If you were in a spacecraft moving at 1000 miles/hour in outer space and you turned off the engines, what would happen to the speed and direction of your spacecraft & why?
In: 13
1000mph isn’t anything special in the context of space travel. It’s actually very slow in cosmic terms.
Locally and short term it’d look like you just keep going straight at constant speed.
Long term, gravity will draw you toward the most gravitationally dominant object (moon, planet, star, galaxy, etc, depending on how far out you are).
If you were travelling radially outward you’ll gradually slow down then fall back toward it. If you’re travelling tangentially, you’ll travel in an elliptical path with the centre of gravity of the system at one focus of the ellipse. If the ellipse approximates a circle there won’t be much change in speed. If not, you’ll accelerate each time you approach the object and slow down as you move further out.
If you’re ever close enough to a body with atmosphere you’ll lose speed to friction until you fall inward, either burning up or landing (destructively unless you’ve accounted for the landing very carefully with heat shield and parachutes).
If there’s no appreciable atmosphere, you’ll continue to travel elliptically until you die from lack of supplies. Other massive bodies will gradually alter your orbit and thousands, millions or billions of years later your path will be altered significantly enough that the ellipse either intersects a body or sends you on an escape trajectory.
OP, most of these responses are nonsense. There is no distance limit for gravity, so whether it’s a planet, star, or distant galaxy, you’ll start falling (accelerating) towards whatever is exerting the most gravity on you. It might be imperceptible at first, but you won’t just keep floating at the same speed and direction until you hit something like many have said.
That’s defined by Newton’s universal law of gravitation.
F= GmM/r^2
Where F is the force of gravity felt by two objects, G is the gravitational constant, M and m are the two masses, and r is the distance between their centers of mass.
1000mph seems fast to most people, but it’s tiny compared to the scale of outer space. It might as well be 0.
https://en.m.wikipedia.org/wiki/Newton’s_law_of_universal_gravitation
If you don’t have any other force (planets, stars etc..) and you don’t have air, you’ll travel at that same speed in the same direction… forever.
however, space is not empty, and there are particles that will slow you down (very slowly) and any planet/rock/star system/anything you find will alter your speed/course etc…
Note that, if you’re running the engines, you’re not going at a constant speed. You’re accelerating.
You don’t maintain your speed by running the engines. You maintain your speed by cutting them off.
To slow down, you need to point your spaceship backwards and fire the engines again.
You can’t deploy airbrakes. The equivalent would be to deploy a solar sail, but that only works near a star.
1000mph is actually very slow compared to most things in space. You’d have to go much faster than that just to enter Earth orbit. Many airplanes can go faster than 1000 mph. If you were near Earth when you cut your engine, you’d just fall back down.
If you were in interplanetary space, a different planet or moon might pull you in, but it might also be the sun. Depends on where you actually were.
It’d carry on as it was before you turned your engines off until it hits either a solid mass or a gravity field. Because there’s no air in space there’s no resistance for the vehicle.
Plenty of good answers already, but I’ll add that it depends on where you are when you stop your engines!
If you’re near Earth, 1,000 mph isn’t fast enough to escape it’s gravity, so you’d travel in an arc around it until the atmosphere slows you down enough to pull you in.
You’d need to be going closer to 20,000 mph to get further away! 1000 mph isn’t even enough to escape the moon’s gravity.
Best chance is you’re far away from everything else, and you continue drifting, with no gravity wells to eat you up.
This was covered perfectly in the Sandra Bullock film Gravity when George Clooney flies away.
If a spacecraft has no engines running, the path is totally controlled by gravity.
So it depends where it is, what direction it is travelling, and how fast.
It could be in a very distant orbit of the earth at about 1 million kilometers. It could be in a solar orbit. It could be on a trajectory from the earth to the moon, or from the earth to mars.
If far away from any celestial object with huge mass, not much would happen – it will travel in the same direction at least for a good time, while the speed may decrease or increase and direction may change depending on where the object with the biggest gravitational pull would be relative to the spacecraft.
Latest Answers