wants to live to see boots on Mars. So anything that can go there NOW rather than in 10 years will have his support. Because he has seen too many of the 10 year estimates always remain 10 years away.

Anyway, I think he is wrong and Musk is clearly right. This time 10 years might really be just 10 years away.

Good point. We have had the tools since the 60's to go to Mars. But not the political will to spend the money.

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