My gut feeling is that we are not going to be able to shift anything over 100 metres diameter, and that global impact affects start at about 1000 metres diameter. Between those two you still have a large population of asteroids. Objects smaller than 100 metres might barely make it to the surface anyway.
What might help on the tracking side is a multilateration system along the lines of GPS, but covering the inner solar system. You could navigate without it but you are working by inference a lot of the time. At least most operations on an asteroid would happen in plain view so there is no reasonable hope of dumping the object on your neighbours capital city without them knowing about it.
For the vast majority of impacts it will be enough to evacuate the impact site. For this there are two basic problems:
Exactly where and when will the impact occur? To answer this we need really accurate tracking. Transponders on the impactor would help a lot.
How do we safely evacuate the target area? What do we do if the target is Calcutta? Move the population to Afghanistan? I bet that will go down well. This is a political problem which can only partly address right now. Improvements are needed.
I bet it works really well against cameras and communications equipment carried by journalists. Possibly better than it would work against actual people.
Well, not really. Remember the wave tank at high school. You would get an interference pattern with standing waves in different places, but still waves.
Yeah a lot depends on how the sail is constructed and how much control you have over it. If you can use Venus to push you back in its solar orbit your sail can be side on to the sun.
A magic material which is reflective only from one side would be really handy right now.
You could reflect sunlight forwards along your orbit around the sun to reduce your closest distance from the sun. You could slingshot off Earth and Venus to direct your trajectory inwards. You could use your sail to capture light reflected from a large planet (Venus would be ideal) to get an impulse towards the sun.
You are right about the difficulty of getting quickly into a sun grazing orbit. A slingshot off Venus might help there.
Look here for information on powered slingshots. My way of thinking about it is that if you approach the sun slowly you spend more time in its gravitational field, so you accelerate more. If you do a burn at closest approach you are going faster on the way out so you spend less time in the same field and lose less speed.
I would guess that the weight of the craft isn't evenly balanced, because of the asymmetrical nature of some of the electrical equipment or some such. Thus, it needs differently shaped wings to compensate, as mechanical or more traditional propulsion mechanisms aren't viable given its limited energy availability.
The second picture in the article gives a more symmetrical view.
The current official world endurance record for a UAV is 30 hours, 24 minutes. This was set by the US robot Global Hawk. Zephyr itself has already recorded an 83-hour continuous flight but representatives from the Federation Aeronautique Internationale (FAI) were not present to witness proceedings.
However, they are at Yuma this time and so the latest flight will go down as an official world record provided the FAI is satisfied its rules have been followed.
They had better hurry up and end the light otherwise the FAI guy might give up and go home.
why is one wing shaped differently than the other, i wonder..
You're right, there is a noticeable extra piece of wing on the right (looking from the rear)
The left wing appears to have an extension on the wing tip with negative dihedral: it points down. The guy on the right appears to be holding the tip extension, perhaps because they are assembling the aircraft.
What happens if you have sweaty fingers? Your fingers would need to be conductive which requires water and a charge carrier like salt. So if you wash and dry your hands frequently they won't conduct very well.
A 3000 square foot sail is about 16 metres across. Imagine what you could do with a sail one kilometre across. To get to Titan: kill your orbit around the sun with your sail. Gravitational slingshot off the sun with a single burn, possibly combining the sail with a solar thermal rocket, then aero-brake in the atmosphere of Saturn, then repeat at Titan. How's that for a fast trip?
More importantly, it's not a satellite owner. I guess the budget's only for hookers and blow.
NASA has lots of assets in low earth orbit.
Woah, NASA has hookers and blow in low earth orbit? Damn it someone send up the black-jack tables STAT and we'll have ourselves a profitable endeavor...
You had your chance when Pete Conrad was on Skylab.
"track space junk and sell the data it collects to satellite owners and companies like NASA"
So, basically, it doesn't *do* anything. They use it like...oh, a telescope or something, and then *sell* their observations.
Yippee. Shouldn't a project funded by federal grants not be eligible to sell their findings but be required to provide them freely to the public? Seems a little wrong to me.
CSIRO patents their discoveries and sells licenses to use them. This doesn't seem very different to me.
I considered using a rotating mirror to scan the sky. The question is whether your system can work fast enough to actually capture more particles that way?
Slashdot Mirror
My gut feeling is that we are not going to be able to shift anything over 100 metres diameter, and that global impact affects start at about 1000 metres diameter. Between those two you still have a large population of asteroids. Objects smaller than 100 metres might barely make it to the surface anyway.
What might help on the tracking side is a multilateration system along the lines of GPS, but covering the inner solar system. You could navigate without it but you are working by inference a lot of the time. At least most operations on an asteroid would happen in plain view so there is no reasonable hope of dumping the object on your neighbours capital city without them knowing about it.
when was the last time a website segfaulted?
Let me check my logs.
For the vast majority of impacts it will be enough to evacuate the impact site. For this there are two basic problems:
Cloud html5 app syncing
They call it syncing but isn't it just centralisation?
It doesn't do anything useful.
Like MOTD?
I bet it works really well against cameras and communications equipment carried by journalists. Possibly better than it would work against actual people.
Well, not really. Remember the wave tank at high school. You would get an interference pattern with standing waves in different places, but still waves.
I'm waiting for someone to come up with a working SEP field.
I am sure the military have had that for a long time.
Finally, a reliable enough power supply for serious home computer work.
Yeah a lot depends on how the sail is constructed and how much control you have over it. If you can use Venus to push you back in its solar orbit your sail can be side on to the sun.
A magic material which is reflective only from one side would be really handy right now.
You could reflect sunlight forwards along your orbit around the sun to reduce your closest distance from the sun. You could slingshot off Earth and Venus to direct your trajectory inwards. You could use your sail to capture light reflected from a large planet (Venus would be ideal) to get an impulse towards the sun.
You are right about the difficulty of getting quickly into a sun grazing orbit. A slingshot off Venus might help there.
Look here for information on powered slingshots. My way of thinking about it is that if you approach the sun slowly you spend more time in its gravitational field, so you accelerate more. If you do a burn at closest approach you are going faster on the way out so you spend less time in the same field and lose less speed.
I would guess that the weight of the craft isn't evenly balanced, because of the asymmetrical nature of some of the electrical equipment or some such. Thus, it needs differently shaped wings to compensate, as mechanical or more traditional propulsion mechanisms aren't viable given its limited energy availability.
The second picture in the article gives a more symmetrical view.
The current official world endurance record for a UAV is 30 hours, 24 minutes. This was set by the US robot Global Hawk. Zephyr itself has already recorded an 83-hour continuous flight but representatives from the Federation Aeronautique Internationale (FAI) were not present to witness proceedings.
However, they are at Yuma this time and so the latest flight will go down as an official world record provided the FAI is satisfied its rules have been followed.
They had better hurry up and end the light otherwise the FAI guy might give up and go home.
why is one wing shaped differently than the other, i wonder..
You're right, there is a noticeable extra piece of wing on the right (looking from the rear)
The left wing appears to have an extension on the wing tip with negative dihedral: it points down. The guy on the right appears to be holding the tip extension, perhaps because they are assembling the aircraft.
Rocheworld is well worth reading if you are into solar sails.
What happens if you have sweaty fingers? Your fingers would need to be conductive which requires water and a charge carrier like salt. So if you wash and dry your hands frequently they won't conduct very well.
Thats why I suggested using the sun for a gravity slingshot.
Am I missing some attempted nuance here?
3000 feet is 914 meters.
On the off chance you're talking about the length of one edge, the sqrt of 914 is 30 meters. So, still, nothing matches 16.
3000 square feet
A 3000 square foot sail is about 16 metres across. Imagine what you could do with a sail one kilometre across. To get to Titan: kill your orbit around the sun with your sail. Gravitational slingshot off the sun with a single burn, possibly combining the sail with a solar thermal rocket, then aero-brake in the atmosphere of Saturn, then repeat at Titan. How's that for a fast trip?
"Each photon of light exerts 0.0002 pounds of pressure"
I was knocked over when I read that!
You should turn down the intensity on your monitor and read /. in the dark.
More importantly, it's not a satellite owner.
NASA has lots of assets in low earth orbit.
If so, why did you post "(satellite owners) and (companies like NASA)" ? And before I forget: whoosh.
I quoted "(satellite owners) and (companies like NASA)". I don't see a problem with "NASA has lots of assets in low earth orbit." Don't they?
More importantly, it's not a satellite owner. I guess the budget's only for hookers and blow.
NASA has lots of assets in low earth orbit.
Woah, NASA has hookers and blow in low earth orbit? Damn it someone send up the black-jack tables STAT and we'll have ourselves a profitable endeavor...
You had your chance when Pete Conrad was on Skylab.
"track space junk and sell the data it collects to satellite owners and companies like NASA"
So, basically, it doesn't *do* anything. They use it like...oh, a telescope or something, and then *sell* their observations.
Yippee. Shouldn't a project funded by federal grants not be eligible to sell their findings but be required to provide them freely to the public? Seems a little wrong to me.
CSIRO patents their discoveries and sells licenses to use them. This doesn't seem very different to me.
I considered using a rotating mirror to scan the sky. The question is whether your system can work fast enough to actually capture more particles that way?