Solar-pumped laser power transmission, a way to dramatically decrease launch costs?
in [Physics]
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From: Androcles on 14 Feb 2010 16:17 "Scott M. Kozel" <kozelsm(a)comcast.net> wrote in message news:b2cc07ef-f00e-4bb4-ba63-8e2f403600f1(a)o26g2000vbd.googlegroups.com... "Androcles" <Headmas...(a)Hogwarts.physics_u> wrote: > > "William Mook" <mokmedi...(a)gmail.com> wrote in message > > That is absolutely correct. It will be on solar orbit. The orbital > period will be 24 hours at 3 million km radius. > ============================================== > You may find it a tad warm 2 million miles from the sun. It will gather > rather more energy than you wanted, and having a 24-hour year it won't > be in sight of Earth for more than 14 hours each Earth day as it > disappears behind the Sun for 10 hours of that period. It would take an enormous amount of energy to put a satellite that far down into the Sun's gravity well. It has been difficult enough to get a satellite into the same orbit as Mercury, which is 35 million miles from the Sun. ============================================== I would say it would take an enormous loss of kinetic energy to put a satellite that far down into the Sun's gravity well, and if anyone did it would vaporise the satellite in a millisecond. If N watts per square meter falls on the Earth then (150million km/3 million km)^2 = 2500N watts per square meter falls on the satellite if it goes where Mooky wants it, by the inverse square law. Think of it as being one foot from a single LED from a bicycle headlight versus a foot away from a kiln. http://www.barometerworld.co.uk/jpg/kiln57.jpg
From: Androcles on 14 Feb 2010 16:22 "William Mook" <mokmedical(a)gmail.com> wrote in message news:7f4558bf-f2c5-44e9-ad08-e9f293d88557(a)q21g2000yqm.googlegroups.com... On Feb 14, 1:33 pm, "Androcles" <Headmas...(a)Hogwarts.physics_u> wrote: > "William Mook" <mokmedi...(a)gmail.com> wrote in message > > news:ec69fe16-04e1-4147-82e8-4f007cb68a41(a)g23g2000vbl.googlegroups.com... > On Feb 12, 5:16 pm, "Androcles" <Headmas...(a)Hogwarts.physics_u> wrote: > > > > > "William Mook" <mokmedi...(a)gmail.com> wrote in message > > >news:fbbddf2d-60ea-4ed3-a183-23e920219728(a)k41g2000yqm.googlegroups.com... > > On Dec 18 2009, 4:43 am, "Androcles" <Headmas...(a)Hogwarts.physics_q> > > wrote: > > > > "Jonathan" <H...(a)Again.net> wrote in message > > > >news:p5SdndXFAKoISrfWnZ2dnUVZ_vWdnZ2d(a)giganews.com... > > > > >I like this idea, Relatively small mirrors would power > > > > the lasers, not huge solar cell arrays. The lasers would > > > > transmit their beams to other satellites that convert it to, and > > > > beam it down, as microwaves. No need for mile-size > > > > collectors in orbit. > > > > What are you babbling about? > > > I can't be certain, but I will say that if you move a solar collector > > array closer to the sun it will gather more energy for a given size. > > ============================================= > > It won't be in Earth orbit then. > > That is absolutely correct. It will be on solar orbit. The orbital > period will be 24 hours at 3 million km radius. > ============================================== > You may find it a tad warm 2 million miles from the sun. It will gather > rather more energy than you wanted, and having a 24-hour year it won't > be in sight of Earth for more than 14 hours each Earth day as it > disappears behind the Sun for 10 hours of that period. The sun is 1.4 million km in diameter. An orbit with a 3 million km radius has a 6 million km diameter. So, the sun subtends only 13.5 degrees of the sky. ======================================================== The Sun subtends 0.5 degrees of sky, same as the moon. http://en.wikipedia.org/wiki/Angular_diameter Try again.
From: Androcles on 14 Feb 2010 17:03 "Jorge R. Frank" <jrfrank(a)ibm-pc.borg> wrote in message news:xNadneYdB4zN9uXWnZ2dnUVZ_tOdnZ2d(a)giganews.com... > Androcles wrote: >> >> "William Mook" <mokmedical(a)gmail.com> wrote in message >> news:7f4558bf-f2c5-44e9-ad08-e9f293d88557(a)q21g2000yqm.googlegroups.com... >> On Feb 14, 1:33 pm, "Androcles" <Headmas...(a)Hogwarts.physics_u> wrote: >>> "William Mook" <mokmedi...(a)gmail.com> wrote in message >>> >>> news:ec69fe16-04e1-4147-82e8-4f007cb68a41(a)g23g2000vbl.googlegroups.com... >>> On Feb 12, 5:16 pm, "Androcles" <Headmas...(a)Hogwarts.physics_u> wrote: >>> >>> >>> >>> > "William Mook" <mokmedi...(a)gmail.com> wrote in message >>> >>> >news:fbbddf2d-60ea-4ed3-a183-23e920219728(a)k41g2000yqm.googlegroups.com... >>> >>> > On Dec 18 2009, 4:43 am, "Androcles" <Headmas...(a)Hogwarts.physics_q> >>> > wrote: >>> >>> > > "Jonathan" <H...(a)Again.net> wrote in message >>> >>> > >news:p5SdndXFAKoISrfWnZ2dnUVZ_vWdnZ2d(a)giganews.com... >>> >>> > > >I like this idea, Relatively small mirrors would power >>> > > > the lasers, not huge solar cell arrays. The lasers would >>> > > > transmit their beams to other satellites that convert it to, and >>> > > > beam it down, as microwaves. No need for mile-size >>> > > > collectors in orbit. >>> >>> > > What are you babbling about? >>> >>> > I can't be certain, but I will say that if you move a solar collector >>> > array closer to the sun it will gather more energy for a given size. >>> > ============================================= >>> > It won't be in Earth orbit then. >>> >>> That is absolutely correct. It will be on solar orbit. The orbital >>> period will be 24 hours at 3 million km radius. >>> ============================================== >>> You may find it a tad warm 2 million miles from the sun. It will gather >>> rather more energy than you wanted, and having a 24-hour year it won't >>> be in sight of Earth for more than 14 hours each Earth day as it >>> disappears behind the Sun for 10 hours of that period. >> >> The sun is 1.4 million km in diameter. An orbit with a 3 million km >> radius has a 6 million km diameter. So, the sun subtends only 13.5 >> degrees of the sky. >> ======================================================== >> The Sun subtends 0.5 degrees of sky, same as the moon. >> http://en.wikipedia.org/wiki/Angular_diameter > > It subtends 0.5 deg at Earth (r_orbit = 1.5e8 km). He's talking about what > it subtends at 3e6 km, 50 times closer. He's off by a factor of 2, due to > failure to multiply by 2 after taking the arcsin. > > r_sun = 0.7e6 km > r_orbit = 3e6 km > theta_sun = 2*asin(r_sun/r_orbit) = 2*asin(0.7/3.0) = 27.0 deg Yeah, ya gotta try to teach. I can hold my hand an inch from the side of a boiling saucepan >||||||||||||||||||||||||||||||||||||||||||||||||||< 1 inch but I'm damned if I'm going to put it 0.02" away from the hotplate. >||< this gap is about 20 thou = 1/50th of an inch. Doesn't he realise he's in the corona? http://www.phys.ncku.edu.tw/~astrolab/mirrors/apod_e/ap010408.html
From: BradGuth on 14 Feb 2010 17:23 On Feb 14, 10:33 am, "Androcles" <Headmas...(a)Hogwarts.physics_u> wrote: > "William Mook" <mokmedi...(a)gmail.com> wrote in message > > news:ec69fe16-04e1-4147-82e8-4f007cb68a41(a)g23g2000vbl.googlegroups.com... > On Feb 12, 5:16 pm, "Androcles" <Headmas...(a)Hogwarts.physics_u> wrote: > > > > > "William Mook" <mokmedi...(a)gmail.com> wrote in message > > >news:fbbddf2d-60ea-4ed3-a183-23e920219728(a)k41g2000yqm.googlegroups.com.... > > On Dec 18 2009, 4:43 am, "Androcles" <Headmas...(a)Hogwarts.physics_q> > > wrote: > > > > "Jonathan" <H...(a)Again.net> wrote in message > > > >news:p5SdndXFAKoISrfWnZ2dnUVZ_vWdnZ2d(a)giganews.com... > > > > >I like this idea, Relatively small mirrors would power > > > > the lasers, not huge solar cell arrays. The lasers would > > > > transmit their beams to other satellites that convert it to, and > > > > beam it down, as microwaves. No need for mile-size > > > > collectors in orbit. > > > > What are you babbling about? > > > I can't be certain, but I will say that if you move a solar collector > > array closer to the sun it will gather more energy for a given size. > > ============================================= > > It won't be in Earth orbit then. > > That is absolutely correct. It will be on solar orbit. The orbital > period will be 24 hours at 3 million km radius. > ============================================== > You may find it a tad warm 2 million miles from the sun. It will gather > rather more energy than you wanted, and having a 24-hour year it won't > be in sight of Earth for more than 14 hours each Earth day as it > disappears behind the Sun for 10 hours of that period. To disagree with Mook is pretty much the same as disagreeing with god. So right there youve got a problem thats nearly insurmountable. For example, I believe his following statement is being extremely conservative of anything our NASA does. Id say at least double those costs if its another all-inclusive birth to grave kind of public funded investment that usually includes job and benefit immortality for most everyone involved. Aerospace systems today cost $10 million per ton to create, and $50 million per ton to put into orbit. An integrated light sail capability is a natural outcome of a solar laser powersat. Btw, we need to get that average wholesale distributed energy cost down to $0.01/kwhr, but dont let any of that get in the way of investing our hard earned public loot, and well need at least ten fold more of that clean energy than suggested by William Mook. Getting ourselves away from Earth is quite another matter, unless its referring to our moon(Selene), its L1 or that our accomplishing Venus L2 and/or conceivably the planet Venus itself. ~ BG
From: William Mook on 14 Feb 2010 20:45
On Feb 14, 5:03 pm, "Androcles" <Headmas...(a)Hogwarts.physics_u> wrote: > "Jorge R. Frank" <jrfr...(a)ibm-pc.borg> wrote in messagenews:xNadneYdB4zN9uXWnZ2dnUVZ_tOdnZ2d(a)giganews.com... > > > > > Androcles wrote: > > >> "William Mook" <mokmedi...(a)gmail.com> wrote in message > >>news:7f4558bf-f2c5-44e9-ad08-e9f293d88557(a)q21g2000yqm.googlegroups.com.... > >> On Feb 14, 1:33 pm, "Androcles" <Headmas...(a)Hogwarts.physics_u> wrote: > >>> "William Mook" <mokmedi...(a)gmail.com> wrote in message > > >>>news:ec69fe16-04e1-4147-82e8-4f007cb68a41(a)g23g2000vbl.googlegroups.com.... > >>> On Feb 12, 5:16 pm, "Androcles" <Headmas...(a)Hogwarts.physics_u> wrote: > > >>> > "William Mook" <mokmedi...(a)gmail.com> wrote in message > > >>> >news:fbbddf2d-60ea-4ed3-a183-23e920219728(a)k41g2000yqm.googlegroups.com... > > >>> > On Dec 18 2009, 4:43 am, "Androcles" <Headmas...(a)Hogwarts.physics_q> > >>> > wrote: > > >>> > > "Jonathan" <H...(a)Again.net> wrote in message > > >>> > >news:p5SdndXFAKoISrfWnZ2dnUVZ_vWdnZ2d(a)giganews.com... > > >>> > > >I like this idea, Relatively small mirrors would power > >>> > > > the lasers, not huge solar cell arrays. The lasers would > >>> > > > transmit their beams to other satellites that convert it to, and > >>> > > > beam it down, as microwaves. No need for mile-size > >>> > > > collectors in orbit. > > >>> > > What are you babbling about? > > >>> > I can't be certain, but I will say that if you move a solar collector > >>> > array closer to the sun it will gather more energy for a given size.. > >>> > ============================================= > >>> > It won't be in Earth orbit then. > > >>> That is absolutely correct. It will be on solar orbit. The orbital > >>> period will be 24 hours at 3 million km radius. > >>> ============================================== > >>> You may find it a tad warm 2 million miles from the sun. It will gather > >>> rather more energy than you wanted, and having a 24-hour year it won't > >>> be in sight of Earth for more than 14 hours each Earth day as it > >>> disappears behind the Sun for 10 hours of that period. > > >> The sun is 1.4 million km in diameter. An orbit with a 3 million km > >> radius has a 6 million km diameter. So, the sun subtends only 13.5 > >> degrees of the sky. > >> ======================================================== > >> The Sun subtends 0.5 degrees of sky, same as the moon. > >> http://en.wikipedia.org/wiki/Angular_diameter > > > It subtends 0.5 deg at Earth (r_orbit = 1.5e8 km). He's talking about what > > it subtends at 3e6 km, 50 times closer. He's off by a factor of 2, due to > > failure to multiply by 2 after taking the arcsin. > > > r_sun = 0.7e6 km > > r_orbit = 3e6 km > > theta_sun = 2*asin(r_sun/r_orbit) = 2*asin(0.7/3.0) = 27.0 deg > > Yeah, ya gotta try to teach. I can hold my hand an inch from the side > of a boiling saucepan>||||||||||||||||||||||||||||||||||||||||||||||||||< > > 1 inch > > but I'm damned if I'm going to put it 0.02" away from the hotplate. > >||< > this gap is about 20 thou = 1/50th of an inch. > > Doesn't he realise he's in the corona? > http://www.phys.ncku.edu.tw/~astrolab/mirrors/apod_e/ap010408.html Again, you know very little of what you're talking about. The size of the solar corona changes continuously throughout the sunspot cycle. The corona actually extends throughout the entire solar system as a 'wind' of particles, however, the densist parts of the corona is usually seen not more than about 1-2 solar radii from the surface or about 690,000 to 1.5 million kilometers at the equator. Near the poles, it is flatter. The so-called 'inner corona' extends about 1/3 of the solar radius ( 230,000 kilometers) above the photosphere and has a spectrum which shows no absorption lines, and an outer corona above it in which spectral lines are present. The inner corona is produced by sun light from the photosphere scattering off of the ionized gases in the inner corona. The corona density is still a very high vacuum by terrestrial standards. The total energy contribution to an object orbiting 3.5 million km away is largely by sunlight regardless. I worked out the energy balance, which showed that a radiator operating well within the range of titanium or tungsten keep the innards of a solar operated laser cool while reflecting ineffective photons (see my patent on this subject) http://www.scribd.com/doc/21832226/Mook-Patent-Solar-Energy-Spectral-Cooling Reflected photons are also used to produce thrust on the satellite, while MEMS based refrigerators keep things cool. The entire surface is only a millimeter thick, with multi-junction PV cells, forming the solar side and nonlinear optical based laser emitter surface forming the far side, with a free electron laser setup forming a sandwich in between. The electrons move through strong electrostatic 'poles' between the sandwich formed by the two surfaces - while photons are emitted normal to their motion. The entire setup is a large surface area synchotron with MEMS elements. 165 m in diameter and only a millimeter thick, massing less than 10 tons - electrons spiraling out - through wigglers - powered by high voltage PV. |