Are astronauts still "weightless" when traveling a straight path to another planet?

Question

Gravity pulls the astronauts to the Earth while the ship propels them forward, thereby causing the orbit. Since everything in the ship is essentially falling, there is the sense of weightlessness. What if the ship is headed to another planet, lets say Mars. Will the astronauts still be "weightless"? Or will their bodies be pulled towards the source of greatest gravity? I get the weightlessness during orbit, but what if they are not in orbit, traveling a straight path to another destination? If they are "weightless", why does this happen if they are no longer in an orbit?

Answer 1

The effect which causes weight is actually an acceleration, and in the case of on the surface of Earth it is due to gravity. Weight may also be caused by acceleration due to motion in a straight line, such as with astronauts during liftoff having their weight "increased".

So to answer your question depends upon if any acceleration or deceleration is happening during the journey. If the astronauts are moving toward another planet at a constant speed, then they are completely weightless. (Well, they will of course be pulled a very tiny amount toward any gravitational sources, but unless they are massive and nearby, the effect will be practically insignificant.) If they are moving under acceleration, then they will feel "weight" based upon the amount of acceleration.

Answer 2

They will still in effect be weightless. This is because the force of gravity is dispersed... much like most forms of energy... When you shine a flashlight at a wall from 1 inch away, the light is bright and its area of influence easily discernable... back to a foot and there is a slight difference in how well the area is illuminated, it is till well lit but covers a larger area... back up to 20 feet and the area illuminated is much larger, however it is all lit more dimly than the original area... back up to 20 yards and the entire wall may be illuminated, but with only a very dim light... gravity acts in much the same way even though it does not spread, its influence weakens as you get further away from the source. By the time you reach an orbital state, it is still strong enough to keep you near the earth, but not srong enough to give you any appreciable weight... so. on a trip to any other planet, you would be in effect weightless.. if this was not the way of things.. we would all simply cease to exist... as that would require that we all "weigh" the same amount we would weigh on any other celestial body, including the sun, other stars, or even blackholes... we would be effectly crushed into a tiny pile of compact molecules...

Answer 3

Once they break their orbit they will indeed feel gravity again. Outer space is not that far away (about a 30 minute drive if your car goes vertically), so the acceleration due to gravity in orbit is about the same as it is right here on Earth.

Of course, they would be accelerating initially to get out of oribit and head towards their destination, and this may well be the larger acceleration at that stage. And of course the effects of Earth's gravity fall as the square of the distance from the centre of the Earth - so quickly.

Flying Earth to moon - a short hop - there is of course a point part way when the gravity of Earth and that of moon cancel.

Answer 4

Unless the rocket engine is firing they will always feel weightless. There is gravity, but they are "falling" freely in their orbit (they are in orbit even when on the way to another planet, orbit around the Sun). In fact sometimes weightlessness is called free fall. It is exactly the same as those free fall rides at amusement parks, only you are many miles high instead of only a few hundred feet, and you are moving not only up and down but sideways too. In fact the only difference between orbiting and falling is the high sideways speed, orbital speed.

Answer 5

Gravity extends indefinitely, so weight never really goes away. To feel weightless you need to be falling. Constant Orbit is accelleration towards the centre of gravity of a planet - the physical equivalent of falling. Space travel is curvy - straight line travel ony occurs in sci-fi; in reality, getting from a to b is a matter of increasing and desreasing orbits.

Answer 6

They will at least feel weightless, although there might be an imperceptible amount of micro-gravity. Once the spacecraft stops accelerating, they will be in stasis until they start to slow down and then enter the orbit of the planet they are traveling to.

Answer 7

When astronauts and their space ship are travelling at the same speed, the astronauts are weightless.

If the ship accelerates or decelerates the astronauts will experience gravity in the ship as their velocity is matched to the ship's velocity.

Answer 8

Responses without sources aren't answers, just opinions.

Weightlessness occurs in a spaceship outside the earth's atmosphere, as long as no propulsion is applied, and that is not rotating.