ALL SCI-FI

[Bud Brewster]

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Hot damn, alltare, you're dead right! Why didn't I think of that?

The video definitely simplified the concept — but I don't think it's actually wrong. It does precede the part about shooting yourself with the statement, " . . . be careful of where you aim!"

As you pointed out, shooting the bullets parallel to Earth's surface would not result in a circular orbit that would bring them back the point in the same orbit occupied by the spacecraft-or-space station 15 hours later, as I suggested.

Actually, shooting the bullets ahead of the orbit — but at a faster velocity — would send them into an ellipse, with an orbit that would take them further away from the Earth until they reached apogee, after which they'd curve back towards perigee and travel along for a while at the altitude the shooter was when he fired them.

Like this.



This throws a serious monkey wrench into my murder plan — until one considers Pye-rate's suggestion!

First of all, the astronaut does not have to fire the weapon exactly parallel to the Earth (as I originally thought) to make this work. He can angle the gun slightly up or down, and this will affect the point at which the bullets will come back to the altitude occupied by the spacecraft's circular orbit.

If this guy is smart enough and hi-tech enough to be an astronaut, I'm certain he could plot out the exact angle he would need to aim the weapon, and then determine the angle of the gun itself at the moment it was fired, with a device that sensed it's relationship to the Earth's surface below.

Or perhaps he could determine which celestial object in the sky to aim at when he reached an exact point in his orbit, so that the angle of the bullets would adopt the ellipse I illustrated above.

By doing this he could insure that the barrage of bullets would reach perigee (or at least cross the spacecraft's orbit at an angle) at the same moment the victim would be located in the spacecraft's circular orbit.

This might seem like a more complicated situation than I originally suggested, based on the video — which was to simply shoot a few hundred bullets ahead of the spacecraft and then wait for them to come back around.

But in fact it's exactly the same set of events, with the only change being that we've acknowledged the need for precise planning to make it work, and we've determined that the bullets will travel in an elliptical orbit before coming back to the "kill zone" where the victim has been deliberately positioned by the killer to meet his fate!

God, don't ya just love this science stuff!
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Is there no man on Earth who has the wisdom and innocence of a child?
~ The Space Children (1958)

[orzel-w]

[Bud Brewster]

[MetroPolly]

Wow, all that brilliant physics, and you didn't address the fact that it all depends on what kind of gun we're talking about.

A revolver and you're golden, shooting wise.

If it's a semi or full automatic, well, you have a problem.
See, an automatic pistol or rifle needs gas pressure to work the reloading mechanism. No air, no gas pressure. You might get one shot, but then zip.

Tip: stick with the old fashioned but reliable revolver.

[alltare]

The gas pressure used to operate gas-operated pistols and rifles is not dependant upon an ambient atmosphere. The exploding gun powder of the cartridge generates expanding gas which not only propels the bullet, it also operates the bolt and associated spent cartridge extraction and reloading of the gun. Therefore, gas-operated guns will work in space. By the way, most semi-autos are blowback-operated, not gas-operated, and adhere to Newton's action/reaction law. They would also work in space.

Most BB guns and pellet guns would require an atmosphere to work, because they rely on compressed atmospheric gas (they have to be "pumped up" in some way) to propel the projectile. But some also use pre-compressed CO2 or air and in that case, they would work in space too.

[MetroPolly]

Well, shoot.

I do think you're right. I thought the fact that an automatic doesn't work properly underwater also applies to a vacuum. Well, I never said I knew everything.

[Bud Brewster]