The other night on Hulu I watched some of the movie Deep Impact. If you haven’t heard of this Earth versus Comet movie it is because it was utterly buried at the box office by that stupidly insulting example of Michael bay’s work, Armageddon. Beside show casing Elijah Wood before The Lord of The Rings, this film was a serious attempt to convey a story about a comet on a collision and the difficulty in diverting it.

Overall this film scores well in its science. It has some concept of the distances and energies involved. In fact the ship dispatched to divert the comet is powered by an Orion drive, something we had considered building; a ship that flies on a series of atomic explosions.

The movie did engage in one of the oldest trope in SF movies, the astronaut who gets separated from the craft and flies off into cold limitless space.

People, this is not the problem Hollywood would have you think it is.

Everything in space is about velocity. Velocity determines the size and period of your orbits. Go fast enough around the Earth and you are in orbit around the planet. Go faster and you may leave the planet but then you are orbiting the sun. Go a hell of a lot faster and you leave the sun’s influence and now you’re orbiting the center of the galaxy.

If you are working over the side on a spaceship lose you grip you may float away, but your velocity did not change all that much. You are still in the same orbit as the ship you left. Yeah it is out of reach but guess what you can move. With just a tiny burp of it orbital thrusters, not its main engines, and they can come and get you. The same is true if that ship is on its way to the moon, or Mars, or even the outer solar system. The difference between your new velocity and your old one, which was the same as the ships, is going to be insignificant compared to the ship’s ability to change its velocity.

But you know, I am starting to get an idea for a story…