SIP devices still have the problem of routing correctly through firewalls and the like. True P2P telephony is difficult with SIP, due to this.
Skype gets around it by using their proprietary protocol.
The much simpler and cleaner and far more open IAX2 protocol (a feature of the open source asterisk pbx) is being used by some devices to get around SIP limitations while still retaining (or exceeding) SIP voice quality.
At least one IAX2 provider, firefly, gets it - (https://www.virbiage.com/products.php) calls to their network are automatically switched to the other user, getting the middleman out of the loop, and dramatically improving voice quality.
Example - I place a call to a friend a block on vonage via vonage on comcast, and the packets get routed through about 17 routers, with a delay of 80ms - to get up the street. I place the same call via firefly - one router, and a delay of 25ms.
Yes, theres windows, mac, and Linux clients. Also clients for most unixen, and several embedded devices....
75% of known asteroids are carbonaceous, which has an empirical formula of CO32-. In other words, there is a 75% chance that more oxygen exists on this asteroid than mankind has ever lifted to orbit.
An s-type consists of nickel, iron, and magnesium - and an m-type - oh, my - what a motherlode one of those would be!
We can't do anything with materials in orbit right now because we don't have any materials in orbit right now.
We don't lack for methods of microgee refining (many experiments have been conducted) but we do lack for machines that have been designed to do it... currently.
With a sufficently large supply of raw materials we can substitute brute force what we currently do via expensive materials currently lifted to orbit - radiation shielding and structual materials, for example. Certainly many key components of a space station would continue to be needed to manufacture on earth, but the bulk structural materials of the ISS could be fashioned in space using in-situ materials - if we had those materials.
Imagine how much faster our space presence would grow if we didn't have to ferry up food and oxygen, just people and advanced devices.
Setting up a whole manufacturing industry in space is a long term investment, and I agree that few would make such an investment... but with the potential payoff in trillions, some will.
Lastly the cost of sending things down is a lot cheaper than sending things up, but you are probably right - most materials we make in space will stay in space.
Considering the mass (8e+10kg estimated), orbital inclination (3.3 deg), and eccentricity (.191276) 2004MN4 is a pretty good candidate for exploration .
The probability estimate needs to be refined to account for the Yorp effect.
Further observations will show approximately what 2004MN4 is made of. I have hope that it's a rocky body with quality ores such as nickel/iron... but only a Deep impact style probe would give us truly hard data.
Now, if you look at the orbital plot, you'll note just how close this rock is right now... and how close it gets not just on april 13, 2029.
While the newspapers and the slashdot articles are focused on the potential impact energy, (m*v), I'm far more interested in m.
This rock has more mass than mankind has put into space since the beginning of the Space age; far, far more mass than is projected to be in the International Space station. And there it goes by, whizzing overhead, on near miss after near miss, for the next couple centuries.
Assume 2004MN is 1% nickel. Earth value of
8,000,000 tonnes of nickel is: 12,200,000,000 US dollars. (well, until the nickel futures market crashes harder than this asteroid will). Value of any material, if it were in earth orbit, is 10,000/lb and that's too many zeros for me to type here. For just the nickel. Oxygen is even more valuable. Slag is valuable.
IF this asteroid contains valuable materials (be they platinum, iron, nickel, gold, oxygen, or carbon), it would be a bonanza for mankind's space efforts.
Divert Dawn (launch date 06/06), or Deep Impact (launch date 01/12/05). Let's Find out!
Can we afford to take a look? Can we afford not to?
An annual contest makes sense
on
Win the X-Prize Cup
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· Score: 5, Informative
Jerry Pournelle has long advocated the establishment of contests for various space related goals. (he also was at the spaceshipone launches - story and pictures here)
Peter's vision of annual space-related contests is slightly different - Each "meet" will have different, specific, goals, each year. At the same time the organization will provide consistency in place, time, and rules that the participants will function under.
NASA's goals are so hopelessly fragmented by internally competing projects and ever changing budgetary reality that they are still mired in finally flying designs mired in 60s thinking.
We are entering a new era. Space advocates can "vote with our feet" - and our new technologies - and our wallets - for whatever we feel is the best way to enter space.
A little fact to throw into this mix. According to US census data, 28 year copyright renewals over the period 1940-1998 were around 15%. 85% of all copyrighted materials fell into the public domain after only 28 years. Now it's somewhere between 90-150 years before any materials fall into the public domain. Scans from the US Census data are at: copyright.taht.net.
The historical new copyright growth rate, year to year, is somewhere between 1.6 and 3%.
Extrapolate materials in the public domain forward to 2150 from there. I did, but the spreadsheet is not in a publishable state just yet, and the numbers are just too obscene to believe.
And then, throw this little thought in the mix.
Since the elimination of reporting requirements,
the copyright growth rate, particularly of documents placed on the internet, looks to be larger than 3%. Much larger.
Slashdot Mirror
SIP devices still have the problem of routing correctly through firewalls and the like. True P2P telephony is difficult with SIP, due to this. Skype gets around it by using their proprietary protocol. The much simpler and cleaner and far more open IAX2 protocol (a feature of the open source asterisk pbx) is being used by some devices to get around SIP limitations while still retaining (or exceeding) SIP voice quality. At least one IAX2 provider, firefly, gets it - (https://www.virbiage.com/products.php) calls to their network are automatically switched to the other user, getting the middleman out of the loop, and dramatically improving voice quality. Example - I place a call to a friend a block on vonage via vonage on comcast, and the packets get routed through about 17 routers, with a delay of 80ms - to get up the street. I place the same call via firefly - one router, and a delay of 25ms. Yes, theres windows, mac, and Linux clients. Also clients for most unixen, and several embedded devices....
An s-type consists of nickel, iron, and magnesium - and an m-type - oh, my - what a motherlode one of those would be!
We can't do anything with materials in orbit right now because we don't have any materials in orbit right now.
We don't lack for methods of microgee refining (many experiments have been conducted) but we do lack for machines that have been designed to do it... currently.
With a sufficently large supply of raw materials we can substitute brute force what we currently do via expensive materials currently lifted to orbit - radiation shielding and structual materials, for example. Certainly many key components of a space station would continue to be needed to manufacture on earth, but the bulk structural materials of the ISS could be fashioned in space using in-situ materials - if we had those materials.
Imagine how much faster our space presence would grow if we didn't have to ferry up food and oxygen, just people and advanced devices.
Setting up a whole manufacturing industry in space is a long term investment, and I agree that few would make such an investment... but with the potential payoff in trillions, some will.
Lastly the cost of sending things down is a lot cheaper than sending things up, but you are probably right - most materials we make in space will stay in space.
Some amount of mass would need to be expended to move it or refined fragments of it into a more suitable orbit.
The probability estimate needs to be refined to account for the Yorp effect.
Further observations will show approximately what 2004MN4 is made of. I have hope that it's a rocky body with quality ores such as nickel/iron... but only a Deep impact style probe would give us truly hard data.
Now, if you look at the orbital plot, you'll note just how close this rock is right now... and how close it gets not just on april 13, 2029.
While the newspapers and the slashdot articles are focused on the potential impact energy, (m*v), I'm far more interested in m.
This rock has more mass than mankind has put into space since the beginning of the Space age; far, far more mass than is projected to be in the International Space station. And there it goes by, whizzing overhead, on near miss after near miss, for the next couple centuries.
Assume 2004MN is 1% nickel. Earth value of 8,000,000 tonnes of nickel is: 12,200,000,000 US dollars. (well, until the nickel futures market crashes harder than this asteroid will). Value of any material, if it were in earth orbit, is 10,000/lb and that's too many zeros for me to type here. For just the nickel. Oxygen is even more valuable. Slag is valuable.
If we just had a booster on the pad with enough oomph, we could get a probe there in a matter of weeks.
IF this asteroid contains valuable materials (be they platinum, iron, nickel, gold, oxygen, or carbon), it would be a bonanza for mankind's space efforts.
Divert Dawn (launch date 06/06), or Deep Impact (launch date 01/12/05). Let's Find out!
This asteroid (and many other NEAs like it) is not just a threat, but an opportunity. It's an opportunity to get a leg up into space.
Can we afford to take a look? Can we afford not to?
Jerry Pournelle has long advocated the establishment of contests for various space related goals. (he also was at the spaceshipone launches - story and pictures here) Peter's vision of annual space-related contests is slightly different - Each "meet" will have different, specific, goals, each year. At the same time the organization will provide consistency in place, time, and rules that the participants will function under. NASA's goals are so hopelessly fragmented by internally competing projects and ever changing budgetary reality that they are still mired in finally flying designs mired in 60s thinking. We are entering a new era. Space advocates can "vote with our feet" - and our new technologies - and our wallets - for whatever we feel is the best way to enter space.
A little fact to throw into this mix. According to US census data, 28 year copyright renewals over the period 1940-1998 were around 15%. 85% of all copyrighted materials fell into the public domain after only 28 years. Now it's somewhere between 90-150 years before any materials fall into the public domain. Scans from the US Census data are at: copyright.taht.net. The historical new copyright growth rate, year to year, is somewhere between 1.6 and 3%. Extrapolate materials in the public domain forward to 2150 from there. I did, but the spreadsheet is not in a publishable state just yet, and the numbers are just too obscene to believe. And then, throw this little thought in the mix. Since the elimination of reporting requirements, the copyright growth rate, particularly of documents placed on the internet, looks to be larger than 3%. Much larger.