I fully agree with this. This is a problem that needs to be approached from both ends simultaneously. The first low cost space transports are going to have small payloads – in the few hundred to few thousand kilogram range. We need to be developing the full range of payloads now to fit these space transports, using orbital assembly as required.

I don’t disagree with much of your analysis, but your key sentence, and the key problem, is that one. Today, there are a few dozen payloads to orbit. Who is going to spend the money to develop reusable transport to serve that market? Nobody, except the odd idiot spending his personal fortune for ideological reasons derived from Star Trek. You need a bigger market first, to pay for the up-front development costs. That’s why the Space Station and lunar base are so important. Potentially, these are markets for space lift that will dwarf any existing market, and, if they are ever commercialized, they are what will pay for your development costs. We’ve been trying to do it the other way around (up-front development of efficient launch vehicles first, reason for their existence second) ever since Apollo, and it hasn’t worked. I see no reason for it to work now.

Dennis: ISS or some commercial facility in orbit is far more important to the opening of at least the cis-lunar economy than simple low cost launch to orbit alone.

Good to hear from you as well. I fully agree with this, as I argued some years ago here,

http://www.speakeasy.org/~donaldfr/sfmodel.pdf

I am agnostic on launch vehicles for the CEV as long as it does not involve developing a new one. I think we should have used the EELVs to take advantage of economies of scale with the Air Force, but if the Falcon-9 is ready in time, I’d love the see them have a go.

Developing — and maintaining! — a new set of launch vehicles for use solely by NASA is the wrong way to go. However, since the decision has been made — and because fratricide will kill the VSE far faster than the wrong launch vehicle — I’ve thrown my support (such as it is) behind the current plan.

— Donald

I worked with tethers for almost ten years and am a great fan of them in their proper place. A spinning tether can toss a payload ten times its length but with the penalty that it reduces the orbit of the tether by the ratio of the weights tossed. A tether would work great for dropping payloads from ISS while giving it a boost.

I like electrodynamic tethers that are also used for momentum exchange as this is the way to recover the lost momentum, assuming you have a power supply to pump the energy into the tether. E-tethers don’t work very well above 2000 km.

For a real transportation system between the Earth and the Moon, tethers can be used to optimize some orbital energy but mostly on the outgo from LEO. The timing is so tight that it is not that valuable for a lot of things.

I guess I am of two minds about tethers, I like them more for LEO to the ground and low LEO orbits rather than for grand schemes. The exception to this is the idea of Paul Penzo of JPL to use very long (1000+ km) tethers attached to Phobos and Deimos to provide a way to drop into, and climb out of Mars orbit without much energy being required. Look up the papers on that idea.

Dennis

Dennis, what are your thoughts on momentum exchange tethers?

= = =

On the main point, recall that sci-fi master Robert Heinlein wrote: “Once you get to low Earth orbit, you are halfway to anywhere. . .”

True, but if you then remain stuck in LEO then “halfway to anywhere” is really no where that is either interesting or useful.

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As no less an expert than Wendell Mendell once pointed out, the incentive to develop local resources is directly proportional to the cost of transport. The higher the cost of importing things the higher the incentive to make do locally. If you are correct re. transportation costs, than there will be relatively little incentive to develop lunar oxygen, et al. If I am correct, than the incentive becomes very high.

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Hi Don! By the way it has been many years since we met, good to see you are still around.

While low cost transport to LEO is important, so is low cost LEO-LLO-LEO costs (or straight to ground). I don’t really buy mass drivers as the holy grail as it is almost impossible to target them at the right point on the Earth, too many transient variables involved. What is important is a transportation system that can move signficant material to and from Earth orbit to the Moon and back. This is why I applaud the COTS effort and hope that there will be a proposal out there that actually has a chance of working.

ISS or some commercial facility in orbit is far more important to the opening of at least the cis-lunar economy than simple low cost launch to orbit alone. The rational is this:

A heavy lifter, no matter the type, is going to cost at least ten billion dollars to develop, if not more (Gordon Woodcock estimates that the current NASA HLLV is going to cost $20 billion). That is a very high energy of inital cost that, while government may absorb that cost, there is little likelyhood that the operational cost is going to be low. For example of this, the NASA budget assumes a CEV budget of $2.4 billion dollars per year between 2012 and 2016. Since they are only talking about two flights per year, this means that the CEV is going to cost about $1.2 billion per flight. Correct me if I am wrong but this is HIGHER than Shuttle costs when it is launched at least four times per year.

A theoretically low cost launcher such as what Elon proposes could get payloads, including a human occupant, to LEO for considerably less but still not cheap. The Russians today launch crew and cargo for pretty reasonable costs, to ISS. With that low cost, and with the ability to store partially complete vehicles at the station, we don’t need heavy lift. I can guarantee you that five Proton’s or Faclon 9’s will be cheaper than a single heavy lift launch. If we couple that with an electric propulsion system to take cargos to LLO, then we have the potential for a commercial system to carry payloads and people to the Moon completely outside of the ESAS system, while allowing the COTS funded developments to help amortize the cost of commercial systems to station to provide an American solution.

Just some thoughts about first steps.

Dennis

Some of the issues in the above discussion of the Anglosphere concept are addressed nicely in Peter St. Andre’s recent post at Albion’s Seedlings.

Interesting. Based on that post, it would seem I am Quaker-oriented. A world view solildy within the Anglo-sphere without being necessarily supportive of American military hegemony.

One still should be designing for substantially lower cost, as this is possible and maximises the return. This quickly leads to even lower costs.

$200-300 million seems a common figure for the development of a low cost 2000-3000 kg payload space transport. Boot legging a rotovator sees payload gradually increase up to about ten times the original amount. (This is an exponential relationship so increasing the payload fivefold costs very little, like fifty original payloads worth of tether system, increasing tenfold costs a lot more.) So it seems sensible to me to start with the development of a space transport in the 100-500 kg payload range. This should reduce initial development costs and increase initial flight rates significantly.

Fuel costs start off at around $10/kg to LEO, lowering to around $1/kg to LEO with the fully developed rotovator system. A 500 kg payload at $100/kg is $50,000 per flight, $5,000 of which is fuel. With high flight rate, operational and maintenance costs should probably also be in a similar range to fuel costs. Hence the dominant costs are initially development and vehicle costs, these set the cost/kg to LEO.

Assuming an equatorial launch site and LEO destination, and about an hour turnaround at each end, around eight flights are possible a day, say 2500 a year. Obviously one would plan on a lot less initially, like one flight a day.

Assuming $100 million average development and build cost amortised per space transport in the fleet and 1000 flights per space transport before retirement, this would cost about a $100/kg to LEO. At full flight rate, such a space transport would have a life span of less than six months. One should probably assume much lower average development costs, significantly higher fleet numbers, (more than three space transports), over which such costs would be spread and many more flights per space transport. In time development and space transport build costs should be in a similar range to fuel costs.

Assuming $10,000/kg of drymass, a nominal, (without rotovator), 500 kg payload space transport might cost $25 million to build. This should quickly decrease to around $1000/kg of drymass or $2.5 million per space transport. On the above assumptions this cost fraction works out at $50/kg and $5/kg to LEO respectively. With a fully developed rotovator this would go down to around $0.5/kg to LEO.

In this fashion, with a fully developed rotovator system, I would expect total costs to eventually get down to below $10/kg to LEO. Without a rotovator, I would still eventually expect less than $50/kg to LEO. This all assumes a mature industry, much like air or sea travel. With such high flight rates space transports reach retirement age in only a couple of years. This makes for a very short developmental generation, and so I expect industry development to be very fast indeed. The space transport design, build and fly cycle should almost be an incrementally improving production line, completing the next vehicle every few months. Costs per kg to LEO will drop rapidly once such a process is started.

I find it a bit ironic to be dismissed by comparison to the “more important” Mr. Jefferson. (Was it me who claimed to be equally or more important than that gentleman?) Although I do not claim to rival him in importance, I am one of the more conspicuous of those who have pointed out that Jefferson’s long-dismissed historical scholarship, on which his better-known writings rest, has in fact been revindicated by recent historical scholarship. Jefferson himself was not an American exceptionalist — he placed the development of free institutions in American unambiguously in a line of descent from the english representative and constitutional institutions that date back to Anglo-Saxon times and beyond, resting his argument on Montesquieu’s research on medieval and pre-medieval constitutionalism. This research has recently been shown to be largely accurate, and in general the continuity of American culture and institutions from its British Isles predecessors, and the continuity of English institutons to pre-Norman Conquest institutions, has been given renewed emphasis from recent research. The whole idea of the “frontier thesis” and American expectionalism was a 19th century romantic nationalist fiction adopted in American schools for propaganda purposes. Ironically the idea of an “authentic American national voice” distinct from European models is in itself a 19th-century import from German models, which have in turn become discredited due to their role in propogating certain unpleasant events in their country of origin 60 years ago.

But don’t take my word for it — my sources are readily available.

I agree. It is my understanding that telecommunications and tourism periodically trade places as the world’s largest industries. The money is there if we can find a way to exploit it.

Pete, I’ll believe $100/kg. LEO transport when I see it. In the mean time, I think it is wisest to assume that’s not going to happen and act accordingly. After all, if you can make a business work at current rates, it’ll take the world by storm at $100/kg. When planning space-based industries, I see every practical and financial reason to assume the worst and hope for the best.

The equipment necessary to mine, transport and process lunar resources will be far more complicated and difficult to develop than Earth to LEO transportation,

While I am not an engineer and will defer to those who are on this, I think this extremely improbable. Anyone else care to comment?

and there will be far less short term economic incentive to do so.

As no less an expert than Wendell Mendell once pointed out, the incentive to develop local resources is directly proportional to the cost of transport. The higher the cost of importing things the higher the incentive to make do locally. If you are correct re. transportation costs, than there will be relatively little incentive to develop lunar oxygen, et al. If I am correct, than the incentive becomes very high.

$500 million in prize money could probably help pay for the development of 2-3 low cost space transports systems and low cost orbital assembly habitat modules to boot. One does not develop low cost space settlements by spending lots of money. That leads to corruption, pork barrel politics and a failure to achieve any results whatsoever. Stupidly high costs have a bad tendency to poison every design they touch, it is much safer to keep one’s distance.