Someone talked the Gray Lady into publishing a boilerplate proposal to fix our space program--let's go to the Moon! (registration required)

Yawn...

These pieces always assume that there's nothing wrong with the way we're doing space that a spiffy new goal won't fix up. And of course, we should not only go to the Moon, but we should do it as an international venture. Sure, why not? After all, just look how well it worked out with the space station...

These people need to realize that, until we tackle and truly solve the problem of access to orbit, the rest of this is pipe dreams, and if we do solve it, we won't have to argue about what we should be spending NASA's money on, because we'll be able to afford it ourselves.

These people need to realize that, until we tackle and truly solve the problem of access to orbit, the rest of this is pipe dreams, and if we do solve it, we won't have to argue about what we should be spending NASA's money on, because we'll be able to afford it ourselves.

This makes the rather huge assumption that what works for small payloads will work for larger ones.

On what basis are you making that assumption?

This makes the rather huge assumption that what works for small payloads will work for larger ones.

I make no such assumption.

--solve the problem of access to orbit--

Yes, this is THE issue (and you admirably keep your focus - while my attention tends to wander;-)

The thing that bothers me about these discussions is they tend to go off in all directions with regard to vehicle design (and I'm certainly guilty of that myself) when really it's a pretty straight forward engineering problem...

Give a number of engineering teams the goal of lowest dollars per ton in orbit (with a minimum tons and orbit diameter specified.) In a few weeks you'd have your answer with regard to two or three good designs, all of which we could probably implement. Oh, you might first have to beat them all over the heads repeatedly with baseball bats to remove any prejudices they harbor. Otherwise, it doesn't matter the form of the design as long as the real cost issue is addressed.

Now personally, I think expendables would turn out to be much cheaper than reusables if it's designed to be simple to manufacture

Anyway... now I have to go read your Fox article.

I make no such assumption.

I'm prepared to believe that small ventures might possibly construct LEO vehicles, but that doesn't solve the problem of space access for large payloads.

I'm genuinely interested in hearing your thoughts on how that problem can be solved economically.

I don't see a real need for large payloads, if small ones can be delivered cheaply enough, but if there's really a market for them, something like Seadragon would probably be fine.

I suppose, in that case, the difficulty I have is with building any kind of reasonable infrastructure for expansion into without large payloads.

If all you are considering is LEO joy rides then fine - but I'm not entirely sure how that differs from the evolutionary dead end we're in now except that its a private dead end.

I can certainly see costs for small payloads coming down, but if you're stuck in LEO with no where to go, the shine will rub off quickly. While I'm prepared to believe there might be a chance of a small LEO vehicle being built privately. I'm not even remotely convinced a private company is going to build a Sea Dragon.

> I suppose, in that case, the difficulty I have is with building any kind of reasonable infrastructure for expansion into without large payloads.

What's "small" and "infrastructure"?

I note that the Conestoga wagon had sufficient capacity to "civilize" the Western US.

Yes, they could make use of raw materials and live off the land ONCE they got there, but they carried most of the food/water for travel.

No, they didn't need to carry air.

Lots of small loads can be substituted for a few large ones unless there are single items that are too big. Are there, or are we assuming that the large loads are necessarily economically efficient?

> I suppose, in that case, the difficulty I have is with building any kind of reasonable infrastructure for expansion into without large payloads.

What's "small" and "infrastructure"?

I note that the Conestoga wagon had sufficient capacity to "civilize" the Western US.

Yes, they could make use of raw materials and live off the land ONCE they got there, but they carried most of the food/water for travel.

No, they didn't need to carry air.

Lots of small loads can be substituted for a few large ones unless there are single items that are too big. Are there, or are we assuming that the large loads are necessarily economically efficient?

What's "small" and "infrastructure"?

I'm making an assumption that the typical payload you could build something cheap to deliver to LEO is going to be in the sub 6,000kg range and with a signficantly constrained physical size.

This limits several things; firstly the sapce you have to build habitats, even inflatables are going to need some rigid components and you're unlikely to have a cargo diameter more than a couple of metres (if that). Secondly, if you want to move orbits, go to the moon, near-Earth Asteroids and the like, you have to get motors into orbit and the fuel.

Lots of small loads can be substituted for a few large ones unless there are single items that are too big. Are there, or are we assuming that the large loads are necessarily economically efficient?

In my opinion there will be loads which will be too large, a moon lander, reasonably sized habs, parts for a moonbase etc...

The problem I see is that even with arbitarily cheap access at the lower range, small cargo, people etc... you're still going to need something big and probably expensive.

A Sea Dragon booster, big and cheap would give you a good $ to LEO ratio, but I'm not convinced it would be all that cheap (q.v. others who've been trying to build large cheap boosters) and certainly not something for the private sector.

I just can't see space developing without sensible government support. This is nothing new for new frontiers and I'm rather suprised at the fuss it causes.

This limits several things; firstly the sapce you have to build habitats, even inflatables are going to need some rigid components

Those can be assembled, as can all the other things you mention.

"A Sea Dragon booster, big and cheap would give you a good $ to LEO ratio, but I'm not convinced it would be all that cheap (q.v. others who've been trying to build large cheap boosters) "

If you are launching large amounts of bulk materials, like construction materials and rocket fuel, your launcher doesnt have to be particularly reliable or safe, as loss of even 50% of payloads would be of no significance.
So you can mass produce your launch vehicles without overly stringent QA, read: cheap.

The business model is pretty simple. Bulk materials are hideously expensive on LEO ( due to current launch costs ) and dirt cheap on earth. Build a "dirt cheap" mass produced expendable launcher, with no particular focus on reliability, and even if you lose 90% of your payloads, you could still be making profit.

Of course, range safety puts some limits on ways your launcher is permitted to fail, but those problems can be worked out.

In short, leave multibillion dollar spacecraft and humans out of your intended payloads, and the task suddenly got alot easier.

Those can be assembled, as can all the other things you mention.

Some of them could over time, but designing many of these things to be assembled in zero-gee is going to make life very complicated and not necessarily make your costs any better. I also doubt if some of these things can be sensibly assembled, e.g. fuel tanks for inter-orbit vehicles and so forth, unless you have a huge number of very small tanks, which will increase the nightmare of the plumbing you have to do.

Wrt to low reliability. Fuel you can afford to loose, but I have separate engineering issues on that. Large hab's and other construction materials, are unlikley in the early stages to be anything like cheap, because we won't have the materials handling and fabrication suggested by the term "raw materials". You're going to have to launch stuff you really need, and its unlikely to be dirt cheap, especially habs, engines, large life support kit and so forth.

and even if you lose 90% of your payloads, you could still be making profit.

That depends on what you are carrying. I think for a long time we're not going to be able to launch payloads you could afford to loose 90% of them.

I'm making an assumption that the typical payload you could build something cheap to deliver to LEO is going to be in the sub 6,000kg range and with a signficantly constrained physical size.

If you don't make that assumption, then your concerns go away. It's not clear to me why we should assume that private launch capability will remain restricted to small payloads? Frankly, I think that getting any launch capability going will be harder than scaling up that launch capability.

I just can't see space developing without sensible government support. This is nothing new for new frontiers and I'm rather suprised at the fuss it causes.

My question here. When will we get sensible government support for space development? Part of the fuss, I think is that people are assuming you think the current NASA mess is a variant of "sensible government support".

It's not clear to me why we should assume that private launch capability will remain restricted to small payloads?

Frankly, I think that getting any launch capability going will be harder than scaling up that launch capability.i>

Looking at the approaches being taken, we have small manned vehicles which will carry limited payloads into orbital hops which might be scaleable to manned orbital joy rides and then back. By the necessity of design these will have low (sub 6,000kg) payload ability and some form of atmospheric ability suggesting wings. The launch dynamics will be based around this in terms of the first stage and so forth.

The dynamics of heavy payloads and the diameter requirements that even inflatable habs or engines will introduce will be much much harder, and I don't see them coming from an evolution from private manned launchers.

So, in short, based on experience, I think scaling will be as much of, if not harder than getting an orbital ability.

When will we get sensible government support for space development? Part of the fuss, I think is that people are assuming you think the current NASA mess is a variant of "sensible government support".

Ack. I can't argue with that part. The way NASA have done things is, in my opinion, wrong headed.

However, I don't for a moment believe that the market is in a position to take over at the moment.

Frankly it should be doing the long range science and research. It shouldn't be running space operations and it shouldn't be building the manned vehicles, except in so much as it can undertake raw-science work.