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This reminds me of a proposal I saw to use pulsars as a sort of "Interstellar GPS," making use of their signals to determine one's location. The description from Selenian Boondocks:

The other [Microcosm proposal] that appeared even more interesting to me was the idea (which I'll dub X-ray Pulsar Positioning System or XPPS for short) of using naturally occuring signals from X-ray Pulsars to provide positioning and attitude data anywhere in the solar system, not just inside the orbit of existing GPS satellites. If something like that works, it could make interplanetary navigation substantially easier, much as GPS has made terrestrial navigation so much easier. GPS is really convenient, and it would be nice to get even some of the benefits of it without having to pay the huge infrastructure costs of setting up systems like that around every interesting planet or moon that we want to settle in the future. All that said, this is just a Phase I SBIR, and it would be interesting to know more about how they were actually planning on doing this. Anyone have any thoughts?

Hmmm... perhaps you'd better tell the folks at Spacex, Microcosm, and Blue Origin about your expert insights in to the costs and benefits of entering the launch market. They may want to rethink their business plans.

None of the X-Prize concepts are anything but rehashing 40 year old technology. Next big technological break-thru might be a working scramjet, but succeeding in that is not for the hobbyists. If you are serioisly looking for better price/performance with existing tech check out these guys. Ablatively cooled rocket engine, that's a real innovation!

This probably is a very pessimistic estimate. For somewhat more optimistic outlook, see Private Space Development Timeline Mind you Elon Musk of SpaceX is planning to launch his semi-reusable Falcon in January, 2004. That is, to orbit. Some other companies, like Microcosm and SpaceDev are on track to launch their low-cost orbital vehicles in quite near future too. If and when X-Prize is won, the efforts ( sub ~million per launch manned suborbital ) and current "cheap" launcher builders will converge and it isnt unreasonable to expect a couple million range manned orbital launches in this decade. Given some competition and general revitalization of industry, expect new high-tech technologies and materials to be employed real fast after initial proofs of concept, thus bringing the price down even further. Imagine, a million dollar orbital trip that could be won on lottery.

I am not yet convinced that the technology exists to make space travel inexpensive enough for any organization that does not have the capability to spend hundreds of millions without seeing a return

Consider that there are multiple private organizations, on a relatively shoestring budgets, in the USA alone, who are doing their own stuff in this area. Check for Microcosm, Flometrics, even a department of a university, not to mention John Carmack's company, XCOR, Burt Rutan's Scaled, all regularly mentioned on the Slashdot. Add other countries - in Europe, for example - in short, a lot of guys are thinking different than you do.

And you won't believe how unsophisticated by today's standards is the technology of the first rockets. Just imagine, they were made out of steel, with almost no computers in the whole lifecycle of devices! It's literally a technology of times half a century back. It's not a technological issues anymore, you just use off-the-shelf components, well, for most of things you need. And you have tons of knowledge for what and how and why to do and not to do. Having all this in, one can wonder, why we still don't fly economically :) .

Very true -- HTP is very unpleasant stuff. One speck of the wrong kind of impurity in your tank, and the whole thing goes up.

Combine that with a simple, pressurized fuel tank instead of turbopumps, and you have a rocket engine with the minimum of moving parts.

Yeah, and atrocious performance, too.

Pressure-fed rockets are much simpler than pump-fed ones -- they have many, many, fewer moving parts -- but they require very substantial tanks, since the tank pressure has to be greater than the combustion chamber pressure in order for the propellant to flow. Since, for weight reasons, you can't want to make your tanks out of 1 inch thick steel, you're stuck with fairly low chamber pressures, and the resulting low thrust.

On top of that, monopropellant peroxide has a very low specific impulse. SMAD3 doesn't give an ISP for mono-H2O2, but it does give a value for "Monopropellant (H2O2, N2H2, etc)" as 150-225 s; combining this with some other information would suggest that H2O2 is at the lower end of this scale.

Beal et. al. got around this by running their rockets off H2O2 and LOX; SMAD has no numbers for this kind of engine, but Mark Wade's site gives numbers from 250-300 s for Beal's design. This is quite respectable, but has the downside of requiring a (mildly) cryogenic oxidizer.

Well, there's at least one project that has a better possibility of reducing launch costs to LEO. Check out Scorpius by Microcosm.

Sure, it's not as sexy as new, untested wizz-bang technologies (like aerospike engines, composite H2 tanks, scramjets, etc.). It pretty much follows LEO on the Cheap by Lt. Col John R. London. After reading this book, you'll start to really wonder why projects like the X-33 and X-34 were funded in the first place. You'll start to see the massive politics behind the space industry.

Well you couldn't be more wrong about what processors are in this sucker!

There's actually 7 on-board, 6 of them are Harris RTX2010's (Harris is now Intersil). This processor can do 6 MIPS at 8MHz.. There is also one Honeywell 1750A that runs the flight program. (2.5 MIPS - The military hybrid of this chip also runs Linux ; .)

Nice little satellite for early 90's.

Well you couldn't be more wrong about what processors are in this sucker!

There's actually 7 on-board, 6 of them are Harris RTX2010's (Harris is now Intersil). This processor can do 6 MIPS at 8MHz.. There is also one Honeywell 1750A that runs the flight program. (2.5 MIPS - The military hybrid of this chip also runs Linux .)

Nice little satellite for early 90's.

Well you couldn't be more wrong about what processors are in this sucker!

There's actually 7 on-board, 6 of them are Harris RTX2010's (Harris is now Intersil). This processor can do 6 MIPS at 8MHz.. There is also one Honeywell 1750A that runs the flight program. (2.5 MIPS - The military hybrid of this chip also runs Linux ; ;.)

In addition to the private ventures mentioned, here are some others:

CFFC
JP Aerospace
Microcosm
Pioneer Rocketplane