The camera covers a little less than 9.7 square degrees, not the whole sky. (It's not a square image but an array of sensor chips, the array is missing corners to more closely follow a circular image shape.)
The page http://www.lsst.org/lsst/science/concept_camera lists the sampling resolution as "better than 0.2 arcseconds" (with 6 color bands per pixel 300nm-1200nm). That would make the moon 9000 pixels wide (assuming 0.5 degree width - it varies a little).
Follow up -"etendue" is effectively a measure of optical throughput which correlates with how many objects can be detected per unit of time. It is the product of the effective area of the primary mirror (m^2) times the effective area of the sky that is covered (degrees^2). The LSST's sensors do not cover quite the full field of view, which likely accounts for the difference between the calculated value of 347 and the claimed value of 320.
From the Pan-STARRS site is this comparison on etendues: USAF Linear 1.5 SDSS 6.0 CFHT 8.0 SUBARU 8.8 Pan-STARRS 60 (It lists LSST as 190, which is wrong.)
...That combination is unique: wide field of view (10 square degrees), short exposures (pairs of 15-second exposures), and sensitive camera (24th magnitude single images, 27th magnitude stacked).... The etendue of LSST is 320 square meters square degrees. A primary mirror diameter of 8.4 m (effective aperture 6.7 m due to obscuration) is the minimum diameter that simultaneously satisfies the depth (24.5 mag depth per single visit and 27.5 mag for coadded depth) and cadence (revisit time of 3-4 days, with 30 seconds per visit) constraints.... The nominal high-SNR sample defined by i25 for point sources) will include four billion galaxies (55 per square arcminute) with the mean photometric redshift accuracy of 1-2% (relative error for 1+z), and with only 10% of the sample with errors larger than 4%. The median redshift for this sample will be z=1.2, with the third quartile at z=2....
Q: Will the full resolution, full depth image data be available to download?
A: Yes. There will be a range of data products and download portals. The LSST data system is being designed to enable as wide a range of science as possible. Standard data products, including calibrated images and catalogs of detected objects and their attributes, will be provided both for individual exposures and the deep incremental data coaddition. For the "static" sky, there will be yearly database releases listing many attributes for billions of objects. This database will grow in size to about 30 PB and about 20 billion objects. As in the SDSS, we expect a power law of user interactions with the data. At one end of this distribution are simple lookup queries or color jpeg cutout downloads. At the other end are huge statistical calculations over the entire database, and image operation scripts on billions of objects. The data management system is budgeted to handle most but not all of that distribution. Institutions joining LSST early, and members of the LSST Science Collaborations, will have the customary advantage of deep familiarity with the LSST system and survey.
True, but silver is only 5.7% better than copper, but copper is 45% better than gold. (conductivity per unit length) On a cost basis, copper is best, except for aluminum, but aluminum's oxide layer often causes problems. Silver's main electronic use is as part of the better sorts of lead-free solder.
Also, calutrons are cool. Mass spectrometry in bulk. Too bad they're so inefficient.
That executive order had a "I'm rubber, you're glue" clause, though: "Sec. 6. Nothing in section 1 of this order shall prohibit transactions for the conduct of the official business of the United States Government by employees, grantees, or contractors thereof."
And a "Nyah, nyah, nyah" clause, as well: "Sec. 11. This order is not intended to, and does not, create any right or benefit, substantive or procedural, enforceable at law or in equity by any party against the United States, its departments, agencies, or entities, its officers, employees, or agents, or any other person."
How would the UN enforce that treaty? Does anyone think they could get the Security Council to vote for enforcement? Anyway, the treaties do not say what some people think. Space resources can be developed and owned, just not as real estate or unmined minerals.
The "Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies" allows in Article 1: "Outer space, including the Moon and other celestial bodies, shall be free for exploration and use by all States...". Article 2 prohibits national appropriation, but not individual ownership. No other article of this treaty prohibits individual ownership, either.
Article 1 Section 1 of the "Agreement Governing the Activities of States on the Moon and Other Celestial Bodies" is a loophole one could drive a starship through: "The provisions of this Agreement relating to the Moon shall also apply to other celestial bodies within the solar system, other than the Earth, except insofar as specific legal norms enter into force with respect to any of these celestial bodies." That can be stretched as far as needed with existing or later national laws, judicial decisions or international treaties. Also the treaty mostly only applies to "States Parties", leaving individuals, corporations and non-signatories unbound. Even if they act under authority of a State Party, however, under Article 6 section 2, they can bring back as much moon rock as they want and not share it with anybody. By Article 1 Section 1, the same is true of asteroids.
Article 11 Section 3 is the one that causes confusion, purporting to bind all organizations and people: "Neither the surface nor the subsurface of the Moon, nor any part thereof or natural resources in place, shall become property of any State, international intergovernmental or non-governmental organization, national organization or non-governmental entity or of any natural person." This actually only apples to real estate and unmined resources on celestial bodies claimed by signatories and the people and organizations under their control. Otherwise Article 6 Section 2 would be meaningless. In the context of other parts of the treaty, it is also clear that any structures and craft on or in such bodies can be owned. Finally, treaties have a hard time binding non-signatories, even when they try.
Deorbiting is cheap - use an elecro-tether, which cuts orbital velocity with no reaction mass (reacting against the Earth's magnetic field), optionally using the energy generated to speed things up with an ion or resistive thruster. Once you start to hit atmosphere, a cheap, low-tech heat shield allows aerobraking for most of the rest, then parachutes. The price to de-orbit could be virtually nothing.
You may laugh, but it may be difficult to refine the raw material without degrading the vacuum around the moon. Tailings will also need to be deorbited or perhaps repurposed as counterweights for centrifugal artificial gravity.
Gold is actually not as good a conductor as copper. It is used in plating contacts because it does not corrode and can make better contact at microscopic scales due to its malleability.
Platinum is a bigger deal because it is used in all sorts of catalysts, not just in exhaust systems but in making drugs and plastics. It is also needed for durable high-temperature dies such as those used to make glass fiber, electrical conductors passing through glass (same tempco), coatings on cutting instruments and turbine blades and much more. The other platinum group metals also have many technical applications and are found in high concentrations in metallic meteorites.
It is a long-term investment in basic research which will expand the capabilities of the human race. Without this research we'll have much less chance of building a space economy or of being able to deflect a future big asteroid. The amount of money they are talking about is less than one shuttle launch.
Engineering skills are not nearly as fungible as money - if we don't come up with some things for the aerospace guys to do, they're more likely to end up working at CostClub or Wall Depot than they are to become biologists or social workers or whatever it is you think is more important. That would be a pure waste.
You don't like it? Fine. Get cracking on what you think is important. But I think the guys at Planetary Research are way smarter and have more vision than people who think like you do.
It's really a 2-D search problem. Rather than mess around with steradians, which nobody understands anyway, I figured how much area the full moon takes up in the sky, which is about pi*(0.25degree)^2. So using Frink, sphere/(pi(0.25degree)^2) gives 210099.6 and change. Coincidentally the moon is about the same size as the foveal area of a human's vision, so it would take over 210,000 people to look in all directions at once.
With telescopes, of course, it would be an even bigger problem. Figuring that a decent low-end professional scope is about 20 inches with a theoretical resolution of 0.3 arcseconds, and assuming square pixels, that's nearly 6E12 pixels to cover a full sphere. (In the real world there are lots of complicating factors, but that's the right order of magnitude.) To make it a little more concrete, if the sensors have 5micron pixel pitch, that would be 148.5m^2 of sensors, or in American, the equivalent of a square sensor 40ft on a side.
In order to get the thing into (most likely lunar) orbit, the velocity has to be as finely controlled as the direction, and the velocity required means it will have around an order of magnitude less energy than a natural asteroid of the same mass. If the velocity is much higher, the thing will just miss the whole earth-moon system by a wide margin if it is pointed in even vaguely the right direction. Even if the direction is also badly out of spec, space is big and the earth is small - the odds of hitting anything are very very low. Even if the lottery-like odds did come up, rocks that size will expend nearly all their energy over 10km up and turn into a cloud of small chunks that will be going at around terminal velocity (at most a few hundred kph) rather than orbital velocity, thus having lost over 99.99% of their energy. And it's almost certain that if it happened, it wouldn't happen over anything more important than ocean or desert.
Actually they are looking at doing a carbonaceous asteroid first, hoping to get something that they can process into fuel and maybe air. "We have no technology to mine in space"
The point is to develop new technology for shifting asteroid orbits (which is going to come in really handy one of these days when a big one comes our way) and to develop techniques for mining and processing raw materials in orbit. It's research.
"It would be far better sending it to someplace we plan to go to....the moon"
Landing (well, gently crashing) asteroids in the moon is also being looked at, but it will require much more investment and time to get going. Initial experiments will be in orbit, most likely lunar orbit.
Space development does not interfere with ecological efforts, on the contrary, over the long term it helps them. This is taking the first baby steps to preventing a great deal of ecological harm by allowing the use of off-Earth natural resources.
How would the UN enforce that treaty? Does anyone think they could get the Security Council to vote for enforcement? Anyway, the treaties do not say what some people think. Space resources can be developed and owned, just not as real estate or unmined minerals.
The "Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies" allows in Article 1: "Outer space, including the Moon and other celestial bodies, shall be free for exploration and use by all States...". Article 2 prohibits national appropriation, but not individual ownership. No other article of this treaty prohibits individual ownership, either.
Article 1 Section 1 of the "Agreement Governing the Activities of States on the Moon and Other Celestial Bodies" is a loophole one could drive a starship through: "The provisions of this Agreement relating to the Moon shall also apply to other celestial bodies within the solar system, other than the Earth, except insofar as specific legal norms enter into force with respect to any of these celestial bodies." That can be stretched as far as needed with existing or later national laws, judicial decisions or international treaties. Also the treaty mostly only applies to "States Parties", leaving individuals, corporations and non-signatories unbound. Even if they act under authority of a State Party, however, under Article 6 section 2, they can bring back as much moon rock as they want and not share it with anybody. By Article 1 Section 1, the same is true of asteroids.
Article 11 Section 3 is the one that causes confusion, purporting to bind all organizations and people: "Neither the surface nor the subsurface of the Moon, nor any part thereof or natural resources in place, shall become property of any State, international intergovernmental or non-governmental organization, national organization or non-governmental entity or of any natural person." This actually only apples to real estate and unmined resources on celestial bodies claimed by signatories and the people and organizations under their control. Otherwise Article 6 Section 2 would be meaningless. In the context of other parts of the treaty, it is also clear that any structures and craft on or in such bodies can be owned. Finally, treaties have a hard time binding non-signatories, even when they try.
17km/s is more like it for a full speed asteroidal impact. This will be going much slower to make lunar orbit. If it somehow is going faster, it won't get near anything, it will miss the rendezvous.
This is a 2.5-3m rock. Rocks that big hit every year. The velocities will not be nearly as high as natural rocks, and even if they were, the destruction possible will be negligible. Even with an nickel-iron rock at full speed, it would break up at 10km or more - no crater, no blast damage.
There have been many instances where satellites in orbit have changed ownership with money transferred here on earth. Bringing things back to earth is not needed.
Not really: using http://impact.ese.ic.ac.uk/ImpactEffects/ , assuming 2.46m sphere, 8g/cc, 17km/s, vertical impact (worst case), - - the asteroid breaks up at 10km above the surface. Medium-sized chunks will be going in the low hundreds of miles per hour when they hit, a few may be going faster. Over 80% of the 9TJ of energy will go into the blast wave, yet measured 1meter from impact the blast from the airburst will only be = 0.1mph wind, 26dB sound, 0.0002bar overpressure. Basically you are only in danger if one of the bits at least the size of a baby's fist actually hits you on the head. Nothing like the danger of, say, a jet falling on your house.
A 500 tonne sphere with a density of 7 g/cc has a diameter of under 3 meters. The earth gets hit with one that size more than once every year already. Even 5000 tonne meteors hit most years. No big deal at all.
Yes, it's a long way. Farther than to the chemist's, even. But it doesn't really matter so long as we have some patience. What matters is energy production mass and reaction mass, and both of these can be reduced to quite low levels if we are willing to take enough time to do the transfer. With current or near future solar technology and ion drives, it is feasible.
Slashdot Mirror
The camera covers a little less than 9.7 square degrees, not the whole sky. (It's not a square image but an array of sensor chips, the array is missing corners to more closely follow a circular image shape.)
The page http://www.lsst.org/lsst/science/concept_camera lists the sampling resolution as "better than 0.2 arcseconds" (with 6 color bands per pixel 300nm-1200nm). That would make the moon 9000 pixels wide (assuming 0.5 degree width - it varies a little).
Follow up -"etendue" is effectively a measure of optical throughput which correlates with how many objects can be detected per unit of time. It is the product of the effective area of the primary mirror (m^2) times the effective area of the sky that is covered (degrees^2). The LSST's sensors do not cover quite the full field of view, which likely accounts for the difference between the calculated value of 347 and the claimed value of 320.
From the Pan-STARRS site is this comparison on etendues:
USAF Linear 1.5
SDSS 6.0
CFHT 8.0
SUBARU 8.8
Pan-STARRS 60
(It lists LSST as 190, which is wrong.)
More to be said - here's the scientific FAQ: http://www.lsst.org/lsst/faq-science
Choice bits:
True, the opportunity cost of deorbiting would be high, though deorbiting is not expensive in itself
True, but silver is only 5.7% better than copper, but copper is 45% better than gold. (conductivity per unit length) On a cost basis, copper is best, except for aluminum, but aluminum's oxide layer often causes problems. Silver's main electronic use is as part of the better sorts of lead-free solder.
Also, calutrons are cool. Mass spectrometry in bulk. Too bad they're so inefficient.
That executive order had a "I'm rubber, you're glue" clause, though:
"Sec. 6. Nothing in section 1 of this order shall prohibit transactions for the conduct of the official business of the United States Government by employees, grantees, or contractors thereof."
And a "Nyah, nyah, nyah" clause, as well:
"Sec. 11. This order is not intended to, and does not, create any right or benefit, substantive or procedural, enforceable at law or in equity by any party against the United States, its departments, agencies, or entities, its officers, employees, or agents, or any other person."
I'll just paste in my post on the earlier thread:
Deorbiting is cheap - use an elecro-tether, which cuts orbital velocity with no reaction mass (reacting against the Earth's magnetic field), optionally using the energy generated to speed things up with an ion or resistive thruster. Once you start to hit atmosphere, a cheap, low-tech heat shield allows aerobraking for most of the rest, then parachutes. The price to de-orbit could be virtually nothing.
You may laugh, but it may be difficult to refine the raw material without degrading the vacuum around the moon. Tailings will also need to be deorbited or perhaps repurposed as counterweights for centrifugal artificial gravity.
Gold is actually not as good a conductor as copper. It is used in plating contacts because it does not corrode and can make better contact at microscopic scales due to its malleability.
Platinum is a bigger deal because it is used in all sorts of catalysts, not just in exhaust systems but in making drugs and plastics. It is also needed for durable high-temperature dies such as those used to make glass fiber, electrical conductors passing through glass (same tempco), coatings on cutting instruments and turbine blades and much more. The other platinum group metals also have many technical applications and are found in high concentrations in metallic meteorites.
It is a long-term investment in basic research which will expand the capabilities of the human race. Without this research we'll have much less chance of building a space economy or of being able to deflect a future big asteroid. The amount of money they are talking about is less than one shuttle launch.
Engineering skills are not nearly as fungible as money - if we don't come up with some things for the aerospace guys to do, they're more likely to end up working at CostClub or Wall Depot than they are to become biologists or social workers or whatever it is you think is more important. That would be a pure waste.
You don't like it? Fine. Get cracking on what you think is important. But I think the guys at Planetary Research are way smarter and have more vision than people who think like you do.
Certainly not in your hot tub. That could totally harsh on your mellow.
With a sidebar to the article: "Will Radioactive Space Bombs Cause Ca. Mutant Zombie Epidemic?"
It's really a 2-D search problem. Rather than mess around with steradians, which nobody understands anyway, I figured how much area the full moon takes up in the sky, which is about pi*(0.25degree)^2. So using Frink, sphere/(pi(0.25degree)^2) gives 210099.6 and change. Coincidentally the moon is about the same size as the foveal area of a human's vision, so it would take over 210,000 people to look in all directions at once.
With telescopes, of course, it would be an even bigger problem. Figuring that a decent low-end professional scope is about 20 inches with a theoretical resolution of 0.3 arcseconds, and assuming square pixels, that's nearly 6E12 pixels to cover a full sphere. (In the real world there are lots of complicating factors, but that's the right order of magnitude.) To make it a little more concrete, if the sensors have 5micron pixel pitch, that would be 148.5m^2 of sensors, or in American, the equivalent of a square sensor 40ft on a side.
In order to get the thing into (most likely lunar) orbit, the velocity has to be as finely controlled as the direction, and the velocity required means it will have around an order of magnitude less energy than a natural asteroid of the same mass. If the velocity is much higher, the thing will just miss the whole earth-moon system by a wide margin if it is pointed in even vaguely the right direction. Even if the direction is also badly out of spec, space is big and the earth is small - the odds of hitting anything are very very low. Even if the lottery-like odds did come up, rocks that size will expend nearly all their energy over 10km up and turn into a cloud of small chunks that will be going at around terminal velocity (at most a few hundred kph) rather than orbital velocity, thus having lost over 99.99% of their energy. And it's almost certain that if it happened, it wouldn't happen over anything more important than ocean or desert.
Actually they are looking at doing a carbonaceous asteroid first, hoping to get something that they can process into fuel and maybe air.
"We have no technology to mine in space"
The point is to develop new technology for shifting asteroid orbits (which is going to come in really handy one of these days when a big one comes our way) and to develop techniques for mining and processing raw materials in orbit. It's research.
"It would be far better sending it to someplace we plan to go to. ...the moon"
Landing (well, gently crashing) asteroids in the moon is also being looked at, but it will require much more investment and time to get going. Initial experiments will be in orbit, most likely lunar orbit.
Interesting, but that is a 12.5W/800lumen bulb which costs about half as much. The bulb that won the prize is 9.7W/900lumens.
Space development does not interfere with ecological efforts, on the contrary, over the long term it helps them. This is taking the first baby steps to preventing a great deal of ecological harm by allowing the use of off-Earth natural resources.
How would the UN enforce that treaty? Does anyone think they could get the Security Council to vote for enforcement? Anyway, the treaties do not say what some people think. Space resources can be developed and owned, just not as real estate or unmined minerals.
The "Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies" allows in Article 1: "Outer space, including the Moon and other celestial bodies, shall be free for exploration and use by all States...". Article 2 prohibits national appropriation, but not individual ownership. No other article of this treaty prohibits individual ownership, either.
Article 1 Section 1 of the "Agreement Governing the Activities of States on the Moon and Other Celestial Bodies" is a loophole one could drive a starship through: "The provisions of this Agreement relating to the Moon shall also apply to other celestial bodies within the solar system, other than the Earth, except insofar as specific legal norms enter into force with respect to any of these celestial bodies." That can be stretched as far as needed with existing or later national laws, judicial decisions or international treaties. Also the treaty mostly only applies to "States Parties", leaving individuals, corporations and non-signatories unbound. Even if they act under authority of a State Party, however, under Article 6 section 2, they can bring back as much moon rock as they want and not share it with anybody. By Article 1 Section 1, the same is true of asteroids.
Article 11 Section 3 is the one that causes confusion, purporting to bind all organizations and people: "Neither the surface nor the subsurface of the Moon, nor any part thereof or natural resources in place, shall become property of any State, international intergovernmental or non-governmental organization, national organization or non-governmental entity or of any natural person." This actually only apples to real estate and unmined resources on celestial bodies claimed by signatories and the people and organizations under their control. Otherwise Article 6 Section 2 would be meaningless. In the context of other parts of the treaty, it is also clear that any structures and craft on or in such bodies can be owned. Finally, treaties have a hard time binding non-signatories, even when they try.
17km/s is more like it for a full speed asteroidal impact. This will be going much slower to make lunar orbit. If it somehow is going faster, it won't get near anything, it will miss the rendezvous.
This is a 2.5-3m rock. Rocks that big hit every year. The velocities will not be nearly as high as natural rocks, and even if they were, the destruction possible will be negligible. Even with an nickel-iron rock at full speed, it would break up at 10km or more - no crater, no blast damage.
There have been many instances where satellites in orbit have changed ownership with money transferred here on earth. Bringing things back to earth is not needed.
Not really: using http://impact.ese.ic.ac.uk/ImpactEffects/ ,
assuming 2.46m sphere, 8g/cc, 17km/s, vertical impact (worst case), -
- the asteroid breaks up at 10km above the surface. Medium-sized chunks will be going in the low hundreds of miles per hour when they hit, a few may be going faster. Over 80% of the 9TJ of energy will go into the blast wave, yet measured 1meter from impact the blast from the airburst will only be = 0.1mph wind, 26dB sound, 0.0002bar overpressure. Basically you are only in danger if one of the bits at least the size of a baby's fist actually hits you on the head. Nothing like the danger of, say, a jet falling on your house.
A 500 tonne sphere with a density of 7 g/cc has a diameter of under 3 meters. The earth gets hit with one that size more than once every year already. Even 5000 tonne meteors hit most years. No big deal at all.
Yes, it's a long way. Farther than to the chemist's, even. But it doesn't really matter so long as we have some patience. What matters is energy production mass and reaction mass, and both of these can be reduced to quite low levels if we are willing to take enough time to do the transfer. With current or near future solar technology and ion drives, it is feasible.
See this on applied chaotic orbits: http://en.wikipedia.org/wiki/Interplanetary_Transport_Network