View Full Version : More bad astronomy in "Mission to Mars"?

2002-Mar-15, 07:28 AM
After the ship was hit by a meteorite, the astronauts left it and headed for the REMO, using their suit jets.
But I seem to recall that there was a scene after that where they ran out of "fuel", and someone remembered to use some sort of hook as propeller.
They shot the hook in the direction where they wanted to go, like a harpoon, and then they "rewinded it", and it pulled them.
I thought this scene was ridiculous. Even though I don't know much physics, it would seem to me that Newton's law of action-reaction would imply that, if you shoot a "harpoon" in zero-g it will go forward, but you will be pushed backward.
This, of course, assuming that the astronaut would move along a line, which seems wrong too. I think shooting a harpoon in zero-g would make the astronaut spin around himself.

Martian Jim
2002-Mar-15, 09:07 AM
i agree, thats stupid.

David Hall
2002-Mar-15, 10:51 AM
Well, since the hook is less massive than a human being, the net effect will be it goes out much farther than you. I agree though that it would probably impart a bit of a spin, since it would be next to impossible to set it right against your center of mass.

It's still a stupid idea.

2002-Dec-16, 08:07 AM
If you'll remember, when they fired the hook at the REMO, they still had fuel left. It was only when the one man (the mission commander, no less) lost his grip on the REMO, that another went after and was told she wouldn't have enough fuel to get back, so she fired the hook just before the point of no return. They all still had fuel left, and this could have aided in stabilization and counteracted the action-reaction event.