Bob Zubrin and I rhetorically duke it out over at Pajamas Media. This exchange actually occurred several weeks ago, but it was only published this weekend.
[Update a while later]
Unfortunately, since I went first, Bob got the last word, but that’s why I have a blog. I’ll note that I find it utterly bizarre that he sees no value in orbital propellant storage (today was the first time I’ve seen his final response). Does he really think that all missions to Mars will originate from the surface of the earth, forever more? I’ll note also that he vigorously kicks the stuffing out of a strawman with talk of the problems of the orbital mechanics. It sort of reminds me of the arguments that missile defense proopponents used to make in places like Scientific American, coming up with some ridiculous way of accomplishing the thing, pointing out how ridiculous it was, and implying that there are no sensible alternatives. He doesn’t even mention Lagrange points, which obviate most of the plane-change issues.
One other thing. I think that his ad hominem attack on Jeff Greason was both gratuitous and laughable. Does he really believe that a) no one else on the Augustine panel favored propellant depots and b) that the only reason Jeff supports them is because they provide a market for a vehicle that he might build some day? Really?
[Update a couple minutes later]
In rereading his final rebuttal, I notice that he didn’t respond to much of what I had to say, particularly with regard to ending Apollo and the difficulty of doing what he wants to do, and making long-term space plans in a representative republic — he just repeated the same things he always writes.
Interesting debate. You know which side I’m on, but I have to give Bob credit for the best line. Re John Holdren: “More recently, Dr. Holdren has been spearheading the Obama administration’s efforts to achieve this objective by rationing the right of businesses to make use of fire.”
As I’ve stated before, Holdren is a crackpot to whom crackpots would point as an example of a REAL crackpot…
The interesting thing is, Bob may have switched sides since then. (At least partially. No matter what position he takes, it will revolve around “Go To Mars ASAP” – the means change, the goal is constant.)
A week or two back, I saw mention of a new Zubrin plan for a minimal Mars expedition built around a handful of Falcon 9 Heavy boosters, and just this week, he endorsed the push to support the NASA Commercial Crew and Space Technology programs. A long-time Mars Society person admitted to me the other day that, as a change from quite recently supporting Constellation, “whiplash” was a reasonable description of the feeling.
I explained to him that Bob is actually very consistant. Whatever he sees as most likely to give him the heavy boost capacity to get to Mars, he’ll support. Good to see he apparently agrees with us that’s the commercial sector now.
Mark Whittington chimes in at Yahoo News:
http://news.yahoo.com/s/ac/20110522/pl_ac/8517023_a_great_vapid_sterile_space_debate
What little residual respect I had for Zubrin just bottomed out.
I’ll note also that he vigorously kicks the stuffing out of a strawman with talk of the problems of the orbital mechanics.
Wayne Hale is guilty of the same thing and neither can plead ignorance.
Whatever he sees as most likely to give him the heavy boost capacity to get to Mars, he’ll support.
The strange thing is that apart from insisting on heavy lift, he is totally pragmatic (and creative) about how to get there. He must know that propellant transfer is a viable option even in the short run. I suspect it is ultimately about money and his judgement what is most likely to get a) his Mars mission funded and perhaps b) get endeavours in which he is himself involved funded. It wouldn’t be the first time a thing like that happened. Apparent proponents of development of space have turned out to be shameless Shuttle-C shills.
he just repeated the same things he always writes
I have a fair number of church ministers in my family and one of them once told me that most ministers have only one sermon, good ones have two and great ones have three or words to that effect. 🙂
Does he really believe that a) no one else on the Augustine panel favored propellant depots and b) that the only reason Jeff supports them is because they provide a market for a vehicle that he might build some day?
Perhaps, in which case it is probably projection. If he doesn’t, it’s worse than that.
I think Zubrin is right about the feasibility of nuclear electric propulsion for manned flight, the power/wt requirements for it to make sense are out of this world.
His point on the cost/kg of payload dropping with increased size of the launch vehicle is right, but only so long as the launch vehicles are expendable.
If it works Skylon could deliver launch costs on the order of $100/kg.
APT would work, and would deliver launch costs on the order of $100/kg.
So I’ll give Rand the win at about 96 to 4.
As with most such debates, the debaters are so self-absorbed that they don’t realize how much they are talking around each other.
Rand, you are arguing “bottom up” to Zubrin”s “top down”. Your rational is one of cynicism of the “grand goal” , his is of disingenuous motives behind any brand of incrementalism. The only way you really differ is in the who, why, what, where and how of distrust.
Zubrin is a driven man who’s been used and discarded when convenient. He only believes in a (using mathematical terms) simply connected graph linking a beginning to a deterministic end. He proves the successive elements along a path and distrusts anything that becomes a distraction. I have found this to be a hallmark of successful NASA mission designers.
He’s right that the grand vision will work, because it did happen before. He is discounting what happened after it succeeded – because when you get down to it, Apollo’s success was more due to American inertia than determination we’d all like to think. Which was why it wasn’t sustainable.
Two different kinds of sword play here. Like in fencing, Zubrin”s using “the target”, an all out attempt at assault w/o regard for defense. You in contrast, hold to a defensive posture and prick at minor level assaults to draw blood. If you are using sabers, he’ll kill you in no time. If foils, you’ll sting him hundreds of times before he wins the match.
All the points here are determined by this, including why the flip to commercial, prop depots/other tech as distractions, ground vs space based departure. Perfectly consistent and understandable.
nooneofconsequence Says: “Apollo’s success was more due to American inertia than determination we’d all like to think. Which was why it wasn’t sustainable.”
Apollo was a race, races, if you’ve a stake, can be entertaining, but a race has to have a finish. It wasn’t sustainable because, as Rand says, space isn’t important, so after the race was over everyone went home.
Perfectly consistent and understandable.
It doesn’t explain his insistence on HLV. Zubrin’s philosophy is trying to achieve spectacular results soon, with proven technology, and without incremental steps, “Mars before this decade is out”, i.e. the Apollo model. But none of that requires an HLV, which is why I believe he has an ulterior motive. Note that I’m not saying it has to be a completely selfish motive (‘I want to be part of it’ or ‘I want to get paid’), it could be an honest belief that Mars exploration is important and that HLV is the only way politicians will fund it. It would still be a dishonest argument of course.
The big problem I see with Zubrin’s big rocket/big project approach is that it would be Apollo redux. We’d land on Mars a few times, cancel the program, and use any remaining boosters as giant lawn ornaments.
I don’t think any discussion of Apollo is complete without talking about the projects that were killed off as collateral damage, such as the MOL and Gemini-B, and more importantly Big Gemini which was going to ferry nine to twelve people to an orbiting space station for less cost than an Apollo on a Saturn IB. Convenient access to space was sacrificied for a moon program that didn’t have any affordable follow-on plan that Congress or the public was willing to fund.
Nah, what’s scary about Zubrin’s response is that after all this time he still doesn’t know Jeff Greason from a bar of soap.. or the history that Rand has with him. That’s pretty shocking and demonstrates why Zubrin has made so little progress over all these years. He comes across as a crazy hermit who never bothers to learn anyone’s name until they appear on his radar as a threat.
MPM – No, I don’t think Bob has an ulterior motive. (I was having these arguments with him fifteen years ago, FWIW.) He wants some sort of HLV because, once the HLV is available, that’s the quickest way he can mount a basic Mars expedition. As you say, he wants spectacular results soon, without incremental steps. I’ve never seen him show any interest in the mechanics of an HLV development, or in the political side effects. Give him an HLV and he’ll give you Mars, and he really isn’t interested in anything else.
George – RE Apollo redux, with the hardware turned into lawn ornaments once Mars is reached successfully, Bob’s response to that argument (back when I still tried to argue with him) was to assert that we Would Not Do That, because Mars was just way too important to stop going to, no matter if it required multiple multi-billion-dollar HLV’s per trip. It simply wasn’t possible that we’d give up Mars once we had it, end of argument, according to him.
He wants some sort of HLV because, once the HLV is available, that’s the quickest way he can mount a basic Mars expedition.
What kind of logic is that? Once RLVs are available (even just tiny ones), then that will be the quickest way to mount a basic Mars expedition. Trouble is, we have neither HLVs (of the size Zubrin is imagining) nor RLVs, not even just the tiny ones. Fortunately we do have EELVs and Falcon 9, and that is currently the quickest way to mount a basic Mars expedition. It will require propellant transfer and storage, and cryogenic upper stages and fortunately we have those too, in fact we’ve had them for more than thirty years.
And it gets better, the large and fiercely competitive propellant launch market that could result from a mission driven exploration program (whether to Mars or to a more realistic destination) could lead to private funding for all kinds of technology development. And then people like yourself would no longer have to lobby Congress for direct funding, you could simply pitch your plans to venture capitalists.
I think the real problem is that people don’t simply want to see some lofty goal (commercial development of space, seeding the solar system with life, exploration of Mars, colonisation) be realised, they want to be part of it and they want to get paid to be part of it. Some don’t want the party to start before they’re ready, and others don’t want the party to have to wait for others to get ready especially since they themselves might be dead and buried at that point.
That’s easy for me to say of course, since it is highly unlikely I’ll ever be involved in any kind of manned spaceflight (except perhaps suborbital flight and even that is doubtful). It is not as if I’m giving anything up if I’m supporting what will benefit commercial development of space most regardless of who end up being the heroes of the new space age. But just because it’s easy it doesnt mean it isn’t true.
You know Bob Zubrin and I don’t, but I can’t shake the impression there are ulterior motives involved. He wouldn’t be the first one to have them, and the ulterior motives are probably not limited to just the bad guys.
MPM, Zubrin doesn’t have any motives beyond the ones he preaches.. he doesn’t have the depth for them.
His point on the cost/kg of payload dropping with increased size of the launch vehicle is right, but only so long as the launch vehicles are expendable.
That’s only true if you have enough usage to amortize the development and fixed annual costs. Economies of scale come from flight rate, not vehicle size.
MfK, “rationing the right of businesses to make use of fire” is a great line but it should say “rationing the right of humans to make use of fire”.
It should be used more often in the battle to preserve western civilization against the warmist barbarians.
MPM – don’t ask me to defend the logic. My guess is, Bob figured out what he thinks is the best way to go to Mars a while back, this best way involves heavy lift, and he’s seen no reason to change his approach yet.
He does have a point of sorts, in that (at least in theory) we already know how to do heavy lift, whereas depots and orbital assembly still need some work. If you utterly ignore how dysfunctional the government booster-development organization is, then a government HLV would look like the quickest lowest-risk option for a cost-is-no-object sprint to Mars.
As I mentioned a while back, he has shown some signs recently of getting past his government-developed HLV focus, moving on to a commercial-developed HLV focus. Progress!
Yes, so long as your goal is “sprint to Mars” you’ll always disagree with people who have the goal of “sustained industrialization and eventual colonization”.
The Zubrin plan:
1) complain a lot
2) ??? A miracle occurs
3) Sprint to Mars.
4) ??? A miracle occurs
5) Return to Mars.
6) ??? A miracle occurs
7) Colonization.
It’s a pleasant variant of magical thinking.
We didn’t need the government to figure out how to build cars and gas stations. The cost per mile for people and things going across the West via covered wagon was high; via stagecoach, higher; via Pony Express, even higher.
By comparison, doing it by car today is a bargain.
For people who have insisted that the entry-level cost is too high for anyone but a government to do a space program, one word and one name:
SpaceX.
Elon Musk.
And, he has company.
The one and only one way to get the cost to orbit down is for the government to stop trying to pick winners and losers, and to let the market do the job. They can be an early-market guarantor like they were post-WWI with airmail, but that’s about the extent of their ability to have a lasting impact.
And, that, my friends, is the real lesson of both Apollo and the Shuttle program. We needed to win that part of the Cold War, no doubt, but that only explains Apollo. The startup of the Shuttle program was the beginning of the end.
SpaceX, Sierra Nevada and Blue Origin (among others) are the end of the beginning.
Imagine where we would be today if back then the US government had put out (a la Air Mail post-WWI) a guaranteed multi-year cargo and passenger manifest to low earth orbit, backed up by a trust fund with sufficient openness in its administration to keep it from being hollowed out like Social Security. Within two years, we would have had a competitive market for LEO transport.
By contrast, Marxists and Fabian socialists (by schooling) that are still counting on living off the government dole (both within the government and working for companies willingly dependent on government largesse) will continue to argue on behalf of their various dinosaurs. They are about as relevant long-term to exploration and migration into space as the Bristol Brabazon has been for commercial aviation – a textbook example of central planning gone amuck. Another example of a good idea done wrong via intimate government involvement were the SST programs of the Sixties. If anyone doubted how major a role the the Federal government played in the American SST program, just remember that it only took one act by the government to bring the entire enterprise to a grinding halt.
In all of this, I’m not arguing completely against a government role here. There is a place for a prestige program like there was a place for the Great White Fleet. Just be careful to understand what it costs and why you’re doing it though, or you could end up with Lyndon Johnson’s foreign policy. Remember all of where that led us? But, to have a Space Guard (a la Coast Guard) would be an excellent idea, and reverting any manned deep space exploration to a uniformed space force still makes sense to me, too. At least, bureaucrats wearing uniforms will take orders and stay on the mission more often than civilians (although not all of the time). Plus, if the bad guys ever do decide to arm themselves up there, we won’t have to deputize anyone or do any more in a panic than we have to.
Zubrin is smart. However, wisdom is something else. Knowing that a government-run be-all-and-end-all program will be subject to waxing and waning or political support from administration to administration doomed most of his previous proposals. This one has a chance, but it sounds very risky. Von Braun’s Mars proposals included a fleet of concurrently-launched vehicles with any one capable of supporting the return of all astronauts, to provide greater assurance of safety. I still think that is an essential element of something like Zubrin’s proposal, which worst-case multiplies its costs linearly depending on how many vehicles per sortie. Orbital assembly would cut the cost of launch of the vehicle components to low earth orbit, but then you have to deal with costs associated with orbital assembly. The initial work being done on orbital propellant depots seems to indicate that it would be workable, though.
What would I do? What Jerry Pournelle has suggested for decades now: prizes. It has worked before, and it can work again. If you want a minimal role for the government and still get there, a really big prize sounds like a workable alternative. For probably the same number of dollars that has led NASA to provide generations of paper rockets, we could have gone back to the moon and beyond; administering a contest in full view of the public would seem to be the lowest-cost and lowest-risk approach.
Will I get the sh*t kicked out of me If I say both sides have good points and bad points?:)
I concede that Zubrin has the unfortunate tendency to ascribe bad motives to people who disagree with his preferred solutions. But to the larger point Zubrin makes about setting mission goals and timelines and the bureaucratic imperatives which waste time and money I think he is right. I also think Zubrin picks a goal and timeline which forces his preferred mission architecture.
The fact is with a growing economy, even with NASA spending at a flat 0.5% of GNP the NASA budget begins to approach in absolute terms the funding NASA had during the Moon Race. Great accomplishments should be possible with such a level of spending by NASA.
The Obama plan for NASA is what I call a Rorschach Plan, for many people tend to see in it what they wish to see rather than what is actually there. In actuality the Obama plan for NASA is a typical Obama non-decision decision because it overpromises and underdelivers. Do you Support ISS? That’s okay because under Obama the ISS flies beyond 2020! Heck maybe as long as the Shuttle program lasted! Do you support HLV? That’s okay because (under the original Obama plan) we start HLV with even better technology beginning at 2015! The Obama Plan is a refusal to make hard choices, by trying to do everything and without any timetable to do it.
The only exception to that Obama mess is the promise to support commercial manned launch services to LEO. That’s fantastic. But that’s also a no-brainer as everyone supports that. The truly controversial part of the Obama plan is reliance on ONLY commercial spaceflight for access to LEO. I give credit to Obama for making that hard choice, though I don’t believe they realized at the time how controversial it would be (which explains why Obama so quickly and effortlessly backed off and gave in to MPCV).
As to the proper size of expendable launch vehicles for minimum payload cost, of course Rand is correct that flight rate is more important than vehicle size. And of course Zubrin is correct that payload costs go down with vehicle size. The point is both factors reach a point of intersection which is at roughly the size of the Falcon Heavy launch vehicle.
When a launch vehicle is so large even a single stage must take water transport to the launch pad or get broken down for land transport it is too big for economic efficiency. Economies of scale break down when it’s size makes it that clumsy. Maybe some nation will break the expendable launch vehicle economic realities with a successful Sea Dragon type heavy launch vehicle or a reusable launch vehicle with airplane type reusability, but until then Falcon Heavy is probably as good as we can reasonably hope for in the near future.
Even Zubrin is on the SpaceX bandwagon now. So maybe now we can all get along with each other?
If they require SpaceX to do the ‘go near, but don’t dock’ mission, I hope they “just” take a giant empty kerosene tank along for the ride. Cryogenic transfers might be hell-on-wheels, but kerosene? And you have to do the launch anyway?
“Propellant Depot? Oh, well, we’ve got one of those, too.”
Henry Vanderbilt said: “He does have a point of sorts, in that (at least in theory) we already know how to do heavy lift, whereas depots and orbital assembly still need some work.”
You’re only partially correct there, Henry. Propellant depots do need work, but after more than a decade of ISS construction I’d say orbital assembly is TRL-9.
Henry Vanderbilt said: “He does have a point of sorts, in that (at least in theory) we already know how to do heavy lift, whereas depots and orbital assembly still need some work.”
Depots, maybe. But Gemini 11-Agena target vehicle was done decades ago. Propellant transfers are routinely done on ISS.. Even autonomous docking has been done by the likes of ASTRO-Nextsat and KIKU-7 (ETS-VII) ..
So if you have autonomous docking of tanker or propulsive stages, non-cryogenic propellant transfers and storage, plus a global launch market with overcapacity, what exactly ARE you missing from mounting a manned mars expedition ?
Zubrin’s assumption is that Mars holds some magical value to whoever happens to land their first. He gives a lot of reasons that don’t really add up for this, but it’s really just It Can’t Be the Moon Since We Already Tried That – So What’s Next. I love the guy’s mission architectures (mainly because they were so amenable to scaling of launch vehicles, budgets, and timelines), then he fell off a cliff when he ventured into Why Everything Else Is Not Worth It. Typical government worker-bee stuff: if it’s possible that reality might disprove your assumptions, just make the project bigger and will never become an issue!
On the plus side, it’s nice to be on the right side of history, and it is pretty clear who wins that argument. On the minus side, history tends to go slower than you expect when you’re actually living it, so none of us are likely to see a sustained presence on Mars. But I fully expect Zubrin to be telling everyone that NewSpace was his idea in 10 years.
Zubrin Believes In Something, it’s just human rationalizing, when someones obsessed like that in their own minds they demonise people who have a different opinion, I see it all the time.
Brad>> The fact is with a growing economy, even with NASA spending at a flat 0.5% of GNP the NASA budget begins to approach in absolute terms the funding NASA had during the Moon Race. Great accomplishments should be possible with such a level of spending by NASA.
One of the problems with Zubrin’s argument is that he applies the same inflation rate to both NASA programs and to the US economy as a whole. That’s not reasonable, considering, just for example, the amount of manufacturing of consumer goods that has moved to low-wage countries, something that does not apply to space hardware. If you discount at the inflation rate implied by the NASA New Starts Index, NASA’s budget today is less than half of it’s Apollo-era peak and has been pretty much constant since the early 70s (and I’ll bet that reflects approximately constant NASA and NASA-related employment).
I’m sure you can do better (i.e., get a lower inflation rate) if you don’t do things the NASA way, but the inflation rate is probably still going to be higher than that in US economy as a whole.
hehe.. Zubrin’s argument about budgets being the same now as back then is simply wrong, even when you use his own numbers. It only works if you define “the same” as within 20% different..
Oh, and you also have to look at the total NASA budget not the human spaceflight budget.. but that’s actually Zubrin’s argument.. all that other stuff is worthless and you should just use it to build a HLV 😉
G’day,
In my view both make a big mistake, that there is money to do either. Trillion dollar deficits can not continue. When the axe falls NASA is going to get the chop like everyone else. After Apollo NASA’s budget went down to the $12B level. If its lucky it will get that.
ta
Ralph
Ed – I won’t debate TRL definitions, but Station on-orbit assembly ops (particularly EVA, I suspect) could surely stand to be cost-reduced an order of magnitude or two before you try to use them to put together a sanely affordable Mars expedition. Station cost $100 billion overall; going to Mars that expensively on current NASA Exploration funding is at best a 25-30 year process (and at worst, endless.)
Reader – Assuming you can design a Mars expedition for primarily docked assembly, you point out the missing element yourself: On-orbit bulk cryo propellant storage and transfer. I’m sure someone will correct me if I’m wrong, but my impression is that for going to Mars (or anywhere much beyond LEO) on chemical propulsion, that extra hundred seconds of Isp more than compensates for liquid hydrogen’s negatives.
I think Zubrin’s love of HLV is basically a blind spot where he thinks, “Once we have an HLV, that will be the easiest way to get to Mars.”, but he doesn’t include the development cost of the HLV in his budget and schedule when he compares his plan against ELV/propellant depot based plans.
Funny that Zubrin got so worked up in opposition to propellant depots. His Transorbital Railroad proposal states:
Cryogenic transfers might be hell-on-wheels, but kerosene?
@Al:
Cryogenic transfers might be hell-on-wheels, but kerosene?
The oxidiser would be a bigger problem as LOX is still cryogenic. It also tends to make up a greater fraction of the total mass than the fuel. Hydrogen peroxide or NTO would be alternatives. As for fuels, kerosene is a good one, but so are various alcohols and hydrazine. My own preference is MMH/NTO because it is operational today and has a very good track record. It’s very toxic and corrosive of course, and its performance is only reasonable, not great like LOX/LH2, but the point is to open up space soon, not to please Greenpeace or win a lowest IMLEO award. As for higher Isp, we could also enlist the help of SEP, which is availale today for transporting storable propellant, but not for cryogenic propellant.
@Henry V.
He does have a point of sorts, in that (at least in theory) we already know how to do heavy lift, whereas depots and orbital assembly still need some work.
Depots certainly do need more work, but we have more than enough to get started right away, and more than enough to achieve two of the main prizes: doing manned exploration and opening up space through creating a large and fiercely competitive propellant launch market as soon as possible and relying on the market to develop cheap lift as a side effect. That will probably be done with tiny RLVs, but if Musk can make it happen with an HLV, then that would be great too.
This is one of my sermons of course. 😉
but my impression is that for going to Mars (or anywhere much beyond LEO) on chemical propulsion, that extra hundred seconds of Isp more than compensates for liquid hydrogen’s negatives.
In the long run certainly, but I’m more interested in opening up space soon. And a hybrid of chemical (both storable and cryogenic) and solar electric propulsion (much, much higher Isp than even LOX/LH2 and TRL-9 to boot) could be more efficient than LOX/LH2 alone, though not more efficient than a hybrid of LOX/LH2 and SEP.
LEO -> EML1/2 with LOX/LH2 (for both crew and cargo)
EML1/2 -> SML1 and LMO with SEP (for storable propellant)
All other maneuvers could use MMH/NTO: TMI, high Mars orbit insertion of the MTV, transfer of a smaller lander to LMO, Mars EDL, TEI of the MTV, high Earth orbit insertion of the MTV and deorbit of the capsule)
This could create a large market for commercial propellant launches soon and it might even turn out cheaper on a NPV basis. More importantly, it could open up space a lot sooner (what I care about most) as well as enabling Mars exploration sooner (what Zubrin cares about).
MPM, Zubrin doesn’t have any motives beyond the ones he preaches.. he doesn’t have the depth for them.
Oh, I wouldn’t underestimate Zubrin. I think he is a man of great depth and creativity. The man is full of original and unorthodox ideas, and also totally focussed on achieving a greater goal. I don’t care too much about that goal myself, but he is going about it very consistently except for the fact that he rules out propellant transfer. I can understand why he doesn’t want to wait for cryogenic depots (neither do I, though for slightly different reasons), but not why he would avoid hypergolics. Sure, I can see why you don’t want to use them if you don’t need to, but since we don’t have an HLV and since we do have hypergolic propellant transfer and since that is enough to achieve his burning desire of doing a basic Mars expedition as soon as possible, I don’t see why he would be against their use. I can’t believe he never thought of the possibility himself and he most definitely must be aware of von Braun’s original plans for Mars exploration that would have used hypergolics exclusively (no LOX/LH2 and/or SEP at all).
MPM, that misses my point.
A tank of kerosene in orbit has value. It isn’t -complete-, but it has value. A follow up rocket deliberately carrying an excess of LOX wouldn’t have to transfer the LOX to get a substantial increase in fuel capacity – it just needs to be able to accept kerosene.
Also, if we’re that concerned about cryogenic propellant transfer, make each tankerload a ‘limpet’ style tank and have the EDS use the SpaceX method of propellant crossfeed under thrust.
:: you point out the missing element yourself: On-orbit bulk cryo propellant storage and transfer.
Im not sure i pointed that out. Who says you cant get to Mars with enough hydrazine ?
Or LOX/Methane if you are willing to invest in modest engine devlopment.
AndrewW: Apollo was a race, races, if you’ve a stake, can be entertaining, but a race has to have a finish. It wasn’t sustainable because, as Rand says, space isn’t important, so after the race was over everyone went home.
Untrue – sometimes the US keeps winning a race, long after it was won. Economically almost always we do this. Militarily we always do this. That is because we don’t want to get caught on the short end of the stick.
Could one have won said space race perpetually – Yes. Was that ever possible with Apollo as designed – NO. Example in point – Saturn V’s were constructed as one-off hand build “pieces of art”. In contrast, near the same time there was a factory in the Ukraine churning out ICBMs one a week … so it was theoretically possible otherwise.
MPM: It doesn’t explain his insistence on HLV. Zubrin’s philosophy is trying to achieve spectacular results soon, with proven technology, and without incremental steps, “Mars before this decade is out”, i.e. the Apollo model. But none of that requires an HLV, which is why I believe he has an ulterior motive. Note that I’m not saying it has to be a completely selfish motive (‘I want to be part of it’ or ‘I want to get paid’), it could be an honest belief that Mars exploration is important and that HLV is the only way politicians will fund it. It would still be a dishonest argument of course.
Of course it does – you just don’t wish to see it. He doesn’t trust intermediate developments that can sideline his project. Ares 1 sidelined it. And he didn’t care about SpaceX until they announced a “HLV enough” derivative he could use.
Now … lets say for laughs, that Jeff Bezo’s (or some other billionaire) decides to fund and make operational prop depots, such that Zubrin could rationally believe he could use them and not be sidelined. In less than 5 minutes, Zubrin would announce a way to do Mars using them that wouldn’t need HLV.
Again – listen – Zubrin doesn’t want to be sidelined. That’s the issue with HLV. And he has been proven correct on this too many times by too many political CF’s. What is so hard to understand about this?
Again – listen – Zubrin doesn’t want to be sidelined. That’s the issue with HLV. And he has been proven correct on this too many times by too many political CF’s. What is so hard to understand about this?
Oh I understand his fear about being sidelined and why that is an argument against incrementalism. I think there’s a real risk that if you give politicians the opportunity of making an intermediate stop at an asteroid they’ll happily accept year after year of further asteroid missions without ever going to Mars. I wouldn’t be too disappointed about that myself, but I can see why Zubrin would be. I still don’t see why this argues in favour of an HLV. In fact, so far it has been the HLV that has sidelined Mars missions.
There is a difference between arguing against incrementalism and arguing against depending on technology development.
Are you seeing something I’m not seeing or am I seeing something you’re not seeing?
I’m a newspace advocate, but I love Zubrin for what he is. Creative, passionate, unyielding.
People like Musk who are shaking up the space industry weren’t inspired by the chances of profit. They were inspired by guys like Zubrin. In Musk’s case, literally Zubrin.
Also, its interesting that Zubrin’s Transorbital scheme is talking up the benefits of propellant depots now. Zubrin is two things: he’s one of those guys who can be convinced by argument, but there is a lag of anywhere from a couple of weeks to a couple of years; and he is a guy who knows which way the wind is blowing.
I still don’t see why this argues in favour of an HLV. In fact, so far it has been the HLV that has sidelined Mars missions.
Precisely my push back to Zubrin in his face as well. I agree.
There is a difference between arguing against incrementalism and arguing against depending on technology development.
When I brought this up, I was accused of “hair splitting”.
Heres precisely the issue – lets use Ares I to demonstrate it. To begin with, accept fully the premise of 4seg+SSME working but one has to live with a non-restartable second stage that you “fall back” to using the SM’s AJ-10 to circularize/insert in orbit.
Now you allow “technology development” … whoops, we go from developing SSME to J-2X, and then because of weight gain performance loss, need 5seg … or even more. All that was needed was to rework the thermal issues (repack and recertify) SSME. So the enemy of good enough became the “more better” … which actually was “less better”.
So hidden in your “technology development” path was a way for things to become irresponsible … while looking like it was responsible.
Fix that and we’re good to go.
Happened more than a dozen times before. Zubrin’s lived through them. And so have many of us.
Now, he’s already got some of that in his plan(s) anyways – like keeping alive a Dragon for extended periods of time, the loiter time on Mars orbit of a return stage? Yes we need substantial development for even his thumbnail sketch.
Are you seeing something I’m not seeing or am I seeing something you’re not seeing?
I dunno. I see what I see. In this case a very determined Bob Zubrin.
Fix that and we’re good to go.
I’m not sure I understand what you mean. What I’m talking about is a plan that doesn’t depend on new technology development for reaching Mars, or at least not unnecessarily so. I agree this rules out depending on cryogenic depots, but I disagree it requires an HLV. There isn’t a binary choice between cryogenic depots or HLVs, neither for exploration nor for commercial development of space. I’ve been critical of both proponents of HLV and proponents of cryogenic depots on this.
Maybe next time you meet him you can ask him what the heck he has against using refuelable storable propellant spacecraft (not full depots) instead of HLVs and instead of cryogenic depots. Does he want to go to Mars or what?
‘Yo dawg, I heard you like Mars, so I put some hypergolics in your tank so you can dream about HLVs while you’re on your way to Mars.’ 😉
I dunno. I see what I see. In this case a very determined Bob Zubrin.
Lol. I wouldn’t mind being stuck in an elevator with Bob Zubrin for a couple of hours. We’ll see which one of us two is more determined. 🙂
Zubrin with HLVs and Depots.
To understand his HLV point of view, you need to realise that his Mars Direct development was supported by the Martin Marietta company. They were trying to sell the (Original?) Ares booster. He had considerable technical support, although he eventually ‘extended’ some of the numbers to make the mission design close. The HLV was critical to his plan, and he didnt’ have the resources to change his plan much.
And doesn’t the Mars Direct plan use a propellant (and LH2) depot on the surface of Mars ?
-E
It’s simple really. The gummint HLV ain’t gonna happen. The Falcon Heavy definitely is going to happen. Zubrin has wisely decided to abandon a path strewn with risks that approach unity and opted for a revamp based on what is probably the closest thing to a certainty in the space biz these days – Elon’s big candle is going to fly and it’s going to fly right. 53 metric tons just became the new standard size Lego block for designing consequential space missions. QED
Sigh.. I talked to Zubrin for 2 hours at ISDC 2010 and the only conclusion we came to is that he hasn’t read anything about propellant depots ever. He openly said to me that he doesn’t care for them and hasn’t read even the ULA papers. Of course we only got to that point after establishing that propellant depots and VASIMR are separable concepts.. and if that doesn’t make any sense to you, try telling him that.
I talked to Zubrin for 2 hours at ISDC 2010
You didn’t need the help of an elevator I presume? 😉