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RE: Planet Found in Habitable Zone Around Nearest Star
August 25, 2016 at 11:18 pm
(August 25, 2016 at 11:14 pm)Rhythm Wrote: Even 1 au isn't a workable margin or error for a low impulse engine which would be traveling at or near it's max speed when it arrived. We'd be stuck with the drone rain you described (and they;d have all the same problems getting closer as the main craft). A total downer (for me, ofc, for me, lol).
Yeah, but a low impulse engine can work continuously for years as the spacecraft approach Proxima Centauri, while the same 1 arc second of error tolerance in the star tracker translates to an ever diminishing fraction of 1 AU.
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RE: Planet Found in Habitable Zone Around Nearest Star
August 25, 2016 at 11:22 pm
(This post was last modified: August 25, 2016 at 11:23 pm by The Grand Nudger.)
Hence the need for a solution other than a straight line rail of a laser. Something that can work for years in any direction required.
I am the Infantry. I am my country’s strength in war, her deterrent in peace. I am the heart of the fight… wherever, whenever. I carry America’s faith and honor against her enemies. I am the Queen of Battle. I am what my country expects me to be, the best trained Soldier in the world. In the race for victory, I am swift, determined, and courageous, armed with a fierce will to win. Never will I fail my country’s trust. Always I fight on…through the foe, to the objective, to triumph overall. If necessary, I will fight to my death. By my steadfast courage, I have won more than 200 years of freedom. I yield not to weakness, to hunger, to cowardice, to fatigue, to superior odds, For I am mentally tough, physically strong, and morally straight. I forsake not, my country, my mission, my comrades, my sacred duty. I am relentless. I am always there, now and forever. I AM THE INFANTRY! FOLLOW ME!
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RE: Planet Found in Habitable Zone Around Nearest Star
August 25, 2016 at 11:27 pm
-or, as I was fantasizing about, a hybrid craft with solutions onboard to compensate for the weaknesses of each individual component.
I am the Infantry. I am my country’s strength in war, her deterrent in peace. I am the heart of the fight… wherever, whenever. I carry America’s faith and honor against her enemies. I am the Queen of Battle. I am what my country expects me to be, the best trained Soldier in the world. In the race for victory, I am swift, determined, and courageous, armed with a fierce will to win. Never will I fail my country’s trust. Always I fight on…through the foe, to the objective, to triumph overall. If necessary, I will fight to my death. By my steadfast courage, I have won more than 200 years of freedom. I yield not to weakness, to hunger, to cowardice, to fatigue, to superior odds, For I am mentally tough, physically strong, and morally straight. I forsake not, my country, my mission, my comrades, my sacred duty. I am relentless. I am always there, now and forever. I AM THE INFANTRY! FOLLOW ME!
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RE: Planet Found in Habitable Zone Around Nearest Star
August 25, 2016 at 11:27 pm
(This post was last modified: August 25, 2016 at 11:33 pm by Anomalocaris.)
(August 25, 2016 at 11:22 pm)Rhythm Wrote: Hence the need for a solution other than a straight line rail of a laser.
The laser propelled spacecraft needn't travel in a straight line. If it's light sail is reflective it can angle the light sail to get off axis thrust. It has considerable room to maneuver laterally and alter its own vector without resorting to chemical thrusters. It just need to be able to signal its location and maneuvers to earth so the laser tracks it and not lose it as it maneuvers.
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RE: Planet Found in Habitable Zone Around Nearest Star
August 25, 2016 at 11:30 pm
(This post was last modified: August 25, 2016 at 11:30 pm by The Grand Nudger.)
Solar -anything- loses it's effectiveness even within the minor distances of our own solar system. It'll be a dead sail at some point along the journey(thus incapable of providing the continuous burns we were talking about)..until it picks back up as it closes in on the next star.
I am the Infantry. I am my country’s strength in war, her deterrent in peace. I am the heart of the fight… wherever, whenever. I carry America’s faith and honor against her enemies. I am the Queen of Battle. I am what my country expects me to be, the best trained Soldier in the world. In the race for victory, I am swift, determined, and courageous, armed with a fierce will to win. Never will I fail my country’s trust. Always I fight on…through the foe, to the objective, to triumph overall. If necessary, I will fight to my death. By my steadfast courage, I have won more than 200 years of freedom. I yield not to weakness, to hunger, to cowardice, to fatigue, to superior odds, For I am mentally tough, physically strong, and morally straight. I forsake not, my country, my mission, my comrades, my sacred duty. I am relentless. I am always there, now and forever. I AM THE INFANTRY! FOLLOW ME!
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RE: Planet Found in Habitable Zone Around Nearest Star
August 25, 2016 at 11:32 pm
(This post was last modified: August 25, 2016 at 11:35 pm by Anomalocaris.)
I meant light sail, not solar sail. Effectiveness of a light sail working with photon pressure of a laser depends on the strength and focus of the laser. We are assuming, I presume, a propulsive laser adaquate to provide thrust out to interstellar distances.
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RE: Planet Found in Habitable Zone Around Nearest Star
August 25, 2016 at 11:35 pm
(This post was last modified: August 25, 2016 at 11:35 pm by The Grand Nudger.)
They're the same thing, the only difference being the source of photons. Speaking of which, if the laser is craft based it needs power, if it's ground (or earth orbit) based it loses effectiveness as it increases in distance due to dispersion.
I am the Infantry. I am my country’s strength in war, her deterrent in peace. I am the heart of the fight… wherever, whenever. I carry America’s faith and honor against her enemies. I am the Queen of Battle. I am what my country expects me to be, the best trained Soldier in the world. In the race for victory, I am swift, determined, and courageous, armed with a fierce will to win. Never will I fail my country’s trust. Always I fight on…through the foe, to the objective, to triumph overall. If necessary, I will fight to my death. By my steadfast courage, I have won more than 200 years of freedom. I yield not to weakness, to hunger, to cowardice, to fatigue, to superior odds, For I am mentally tough, physically strong, and morally straight. I forsake not, my country, my mission, my comrades, my sacred duty. I am relentless. I am always there, now and forever. I AM THE INFANTRY! FOLLOW ME!
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RE: Planet Found in Habitable Zone Around Nearest Star
August 25, 2016 at 11:40 pm
(This post was last modified: August 25, 2016 at 11:43 pm by Anomalocaris.)
(August 25, 2016 at 11:35 pm)Rhythm Wrote: They're the same thing, the only difference being the source of photons. Speaking of which, if the laser is craft based it needs power, if it's ground (or earth orbit) based it loses effectiveness as it increases in distance due to dispersion.
You can use a very large phased array of separate laser emitters to achieve the effect of a single emitter with an truly enormous aperture, say aperture equal to the diameter of the earth, or even diameter of earth's ambit around the sun. This would produce a beam of extremely high level of focus and low dispersion, such that it would have hardly dispersed at all at 4 light years. The beam need not be very intense, since it would have years or decades to impart thrust.
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RE: Planet Found in Habitable Zone Around Nearest Star
August 25, 2016 at 11:47 pm
(This post was last modified: August 25, 2016 at 11:48 pm by The Grand Nudger.)
That's an awfully stretched solution to a very practical problem. Why do that instead of sending a hybrid craft?
I am the Infantry. I am my country’s strength in war, her deterrent in peace. I am the heart of the fight… wherever, whenever. I carry America’s faith and honor against her enemies. I am the Queen of Battle. I am what my country expects me to be, the best trained Soldier in the world. In the race for victory, I am swift, determined, and courageous, armed with a fierce will to win. Never will I fail my country’s trust. Always I fight on…through the foe, to the objective, to triumph overall. If necessary, I will fight to my death. By my steadfast courage, I have won more than 200 years of freedom. I yield not to weakness, to hunger, to cowardice, to fatigue, to superior odds, For I am mentally tough, physically strong, and morally straight. I forsake not, my country, my mission, my comrades, my sacred duty. I am relentless. I am always there, now and forever. I AM THE INFANTRY! FOLLOW ME!
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RE: Planet Found in Habitable Zone Around Nearest Star
August 25, 2016 at 11:50 pm
I think a beam focused enough to provide propulsion over interstellar distances would need a phased array of emitters. No single emitter would have aperture large enough to avoid excessive dispersion. So I don't think it's a stretched solution.
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