I suspect you like crypticism
...
I get it. The math is nowhere near beyond me. The picture's just not that good a comm sketch given as is.
Mars Colony financing
No offense...but perhaps you could explain to us mathematically why you think chemical rocket plus your propellant depots would win out over say NTR like Triton. A Triton launched from earth by a chemical rocket gets fueled in orbit (either/or earth orbit or your mentioned lunar libration points) It could take the propellant H2 and 02 in the same molar ratios as your chemical rockets with an added twist: The H2 is heated by the nuclear reactor of the Triton and supplemental 02 is added after it ejects from the reactor nozzle, like a type of afterburner. You would be getting the energy of both the chemical reaction and the nuclear thermal one combined. How could the chemical rocket by itself possible match the performance in terms of thrust/power/SI of that?HopDavid wrote:I suspect the math is beyond your reach.
Quoting a post from nasaspaceflight's NTR/BNTR/NEP thread:williatw wrote: No NTR don't but I think a variant called "Timberwind"
"You may have heard of another NTR design looked at in the early 90s under a program called Timberwind--this was a "particle-bed" design, where instead of having fuel elements in channels, they were a bed of tiny particles. This design is incredibly dangerous (and I have spoken to a number of people that worked the program) because any localized melting of the fuel particles tends to weld them together, and block coolant flow. This leads to more melting and welding, and bam...you've fused the core and melted the reactor--not through fission heating, but through decay heat. ..."
Followed your link...seems that there is a difference of opinion as to whether NTR could be developed safely with arguments fore and against hardly a consensus. Okay..so we should just stick to chemical rockets that of course never fail or blow up or kill and injure people. We should just reconcile ourselves to chemical rockets because nuclear is just to scary and dangerous. Triton I believe is far more recent than Timberwind, perhaps the tech has improved since then. Also I am talking about using it only in space not as a launch system as I believe Timberwind was to be used for. I thought it was supposed to be an upper stage to be used to launch SDI components. Sure if polywell rockets are ever developed I am sure there will be people who will discover the hidden incredible dangers of it as well.HopDavid wrote:Quoting a post from nasaspaceflight's NTR/BNTR/NEP thread:williatw wrote: No NTR don't but I think a variant called "Timberwind"
"You may have heard of another NTR design looked at in the early 90s under a program called Timberwind--this was a "particle-bed" design, where instead of having fuel elements in channels, they were a bed of tiny particles. This design is incredibly dangerous (and I have spoken to a number of people that worked the program) because any localized melting of the fuel particles tends to weld them together, and block coolant flow. This leads to more melting and welding, and bam...you've fused the core and melted the reactor--not through fission heating, but through decay heat. ..."
Given that reaction mass is super heated, reactive chemicals, the rocket engine and nozzle materials are vulnerable to burning and melting. What is the temperature of the this nuclear heated hydrogen and oxygen? What is the life span of your nuclear rocket engine?williatw wrote:No offense...but perhaps you could explain to us mathematically why you think chemical rocket plus your propellant depots would win out over say NTR like Triton. A Triton launched from earth by a chemical rocket gets fueled in orbit (either/or earth orbit or your mentioned lunar libration points) It could take the propellant H2 and 02 in the same molar ratios as your chemical rockets with an added twist: The H2 is heated by the nuclear reactor of the Triton and supplemental 02 is added after it ejects from the reactor nozzle, like a type of afterburner. You would be getting the energy of both the chemical reaction and the nuclear thermal one combined. How could the chemical rocket by itself possible match the performance in terms of thrust/power/SI of that?HopDavid wrote:I suspect the math is beyond your reach.
If delta V budget is under 5 km/s, a single stage, reusable chemical rocket is doable. This is my chief reason for wanting to bust the delta v budget into smaller hops. A large part of the high cost of spaceflight is the expensive hardware that gets thrown away.
Those are engineering problems, that’s what engineering is for to solve problems like this. NERVA beget Timberwind, Timberwind beget Triton, Trion will hopefully lead to whatever is beyond that. To what appears to be your basic point: it is a lead pipe cinch that nuclear rockets would sometimes suffer catastrophic failure like chemical rockets, with resulting loss of life and destruction of payload. No matter what improvements in design technology are made the risk will never be zero. Just like it will never be for chemical rockets. Who gets to decide whether the improvement in performance out ways the risks involved? If they are only to be used in space from earth orbit and beyond then the people who choose to pioneer space should have a practical and morale right to decide. Anyone who has the Cajuns to go to Mars or the Moon to live the rest of their lives there is inherently someone who is willing to accept risk far greater than most of us who live on earth. They are called "Pioneers". It was not safe to come to America for many of these posters European ancestors 400 years ago. The Roanoke colony disappeared without a trace, half the population of Jamestown died the first year, similar loss of life in Plymouth Colony. Thanksgiving was a much about celebrating that they were still alive then anything else.HopDavid wrote: Given that reaction mass is super heated, reactive chemicals, the rocket engine and nozzle materials are vulnerable to burning and melting. What is the temperature of the this nuclear heated hydrogen and oxygen? What is the life span of your nuclear rocket engine? If delta V budget is under 5 km/s, a single stage, reusable chemical rocket is doable. This is my chief reason for wanting to bust the delta v budget into smaller hops. A large part of the high cost of spaceflight is the expensive hardware that gets thrown away.
No, that wasn't my basic point.williatw wrote: To what appears to be your basic point: it is a lead pipe cinch that nuclear rockets would sometimes suffer catastrophic failure like chemical rockets, with resulting loss of life and destruction of payload. No matter what improvements in design technology are made the risk will never be zero.
Once again, for economical spaceflight, we need reusable vehicles.
If a 747 were thrown away each trip, no one could afford a transcontinental ticket.
Given superheated, corrosive reaction mass, I don't see the engines you imagine having a long life span.
Relevant to financing a colony: http://www.economist.com/node/21540395
[/b]Seasteading
Cities on the ocean
Seasteading: Libertarians dream of creating self-ruling floating cities. But can the many obstacles, not least the engineering ones, be overcome?
Thx, from your link: The long arm of the lawhanelyp wrote:Relevant to financing a colony: http://www.economist.com/node/21540395[/b]Seasteading Cities on the ocean
Seasteading: Libertarians dream of creating self-ruling floating cities. But can the many obstacles, not least the engineering ones, be overcome?
The technical challenges are daunting enough. The legal questions that seasteads would face are no less tricky, and call into question whether it would really be possible to create genuinely self-governing mini-states on the oceans. Until seasteaders are ready to cut their ties with the land altogether, they will want to build their colonies not much more than 12 nautical miles (22km) offshore—the limit of countries’ territorial waters—otherwise travelling to and from the seastead will take too long. But the laws of the sea give countries powers to enforce some criminal laws up to 24 nautical miles out and to regulate some economic activities in a 200-mile “exclusive economic zone”. Ships are granted exemptions, but a seastead tethered to the seabed would not qualify.
Some countries (notably America) assert the right to extend their jurisdictions, in matters affecting their citizens, across the entire planet. And like any other seagoing structure, a seastead would be obliged to register with a “flag state”, to whose maritime laws it would be subject. Some flag states are lax about enforcement but if, say, America disapproved of the goings-on aboard a seastead, it could lean on such states to get tough—and offer enforcement on their behalf. In the 1960s Britain’s government shut down pirate-radio ships not by sending the navy to attack them but by banning British suppliers and advertisers from doing business with them. In all, the leaders of the seasteading movement concede that they will have to avoid getting into anything too provocative—drugs, pornography or money-laundering, for example. As for taxes, America already demands that its citizens pay income tax even when they are living abroad—and that would include living on a seastead. There is nothing to stop other countries following suit and indeed getting extraterritorial about other taxes too. Until seasteaders are able to bank their money with independent, ocean-going financial institutions, they may not be able to escape the taxman’s clutches. Exactly to my point about a Mars Colony..it would be tough for any country to enforce its laws about taxes or anything else when it takes months to get there. Unlike seasteads all bets would be on in the case of mars. Love to see the IRS collect Taxes from people living on Mars(US citizens or not) or investors on earth with secret accounts in the bank of Mars.
Unknown what the lifespan of a Triton or smiliar NTR would turn out to be since they haven't been developed yet. Of course..what is the life span of a chemical rocket? Since our chemical rockets to date are expendable, we really don't know how many times they could be re-used.HopDavid wrote: Given that reaction mass is super heated, reactive chemicals, the rocket engine and nozzle materials are vulnerable to burning and melting. ...What is the life span of your nuclear rocket engine?
I don't know about the seastead issue. There is precedent for artificial island self rule. The UK knows all about it.
http://en.wikipedia.org/wiki/Principality_of_Sealand
There are other examples.
http://en.wikipedia.org/wiki/Principality_of_Sealand
There are other examples.
RL-10s are reliable workhorses that have been in use for awhile. It's thought they could do multiple burns.williatw wrote:Unknown what the lifespan of a Triton or smiliar NTR would turn out to be since they haven't been developed yet. Of course..what is the life span of a chemical rocket? Since our chemical rockets to date are expendable, we really don't know how many times they could be re-used.
ULA proposes reuse of these engines in their depot architecture.
"Thought" they can be re-used isn't the same as data. But consider this: lets assume for the sake of argument that a Triton NTR can only be used a max of 5X times(there & back) before it is toast, but a chemical rocket can be re-used let us say 25 times (there and back). Considering the much greater SI of NTR 800-1200s vs 450s for a chemical rocket in a given block of lets say 12 years, and you and I were competing shipping companies. Who could haul the most cargo to Mars at a profit? I can haul more cargo per trip, my launch windows are wider than yours so I can launch more often because I have more DeltaV, and my trip times are faster. I can use the same propellant banks as you can but haul how many times the payload(at a profit) than you can in a given block of time. Even though my shipping cost are higher than yours because of my less re-usable system, in a given block of time I would make more profit than you would because of greater cargo volume.HopDavid wrote:RL-10s are reliable workhorses that have been in use for awhile. It's thought they could do multiple burns.
ULA proposes reuse of these engines in their depot architecture.
No. You mean revenue. In a given block of time you would have more revenue because of the greater cargo volume. Then if your costs are the same as his, you would be left with more profit, but costs are the question, aren't they.... in a given block of time I would make more profit than you would because of greater cargo volume.
Aero