ME--"Ken has been vigorously promoting the NASA plan I dislike the most I've ever heard of from NASA."--

Heh, heh, heh. I've been promoting a NASA Plan? Really? Would that be the NExT Plan that I've derided in other posts as lacking a clear vision of what to do at any of the destinations they propose? Which, as I've also noted, is probably intentional as it's intended to be a top-level study. On a personal level, I feel that what I've seen of it to date is pretty weak product for all of the investment.

Or have I been vigourously promoting some other plan I'm not aware of?

What I have been advocating,
irrespective of whether NASA agrees or not,
irrespective of whether Buzz Aldrin agrees or not,
irrespective of whether the NSS agrees or not,
is an EML-1 project as the next reasonable, logical and readily achievable step beyond ISS.

I've listed a lot of good reasons for doing so. Some are also listed below. They didn't come from one source, some I've never seen elsewhere. Few have been adequately debunked here for me to discard them. As I've noted again and again and again and again and again, it's not just about delta V.

As a relative "outsider" with regards to the space industry, I have the benefit of not being tied to any particular agenda. My analyses are the result of comprehensive research over a number of years, little data points that I pick up here and there that eventually come together to form a logical mosaic of space activities. I have been blessed with many unique opportunities to peek into the space world, but in the end I am not welcome within its ranks professionally. Darn that taint of filthy lucre.

This is part of the reason that the NSS is the only space advocacy organization that I am actively affiliated with.

[Full disclosure: I am also a member of the Moon Society, but for very specific reasons, largely related to their publication, the Moon Miner's Manifesto, which is really good stuff, definitely worth the investment. I am not active in their activities]

My concern is with how to make space relevant and of interest to the broadest swath of the human population possible, part of the philosophical impact of my experiences in the SGF at UNISPACE III.

Again, I am not a NASA flack. I don't put my arms around EPG. I'm not an NSS shill.

I am an analyst that looks at
possibilities, not limitations,
capabilities, not restrictions,
assets and liabilities,
risk and rewards.

ME--"Ken has compared the Langrange base as an airport Hub. It should be noted that none other than Buzz Aldrin supports this idea, but as an engineer who specializes in cutting waste and inefficiency it makes me want to gag."--

With a spoon? (Sorry, bad Valley Girl joke I just couldn't pass up)

So if I can misread your statement above, are you implying that Mr. Aldrin is an engineer who doesn't specialize in cutting waste and inefficiency? Or perhaps one who advocates waste and inefficiency?

Seriously, Mr. Aldrin's work in orbital mechanics over the last few decades is nothing short of astounding, from the Mars Cyclers to an orbit that loops endlessly around the Moon and Earth (i.e. orbital hotel). He may have also been involved with the design of the free-return trajectory that helped Apollo 13, but I'm not certain. I know he did outline some kind of unusual Lunar orbit stuff back in the day.

I don't know how he perceives the delta-V issue, but if he's willing to propose an EML-1 station, given what I know he knows about orbital mechanics, then I consider that adequate support for the conclusions I myself have drawn.

I'm pretty sure there's a kind of orbit where you can pass in front of the Moon in its orbit instead of behind it, and thereby get a kind of gravity brake (instead of a gravity boost) relative to both bodies' motion around the Earth, and possibly slide into a low energy trajectory around the back of the Moon and into L-1, thereby reducing your overall delta-V requirement.

As I haven't looked at that stuff in a little while I haven't been confident enough to bring it up to date (and I don't feel like looking it up right now), but I'm willing to throw it into the kitty. Another little edge.

ME--"1) You don't build a hub for 2 air flights a year. Hubs are used because they promote overall efficiency eventhough individual travelers find them inefficient. A single plane following typical routes between nonhub cities uses far more fuel than if it flew direct. The system is efficient overall because large planes are used between hub cities transporting a large number of people more fuel (or cost) efficiently than could be justified by the volume between smaller cities. Without high volume hubs make no sense. Building a hub at the start of the airline industry would have been a huge waste of money. It is putting the cart before the horse."--

Please see my answer below. And remember that I'm not proposing that the "hub" serve no other purpose whatsoever than as a transit node. Delta-V is but one factor amongst many.

ME--"2) Ken has not really addressed the issue that going through a Lagrange base makes transfer to any near term objects such as NEOs, Mars, and the Moon harder. Ken listed a bunch of references for delta V estimates, but I didn't have any problems with his numbers.

It was the application I disagreed with. "--

Here we have to look also at the reply I gave to Raoul regarding orbital refueling. Two factors to consider: 1) The kinds of trans-LEO transportation we're talking about, and 2) How you tie those together logistically.

For the both issues, we have to look at how our trans-LEO transportation will be developed.

Under the doctrine that it is the destination that is paramount in design capability, you optimize the capabilities to the minimum (with some margin for safety) necessary so that you can build each one as inexpensively as possible. Nevertheless, each one will be individually custom built. You save on fuel tank mass, you can use smaller engines, have to carry less fuel, etc. But for a robust and permanent space infrastructure this approach is penny-wise, pound-foolish.

You also have to support the manufacturing capabilities of:
a Mars vehicle
a Moon vehicle
a NEO vehicle
an ISS vehicle
a GEO vehicle (assuming you want to do anything there. I do)
an EML-1 vehicle (if you want to go there, I do)

Six manufacturing assembly lines. Six. How cost efficient is that?

Under this doctrine, you wouldn't use a Mars vehicle to go to the Moon. You wouldn't use either to go to a NEO. GEO and EML-1 would probably end up being ignored.

The particular vehicle for a particular project may seem cheaper, but the overall cost of your space infrastructure is going to go up dramatically. On the macro scale you're in big trouble, and you have to start thinking about which projects and benefits can be sacrificed. And each destination becomes a cul-de-sac, just like the ISS is right now.

Under the doctrine that it is the capabilities that are paramount, your task becomes much simpler to design across a broader array of projects and endeavours.

It may turn out that a unique core element can be designed that proves adaptable to a number of missions. A core element (be it lifting body, capsule, or caplet [my name for an RV sized cylinder] that can be launched on a modified D-IV-H or A5) launched to ISS can then be fitted with a heat shield for Earth return, a propulsion unit for travel outbound to at least the Moon's surface distance-wise, or legs/skids/whatever for landing on a surface.

One supply assembly line with a few auxiliary feeders. One.

As far as space infrastructure goes, you're golden and all of a sudden things like going to GEO or EML-1 make sense. It's also far easier to design and build a disposable heat shield for Earth return than an entirely new vehicle for a trip to a NEO.

Link a few caplets together and you have a cheap and dirty space station for LEO or EML-1. Dump a couple on the Moon as auxiliary hab units or use them as hoppers.

All of a sudden you're mass producing the elements because you're going to be having regular traffic between LEO (ISS) and points beyond, and you're going to be leaving some of those elements there.

Again, why do we want to have cislunar Trans-LEO maneuvering capability?

-So we can fix $600.0Mn satellites like ADEOS instead of throwing them away.
-So we can go to GEO to start cleaning out the garbage. Same with LEO
-We can fix XM's Rock and Roll solar panels instead of writing off the satellites,
-We can refuel existing assets to extend their lives and utility (and because only humans have mastered the art of duct tape!),
-We can do servicing runs to EML-1 to upgrade SOHO or NGST or Genesis or others.
-So we can establish an early, orbital NEO watch capability (and EML-1 is really the best for that, LEO and GEO are just too darn crowded)
-So the ISS becomes more than just an isolated science outpost.
-We can do all of the important work that needs to be done on the Moon such as:
*Detecting NEOs from a stable platform
*Crater counting and dating
*Mining oxygen from the regolith for rocket fuel and life support
*Mining SPS materials from the regolith
*Mining industrial metals like titanium, aluminium, iron and so forth
*Looking for PGM asteroid remains so we don't have to tear up our own planet to get it
*Practicing for Mars

Fourteen reasons why designing for capabilities make sense. There are many, many more, but these are the obvious ones.

[LEO: Salvaging STS-ETs. EML-1: Teleoperation of Lunar probes, Micro-g freeflyer rendezvous point, Mission to NEO, Assembly point of Mars mission done right. Moon: Nanotech Lab, Anhydrous optics, Archive of Humanity, Lunar calendar cathedral (gee, there's another nine)]

Each one is value-added for Earth-based interests. Put together they provide a compelling story for why it is important that we go to space. Everyone, not just engineers and scientists. A reason for the general public to believe that their tax or investment dollars aren't being thrown into a black hole.

Under this doctrine it makes sense to have a transit node in LEO, the ISS is the logical choice, and a transit node at EML-1, to which you can get from ISS with effectively no plane-change penalty.

The first as the launchpad trans-LEO, as well as inspection and emplacement point for LEO satellites post-launch, a lab bench for biologists and chemists to run real experiments instead of remote-control automated experiments, quarantine for Mars Sample Returns, fuel depot.

The second serves as communications node, servicing and upgrade center on the Interplanetary Superhighways, power source for Lunar activities, GEO ops facility, Lunar emergency room, launching point for Lunar landings, etc., etc.

Traffic. If you design a common core, that element will go back and forth from the Earth to ISS, from ISS to LEO to ISS, from ISS to EML-1 to ISS, from EML-1 to GEO to EML-1, from EML-1 to the Moon to EML-1, from the Moon to the Moon, from EML-1 to NEO to EML-1. From EML-1 to Mars.

I'm hoping some guy figures out a cheap and reliable Al/LOX engine for cislunar operations. Talk about your cheap fuel. In any event it's going to make sense to stockpile propellant at ISS, EML-1 and on the Moon.

Preferably from the Moon, sooner rather than later, but early on, yeah, we're going to have to launch propellant from Earth with its associated costs. Long term, though, it'll likely work out to be cheaper for better overall results. Besides, are the Martians proposing to have Mars serve as the fuel source for cislunar operations? Mars is a loooong supply line, fraught with peril.

Permanent and robust architecture. We have the rare opportunity of a tabula rasa in which to expand our capabilities and experiences. We can do it right the first time, using the best of what we've learned here on Earth. Or we can continue to fritter away our resources at snatch and grabs.

I don't believe that mission-specific optimization of design is the way to go. In fact, I firmly believe that it is absolutely the wrong path for our space future.

ME--"3) This is also where I disagree with Gary on a related infrastructure issue. I don't think we can commit to Martian colonization and cycler spacecraft until we send some missions of exploration there. I also think we need CATS for colonization."

Two words, ME:

Mass production

It is the only way that space is going to make any sense as an objective.

Regards,
Ken