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Presumably, we'd launch more of them, *if* we wanted to go back to the Moon.

Hasn't been the case in practice. Saturn V, Shuttle, Constellation, and now SLS have all sucked oxygen out of the room for actual exploration and development of the Moon and elsewhere. They've never achieved the launch frequency, reliability, or cost savings to justify their use. And aside from the Saturn V era, we've never had the need for the capabilities (particularly, the large payload and fairing size) these rockets bring,

For example, this blog post discusses an alternate past where the Shuttle wasn't built and NASA instead continued on with the Saturn 1B and a small reusable manned vehicle (say 3 people plus cargo, a bit better than the Apollo capsule in payload).

They could have still flown everything that the Shuttle flew for 30 years and have a demonstration of a reusable vehicle at a small fraction of the cost of the Shuttle.

Another alternate past. Consider that we knew after the Challenger accident that the Space Shuttle would never achieve a launch frequency that would be economical. Discontinue the Shuttle in 1990. From that point on, there was only one thing that ever required the features of the Shuttle, the Hubble Telescope repair missions which simply weren't valuable. Instead, hustle the development of the EELV (Evolved Expendable Launch Vehicle) program (which built the Delta IV and AtlasV rockets) so that it was developed a decade earlier in the early 1990s instead of the early 2000s.

Then everything that was done with the Shuttle could then be done with EELVs, such as building the ISS or launching space telescope replacements for Hubble, with the use of EELVs, saving tens of billions of dollars over the 20 year period through 2010 and boosting commercial space flight in the process. And when Falcon 9 was developed, it would easily slide into this NASA strategy where everything is launched on rockets of that size.

How do you plan to get this sort of mass production-enabled experimentaiton and process refinement with Skylon?

High launch frequency.

The Shuttle could likewise have been refined to reduce maintenance.... but the vehicle wasn't in the sort of production/design environment that jets are in that enables such refinement.

That's due to poor strategic direction and design decisions. For example, they could have gone with a two person RLV on the Saturn IB. Then they could have afforded the high launch frequency that one needs to enable and justify those things.

Exactly what munitions has Defense Distributed shipped? I could see this law applying to firearms, but how does it apply to a description of a firearm? If I emailed a photo of a gun to someone in Brazil, would I be shipping munitions? I think not. I'd be sending a photo.

I imagine the photo would have to be sufficiently detailed that it could contribute to design and construction of similar weapons (perhaps a sequence of pictures of gun cleaning procedures). The law is that broad.

The State Department isn't going to go after anyone with an email account and a digital camera, but I think they will go after government agencies and contractors that happen to do such things. Here's a story I heard from one of the people involved. I wrote this comment:

When I worked at JP Aerospace in Sacramento (2006-2009), this was a problem for us. JP Aerospace is a non-profit aerospace research group that currently launches mostly high altitude experimental, unmanned balloons. It also does balloon-based rocketry (the part that fell afoul of ITAR, so I understand).

At one point before my time, Jim âoeJ.P.â Powell had invited a school group from what I understand was Poland to visit the JP Aerospace facilities. This group was sponsored by the Department of State, who I dimly recall, had arranged the visit as part of a larger tour of places of scientific and technological interest.

The trip was canceled by another part of the Department of State, the part that handles ITAR. The only thing J.P. got was an apology.

The link above is to another story of the harm coming from ITAR.

This is not about the First Amendment. What they were doing was a brazen violation of ITAR

While technically correct, I disagree on its relevance to the First Amendment. ITAR is one of the more egregious violations of the First Amendment by the US federal government today. I don't understand how one can get such sprawling restrictions on speech and information for ITAR covered subjects (the US Munitions List which includes rocketry and encryption, BTW) when the First Amendment is such a broad ban on such regulation. But it happened.

And it is remarkably harmful to US competitiveness in areas subject to the law, such as aerospace (a foreign student can study aerospace openly in college, which has an exemption from ITAR, but they need a hard to get green card in order to work in aerospace due to ITAR).

Should Defense Distributed decide to contest this in court, I would contribute to their defense fund.

Or we, being libertarian, could consider private side approaches. While space-based private exploration and science is in its infancy, it's worth noting that it is done.

For example, the Planetary Society has several projects cooking. I don't agree with the ideological baggage that comes attached (they're uncritical boosters of NASA's unmanned science program), but at least they practice what they preach. One could do worse than send them some money.

There's also a large number of non profits developing launch prototypes all over the world. I think that's a bit oversaturated, but I do volunteer on occasion for JP Aerospace, who does high altitude balloons and the occasional balloon-launched rocket.

And of course, there are actual start ups to invest in. I have an non-business interest in Altius Space Machines because I'm acquainted with the founder, Jon Goff who is one of the more insightful bloggers out there on space development topics.

The "most expensive method possible" was not used.

Well, name a more expensive method that still works and would fall within the budget.

An excellent example of spending less money up front, but being forced to spend more later to work around issues on a compromised system that wouldn't have occurred if enough money had been spent on designing it right in the first place.

A vast amount of money was spent up front. Keep in mind that they built a number of orbiters at roughly $2 billion apiece, plus development costs, and Earth-side infrastructure.

The problem wasn't the lack of funds to build the Shuttle, but the design itself was too amibitious. I consider this essay a great explanation of the problem.

What if they had intentionally bitten off a smaller task at first. What if they had retired the Saturn V, and slimmed down the staff for the Saturn IB (or better yet, auctioned it off or allowed the companies involved to commercialize it), and then done a much smaller first generation âoeshuttleâ? This shuttle might have only been capable of putting a couple thousand pounds into orbit, and might not have gone straight to an operation vehicle. This wouldnâ(TM)t have been a program trying to keep as much of the Saturn team together as possible, or an attempt to replace all existing rockets in one fell-swoop. It wouldâ(TM)ve been an X-vehicle in reality.

In other words, keep the Saturn 1B and build a much smaller shuttle capable of carrying 2-4 people or in the unmanned version a ton and a half of payload. I think the US would have much more than a space program these days, if they had gone that route.

Isn't the hot air around the returning vehicle a plasma? If it is, can you repel it with proper use of electromagnetism?

Jon Goff, an aerospace engineer whose blog you should probably read in general because it's awesome and chock full of great aerospace analysis/ideas, had a rather intriguing discussion a few months ago about doing pretty much what you describe, applying magnetohydrodynamics to the problem of thermal protection during atmospheric reentry:

http://selenianboondocks.com/category/mhd-aerobraking-and-tps/

(Jon Goff's an engineer with Masten Space Systems, the company that won the most recent Lunar Lander Challenge)

Can but won't. Saying a heavy lifter will be chosen in 2015 is doublespeak for never. If NASA was really meant to send somebody somewhere it would have most likely only meant Ares-I gets canceled and serious Ares-V development begins.

(allow me to recycle a comment of mine from a few days ago)

You don't need a heavy lifter for space exploration. In fact, it just eats up the funds you'd need for actual exploration. There's a reason that each of the times that a country has developed a heavy lift rocket in the past it's been canceled after a handful of launches due to being far too expensive. Heck, the US's and world's current heaviest launcher, the Delta IV Heavy, has only been launched 3 times in the 6 years it's existed, and it's much smaller than the 160mt Ares V design. Unlike the Ares V, the Delta IV infrastructure is also useful for medium-lift launches; with the Ares V you'd have to spend billions of dollars a year paying the standing support army and maintaining infrastructure even when you're not launching anything.

A better alternative is propellant depots, allowing you to use smaller, pre-existing launchers and refuel in space to get to where you want. Propellant depots play an important role in NASA's new plans:

http://selenianboondocks.com/wp-content/uploads/2009/07/Depot-Centric_Human_Spaceflight.pdf
http://nspires.nasaprs.com/external/viewrepositorydocument/cmdocumentid=230949/Section4.pdf

Pick a heavy lifter that can get the job done, put some intelligent technial people in charge of it, give them the money and resources to get it done, and LEAVE THEM ALONE for the next decade.

You don't need a heavy lifter for space exploration. In fact, it just eats up the funds you'd need for actual exploration. There's a reason that each of the times that a country has developed a heavy lift rocket in the past it's been canceled in a few years due to being far too expensive.

A better alternative is propellant depots, allowing you to use smaller, pre-existing launchers and refuel in space to get to where you want. Propellant depots play an important role in NASA's new plans:

http://selenianboondocks.com/wp-content/uploads/2009/07/Depot-Centric_Human_Spaceflight.pdf
http://nspires.nasaprs.com/external/viewrepositorydocument/cmdocumentid=230949/Section4.pdf

Just as an example of how they do things over at SpaceX, two people can make Falcon 9 fuel tank in 19 days.
http://selenianboondocks.com/2010/03/visit-to-spacex/

Guess when the most problems occur ... first 100 miles.

Keep in mind that NASA hasn't left LEO in 35 years. If they send people beyond Earth orbit, then the launch will no longer bear the lion's share of problems. For example, the risk of losing a crew in a Constellation-style lunar mission was thought to be 1 in 60 (according to the Exploration Space Architectures Study). That's far larger than than the 1 in 600 to 1 in 2000 risk of loss of crew from the assorted launch options studied by the ESAS.

All that remaining risk isn't bundled into reentry (which incidentally isn't part of launch for an expendable rocket).

Orbiting Fuel Depots, 'bout time. Use of the LaGrange points, asteroids, yes! Scifi has known this for years, 'bout time that NASA caught up and went for long term development of space instead of quick one-shot missions.

This. Not everybody realizes that the vast majority of mass you need for space missions (particularly those beyond Earth orbit) is fuel. Fuel itself is cheap, and nobody cares if you lose it, so you can just launch it up to a fuel depot to whoever the lowest bidder is (making it a great catalyst for commercial space startups). Then you can launch the much-lighter unfueled spacecraft up by itself (or construct it in orbit), allowing you to launch much more elaborate spacecraft using smaller rockets. Fuel depots are a HUGE technology multiplier in spaceflight. It's really a shame that NASA's prior architecture for various political reasons was pretty much explicitly constructed to avoid any use of fuel depots or in-space refueling.

Aerospace engineer Jon Goff at "Selenian Boondocks" has some really great write-ups and conference papers about propellant depots and how they can benefit a human spaceflight architecture:
http://selenianboondocks.com/2009/09/space-2009-papers/
http://selenianboondocks.com/2009/07/depot-centric-human-spaceflight/

One of the old arguments against propellant depots is that the technology is untested, although ULA just reported on the results of their in-space tests this month:

http://selenianboondocks.com/2010/01/additional-av-017-flight-experiment-information/

Orbiting Fuel Depots, 'bout time. Use of the LaGrange points, asteroids, yes! Scifi has known this for years, 'bout time that NASA caught up and went for long term development of space instead of quick one-shot missions.

This. Not everybody realizes that the vast majority of mass you need for space missions (particularly those beyond Earth orbit) is fuel. Fuel itself is cheap, and nobody cares if you lose it, so you can just launch it up to a fuel depot to whoever the lowest bidder is (making it a great catalyst for commercial space startups). Then you can launch the much-lighter unfueled spacecraft up by itself (or construct it in orbit), allowing you to launch much more elaborate spacecraft using smaller rockets. Fuel depots are a HUGE technology multiplier in spaceflight. It's really a shame that NASA's prior architecture for various political reasons was pretty much explicitly constructed to avoid any use of fuel depots or in-space refueling.

Aerospace engineer Jon Goff at "Selenian Boondocks" has some really great write-ups and conference papers about propellant depots and how they can benefit a human spaceflight architecture:
http://selenianboondocks.com/2009/09/space-2009-papers/
http://selenianboondocks.com/2009/07/depot-centric-human-spaceflight/

One of the old arguments against propellant depots is that the technology is untested, although ULA just reported on the results of their in-space tests this month:

http://selenianboondocks.com/2010/01/additional-av-017-flight-experiment-information/

Orbiting Fuel Depots, 'bout time. Use of the LaGrange points, asteroids, yes! Scifi has known this for years, 'bout time that NASA caught up and went for long term development of space instead of quick one-shot missions.

This. Not everybody realizes that the vast majority of mass you need for space missions (particularly those beyond Earth orbit) is fuel. Fuel itself is cheap, and nobody cares if you lose it, so you can just launch it up to a fuel depot to whoever the lowest bidder is (making it a great catalyst for commercial space startups). Then you can launch the much-lighter unfueled spacecraft up by itself (or construct it in orbit), allowing you to launch much more elaborate spacecraft using smaller rockets. Fuel depots are a HUGE technology multiplier in spaceflight. It's really a shame that NASA's prior architecture for various political reasons was pretty much explicitly constructed to avoid any use of fuel depots or in-space refueling.

Aerospace engineer Jon Goff at "Selenian Boondocks" has some really great write-ups and conference papers about propellant depots and how they can benefit a human spaceflight architecture:
http://selenianboondocks.com/2009/09/space-2009-papers/
http://selenianboondocks.com/2009/07/depot-centric-human-spaceflight/

One of the old arguments against propellant depots is that the technology is untested, although ULA just reported on the results of their in-space tests this month:

http://selenianboondocks.com/2010/01/additional-av-017-flight-experiment-information/

The real key demand for this technology is launching propellants to an orbital depot. The political climate has changed (temporarily I would say) so it's ok to talk about propellant depots again. ULA are doing some interesting research. That's actual hardware being risk reduced there. Once you have propellant on-orbit you can plan deep space missions using Soyuz class vehicles - going beyond LEO doesn't need Saturn class launchers. That's the cost comparison that we have to look at.. not "is it cheaper than Soyuz?" but "is it cheaper than Apollo?"

FYI, it's not a directed budget cut towards NASA -- every single non-military agency has been told by the Obama administration that they may see cuts of 5-10% in order to reduce the deficit.

http://www.spacepolitics.com/2009/11/17/sharpening-the-budget-cleaver/
http://www.google.com/hostednews/ap/article/ALeqM5hBr0LFXMFF1HE6-n_ZTN1829QS1QD9BUTPVG0

On the plus side, if there is in fact a budget cut, it'd hopefully be the cover NASA needs to shut down/reduce its politically well-guarded Marshall Space Flight Center (MSFC), which uses up a huge part of NASA's budget, but due to its chronically incompetent management has spectacularly failed in basically all of its large projects over the past 30 years.

$1.6B for the satellite? - wow.

The US Department of Defense is the only organization I've ever seen complain about launch costs being too low. Namely, they're willing to pay much more for a launch in order to insure the payload makes it. From what I understand, the cost above is a bit on the expensive side, but not the most expensive satellite that the DoD has put up.

Only if the costs are proportional, though, right? If one can do 7 Delta IV launches for the cost of 1 Ares V launch, then there *is* a strong argument. Costs ought to be figured out to probably 2040 or so and include Mars mission capability.

My view is that yes, they probably can do 7 Delta IV Heavy launches for the price of a Ares V launch. Plus they can launch unmanned payloads now. We could be launching lunar missions now, not ten or twenty years from now.

So, if the Ares V can put 70 tons on the Moon you'd need to go to a 14:1 ratio?

The Ares V has two efficiencies in its favor. First, it can launch directly to lunar transfer orbit (LTO). Using a Delta IV Heavy or equivalent requires assembly and fueling in low Earth orbit. So in the long run with appropriate infrastructure for the Ares V and the Delta IV Heavy, 14:1 ratio may well be accurate. And there is as I mentioned in a previous post some economy of scale in payload size. Even so, it may well turn out that the Delta IV Heavy (and Atlas V Heavy) would be cheaper in the long run.

As I mentioned above, the Delta IV Heavy could be launching now for lunar mission support. Even with the relatively crude Apollo-era Lunar Module "truck" that delivers 5 tons of payload to the Moon for the cost of say 5 Delta IV Heavy launches, that means that you could have significant activity on the Moon by the time Ares V hypothetically would be developed.

Further, and this is a key point that I don't think most heavy lift advocates understand, by buying a lot of 20-25 ton payload launches from multiple commercial launch providers, the US would be providing considerable incentive for larger commercial vehicles. Recall after all, that commercial launch has only recently gone to this payload range. I don't see a 180 ton payload vehicle in the cards, but easily 40-50 ton vehicles, maybe more, by the time Ares V would hypothetically come about. Incremental investment in commercial space launch is in my view far superior to NASA competing with commercial launch.

So why did the NASA study conclude the Ares I was 2x safer than a Delta IV solution? Just BS for the sake of perpetuating the program?

As far as I can tell, yes, that was bullshit. Whether it was intentional or not, the ESAS has a number of biases in favor of Ares I type vehicles. Overestimates of the safety of the SRBs (and to an extent other solid rocket motors including those used on the Atlas V Heavy) by what appears to me to be a factor of ten are only one of the problems. There's also apparently lowered standards for vehicles that depend on solid rocket motors for the first stage. Inaccurate mass numbers for the EELVs. Thrust oscillation (despite it being a problem for all solid rocket motors including the Space Shuttle) was completely ignored. And they treated crew escape from a complete solid motor rupture as being just as easy to escape from as the equivalent failure from a liquid propellant stage, even though the latter is more survivable due to slower combustion speed and lower heating of the escape vehicle (in particular, no melting parachute).

I'd like to see NASA

$1.6B for the satellite? - wow.

The US Department of Defense is the only organization I've ever seen complain about launch costs being too low. Namely, they're willing to pay much more for a launch in order to insure the payload makes it. From what I understand, the cost above is a bit on the expensive side, but not the most expensive satellite that the DoD has put up.

Only if the costs are proportional, though, right? If one can do 7 Delta IV launches for the cost of 1 Ares V launch, then there *is* a strong argument. Costs ought to be figured out to probably 2040 or so and include Mars mission capability.

My view is that yes, they probably can do 7 Delta IV Heavy launches for the price of a Ares V launch. Plus they can launch unmanned payloads now. We could be launching lunar missions now, not ten or twenty years from now.

So, if the Ares V can put 70 tons on the Moon you'd need to go to a 14:1 ratio?

The Ares V has two efficiencies in its favor. First, it can launch directly to lunar transfer orbit (LTO). Using a Delta IV Heavy or equivalent requires assembly and fueling in low Earth orbit. So in the long run with appropriate infrastructure for the Ares V and the Delta IV Heavy, 14:1 ratio may well be accurate. And there is as I mentioned in a previous post some economy of scale in payload size. Even so, it may well turn out that the Delta IV Heavy (and Atlas V Heavy) would be cheaper in the long run.

As I mentioned above, the Delta IV Heavy could be launching now for lunar mission support. Even with the relatively crude Apollo-era Lunar Module "truck" that delivers 5 tons of payload to the Moon for the cost of say 5 Delta IV Heavy launches, that means that you could have significant activity on the Moon by the time Ares V hypothetically would be developed.

Further, and this is a key point that I don't think most heavy lift advocates understand, by buying a lot of 20-25 ton payload launches from multiple commercial launch providers, the US would be providing considerable incentive for larger commercial vehicles. Recall after all, that commercial launch has only recently gone to this payload range. I don't see a 180 ton payload vehicle in the cards, but easily 40-50 ton vehicles, maybe more, by the time Ares V would hypothetically come about. Incremental investment in commercial space launch is in my view far superior to NASA competing with commercial launch.

So why did the NASA study conclude the Ares I was 2x safer than a Delta IV solution? Just BS for the sake of perpetuating the program?

As far as I can tell, yes, that was bullshit. Whether it was intentional or not, the ESAS has a number of biases in favor of Ares I type vehicles. Overestimates of the safety of the SRBs (and to an extent other solid rocket motors including those used on the Atlas V Heavy) by what appears to me to be a factor of ten are only one of the problems. There's also apparently lowered standards for vehicles that depend on solid rocket motors for the first stage. Inaccurate mass numbers for the EELVs. Thrust oscillation (despite it being a problem for all solid rocket motors including the Space Shuttle) was completely ignored. And they treated crew escape from a complete solid motor rupture as being just as easy to escape from as the equivalent failure from a liquid propellant stage, even though the latter is more survivable due to slower combustion speed and lower heating of the escape vehicle (in particular, no melting parachute).

I'd like to see NASA

You're not going to land an outpost on the Moon with a 70mt launcher, and you're definitely not going to go to Mars with that.

This is a common belief, but there doesn't seem to be much evidence for it. With existing and/or straightforward upgrade launchers it seems quite reasonable to do a lunar outpost (and perhaps even a Mars outpost), no super-heavy-lift required. Just take a look at the studies done for NASA before Michael Griffin came in and tossed all the prior work out. You just need to take advantage of things like in-orbit assembly, propellant depots, etc.

http://selenianboondocks.com/category/lunar-exploration-and-development/
http://exploration.nasa.gov/documents/reports/cer_final/Boeing.pdf
http://exploration.nasa.gov/documents/reports/cer_final/tSpace.pdf
http://exploration.nasa.gov/documents/reports/cer_midterm/tSpace.pdf
http://exploration.nasa.gov/documents/reports/cer_final/Lockheed_Martin.pdf
http://exploration.nasa.gov/documents/reports/cer_final/Schafer.pdf

It seems to me that Direct really is the better START PATH to the moon.

I like the DIRECT design and think it's the most straightforward way to get a heavy lift rocket if it's truly needed, but I'm still not convinced that a heavy lift vehicle is really needed for a lunar architecture. What are your thoughts on using things like orbital fuel depots to enable a lunar architecture using only vehicles in the class of the Delta IV Heavy and SpaceX Falcon 9?

What's uncertain is how well an experienced pilot with very little technical knowledge [wikipedia.org] can run a huge agency that has extremely complicated technical problems.

This is a popular meme amongst the technically-inclined (a group in which I include myself), but when it comes down to it, a NASA administrator with a high level of technical expertise is largely what got us into the current mess we're in. Nobody would dispute that the prior administrator, Michael Griffin is a technical expert, with several masters degrees (aerospace, civil, and electrical engineering) and a PhD in aerospace engineering.

Unfortunately, as often happens with us technical types, he ended up getting obsessed with a particular technical idea and ended up blocking out potentially-superior alternatives. In Griffin's case, he designed a novel shuttle-based manned rocket (using a solid rocket as a first-stage) prior to becoming administrator, and once he became administrator he put NASA's weight behind his pet design and clamped down on engineers who raised concerns. According to some recently-leaked NASA documents, the supposedly-unbiased ESAS study which selected NASA's current rocket design in fact gave safety exemptions to Griffin's pet design while unfairly penalizing competing designs. Fast forward to the present, and it's looking like the issues with Griffin's design (now called the Ares I) are fundamental design problems with costs ballooning skywards.

While technical proficiency is nice, it's not the most important thing in a manager of a program like NASA. Far more important is the ability to judge things in an unbiased manner, and being able to listen to your subordinates when they voice concerns.

"The NASA budget for 2010 has been announced, up 5% on 2009. Human space flight plans to be reviewed."

I'm quite glad to hear that this review of NASA's spaceflight plans is occurring, and from what I've read seems to be quite good at minimizing outside/political/industry influence and making sure that the recommendations will truly be the best ones possible. The only problem is that NASA and/or the administration might end up ignoring those recommendations for political reasons (e.g. making sure jobs remain in particular congressional districts).

Evidence has recently been leaked that the NASA's ESAS study which settled on the homebuilt Ares I (based on then-Administrator Mike Griffin's pet design) over the already-existing commercial EELV rockets was deeply flawed. Basically, the flawed 60-day ESAS study (often relied on by certain NASA officials to defend their plans) had a number of major problems:

(from Selenian Boondocks, with parts of the leaked study available on Wikileaks )

• Exceptions given in the ground rules and assumptions on maximum dynamic pressures to In-line SRM based crew launch concepts that weren't given to any other vehicles (without the exception, all of the five-segment Stick concepts would've been ruled out from the start).
• Unrealistically assuming a fixed LAS mass regardless of first stage characteristics (like T/W, max-Q, and whether you can shut them down or not).
• Inaccurate dry mass numbers for existing EELV upper stages (just as some of the guys on NASASpaceflight.com had been saying for years now).

As things currently stand, the Ares I has been running into major problems, many believe it to have fundamental design flaws, and projected development costs are running into the $30-$50 billion range. Meanwhile, a couple weeks ago a NASA-commissioned independent study confirmed that the commercial EELVs would be able to fulfill NASA's needs of transporting NASA's orbital and lunar spacecraft, with estimated costs of a few billion dollars (about an order of magnitude less than the Ares program). That's to say nothing of SpaceX and COTS-D, which could do the job for around $1.5 billion dollars of development costs.

And actually, it's not even necessary to launch the Ares I design on the Delta IV Heavy, just an Atlas V, according to some.

Jon Goff is a great rocketry blogger. He pushes the orbital propellant depot hard and this is why. Once you have it going, it boosts the capabilities of your launch infrastructure considerably. Since you no longer have to launch fuel with lunar missions, you can fit a lot more vehicle on smaller rockets. The Ariane 5 is another rocket that can carry an unfueled Orion or propellant. Another important aspect is that this approach is highly scalable. You can use the same tricks to fuel other big missions, manned or not. It's a shame that NASA has done almost nothing with this concept.

I suspect there's a longer-term plan to swap out the 9 Merlins on the bottom of the Falcon 9 with two bigger rockets. Except that nobody inside of SpaceX is going to breathe a word about it until the right time.

It would be a natural continuation in the sequence of engine designs they've done. My take is that they're focusing on launching falcon 9 right now. They need that to go well. But there's no reason they couldn't have bigger engines on the drawing board.

Please read my comment again.

I said Ares I / Orion replaced by the Falcon 9 / Dragon. Not the Falcon 9 Heavy being used to lift the Ares I.

And actually, it's not even necessary to launch the Ares I design on the Delta IV Heavy, just an Atlas V, according to some.

I suspect there's a longer-term plan to swap out the 9 Merlins on the bottom of the Falcon 9 with two bigger rockets. Except that nobody inside of SpaceX is going to breathe a word about it until the right time.