Thanks Issac. I have been writing and speaking about this concept for over 15 years and been told I was crazy too many times to count. I wish them luck. This could be the game changer.Steve Mickler
DARPA's new "Phoenix" program seeks to harvest/repurpose dead satellites:http://www.darpa.mil/NewsEvents/Releases/2011/10/20.aspx
Quote from: Solman on 10/21/2011 06:54 pmThanks Issac. I have been writing and speaking about this concept for over 15 years and been told I was crazy too many times to count. I wish them luck. This could be the game changer.Steve MicklerStill crazy, because it won't be cost effective for decades. The issue isn't the robotics. The issue is the energy to and from GSO and the cost of launch.
Only if you don't change your ways of doing things. As you know, I have discussed using the aluminum as propellant
Still crazy, because it won't be cost effective for decades. The issue isn't the robotics. The issue is the energy to and from GSO and the cost of launch.
Quote from: Solman on 10/21/2011 07:28 pm Only if you don't change your ways of doing things. As you know, I have discussed using the aluminum as propellant Not going to happen in near earth environment, totally nonviable. the effects from aluminum in solid motors is still felt and there will be similar effects.
Quote from: Jim on 10/21/2011 07:34 pmQuote from: Solman on 10/21/2011 07:28 pm Only if you don't change your ways of doing things. As you know, I have discussed using the aluminum as propellant Not going to happen in near earth environment, totally nonviable. the effects from aluminum in solid motors is still felt and there will be similar effects. Jim we've already discussed this - the aluminum is exhausted as a gas and doesn't have anything to condense on.
Quote from: Jim on 10/21/2011 06:59 pmQuote from: Solman on 10/21/2011 06:54 pmThanks Issac. I have been writing and speaking about this concept for over 15 years and been told I was crazy too many times to count. I wish them luck. This could be the game changer.Steve MicklerStill crazy, because it won't be cost effective for decades. The issue isn't the robotics. The issue is the energy to and from GSO and the cost of launch.on the other hand in a "time of war" cost will be trumped by the needs to keep operations running?
Aside from the cost of launching such a scavenger to GEO I worry about all the debris created while tearing old sats apart to harvest their innards. Don't we have enough trouble with man-made trash in space already?
Quote from: Solman on 10/22/2011 09:16 pmQuote from: Jim on 10/21/2011 07:34 pmQuote from: Solman on 10/21/2011 07:28 pm Only if you don't change your ways of doing things. As you know, I have discussed using the aluminum as propellant Not going to happen in near earth environment, totally nonviable. the effects from aluminum in solid motors is still felt and there will be similar effects. Jim we've already discussed this - the aluminum is exhausted as a gas and doesn't have anything to condense on.It will combine into particles
Quote from: beb on 10/22/2011 02:11 pmAside from the cost of launching such a scavenger to GEO I worry about all the debris created while tearing old sats apart to harvest their innards. Don't we have enough trouble with man-made trash in space already? Besides being cautious, parts could be retrieved. It's not trash it's recycling. It's not a problem - it's an opportunity.Steve
Quote from: Prober on 10/22/2011 09:14 pmQuote from: Jim on 10/21/2011 06:59 pmQuote from: Solman on 10/21/2011 06:54 pmThanks Issac. I have been writing and speaking about this concept for over 15 years and been told I was crazy too many times to count. I wish them luck. This could be the game changer.Steve MicklerStill crazy, because it won't be cost effective for decades. The issue isn't the robotics. The issue is the energy to and from GSO and the cost of launch.on the other hand in a "time of war" cost will be trumped by the needs to keep operations running?And launching more spacecraft will fix the need
Quote from: Solman on 10/22/2011 09:21 pmQuote from: beb on 10/22/2011 02:11 pmAside from the cost of launching such a scavenger to GEO I worry about all the debris created while tearing old sats apart to harvest their innards. Don't we have enough trouble with man-made trash in space already? Besides being cautious, parts could be retrieved. It's not trash it's recycling. It's not a problem - it's an opportunity.SteveI agree 100% Did you write up a paper on this?Also see this as a means insurance companies will pay to fix an out of orbit device.
1.If asteroid mining is developed quickly, those propellants do not need to be launched from Earth.2. Building and launching a new military sat is expensive and unlikely to happen quickly even in a time of war.
Prove it.
Quote from: Solman on 10/22/2011 09:23 pm Prove it. The burden of proof is on you. What evidence do you have to the contrary to support your claim? Alumina and aluminum particles in solid propellant exhaust is a well known phenomena, and it occurs before interaction of the plume with the atmosphere (in the chamber, for that matter; it increases radiative heat transfer). Why is there any reason to expect different behavior on orbit?
First - no evidence has been presented that aluminum released as a hot gas in orbit will condense.
First - no evidence has been presented that aluminum released as a hot gas in orbit will condense. There is nothing for it to condense on and as it expands the partial pressure drops to extremely low level. The problem with solids is incomplete combustion of the aluminum mixed into the propellant. Steve
Quote from: Solman on 10/23/2011 08:38 pm First - no evidence has been presented that aluminum released as a hot gas in orbit will condense. There is nothing for it to condense on and as it expands the partial pressure drops to extremely low level. The problem with solids is incomplete combustion of the aluminum mixed into the propellant. SteveAnd using straight, solar-heated aluminum solves that issue? Seems to me that would be a lot like completely incomplete () combustion, given you're not burning the aluminum at all. The aluminum will start condensing into a liquid at above 3100K. Just how hot are you planning to run this solar thermal system to get decent expansion before you hit this temperature point? Unless you have test data confirming your assertion, I would say you're on shaky ground. So, do you have the empirical results to back this up?
The theoretical limit of a parabolic(image forming) solar concentrator mirror is the roughly 10,000 deg. F surface temperature of the Sun and although the argument is way over my head, I believe non-imaging optics placed in that focus can exceed that. At any rate, over 4000K is doable, so the aluminum may be heated to a liquid in one chamber and then injected into an extremely hot chamber to vaporize it before exhausting it. Provided it is possible to exhaust only gas, this gas can cool way below the temp at which it can liquefy it without condensing provided there is nothing for it to condense on. The people on the recent-ish Paris to Rio flight that crashed when super cooled water vapor condensed on the pitot tubes had sad personal experience with this.Steve
Quote from: Solman on 10/25/2011 12:04 am The theoretical limit of a parabolic(image forming) solar concentrator mirror is the roughly 10,000 deg. F surface temperature of the Sun and although the argument is way over my head, I believe non-imaging optics placed in that focus can exceed that. At any rate, over 4000K is doable, so the aluminum may be heated to a liquid in one chamber and then injected into an extremely hot chamber to vaporize it before exhausting it. Provided it is possible to exhaust only gas, this gas can cool way below the temp at which it can liquefy it without condensing provided there is nothing for it to condense on. The people on the recent-ish Paris to Rio flight that crashed when super cooled water vapor condensed on the pitot tubes had sad personal experience with this.SteveOver 4000K will melt any practical material (and plenty of impractical ones). That was my point. Furthermore, you seem to think that nucleation sites are critical for a phase change. They assist, and commonly listed melting points and freezing points assume them. However, you cannot cool something indefinitely without a phase change.There's an absolute point where you have homogeneous nucleation, and resultant phase change. That is exactly what will occur with your solar aluminum rocket, even if you have pure aluminum gas (a neat trick in and of itself).
You make bald assertions that "The energy required to assemble this material in one place in GEO is quite low [...]". What is the energy required? Altitude is easy in GEO ... inclination and true anomaly are the hard part. Do the math and show the math if you want to be taken seriously."Technological Readiness: The proposed FTD-1 mission could include a small humanoid type robot and tools to test both teleoperation in GEO and techniques for dismantling dead satellites. Alternately. it could actually rendezvous with a NEO and return a sample. If that sample was fairly large and included some platinum; public attention would be galvanized." How does your statement address readiness? Why is a humanoid robot included ... what requirement is it addressing? Why are you talking about two very different missions in the same breath? Start with the most simple complete and coherent story and don't add anything unless you've got a good reason to dilute your message.
Looking for reasoned seasoned disinterested opinions on whether or not terrestrial bandwidth capabilities will overtake a critical volume of present satellite communications. I imagine, but it is only a conjecture, that as terrestrial networks are back-filled and run out into one nowhere after another, that there will still be some new application that cannot at that time be offered ubiquitously by cable, and therefore is offered by satellite. In other words, if terrestrial communications keep increasing in bandwidth, for satellites to survive will require markets in types of media we've only considered sci-fi till now. Better than 3D. Smellovision? How far am I off? I would prefer to be assured that this low hanging fruit, where the hammer can fall first in reducing launch costs, is not going to be snatched by some feral critter called fiber optics.
SOL.
For those who feel that nuclear power has a role to play but are frustrated by costs and politics; there are 44 Russian nuclear reactors in orbit aren't there? Perhaps the Russians would be willing to sell in the event that they could be reanimated or recycled. They aren't in GEO but rather in high orbits so there would need to be some energy expended, but they could be brought to GEO to be worked on. Might make a decent thriller to have the bad guys robotically seize one of these sats for nuclear blackmail - de-orbit over a city and you've got one heck of a dirty bomb possibly. An avatar based industrial facility in GEO has potentially unlimited material
Quote from: Solman on 11/05/2011 07:53 pm For those who feel that nuclear power has a role to play but are frustrated by costs and politics; there are 44 Russian nuclear reactors in orbit aren't there? Perhaps the Russians would be willing to sell in the event that they could be reanimated or recycled. They aren't in GEO but rather in high orbits so there would need to be some energy expended, but they could be brought to GEO to be worked on. Might make a decent thriller to have the bad guys robotically seize one of these sats for nuclear blackmail - de-orbit over a city and you've got one heck of a dirty bomb possibly. An avatar based industrial facility in GEO has potentially unlimited material More fanasty Not some, but a lot of energy. Too much to make worthwhile, unless there a new unknown propulsion system developed
Quote from: Jim on 11/06/2011 12:47 pmQuote from: Solman on 11/05/2011 07:53 pm For those who feel that nuclear power has a role to play but are frustrated by costs and politics; there are 44 Russian nuclear reactors in orbit aren't there? Perhaps the Russians would be willing to sell in the event that they could be reanimated or recycled. They aren't in GEO but rather in high orbits so there would need to be some energy expended, but they could be brought to GEO to be worked on. Might make a decent thriller to have the bad guys robotically seize one of these sats for nuclear blackmail - de-orbit over a city and you've got one heck of a dirty bomb possibly. An avatar based industrial facility in GEO has potentially unlimited material More fanasty Not some, but a lot of energy. Too much to make worthwhile, unless there a new unknown propulsion system developed You mean like a solar thermal rocket that can use almost anything as propellant?
You mean like a solar thermal rocket that can use almost anything as propellant?