Space Cowboys Essay Example

make connections on the satellite that causes the whole mission to become a disaster and creates the greatest action sequences in the film... To be honest, there wasn't a lot of actual astronomy in the movie, but there was a lot of space action.

Surprisingly, the physics of space travel was fairly realistic in the movie. They made a lot of the usual mistakes, which I'll mention briefly below. The engineer says that IKON, the Russian satellite, is at a height of 1000 miles and losing altitude at 8000 meters per day. Ignoring the mixed units, these numbers don't really work. A satellite at an altitude of 1000 miles would stay stable in its orbit for centuries. The main reason a satellite's orbit would decay is due to friction with the Earth's atmosphere.

Most people think that an object in orbit is above the atmosphere, but in reality, there is air up that high, it's just incredibly thin. Over years, drag against the air slows the satellite down, which in turn lowers the orbit. Read the An object at an orbital height of just 500 kilometers or so would be able to stay in orbit for a long time. Look at Hubble; it orbits at roughly 600 kilometers and has been in orbit since 1990. Granted, it has needed a reboot because its orbit has dropped somewhat, but it was never really in danger of dropping onto the Earth.

At an orbit twice that high, the drag is extremely low. For a satellite to drop eight kilometers (5 miles) per day

at that height is pretty silly. Also, the Shuttle cannot get that high. The highest the Shuttle can get is about 900 kilometers (560 miles), but that's a highly elliptical orbit and a tough one to manage.

Its usual height of the Earth's surface is about 300 kilometers or a bit more. During a tour, a kid asks, "What would happen if you jump on a trampoline in space? " The engineer replies, "You'd go up... and up.

Actually, you cannot jump on a trampoline in space! Well, you can, but you need to set things up correctly. On Earth, you stand on a trampoline and jump up gently to get you started.

Gravity pulls you back down, and you kick with your legs to get higher on the next bounce. That won't work in space. If you stand on the trampoline and push off it to get yourself started, you'll just keep going away from it. It might as well have been a wall or a floor; without gravity, you just keep going in the direction in which you pushed yourself Another kid asks, "Can you hit a baseball to the Moon in space? " and she says, "Yes; you just need to knock it halfway there, about 100,000 miles, and the Moon's gravity will take it from there. That's not correct; the Moon's gravity doesn't take over halfway there. The Moon is a lot less massive than the Earth, and so its gravity is correspondingly less.

In other words, the weaker gravity of the Moon means you have to be much closer to the Moon than the Earth for the gravity to balance. The Moon has about

1/80 the mass of the Earth. If you go through the math, you'll find that halfway between the Earth and Moon (which she correctly gives as about 100,000 miles away) the Earth's gravity is still 80 times that of the Moon's. If you calculate where the gravity just balances, you'll find that it goes as the square root of the mass ratio. In other words, you have to be the square root of 80 times closer to the Moon than the Earth, which is equal roughly to 9.

That means you need to be about 216,000 miles from the Earth or about 24,000 miles from the center of the Moon. That's a long way to hit a ball! Again, I liked the movie. There aren't any surprises in it, but it was fun, funny, and depicted NASA and space exploration in a mostly positive light. If you get a chance to see it in the theaters, take it, but it will rent well too.