SUBSIM Radio Room Forums - View Single Post - Negr, explain Chernobyl and refute Nuke asteroid defense.

SUBMAN1 · 01-19-06, 06:04 PM

Found a basic description of what I describe above:

One of his most interesting proposals is solar redirection. It envisions using sunlight to deflect asteroids and comets. A giant concave mirror made of ultrathin aluminum would be ferried to a point in space fairly close to the asteroid. The mirror would act as a solar collector, focusing sunlight on the asteroid with the help of a secondary mirror. The focused beam of light would heat a small spot on the asteroid and vaporized rock would shoot into space, pushing the asteroid in the opposite direction.

Unlike the schemes involving nuclear explosives, the solar collector would apply constant pressure to the asteroid rather than a single push. Melosh calculates that a mirror about 1/2 mile wide could deflect asteroids up to 2 miles in diameter if it operates for a year. The system would be even more effective against comets.

Another option:

There are more options for deflecting an asteroid or comet than for destroying one. If an asteroid is spotted years or decades before impact, mass ejection redirection could possibly push it to a safe trajectory by simply crashing an interceptor rocket into it. The impact would dig a crater in the asteroid's surface, blowing a large amount of material out into space. Obeying Newton's Third Law of Motion--every action must have an equal and opposite reaction--the asteroid would be pushed in the direction opposite to that of the blow-off material. It wouldn't be a strong push, but it would be enough to alter the asteroid's orbit so that it misses the Earth several years down the road.

Here is the bad idea associated with Nukes:

This approach won't work, however, if there's less advance warning. If it's a few months from Earth, it will need a much bigger push. Crashing a rocket into the object won't do it--only a nuclear explosion on the surface would blow off enough material. But such a move would be risky. The latest scientific evidence suggests that most asteroids and comets are quite fragile. Instead of deflecting the object, a surface explosion might fracture it into dozens of large pieces that could head toward Earth on the same trajectory as before. And some scientists believe that a shower of fair-sized chunks would be more devastating to Earth than if the original object were left alone.

Tungsten bullets:

Here's how it would work: Say an asteroid is racing toward Earth at a typical speed of 67,000 miles per hour. If a dense tungsten bullet hit the asteroid at that speed, it would dig a deep hole into the asteroid's surface, vaporizing itself in the process. If another tungsten bullet was following directly behind the first one, it would travel into the hole and dig a little deeper. And if a whole string of tungsten bullets were properly aligned, they'd drill a hole right through the asteroid.

Now imagine hundreds of thousands of tungsten bullets strung together by lightweight fiber to form a 3-dimensional lattice. If such a structure were deployed in front of a speeding asteroid, it would slice and dice the asteroid into small, harmless rocks. At the Livermore conference, this proposal came to be known as the kinetic-energy cookie cutter. It would work just as well on comets, which are believed to be made mostly of ice.

With the bullets weighing about 3/4 oz. each, a lattice containing several million of them could be launched into space using a heavy-lift rocket like the Russian Energia. Such a lattice would be big enough to pulverize the smaller asteroids and comets, those with diameters of about 600 ft.

01-19-06, 06:04 PM	#27
SUBMAN1 Rear Admiral Join Date: Apr 2005 Posts: 11,866 Downloads: 0 Uploads: 0	Found a basic description of what I describe above: One of his most interesting proposals is solar redirection. It envisions using sunlight to deflect asteroids and comets. A giant concave mirror made of ultrathin aluminum would be ferried to a point in space fairly close to the asteroid. The mirror would act as a solar collector, focusing sunlight on the asteroid with the help of a secondary mirror. The focused beam of light would heat a small spot on the asteroid and vaporized rock would shoot into space, pushing the asteroid in the opposite direction. Unlike the schemes involving nuclear explosives, the solar collector would apply constant pressure to the asteroid rather than a single push. Melosh calculates that a mirror about 1/2 mile wide could deflect asteroids up to 2 miles in diameter if it operates for a year. The system would be even more effective against comets. Another option: There are more options for deflecting an asteroid or comet than for destroying one. If an asteroid is spotted years or decades before impact, mass ejection redirection could possibly push it to a safe trajectory by simply crashing an interceptor rocket into it. The impact would dig a crater in the asteroid's surface, blowing a large amount of material out into space. Obeying Newton's Third Law of Motion--every action must have an equal and opposite reaction--the asteroid would be pushed in the direction opposite to that of the blow-off material. It wouldn't be a strong push, but it would be enough to alter the asteroid's orbit so that it misses the Earth several years down the road. Here is the bad idea associated with Nukes: This approach won't work, however, if there's less advance warning. If it's a few months from Earth, it will need a much bigger push. Crashing a rocket into the object won't do it--only a nuclear explosion on the surface would blow off enough material. But such a move would be risky. The latest scientific evidence suggests that most asteroids and comets are quite fragile. Instead of deflecting the object, a surface explosion might fracture it into dozens of large pieces that could head toward Earth on the same trajectory as before. And some scientists believe that a shower of fair-sized chunks would be more devastating to Earth than if the original object were left alone. Tungsten bullets: Here's how it would work: Say an asteroid is racing toward Earth at a typical speed of 67,000 miles per hour. If a dense tungsten bullet hit the asteroid at that speed, it would dig a deep hole into the asteroid's surface, vaporizing itself in the process. If another tungsten bullet was following directly behind the first one, it would travel into the hole and dig a little deeper. And if a whole string of tungsten bullets were properly aligned, they'd drill a hole right through the asteroid. Now imagine hundreds of thousands of tungsten bullets strung together by lightweight fiber to form a 3-dimensional lattice. If such a structure were deployed in front of a speeding asteroid, it would slice and dice the asteroid into small, harmless rocks. At the Livermore conference, this proposal came to be known as the kinetic-energy cookie cutter. It would work just as well on comets, which are believed to be made mostly of ice. With the bullets weighing about 3/4 oz. each, a lattice containing several million of them could be launched into space using a heavy-lift rocket like the Russian Energia. Such a lattice would be big enough to pulverize the smaller asteroids and comets, those with diameters of about 600 ft.