Heavy, Man….Heavy

Destinations beyond LEO beckon -- a view of moonrise from the ISS

Destinations beyond LEO beckon — a view of moonrise from the ISS

A basic principle of spaceflight is that simpler is preferred to the more complex.  The use of a heavy lift launch vehicle (HLV) is “simpler,” in that fewer launches of big rockets creates less risk than an architecture requiring multiple launches of smaller ones.  Woven into our current debate about future strategic directions in space are arguments over whether to develop and use an HLV for human missions beyond low Earth orbit, and if so, what type.  In brief, the problem flows from the fact that even when using the largest rockets, we arrive in orbit with empty fuel tanks.  To go beyond LEO we must carry a fully fueled Earth departure stage, which is very heavy.  Thus, the requirement for “heavy lift.”

An alternative to a heavy lift vehicle is the fuel depot, in which caches of rocket fuel are collected and stored over time.  When we are ready to leave on a trans-LEO mission we re-fuel our rocket at the depot in space and go.  A variant of the depot concept employs separate launch, rendezvous and the assembly in orbit of multiple pre-fueled pieces, all launched within a short period of time.  Each approach presents its own technical and fiscal challenges.

The possible use of the promised future Falcon Heavy (FH) launch vehicle to conduct human missions to the Moon was the topic of a recent AmericaSpace article.  I found this piece particularly interesting as the debate about the use of FH vs. the NASA Space Launch System (SLS) has some historical resonances with a previous round of lunar exploration, namely when America raced the Soviet Union to the Moon.

Although the fuel depot/HLV debate is one side of the architectural argument, I will set that aside for now and focus here on the type of heavy lift vehicle needed.  Based largely on the limited payload capacity of Falcon Heavy (53 tons to LEO) compared to the NASA developed SLS system (initially, 70 tons, expandable up to 130 tons), the article at AmericaSpace questions the capability of the Falcon Heavy to conduct lunar exploration.

The Falcon Heavy consists of three Falcon 9 rockets strapped abreast. The 3 rockets contain nine engines each, resulting in 27 engines firing simultaneously at launch.  Although claimed to be tolerant of engine out conditions, obviously if too many failures occur, loss of vehicle would ensue.  The FH uses liquid oxygen (LOX) and kerosene, a tried and proven fuel system, containing somewhat lower total energy than the liquid oxygen LOX)-liquid hydrogen (LH2) of the SLS.  The specific technical details of Falcon Heavy suggest a parallel with a previous trans-LEO launch vehicle: the Soviet N-1 rocket, the super HLV that the USSR designed and built in their failed bid to beat America to the Moon.

The N-1 rocket contained four stages (30 engines in the first stage), all burning LOX-kerosene (as the Soviets had yet to master the difficulties of developing and flying high-energy cryogenic hydrogen engines and LOX-kerosene is more forgiving).  At liftoff, it produced over 11 million pounds of thrust.  Keeping such a behemoth stable during launch was a major challenge but unavoidable; the N-1 used carefully balanced throttling and gimbals on each engine to control and steer the vehicle.  In contrast, America’s Saturn V produced 7.5 mission pounds of thrust and used LOX-kerosene only in its first stage; both the S-II and S-IVB upper stages used LOX-LH2 fuel.  Even with the greater thrust produced by the Soviet N-1, it would have placed only 90 tons into LEO and sent 24 tons to the Moon; the Saturn V put 120 tons in space and delivered 45 tons to translunar injection.  Energy is the ability to do work and equals thrust times the length of the burn.  Because of its propellant, the N-1 had lower total energy even though its thrust was greater than the Saturn V, resulting in lower delivered payload mass.

The differences between the N-1 and the Saturn V are similar to those between the Falcon Heavy and the SLS core.  FH uses 27 LOX-kerosene engines to put 53 tons into LEO; the relatively low specific impulse resulting from the use of these propellants results in a performance of about 12 tons into translunar injection.  Thus, a lunar mission mounted with the FH would require multiple launches (at least 3 and possibly as many as 6 to conduct a complete lunar mission).  The SLS uses cryogenic hydrogen propellant and puts 70 tons in LEO and can send about 25 tons to the Moon.  A complete lunar landing mission could be done with two SLS core vehicle launches.  Incidentally, in the argument about which vehicle will be ready for flight first, I note that we could have had a 70 ton HLV flying now if a sane decision to build Shuttle side-mount had been taken before Shuttle retirement.  But I digress.

While both the N-1 and FH are comparable in their number of rocket engines, their layout and functioning are different.  The N-1 was a single vehicle with propellant tankage, lines and structure all common – feeding the 30 NK-15 engines simultaneously.  The ring-like arrangement of the N-1 engines was intended to take advantage of symmetry to handle failures through balanced shutdown of engine pairs.  But with thirty engines all firing simultaneously, instabilities (if they developed) would likely to lead to catastrophe.  Falcon Heavy is designed to operate in unison in a more linear fashion as three vehicles strapped together, although supposedly cross feeds are envisioned to even out flow rates and variations in thrust.  It remains to be seen how FH will handle instabilities.

In terms of historical performance, the Saturn V flew 13 times, with one partial failure on the second (unmanned) mission caused by severe “pogo” (longitudinal oscillations) during second stage firing.  The N-1 flew four times, never successfully.  A catastrophic explosion of the vehicle during the second N-1 launch killed several high-ranking Soviet officials and their lunar program never recovered.  The N-1 design was barely sufficient for its stated purpose and this marginal performance led to the complete collapse of the Soviet lunar program.  In contrast, enough mass margin was built into the Saturn V that an augmented, heavier version of the Lunar Module (including a surface rover) was flown on the later missions, thus extending the range and stay time of crew on the Moon, along with a commensurate increase in mission return.

There is a limit to how much even the largest HLV can carry into space.  Eventually, we will reach a stage where a single, double or even multiple launch cannot accommodate all of the mass required for a mission.  A case in point is the current Design Reference Mission for Mars, which requires not only seven (7) 120 ton HLVs (plus a separate crew launch) but also a nuclear thermal rocket (NTR) for the Earth departure, a piece of technology with which we experimented 50 years ago and will require tens of billions of dollars to develop an operational model.  If we cannot develop this NTR, an all-chemical propulsion Mars mission could require as many as a dozen HLV launches.  All things considered, the resources and complexities of this mission concept approach the outer edges of what is possible.  I leave judgment as to the likelihood of such a mission ever flying to the delicate sensibilities of the reader.

The use of either the FH or SLS launch vehicle for trans-cislunar missions requires multiple launches; SLS will require fewer launches than the FH.  The choice of which to use is not exclusively related to cost but also to architectural complexity.  In general terms, the fewer launches required for a given mission, the better.  But other considerations may drive the mission design to more launches.

In short, although an HLV makes trans-LEO missions possible, future human missions to a variety of Solar System destinations will require us to eventually learn how to assemble and fuel large complex craft in space.  The basic requirement for any human Mars mission is about a million pounds in LEO, a value well beyond the capability of any HLV, existing or envisioned.  Moreover, I would argue the height of fiscal and technical irresponsibility is undertaking a planetary mission whose principal architectural strategy requires launching (energy) everything (material) we need out of the deepest gravity well (Earth) in the inner Solar System.

The current controversy over HLV or fuel depots is transitory.  Eventually, we will assemble and fuel trans-LEO missions in space because that is the inevitable direction in which we must evolve to become “space faring.”  Using an HLV in the early stages of cislunar development can jump start a permanent spaceflight capability, including developing the essential skill of using off-planet resources of materials and energy.  There will come a time when this debate will seem to our descendants as arcane as medieval arguments about the number of angels that can dance on the head of a pin.

Previous posts on heavy lift:

To do the heavy lifting

HEFT, Lies and Videotape

This entry was posted in space policy, space technology, Space transportation. Bookmark the permalink.

67 Responses to Heavy, Man….Heavy

  1. Billgamesh says:

    “-we could have had a 70 ton HLV flying now if a sane decision to build Shuttle side-mount had been taken before Shuttle retirement.”

    The three biggest disappointments I have had have been when first no one realized what a game changer the ice on the Moon was in 2010, then when Sidemount did not happen (that broke my heart), and now the lack of action on planetary defense after the Chelyabinsk meteor. It is not only impacts that should be driving us into space- it is the possibility of an engineered pathogen bioterror event. This is serious stuff.

    IMO the “debate” on which vehicle will do the job is nothing but PR and political favors repaid. The kerosene burner is……profoundly mediocre.

    “-the height of fiscal and technical irresponsibility is undertaking a planetary mission whose principal architectural strategy requires launching (energy) everything (material) we need out of the deepest gravity well (Earth) in the inner Solar System.”

    It is true: we may be too stupid to survive.

  2. billgamesh says:

    From the article (Shannon is my idea of the real Obi Wan Kenobi);
    “Space Launch System opponents suggest that the SLS program should cancel until a mission requiring such a rocket is identified. John Shannon, also with Boeing, recently stated, “This ‘SLS doesn’t have a mission’ is a smokescreen that’s been put out there by people who would like to see that [program’s] budget go to their own pet projects.”

    Dr. Spudis hits the nail sqare on the head;
    “-we could have had a 70 ton HLV flying now if a sane decision to build Shuttle side-mount had been taken before Shuttle retirement.”

    The three biggest disappointments I have had have been when no one realized what a game changer the ice on the Moon was, when Sidemount did not happen (that broke my heart), and now the lack of action on planetary defense after the Chelyabinsk meteor. It is not only impacts that should be driving us into space- it is the possibility of an engineered pathogen wiping out the human race on Earth. This is serious stuff.

    “-the height of fiscal and technical irresponsibility is undertaking a planetary mission whose principal architectural strategy requires launching (energy) everything (material) we need out of the deepest gravity well (Earth) in the inner Solar System.”

    “Eventually, we will reach a stage where a single, double or even multiple launch cannot accommodate all of the mass required for a mission.”

    Which is why we need a Moonbase. Launching a HLV with hydrogen upper stages from an underground lunar silo will lift what is needed- especially for nuclear missions.

    There is no cheap- Falcon “heavy” is a profoundly mediocre lash-up and IMO destined for the same fate as the N-1.

  3. Brock says:

    Debating the technical merits of SLS is sort of like counting angels on the head of a pin, isn’t it? The thing doesn’t exist, and it never will. It’s a paper-rocket justification for pork-barrel spending, and nothing more.

    • Paul Spudis says:

      The Falcon Heavy is a paper rocket as well, so it’s apples to apples.

      • Glenn says:

        It’s arguable if enough of the existing Falcon 9 hardware & designs will be used in Falcon Heavy for it to count as ‘not a paper rocket.’ (For example, are the engines flying in current Falcon 9 launches the ones that will fly the Heavy? Admitted that the entire cross-feed system is new, and it’s a big chunk of the design.)

        How much of SLS is already qualified hardware and how much is new work?

        • Paul Spudis says:

          How much of SLS is already qualified hardware and how much is new work?

          SLS uses the four-segment SRB that Shuttle used, the Shuttle ET (modified for in-line load bearing), and the RS-25 (Shuttle Main Engine) for its core stage. It has at least as much (if not more) flight heritage as Falcon and over a longer (30 year) period of time. So there are paper rockets and “paper rockets.”

          • Glenn says:

            OK, so it sounds like both systems are new airframes/systems using lots of flight-qualified parts. (Setting aside the ‘maturity’ of the parts and the percentage. And yes, details matter.)

          • Paul Spudis says:

            (Setting aside the ‘maturity’ of the parts and the percentage. And yes, details matter.)

            The details matter so much that they can be “set aside”?

    • billgamesh says:

      Paper rocket?

      The 5 segment SRB; 3.6 million pounds of thrust each.

      The 450 second ISP of the SSME; Makes a merlin look like what it is- mediocre.

      The J2X; also makes a merlin look mediocre.

      The Orion escape tower makes the dragon look like what it is; mediocre.

      http://www.youtube.com/watch?v=wbIjG82UpOs

      http://www.youtube.com/watch?v=hDCCBgppG4s

      http://www.youtube.com/watch?v=MjQ0j1a9RcA

    • The SLS is a paper rocket only if you think Boeing Aerospace can’t build rockets anymore:-)

  4. Warren Platts says:

    As the AS article and others points out, the FH will require a Centaur-like upper stage to be a truly capable BLEO launcher. But the article then goes on to say that “to build, visit, and maintain a lunar orbiting outpost will dictate doing so in very small chunks”. This is not true: the FH could launch up to 50 mT dry mass ground integrated “chunks”–twice the size of the “chunks” generally used to build ISS, if I’m not mistaken.

    In any case, SLS is going to require multiple launches as well as FH if we want to do anything besides Lunar flybys. Thus it’s not a question of single launches versus multiple launches; it’s merely a question of how many multiple launches there are going to be.

    Then there is the rate of manufacture–this is the real problem IMO: I’ve seen two projections: 1 every other year and 1 every year. Thus, even going with the optimistic rate, that’s a total launch weight of 130 mT/year max; for comparison, EELV’s launched about 200 mT last year alone, even in the absence of a BEO HSF program. If SLS could match the old Shuttle rate of 6 per year that would be one thing–and I would be all for it–but that’s clearly not going to happen.

    At this point, “Joe” will pipe in to say that “the schedule is dictated by the current (politically appointed) NASA leadership and are intended to make the SLS/MPCV look as bad as possible.” Now, I can’t read the minds of Bolden and Garver, so Joe may very well be correct about their intentions; but if they really want to kill US HSF, it would make more sense for them to dictate impossibly optimistic launch rates. However, I grant it’s possible they’re just crazy. Either way, it does not at follow that a schedule that makes SLS/MPCV look as good as possible will turn out to be realistic. If history is any guide, the more pessimistic projections will turn out to be the case–if we’re lucky…

    To expect a robust HSF program at the projected launch rate of 130 mT per year is simply untenable. Hence the pathetic grabbing at meteoroids a la the recent Keck KISS study. Thus, to persist in supporting SLS/MPCV evidently depends on hope: hope that either NASA will be able to magically increase the flight rate on the current budget or that more money will be forthcoming in the out years. Odds of either occurring are next to zero and almost as slim, respectively IMHO.

    The AS article was in response to an Aviation Week op-ed by Peter Wilson: he argues that the untenability of SLS as the linchpin of the US HSF program will eventually become evident to all, and that cancellation or mothballing several years down the road is a realistic possibility. Therefore, it’s better to cut our losses now. I personally find this logic hard to argue against. YMMV….

    • Paul Spudis says:

      If SLS could match the old Shuttle rate of 6 per year that would be one thing

      Depends on what you’re trying to do. In our lunar resources outpost architecture, we use a 70 metric ton HLV that flies only twice per year during maximum activity and once per year after our production goals are satisfied. The only need to fly 6 or more HLVs is if you’re trying to implement the Mars reference architecture to which I refer, and I happen to think that is very unlikely.

      • Dr. Spudis, how many, in total, SLS launches do you estimate would be required to establish a water production facility at one of the lunar poles capable of producing at least 1000 tonnes of water annually?

        Marcel

        • Paul Spudis says:

          Marcel,

          In theory, none – because one could imagine an architecture that doesn’t use SLS. In our lunar return plan, we have two 70 ton HLV launches per year for about 6-7 years to fully establish the water processing outpost at one pole of the Moon.

  5. DougSpace says:

    There’s two things not being given enough attention here:
    1) How adequate FH & SLS are for sending a one-way robotic mission to the Moon or Mars (respectively) and
    2) How adequate FH & SLS are for human missions when propellant is being produced on the Moon and Mars (respectively).

    My estimate is that in early missions, single launches of the FH can send enough telerobotic hardware one-way to the lunar surface to make be useful (9 tonnes in as much as 110 m^3). The equipment would be decent size, be redundant, and have plenty of spare parts. Alternately, there’s Adamo’s lunar surface rendezvous concept.

    Obviously, in a Zubrin-like approach, a one-way Martian craft could fairly easily produce the return fuel simply by bringing the hydrogen, sucking in the atmosphere, and having enough power. This dramatically reduces the mass needed to be launched from Earth.

    Also, this article doesn’t give enough treatment to the feasibility of the capability from two launches and a single docking event of the FH. This gets the mass up to 106 tonnes which is respectably close to the Saturn V’s 117 tonnes.

  6. I never really understood the debate between a heavy lift vehicle and fuel depots since they are inherently complimentary to each other.

    A heavy lift vehicle is going to make it a lot easier to deploy fuel manufacturing water depots practically anywhere in cis-lunar space and even in orbit around Mars. But the key to refueling space vehicles via space depots is my mining extraterrestrial fuel resources at the lunar poles, on the moons of Mars, and by importing large meteoroids into cis-lunar space. The manufactured water can then be sent out of these low gravity wells to orbiting space depots that use solar energy to convert water into rocket fuel.

    The SLS is already showing what a game changer its going to be as far as pioneering the solar system. Brand Griffin’s Skylab 2 concept shows just how remarkable the SLS is going to be once you start taking advantage of its heavy lift capabilities and its large payload faring size.

    He proposes using the hydrogen tank from the SLS derived upper stage (CPS) as a deep space habitat. The outfitted LH2 tank would have a pressurized volume of 495 cubic meters while weighing less than 16 tonnes. It ISS required 15 launches for its 15 pressurized modules for a pressurized volume of 837 cubic meters.

    So in theory, the SLS could easily place three Skylab 2 modules into orbit with a– single launch– for a pressurized volume of 1485 cubic meters without the need for any new water or food supplies for at least three years. Wow!

    The SLS is going to be a remarkable machine.

    Anyone interested in getting a pdf copy of Brand Griffin’s Skylab 2 poster, can email me at: newpapyrsus@yahoo.com

    Marcel F. Williams

  7. Joe says:

    Glen,

    Because Space X is rather secretive about their work it is hard to tell exactly what hardware on the hypothetical Falcon Heavy would be common to the current Falcon 9.

    However, my understanding is that the Falcon Heavy will use the same configuration as the first stage of what Space X calls the Falcon 9 v1.1. It is not yet in operation either, but if it ever is it would use Merlin D engines (as opposed to the Merlin C engines used on the current Falcon 9). The Merlin D is supposed to have considerably improved performance over the Merlin C, so while it may have some common components it is essentially a new engine. Additionally the Falcon 9 v1.1is supposed to have an octagonal engine arrangement as opposed to the rectangular one of the current Falcon 9. That makes it an entirely new first stage.

    The Falcon Heavy would then have to integrate three of these new Falcon 9 v1.1first stages into a working unit (complete with the cross feeding already described).

    The Falcon Heavy is much more of a brand new rocket (or paper rocket if you prefer) than the SLS.

  8. Michael says:

    Twenty Seven engines scare me; not saying it won’t work, just that the idea scares me. The N1 discussion seems appropriate.

    EVA on the other hand seems normal and realistic. To my way of thinking if we cannot do EVA (or are scared to do so) we might want to consider staying home.

    On the other hand these days I have a lot more faith in Space X than NASA. Caught between the Devil and the deep blue sea I suppose.

  9. billgamesh says:

    “I never really understood the debate between a heavy lift vehicle and fuel depots since they are inherently complimentary to each other. ”

    I understand it perfectly; private space wants nothing to do with a heavy lift vehicle using “their” funding for hobby rocket tourism and the fuel depot is there way to do away with the competition.

    Except a cryogenic fuel depot in space probably will not work. It has never even been attempted due to the difficulties involved; the ISS uses storable propellents for station keeping and high pressure oxygen tanks for storage.

    Low ISP storable propellents make for HUGE depots and departure stages. I have pointed this out many many times on forums and no one wants to talk about it. An HLV does not complement depots- it is inherently superior to any storage depot because of the higher ISP of cryogenic propellents. Launching from the Earth OR from a Moon base is best done using liquid hydrogen and oxygen and resorting to storables away from these launch site only when it is unavoidable. That means inserting into lunar orbit after a couple days journey from Earth or inserting into geostationary orbit after a couple days journey from the Moon.

    Deep Space flight outbound and away from the Earth’s Magnetosphere requires nuclear propulsion due to the need for hundreds of tons of cosmic radiation shielding.

    Again, I repeat these obvious conclusions constantly on this and the only other forum I comment on and no one ever seems to be able to provide any data to change my mind.

    • Robert Clark says:

      It is not just NewSpace that argues in favor of depots but United Launch Alliance(ULA), which is composed of Boeing and Lockheed, also argues in favor of it. Note this is the case even though both Lockheed and Boeing have big stakes in the SLS since Lockheed is building the Orion, and Boeing the SLS core stage.
      ULA has written numerous reports on the advantages of propellant depots even including cryogenics. As they describe it, the boil off problem can be limited by several well known techniques.
      NASA has also written reports supporting propellant depots even if using the SLS.

      Bob Clark

    • denniswingo says:

      I understand it perfectly; private space wants nothing to do with a heavy lift vehicle using “their” funding for hobby rocket tourism and the fuel depot is there way to do away with the competition.

      Hmmm…. I don’t know who you are but what you are stating as impossible is what Wernher Von Braun had as his baseline in the 1958 classified (then) report to president Eisenhower.

      http://en.wikipedia.org/wiki/Project_Horizon

      Von Braun thought it was completely doable and this was the basis of his Earth Orbit Rendezvous approach. Lunar Orbit Rendezvous (LOR) was chosen over EOR solely for the sake of expediency to get us to the Moon before Kennedy’s deadline. When LOR was chosen Von Braun told his people that his fear was that with no infrastructure in place in space that it would be easy for the politicians to cancel the program after a few launches.

      Von Braun was right on both counts, just who are you and what is your expertise that you know more than him?

  10. John Strickland says:

    This debate goes round and round but some good comments have been made here.
    Some basic points:
    _ I agree there is no real conflict between an HLV and depots. We will need both.
    - What we do not need is another expendable giant rocket that is too expensive to use for more than 1 launch per year. Since I live only 100 miles from McGregor, TX, where the rumble of the Grasshopper tests is signaling a new space age with vastly cheaper launches, to those who are paying attention, it is becoming more apparent that relatively few Falcon Heavy launches will be fully expendable. The two side boosters will be very easy to recover due to their slower speed. This should see at least another 50% price drop in Musks posted prices in a couple of years.
    _The latest buzz tonight is talking about a possible follow-on to the Grasshopper or even the Falcon 9 iteself, the Falcon 9R (where R stands for REUSABLE!). The current Grasshopper landing legs are rather massive, where the new landing legs would weigh less than a Tesla Model S car.
    _ we will need multiple launches per year of any type of rocket to support Lunar and Mars expeditions. The mass of the expeditions, if we are serious about it, will be thousands of tons, not hundreds. It takes equipment to do anything, and equipment has mass. This implies more like a launch a month, not a launch a year. At about $2 billion estiamted per launch, an SLS based program would require $20 billion a year for the expedition launches alone.
    _ We need to realize the need for a whole set of fully re-usable IN-space vehicles that once launched into orbit, will not re-enter but go between LEO and L1/L2 or L1/Lunar surface or LEO to GEO and back etc. Tankers, cargo vehicles, crew vehicles, etc will be needed.
    _ Some of those vehicles will need an HLV to first get them into LEO where they can then be used anywhere in space.
    _ We will also need re-usable capsules designed to be tankers to bring fuel into orbit before any Lunar fuel production system exists.
    _ Since Musk said he could duplicate the SLS for about $2.5 billion,(the Falcon 20) I still expect the SLS program to eventully collapse once Musk’s further intentions become obvious. When that happens the big space companies will meet their “IBM Moment” the realization that they cannot compete and cannot catch up with Musk.

    • billgamesh says:

      “-there is no real conflict between an HLV and depots. We will need both.”

      Cryogenic depots, like reusable rockets, are a myth. A HLV is superior and makes depots a waste of time and money. Just like a half a century ago. Physics has not changed.

      “What we do not need is another expendable giant rocket-”

      Actually, that is all we ever needed. We threw the original HLV away and as a result went in endless circles for thirty years.

      “-the Falcon 9R (where R stands for REUSABLE!). The current Grasshopper landing legs are rather massive, where the new landing legs would weigh less than a Tesla Model S car.”

      Less than a Tesla? That is pretty much the payload of Falcon. Lifting legs into space does not accomplish much except lifting legs into space. Reusability, like cryogenic fuel depots, is a myth.

      “At about $2 billion estiamted per launch, an SLS based program would require $20 billion a year for the expedition launches alone.”

      Stop making things up.

      “-the realization that they cannot compete and cannot catch up with Musk.”

      It is Musk that cannot compete or catch up. The SLS is superior in every way. SpaceX is a house of cards that will collapse on itself sooner or later. The sooner the better for space exploration.

      An HLV with hydrogen upper stages going to the Moon is what is required; not the circus of private space scamming tax dollars to subsidize space clown tourism. Worthles grassphopper stunts and ridiculous promises of retirement condos on Mars do not a space program make.

    • NASA estimates cost for the SLS at about $500 million per launch if there are at least 6 launches per year. Our previous heavy lift vehicle, the Space Shuttle, had a cost around $450 million.

      The super high cost for the SLS are estimates for the extremely infrequent launch scenarios proposed by the Obama administration which never wanted the SLS. The Space Shuttle would have had similar high cost if it were only allowed to fly once every year or so.

      Marcel F. Williams

    • Robert Clark says:

      Some good points here. When NASA needed to implement the VSE they decided to make it bigger than Apollo. Unfortunately, such a hugely expensive project could not be sustained.
      This has had the unfortunate effect of poisoning any consideration of lunar missions by the current administration because of the belief any lunar landing mission must be hugely expensive.
      However, this is not the case. By going small, individual lunar flights can be made at costs that NASA would consider to be in the “discovery mission” class. Such small missions would have also drastically reduced development costs.
      One such plan was “Early Lunar Access” of the early 90′s:

      Early Lunar Access – Encyclopedia Astronautica.
      American manned lunar base. Study 1993. Early Lunar Access (ELA) was a “cheaperfasterbetter” manned lunar mission study, carried out by General Dynamics in 1992-93.
      It was intended as a joint US-European pathfinder for NASA’s more capable 4-man First Lunar Outpost (FLO). The project tried to reduce total costs by a factor of ten compared with Apollo, by utilizing existing launch vehicles rather than developing a large Saturn V-class rocket.

      http://www.astronautix.com/craft/earccess.htm

      Note this plan would also have given us the much-desired Moon base.
      At the time it was proposed, it used the shuttle and Titan IV as launchers because that was available then. But now it could be done by the Delta IV Heavy, Ariane 5, and/or Atlas V (with side boosters) as launchers.
      And if the Falcon Heavy really does hit the $1,000 per pound price point then it could reduce costs not just by an order of magnitude, but by two orders of magnitude over that of Apollo, or of Constellation.

      Bob Clark

  11. Joe says:

    Warren Platts says: May 3, 2013 at 10:31 am
    “At this point, “Joe” will pipe in to say that “the schedule is dictated by the current (politically appointed) NASA leadership and are intended to make the SLS/MPCV look as bad as possible.” Now, I can’t read the minds of Bolden and Garver …”

    Since you already said it, I will not have to, thank you.

    As to the rest of your diatribe: the current “plan” is to (1) develop the first iteration SLS (70 tons) by 2017, (2) fly it once in 2017 on a test flight, (3) then fly it only one more time on a vaguely defined “operational” mission four years later in 2021. After that the 70 ton version is abandoned to pursue the bigger vehicle to be brought on line no earlier than 2025, with it to be used no more than once a year.

    You do not have to be Sherlock Holmes (much less a mind reader) to know that anyone proposing such a – well lets be polite and call it unusual – development/flight plan is trying to put the system in question in the worst possible light possible.

  12. Andrew W says:

    Comparing the Falcon Heavy with the N1 is of limited use as the N1 was a rocket designed with 1960′s Soviet technology.

    If you’re only planning to go to the Moon a dozen times over 10 years doing it with a Saturn V class HLV probably makes sense, but if you want to actually establish permanent Lunar activities, accepting the loss of smaller lumps of hardware from the occasional launch failure, rather than bigger lumps is probably the better option, because you’ll have a production line running for each component of hardware, so if one EDS is lost, just promote the launch of the next EDS.

    Another point is that permanent Lunar activities will be expensive by any standards, launch costs are going to be critical to the success, Falcon Heavy is the cheaper $/kg option.
    SLS proponent are remarkable in their ability to overlook what’s actually affordable.

  13. Joe says:

    This whole topic would be amusing were it not so sad.

    The whole debate goes like this:
    (1) Question: Why is the SLS flight rate so low?
    Answer (from the Space X supporters): Because the SLS is so expensive that you cannot afford more payloads.

    (2) Question: Why is the SLS so expensive?
    Answer (from the Space X supporters): Because it fly’s so few times.

    (3) Question: Why will the flight rate for the Falcon Heavy be significantly higher?
    Answer (from the Space X supporters): Because the Falcon Heavy is so much cheaper more payloads will be affordable.

    (4) Question: Why is the Falcon Heavy so much cheaper?
    Answer (from the Space X supporters): Because its flight rate will be so much higher.

    It is a circular argument that makes no sense, but they are wedded to it and will repeat it over and over again no matter what.

    • DougSpace says:

      (1) Question: Why will the Falcon Heavy be so much cheaper?
      Answer (from a Falcon Heavy supporter): Because the flight rate will be so much higher.

      (2) Question: Why will the Falcon Heavy flight rate be so much higher?
      Answer (from a Falcon Heavy supporter). Actually, it’s the flight rate of the Falcon 9 upon which the Falcon Heavy is based, which will be high because there is a large market for the Falcon 9. The Falcon Heavies are largely just some more Falcon 9′s coming off the busy assembly line.

      (3) Question: Why will the SLS be so expensive?
      Answer (from an SLS realist). Because its flight rate will be so low.

      (4) Question: Why will the SLS flight rate be so low?
      Answer (from an SLS realist). Because there is no market for it.

      Compare the launch manifest for the Falcon 9 compared to the SLS. When do you expect the launch manifest of the SLS to be as comparable as that of the Falcon 9?

      • Paul Spudis says:

        Actually, it’s the flight rate of the Falcon 9 upon which the Falcon Heavy is based, which will be high because there is a large market for the Falcon 9. The Falcon Heavies are largely just some more Falcon 9′s coming off the busy assembly line.

        The Switch — equating Falcon Heavy with Falcon 9, which are two entirely different launch vehicles. The Falcon Heavy has not been built and has not been shown to work. By this standard, the SLS has already flown 135 times because it is made of Shuttle parts.

        Compare the launch manifest for the Falcon 9 compared to the SLS. When do you expect the launch manifest of the SLS to be as comparable as that of the Falcon 9?

        The Bait — anyone can draw up a manifest. Completing it successfully is something else. To date, Falcon “anything” has not successfully launched an ounce of commercial payload.

    • denniswingo says:

      The Falcon heavy currently has an advertised launch price of $84m dollars. It has customers and a launch date. That price is competitive with the Ariane V. Elon has just made tons of money in the stock market. What makes you think with such vigor, that they won’t fly?

  14. Andrew W says:

    (4) Question: Why is the Falcon Heavy so much cheaper?
    Answer (from the Space X supporters): Because its flight rate will be so much higher.

    No, because SpaceX has demonstrated the ability to build and launch rockets more cheaply than is done under the established system, irrespective of flight rates This brings about the possibility of a virtuous circle, cheaper launch rates generating more payload bringing about still cheaper launch rates etc.

    • billgamesh says:

      “-SpaceX has demonstrated the ability to build and launch rockets more cheaply than is done under the established system,-”

      The infomercial just goes on and on. The three people making comments on this thread critical of the private space flim flam cannot continue to answer the same canned advertising slogans from the endless legions of Musk’s deluded sycophants; well we could but what would be the point?

      What has been “demonstrated” is the ability to rebrand taxpayer funded technology obtained gratis as “innovation.” More bluntly; claiming payment for work they did not do. Not only that but…..well, I can just paste my own canned response (fair enough considering);

      A hobby rocket docking with a blow-up tent is all they need to cash in. But even this cheap and nasty minimum requires far more money than they can charge for there to be any profit left over. The solution is to get rid of any other space concern sucking up “their” money. Not only get rid of the competition but use the organization they are trying to destroy to fund their business plan and for nearly free research and development-all the while demonizing that same enabling resource as wasteful and unnecessary. What a deal!

      Of course it seems cheap; for token payment they have used NASA engineers, labs, and launch facilities AND sucked up a billion or two in “seed money.”

      Actually, there is no cheap.

      • denniswingo says:

        What has been “demonstrated” is the ability to rebrand taxpayer funded technology obtained gratis as “innovation.” More bluntly; claiming payment for work they did not do. Not only that but…..well, I can just paste my own canned response (fair enough considering);

        I am curious. Exactly what rebranded taxpayer funded technology are you talking about?

  15. billgamesh says:

    “Comparing the Falcon Heavy with the N1 is of limited use as the N1 was a rocket designed with 1960′s Soviet technology.”

    Bad news; the merlin engine used by the Falcon is also 1960′s tech and burning kerosene and LOX dates back to the 50′s. Using clusters of low thrust engines was a stop gap in the early space program until more powerful engines and propellents were available. It is a good advertising trick to claim so many engines is somehow an intentional design feature but in reality it is just going cheap and not desirable in any way. The same false claim is made about kerosene as being “superior” to hydrogen because it is more dense and thus needs a smaller stage. Actually, the 100 seconds difference in ISP means the hydrogen burning vehicle will always put a much larger payload up. The real reason SpaceX uses kerosene exclusively is because a liquid hydrogen turbopump has to be about 10 times more powerful than one pushing kerosene and they cannot afford it.
    There is no cheap.

    The N-1 was actually superior to the falcon heavy one respect; At least it had a real escape system instead of an inadequate dual purpose hypergolic system intended to keep inflatable space tourist stations in orbit.

  16. Robert Clark says:

    I’m also not sanguine about the 27 engines on the Falcon Heavy. However, the scuttlebutt on NasaSpaceFlight.com is that SpaceX is planning on a 650,000 lb. thrust methane engine to be used on a later version of a heavy lift vehicle.

    Bob Clark

    • billgamesh says:

      “-SpaceX is planning on a 650,000 lb. thrust methane engine to be used on a later version of a heavy lift vehicle.”

      Uh-huh. Thanks for that exciting new maybe on the SpaceX infomercial that is always playing somewhere.

      However, a far superior engine exists and has flown- the RS-68A. Why build an entirely new engine with an inferior performance? Maybe because it will allow SpaceX to scam yet more tax dollars on useless projects.

      http://en.wikipedia.org/wiki/RS-68

  17. Joe says:

    Well it appears my post on the circular logic of the Space X justifications stirred up a little discussion. It also appears that the attacks on it have been well refuted by others. Still I will add a little on a couple of points:

    DougSpace says: May 4, 2013 at 11:35 pm
    “Compare the launch manifest for the Falcon 9 compared to the SLS. When do you expect the launch manifest of the SLS to be as comparable as that of the Falcon 9?”

    There are levels of negotiations that are gone through before reaching an actual launch contract. Without trying to play lawyer they include: (1) Memos of Understanding (MOU’s), (2) Memos of Agreement (MOA’s), and then finally (3) an actual contract.

    I do not expect the manifest for the SLS, ULA’s EELVs, or those of any other launch providers to look like that for the Falcon 9 because none of those projects put out breathless press releases every time they agree to an MOU and add that possible customer to their manifest as if an actual contract had already been signed. It would be a good idea if you used 1/10 of the skepticism you direct to NASA, ULA, etc. in your evaluations of Space X.

    Andrew W says: May 4, 2013 at 6:20 pm
    “(4) Question: Why is the Falcon Heavy so much cheaper?
    Answer (from the Space X supporters): Because its flight rate will be so much higher.
    No, because SpaceX has demonstrated the ability to build and launch rockets more cheaply than is done under the established system, irrespective of flight rates …”

    My reply will be redundant but only because your (unsubstantiated) assertion is redundant.

    Current cost for CRS cargo delivery to the ISS by Space X is as follows: (1) By terms of the CRS contract each Space X flight costs the government about $133 Million. (2) By Space X own facts sheets CRS-1 and CRS-2 have delivered an average of 1041 lbs. to the ISS. That comes out to $281K/kg. Those are the only supposedly “operational” missions Space X has flown and thus the only ability they have demonstrated. That is indeed remarkable but not in the way you would like it to be. It is remarkable because $281K/kg (pound for pound) is so remarkably high.

    • Warren Platts says:

      Dry mass of Dragon = 4200 kg; CRS-2 cargo was 677 kg; CRS-2 downmass was 1370 kg. Thus $133M / 6247 kg = ~$21K/kg. So you’re only off by an order of magnitude, Joe…

      Also, we have to keep in mind that the $133M is not just for the cost of the F9 LV, it also includes the cost for the use of the Dragon capsule–a highly complex, pressurized spacecraft capable of docking with ISS and bringing stuff back down to Earth–something no other cargo vehicle can do. Also, the up mass cargo will increase by an order of magnitude eventually, nearly halving the average cost/kg to ~$12K/kg.

      Still, even that cost seems admittedly rather high; but NASA doesn’t have a whole lot of leverage when it comes to negotiating the price of servicing ISS, now does it? SLS is no competition. Using that gargantuan beast to service ISS would be gross misallocation of resources. But watch what happens…

      • Paul Spudis says:

        This discussion started by comparing the “new paradigm” of “commercial” cargo delivery to ISS vs. delivery by the Space Shuttle. If you’re going to include the use of Dragon as a “benefit” to ISS cargo delivery, then the Shuttle Orbiter mass must also be included in the analysis for direct comparison. The mass of a Shuttle plus cargo is about 120 metric tons. Flying at an generously estimated average cost of about $2 billion per flight, that works out to about $16,000 per kg to ISS. So the “old paradigm” was still cheaper than the “new paradigm.” And much more capable as well.

        • Warren Platts says:

          You’ve got no argument with me Paul when it comes to the Shuttle! I think they should have kept it going; it was a very elegant way to transport a lot of people/cargo to space. Heck, they could have kept Shuttle going at a moderate pace, and still had $$$ left over to develop the Sidemount cargo version. We could have had both….

        • Robert Clark says:

          Thanks for that discussion. It gave me some ideas on further benefits of ESA developing the all-liquid version of the Ariane 6.

          Bob Clark

      • Joe says:

        Warren Platts says: May 14, 2013 at 8:33 am
        Dry mass of Dragon = 4200 kg; CRS-2 cargo was 677 kg; CRS-2 downmass was 1370 kg. Thus $133M / 6247 kg = ~$21K/kg. So you’re only off by an order of magnitude, Joe…

        You are incorrect in that statement. According to the facts sheet that Space X themselves put out the up-mass (cargo) delivered on CRS-1 was 882 lbs. They (to the best of my knowledge) did not put out a facts sheet for CRS-2, but a Space X press release listed the CRS-2 up-mass as 1200 lbs. I said (quite accurately) that Space X delivered (by their own documentation) an “average of 1041 lbs. to the ISS” on CRS-1 and CRS-2. Down mass has nothing to do with cargo delivery to the ISS nor does the mass of the carrier vehicle (so it is puzzling that you mention them in a discussion of cargo delivery to the ISS).

        Additionally even if you are hypothetically granted that the CRS-1/CRS-2 up-mass was your claimed “677 kg” (1489.4 lbs.) for both flights (obviously not the case) that would be about 1.4 times the 1041 lbs. amount I stated, not an order of magnitude (which would be a factor of 10). That would make the cost per lbs. “only” $196K/kg.

        Also, we have to keep in mind that the $133M is not just for the cost of the F9 LV, it also includes the cost for the use of the Dragon capsule–a highly complex, pressurized spacecraft capable of docking with ISS and bringing stuff back down to Earth–something no other cargo vehicle can do.

        Heard that one before the trouble is Space X still lists the cost of a Falcon 9 launch (in words that strongly imply it is total mission cost) as $54 Million. What you are arguing is akin to a guy offering to sell you a used car for $10,000, and then saying “Oh, you wanted wheels on that car, that will cost $25,000.”

        Also, the up mass cargo will increase by an order of magnitude eventually, nearly halving the average cost/kg to ~$12K/kg.

        So, “order of magnitude” again. That is a rather extraordinary increase in payload (especially when no rationale is given).

        Still, even that cost seems admittedly rather high; but NASA doesn’t have a whole lot of leverage when it comes to negotiating the price of servicing ISS, now does it?

        At last something we can agree on. Due to bad decisions made by past (and especially) the current administration NASA is in a weak position in dealing with any launch provider trying to take advantage of them whether that is the Russians or Space X. The difference between us is that (at least where Space X is concerned) you seem to think that is a good thing.

  18. Grand Lunar says:

    Another option for heavy lift would’ve been the wide body Atlas V, the one produced with the Phase 2 developement.

    When you think about it, it gives far more flexibility than SLS could.

    A single body version gives you access to LEO that isn’t overpowered (I don’t know what the numbers are for it, though).
    The three body version (Phase 2) gives 70 tons LEO.
    And a five body version (Phase 3A) gives 100 tons LEO.

    Such flexibility seems to make this the logical choice for a launch vehicle to support the developement of cislunar space.

    Incidently, have you read this yet?
    http://www.nasaspaceflight.com/2013/05/return-moon-send-nasa-square-one-bolden/

    This sort of thinking by Bolden is ridiculous.

  19. Joe says:

    Warren Platts says: May 15, 2013 at 10:46 am

    “Not to mention the fact that the cost of developing the Atlas Phase 2 would be about the cost of single year of SLS development….”

    The 2012 SLS Budget is $1.8 Billion. The proposed budget (by the Congress, the Obama Administration requests less) is $2.1 Billion. So assuming those numbers hold you are asserting that the entire Atlas Phase 2 could be developed for no more than $2.1 Billion.

    That is interesting given that on page 7 (the Summary) of the paper to which you link, the authors say:

    “In the end, the combination of modular construction and evolutionary design enabled the deployment of two separate launcher systems within 5 years and for less than a combined $5.5B, and can offer similar economies when expanded to the HLLV.”

    They are referring to the development of a new family of upper stages (not an entire new vehicle – which would be more complex and thus more expensive). Yet even that is over twice the numbers you assert. You are trying to go far beyond what the actual engineers in the paper to which you link are suggesting.

    Perhaps you should try again.

  20. Grand Lunar says:

    I assume this is the relevent quote:

    “In the end, the combination of modular construction and
    evolutionary design enabled the deployment of two separate launcher systems within 5 years and for less than a
    combined $5.5B, and can offer similar economies when expanded to the HLLV.”

    If so, that’s a great deal.

    The paper mentioned a possible engine to replace the dual RD-180s. It sounds like a possible fit for Dynetics idea of bringing back the F-1A.

  21. Joe says:

    Grand Lunar says: May 15, 2013 at 7:22 pm

    You may not believe this but I actually do not like playing the “skunk at the garden party” in these discussions, however on page 2 of the document you will find the following:
    - “The actual Delta IV development cost was $3.5B, including a $0.5B USAF investment
    - “The Atlas V equivalent was $2B, including a $0.5B USAF investment.”

    That is $6.5 Billion for what appears to be the first stages only and the money was spent in the 1990s. To find out how great a deal it is you would have to adjust the $6.5 Billion for inflation over the last decade and a half and then strip the upper stage costs out of the Block I (the 70 Metric Ton) version of the SLS to make the comparison.

  22. Robert Clark says:

    If those are accurate numbers, then that is very interesting. Many knowledgeable commentators on the industry have noted that NASA’s commercial space program was presaged by the Air Force’s partnership with industry in developing the EELV’s.
    This would provide further evidence that such partnerships can result in dramatically reduced costs to the government.

    Bob Clark

  23. Joe says:

    Robert Clark says: May 16, 2013 at 10:08 am

    At the risk of repeating myself.

    To find out how great a deal it is you would have to adjust the $6.5 Billion for inflation over the last decade and a half and then strip the upper stage costs out of the Block I (the 70 Metric Ton) version of the SLS to make the comparison.

    The current cost estimates for the SLS Block I is $19 Billion. No way I know of to tell how that breaks down between Upper Stage and Core Vehicle but it is certainly a lesser figure since the upper stage requires development and certification of the J2X engine. If the first stage development cost is as low as $10 Billion, then that $6.5 Billion figure (when adjusted for inflation) would be a literal wash.

    I have nothing against the concept of an EELV derived HLV, but there is nothing in the paper that suggests it is dramatically cheaper than a Shuttle derived HLV.

    • Robert Clark says:

      I wasn’t arguing against the SLS (which I’m not opposed to.) What I was commenting on is the cost savings to the government by following the cost-sharing approach of commercial space. For the Delta IV, the development cost paid by the government was $500 million out of $4 billion, a saving of 88%(!)

      For the Antares, NASA paid only $288 million out of the $472 million development cost as of 2012:

      Antares Rocket Cost Estimated at $472-Million.
      http://spaceports.blogspot.com/2012/05/antares-rocket-cost-estimated-at-472.html

      This is why I say that commercial space will become the predominate method for creating new launchers/spacecraft going forward.
      The Antares is a 5 metric ton class launcher. This would be sufficient for a half-Dragon sized capsule. So any industrialized country could develop its own independent man capable launcher for ca. $288 million.

      Robert Clark

      • Robert Clark says:

        For the Delta IV, the development cost paid by the government was $500 million out of $4 billion, a saving of 88%(!)

        Oops, the total development cost for the Delta IV was $3.5 billion. So the saving to the Air Force was 86%.

        Bob Clark

  24. Grand Lunar says:

    It may be debatable as to which is cheaper.

    There is, however, the question of reoccuring costs, the use of a single customer launch vehicle VS one that has multiple users (even if not always as an HLV), and flexibility.
    As I pointed out in a previous post, it can be used in single body form for LEO (without being overpowered), and three or five body form for HLV.

    That, I believe, is a strong selling point.

  25. Joe says:

    Grand Lunar says: May 17, 2013 at 8:31 pm

    - It is certainly easier to make a case that the recurring costs of an EELV HLV might be less than that for a SDHLV, however a couple of points for consideration.

    - In considering HLV only there is no reason a SDHLV could not have more than one customer just as an EELV HLV could.

    - As for non HLV versions of the HLV, the fact that the HLV version of the proposed EELV vehicle (according to the article) would require a “cross-feed” capability means that the tankage could not be truly common with that for non HLV configurations.

    - Considering only the cross-feed issue you are correct that the engines could be common. But there is another consideration. To be certified for use on crewed launches would require additional data streams be available (primarily for potential abort) this causes further changes to the tankage and changes to the engines as well. One of the reasons the EELV HLV was not pursued further at the time was that, while the line engineers were very enthusiastic about the concept a number of their superiors were not (due to worries about potential expenses making them less competitive in regular satellite launches – this same concern stopped a proposal to develop the proposed ACES upper stage as a joint DoD/NASA project). I am aware that there is work in progress now intended to make the an Atlas V compatible with crewed launch but the results are not yet assured.

    I am not endorsing (or for that matter attacking) the concept of an EELV derived HLV. While I still believe a SDHLV is the lowest risk, development
    cost option and that its recurring cost can be approximately equivalent to an EELV HLV, I think your strongest argument is that in the long run possible greater flexibility using(where possible) common hardware might lead to lower recurring cost.

  26. Joe says:

    Robert Clark says: May 18, 2013 at 10:17 am

    Fair enough. But as I seem to have been cast in the role of the skeptic a few points to consider.

    These cost sharing plans that assume the private contractor will pick up the majority of development cost (assume your 88%) also assume that there will be a stable market for the hardware services that will allow the private contractor to recoup its development expenditures (not to mention making a profit). In the case of both the EELV program and the COTS program that market (accurately or not) was assumed by all players. For anything aimed at BEO activities (HLV or Orbital Propellant Depot – just to get that side argument off the table) that means a reliable market for extensive activities over an extended period of time in BEO.

    Take a look at recent history. All it took to unilaterally end the Lunar return program was an election that did not hinge on space policy. That decision was made without any coordination outside the new (at that point) White House (not even anybody at NASA below the Bolden/Garver level was consulted or even informed). When Congress forced the SLS on the administration, they established a program for the Block I SLS that would have it be flown only twice (over a period of four years) before being abandoned. Any private contractor that accepted 88% of the cost for development of either of those programs would be guaranteed to lose lot money.

    Put yourself (hypothetically) in the position of an official of an Aerospace Company being asked to enter such an agreement. Given that history would you enter into such an agreement?

    As much as you (and I) might wish it to be otherwise there is not now (nor will there be in the foreseeable future) a viable commercial BEO market.

    Absent a credible long term government commitment to a BEO program the kind of contracts you are espousing will simply not happen.

    • denniswingo says:

      You have now stated twice that the Falcon Heavy has “customers and a flight date” and been asked once for specifics. However you have not responded.

      I did respond, you just did not read it.

      Here is the manifest.

      http://www.spacex.com/launch_manifest.php

      It says a Falcon Heavy flight this year. While that is fairly specific, there has been a history of slips. I find it odd that it is so easy to discount something that SpaceX is already working on to fly and say that it will not happen.

      Also, their bread and butter market is going to be GEO comsats. They have a better price than the Ariane V and if the vehicle proves out it will be a formidable competitor to the Europeans. SpaceX already has several contracts to fly GEO birds on the Falcon 9 1.1. ESA and Arianespace is specifically designing the Ariane V ME to compete with the Falcon Heavy. They think it is going to fly, what gives you such confidence that it will not?

  27. Grand Lunar says:

    Interesting points to consider.

    Here’s another possibility that I found here:
    http://www.spacelaunchreport.com/sls2.html

    An SDLV with no (large) solids, basically.
    The only solid mentioned is the one used already by the Atlas V.

    Doesn’t seem as flexible a concept, unless the single stage version of the droppable booster is used for LEO flights.
    It may give motive for greater production of expendable RS-25s.

    Perhaps one could compare an all liquid SDLV to that of the side-mount SDLV that Spudis often mentions. One may be faster to develope, while the other is lighter in weight and drops an entire contractor chain.

  28. Joe says:

    denniswingo says:
    May 19, 2013 at 2:47 pm
    Considering that the Falcon heavy already has customers and a flight date I am fairly well convinced that it will fly. It is by far an optimal system for exploration, but there are ways to fix that very inexpensively.
    Paul Spudis says:
    May 19, 2013 at 4:09 pm
    What customers and what flight dates?
    denniswingo says:
    May 19, 2013 at 2:49 pm
    The Falcon heavy currently has an advertised launch price of $84m dollars. It has customers and a launch date. That price is competitive with the Ariane V. Elon has just made tons of money in the stock market. What makes you think with such vigor, that they won’t fly?

    You have now stated twice that the Falcon Heavy has “customers and a flight date” and been asked once for specifics. However you have not responded.

    Given that (according to Space X own website) the Falcon Heavy will depend on the Merlin D engines (not yet flown), presumably the octagonal arrangement new Falcon 9 v.1.1 engine alignment – a new and un-flown entire first stage – and then have to integrate that new first stage into a” three barrel” configuration complete with a cross feed system the “fact” that they have a firm launch date is “very interesting”. What is your source for this assertion?

    If they have already signed launch contracts for there as yet non-existent vehicle that is also intriguing. What is your source for this assertion?

    The $84 Million launch cost is also interesting. Space X has been advertising (in press releases) the launch cost as $120 Million. So apparently the launch cost of the Falcon Heavy has dropped some 30% (even more amazingly it is now 36% less than what Space X charges under the CRS contract for launches of the current iteration of the Falcon 9). What is your source for this assertion?

  29. Joe says:

    denniswingo says: May 21, 2013 at 1:09 am

    That does not address the issues of launch date and customers.

    It does answer where you got your launch numbers (though you might have included the $128 Million figure). The wise buyer always reads the fine print, however. Note the statement directly above the pricing:

    “SpaceX offers open and fixed pricing for launch services based on SpaceX’s standard statement of work. Additional mission assurance activities or other non-standard services are available for an additional charge. “

    It would be interesting to know how much those additional (and needed) services would cost.

  30. billgamesh says:

    “For anything aimed at BEO activities (HLV or Orbital Propellant Depot – just to get that side argument off the table) that means a reliable market for extensive activities over an extended period of time in BEO.”

    It is not an “aside”; SpaceX is using the concept of the depot to demonize the HLV-with-hydrogen-upper-stages -to-the-Moon-requirement. They are not specifying a storable propellant but rather intimating cryogenic propellants will be stored and used and thus appear to make the classic HLV with cryogenic propellants a waste of money.

    Consider the number of Falcon “heavy” flights needed to fill up a depot with storable propellants for a flight to the Moon or beyond. Comparing this number with the number of tons soft-landed on the lunar pole after having flown direct from Earth on a HLV with hydrogen upper stages, it becomes obvious what a ludicrous scam private space is attempting.

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