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Annom
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Re: 1 in 45000 chance of asteroid stike in 2036 [Re: Newbie]
#6589673 - 02/20/07 02:57 PM (17 years, 1 month ago) |
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Yeah, we should try to deflect the asteroid, not destroy it. It's hard to vaporize a large asteroid and it's hard to estimate how much energy you need.
What you first want is a reconnaissance spacecraft to get more information about its structure, orbit and rotation.
Deflecting it with a nuke is a good and feasible idea, but there will be many opponents against putting a large nuke on top of a rocket and sending it into space.
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TameMe
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Re: 1 in 45000 chance of asteroid stike in 2036 [Re: Annom]
#6589690 - 02/20/07 03:00 PM (17 years, 1 month ago) |
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deflecting it with gravity is alot cheaper and easier
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Colbadol
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Re: 1 in 45000 chance of asteroid stike in 2036 [Re: TameMe]
#6589700 - 02/20/07 03:03 PM (17 years, 1 month ago) |
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Quote:
TameMe said: deflecting it with gravity is alot cheaper and easier
yeah right....
the MOST expensive thing about space travel is lifting the weight up off the earth and our of our atmosphere. Rocket fuel, etc. There is no way we could lift an object massive enough to affect the gravity of an asteroid.
gravity only works for SUPER massive objects. Think of how MASSIVE the Earth is...gravity is not that strong for such a massive object. A Tiny magnet can overcome the force of gravity from the MASS of the Earth.
the best way to move the asteroid is Tsar Bomba. hell, we already have nukes just sitting around. lets use a whole bunch of those.
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Annom
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Re: 1 in 45000 chance of asteroid stike in 2036 [Re: TameMe]
#6589702 - 02/20/07 03:03 PM (17 years, 1 month ago) |
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Very true. The problem is that you need to start a long time before a possible collision. This means that your orbit estimate is less accurate at decision point.
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Annom
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Re: 1 in 45000 chance of asteroid stike in 2036 [Re: Colbadol]
#6589739 - 02/20/07 03:13 PM (17 years, 1 month ago) |
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Quote:
the MOST expensive thing about space travel is lifting the weight up off the earth and our of our atmosphere. Rocket fuel, etc.
I think it's more expensive to place a nuke on a rocket because the general public does demand a VERY safe mission with nukes. Safety is one of the reasons why manned missions are so expensive.
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There is no way we could lift an object massive enough to affect the gravity of an asteroid.
A 1000kg mass was enough to deflect Apophis enough to avoid a collision with Earth in our study project.
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gravity only works for SUPER massive objects.
No! There is a gravitational attraction between you and me at the moment. It's small but it's there. The very small force can create a relatively large change in orbital velocity when it acts for a long time. F=ma.
I can look for some numbers in our report if you want.
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Colbadol
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Re: 1 in 45000 chance of asteroid stike in 2036 [Re: Annom]
#6589817 - 02/20/07 03:27 PM (17 years, 1 month ago) |
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i took university physics. i know gravity is always there. what im sayin is that it's sooooooooo small. you wanna follow an asteroid for years to move it? remember. the asteroid pulls on you too. you would need to continually use energy to keep your massive mass at distance. you might as well fling that object into the asteroid like pool and hope it has enough kinetic energy to knock it around.
it's innefficient, imo.
of all of the known forces; gravity, electromagnetic, strong and weak nuclear, gravity is by FAR the weakest.
we have nukes. deflecting asteroids with them is their best possible use. id bet we could make launch-safe nukes which in the effent of a failure wouldnt ignite or pollute even if they crashed to earth. we could activate them by machines. And it would be cheaper than using gravity. and we wouldnt have to man a 1-way rocket full of nukes to an asteroid
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TameMe
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Re: 1 in 45000 chance of asteroid stike in 2036 [Re: Colbadol]
#6589826 - 02/20/07 03:30 PM (17 years, 1 month ago) |
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dude you're wrong....it's science
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Colbadol
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Re: 1 in 45000 chance of asteroid stike in 2036 [Re: TameMe]
#6589828 - 02/20/07 03:31 PM (17 years, 1 month ago) |
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Quote:
TameMe said: dude you're wrong....it's science
i didnt say your plan wouldnt work. im saying it's not the most efficient idea.
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TameMe
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Re: 1 in 45000 chance of asteroid stike in 2036 [Re: Colbadol]
#6589833 - 02/20/07 03:32 PM (17 years, 1 month ago) |
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its definetly more efficient...you don't have to burn fuel to go in the same orbit as the asteriod...you just stay along side it for a few days or weeks..and the orbit changes a tiny bit..which is good enough
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Asante
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Re: 1 in 45000 chance of asteroid stike in 2036 [Re: Annom]
#6589837 - 02/20/07 03:33 PM (17 years, 1 month ago) |
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Quote:
I think it's more expensive to place a nuke on a rocket because the general public does demand a VERY safe mission with nukes. Safety is one of the reasons why manned missions are so expensive.
Nuclear weapons are very safe, and public opinion will be easily swayed, especially with phrases like "the impact of the asteroid would be ten million times more destructive than the nuke we'll send to intercept it."
It will make good television
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What you first want is a reconnaissance spacecraft to get more information about its structure, orbit and rotation.
How about having a nuke aboard the reconnaissance vessel? It investigates the nuke, then takes the appropriate distance and explodes at the required yield (a modern nuke can be set to go off with a bigger or smaller bang, strange as it sounds)
A 20 ton juggernaut like Tsar Bomba can only go off with one tremendous bawoosh, but you can distance it further to decrease its effect.
What they'd probably do is send a MIRV nuke on a spacerocket, which close to the target comes apart into say 10 warheads, which can individually be navigated and set off to get the engineering job done.
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there will be many opponents against putting a large nuke on top of a rocket and sending it into space.
They will be entirely ignored and made to look stupid in the media so they'll pose no harm to the mission
Can you give us more specifications about your proposed mission Annom? It sounds very interesting!
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Colbadol
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Re: 1 in 45000 chance of asteroid stike in 2036 [Re: TameMe]
#6589858 - 02/20/07 03:38 PM (17 years, 1 month ago) |
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Quote:
TameMe said: its definetly more efficient...you don't have to burn fuel to go in the same orbit as the asteriod...you just stay along side it for a few days or weeks..and the orbit changes a tiny bit..which is good enough
the asteroid isnt just flying free of influence for your 1000kg object to take over. it's being pulled to the earth by a MUCH STRONGER force. it was mentioned earlier that this asteroid will flyby in 2020, and get pulled to hit again in 7 years. all your little object will do by orbiting around it is create two objects spinning around a center of mass...both hurling towards the earth.
your plan could work well for a really small asteroid. i guess im thinking bigger.
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Asante
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Re: 1 in 45000 chance of asteroid stike in 2036 [Re: TameMe]
#6589874 - 02/20/07 03:45 PM (17 years, 1 month ago) |
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The problem is that an asteroid will fly like 5km/second towards us.
It takes a LOT of flying at say 7km/s before you meet the asteroid deep enough in space, to have it flying towards earth for several weeks to let the gravity do its thing.
A nuke can be immediately deployed when its there, it takes effect in a millionth of a second, whereas gravity would take lets say ten days.
If the gravity ship itself flies at 5km/s it needs to fly along with the comet for 10 days at 5km/s (grabs calculator) that would mean that your gravity vessel will have to meet 4.32 million kilometers deeper into space than a nuke would. (12 earth-moon distances) That means that the gravity ship has got to be launched when the asteroid is about 10 million km away (30 earth-moon distances) whereas a nuke can be deployed when the asteroid is only 0.33 million km, 1 earth-moon distance away.
We may not have the time for a gravity ship.
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Annom
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Re: 1 in 45000 chance of asteroid stike in 2036 [Re: Colbadol]
#6589907 - 02/20/07 03:53 PM (17 years, 1 month ago) |
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you wanna follow an asteroid for years to move it? remember. the asteroid pulls on you too. you would need to continually use energy to keep your massive mass at distance.
Yes, that's why we used an ion thruster.
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you might as well fling that object into the asteroid like pool and hope it has enough kinetic energy to knock it around.
This was not enough with a 1000kg mass on Apophis and with a reasonable collision velocity.
I don't disagree with nukes being a good method, but using gravity is very possible. The problem with nukes is that the general public is paranoid about anything with the word nuke in it.
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Asante
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Re: 1 in 45000 chance of asteroid stike in 2036 [Re: Annom]
#6589992 - 02/20/07 04:11 PM (17 years, 1 month ago) |
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Seriously, if a doomsday rock is on collision course with earth I think it would be very easy to sway public opinion towards nuking it.
First they scare the bejesus out of people (which is easy to do with such a thread and some nifty CGI dramatisations) and then the world leaders announce a press conference and amidst a flock of impressive scientists they announce they're going to nuke it.
The public would readily cheer it. Nuking a lifeless threat to humanity rocks it gives us a unified goal and a climactic resolution.
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Annom
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Re: 1 in 45000 chance of asteroid stike in 2036 [Re: Colbadol]
#6590064 - 02/20/07 04:25 PM (17 years, 1 month ago) |
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Another problem with a nuke to deflect the asteroid is that this guy argues that some porous asteroids might somehow be able to "absorb" the energy without deflecting much(I haven't read the details). If this is true it would require nuclear tests in space before an actual mission.
I'm not saying nukes aren't a good idea or are impossible, just giving the info I have.
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It will make good television
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Can you give us more specifications about your proposed mission Annom? It sounds very interesting!
Here is a result of our orbit simulation, we only used F=ma and the masses and initial position of all objects to make the simulation. We used a RK4 numerical integration method. It is a dynamic program, but I can't show that here. It might still give an idea of the orbits:
I just read that our total mass is 10000kg (not 1000kg as I thought). That makes it a lot more expensive! (it wasn't our goal to pick the best method, but to work out the gravity method.)
The ion thrusters can't fire at the asteroid because that would "undo" the gravitational force(no change in momentum of the closed system). Therefore the mass should fly at an optimal 450m in front of the asteroid and the ion thruster should aim the ions on both sides of the asteroid.
This would create a constant acceleration of 6.6*10-12 m/s2. This acceleration would result in an increase in distance of passing earth of 30.000km after 17 years. According to our simulation this means that Apophis will pass Earth at 230.000km in 2029 (it didn't actually hit earth in our simulation, but 230.000km is "close".)
Flying the mass on side of the asteroid didn't significantly deflect the asteroid. The mass should always fly in front or behind the asteroid.
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Sheepish
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Re: 1 in 45000 chance of asteroid stike in 2036 [Re: Asante]
#6590074 - 02/20/07 04:27 PM (17 years, 1 month ago) |
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I hope it hits Earth
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Annom
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Re: 1 in 45000 chance of asteroid stike in 2036 [Re: Asante]
#6590079 - 02/20/07 04:28 PM (17 years, 1 month ago) |
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Quote:
Wiccan_Seeker said: Seriously, if a doomsday rock is on collision course with earth I think it would be very easy to sway public opinion towards nuking it.
I agree, but what if there is a 1 on 45000 chance?
If we are sure about doomsday, then I'm sure the general public doesn't care about a nuke.
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Colbadol
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Re: 1 in 45000 chance of asteroid stike in 2036 [Re: Annom]
#6590217 - 02/20/07 05:05 PM (17 years, 1 month ago) |
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Quote:
Annom said: I just read that our total mass is 10000kg (not 1000kg as I thought). That makes it a lot more expensive! (it wasn't our goal to pick the best method, but to work out the gravity method.)
maybe we could fling our moon into orbit. that might do something. or at least SOME other in-space object.
cool study btw.
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