How fast does a space ship go in outer space?

Question

I heard that rockets can move faster in space because there i no air resistance. So Let's say a space ship just left earth's atmosphere and is headed towards the moon. How long would it take from there? Another question: How long can it take to leave the atmosphere?

Answer 1

It is a hard answer based on all the different types of propellants, and we don't necessarily have to use rockets. Anyways, yes, there is no air resistance, actually, no resistance, so once you hit your max velocity from the rockets, you turn them off and you keep going at that speed, so all it takes is a quick burn of the rockets. Many advances have been made, along with the tether that they have been working on for a while, unfortunately, these tend to get seperated by debris.

Ok, so, to answer your basic answers, the shuttle takes about 20 minutes to leave the atmosphere, and the last moon trips were roughly 2-3 days one way. However, this isn't just get into space, aim yourself at the moon and fire the rockets...

The apollo trips used a slingshot method, which basic makes a trip around the earth to build up speed then they fire the rockets for a brief period to set the course, the rockets really have nothing to do with the speed, it was the velocity gathered by the earths gravitational pull.

So, conventional rockets alone really won't get you to the moon all that fast, and just for fun, using Jet engines, like on a 747 would take 27 days (granted they wont work in space).

Several other option are using solar sails, and some new technolgies that in essence reflect particles off the craft to get it moving, but it takes a long time to gather up speed so they are better suited for longer travels. Also you have the Ion engine, usining an ionized gas to propel the ship, 10x faster than conventional chemicals, but once again, it takes a while to build up speed.

You can do some google searches on space tethers, since this is one of the best ideas so far, at least I think.

Here is a link for solar sails:
http://www.space.com/businesstechnology/technology/m2p2_winglee_010621.html

Answer 2

Most rockets "leave the atmosophere" within minutes, and reach orbital speed under half an hour. Minimum orbital speed is about 18,000 mph. For fuel efficiency, moon-bound rockets are accelerated to about 22,000 mph or so to escape the earth's pull, and takes a few days to reach the moon. We can get to the moon a lot faster if we wanted to, but it would require more fuel for a given payload. The moon being 250,000 miles away, one would think that going at 22,000 mph would only take about 12 hours to get there, but in fact the speed drops as the spacecraft leaves the earth. It's a lot like throwing a ball up into the air onto the top of a building.

Answer 3

Here's the deal: yes, there is no air resistance, but what that actually means is that a rocket can basically "coast" forever, without losing speed to air friction, influenced only by its own thrust and the gravity of nearby large masses like Earth or the moon.

Second question first: most launch vehicles are designed such that they reach orbital velocity (of about 17,000mph) by the time they reach orbital altitude (above 60 miles minimum). This is a fairly efficient approach in terms of fuel economy, and is a not-terribly-uncomfortable G-force acceleration for a healthy human. This portion of the trip is only a few minutes.

However, this only gets you into low Earth orbit, and it took something several hundred pounds of fuel for every 1 pound of payload to get there. You are still trapped by nearly the same gravity as on the surface of Earth even though you are in a stable orbit. To escape Earth's gravity, you must burn more fuel, and remember, it took several hundred pounds of fuel to get each pound of fuel you have brought this far.

Now to your first question, you ignite stage 3, which will allow you to begin gaining more altitude. In order to permanently escape Earth's gravity, you need to get to about 25,000mph. The 3rd-stage engine is probably much smaller than the first and second-stage engines, so your burn probably will be for a much longer time. If your calculations regarding your position, speed and trajectory were correct, you'll aim precisely for insertion into lunar orbit, which you'll get about halfway to in a day or 2. You may ask, "If I'm going 25,000mph and the moon is only 220,000 miles, shouldn't I get there in only about 9 hours?" The answer is that you will orbit Earth in ever-widening orbits during and after your burn, greatly increasing the distance travelled. Altogether, a trip to the moon requires over a half-million miles maybe? I'm kinda guessing here, if anyone else has more info on lunar trajectories please feel free to correct me.

Oh, and by the way, remember that, since there is no friction to slow you down, the only way to keep from over-shooting the moon is to bring even more fuel so you can point the opposite direction and slow yourself down to a speed of less than (I think)about 5000mph for a stable lunar orbit.

So altogether, count on it taking several days to get there. Now if you have $100 billion to burn instead of just 10, you could get there in less than half a day.

Answer 4

Around 28.000 kph is the speed of a vehicle orbiting the Earth in Low Earth Orbit of around 300 km.

Around 40.000 kph is the speed needed for a vehicle leaving the Earth.

Around 250.000 kph is the current maximum speed of a publicly know manmade object, Helios 2

It takes around 3 days for an Apollo vehicle to go the moon, it takes more time since the moon is moving.



"How long can it take to leave the atmosphere?"

To reach orbital speed from ground to Low Earth Orbit of around 300 km, it usually take 8 to 10 minutes using vehicles known to the public.

Answer 5

Energy travels at the speed of light. So even if you turn your entire ship into pure energy the maximum speed is the speed of light. There is nothing that can travel faster than the speed of light through space. The only way to do it is to manipulate space itself, the principle behind Star Trek's warp drive. The ship, relative to the local space it is in, is traveling at a speed slower than the speed of light but somehow the warp drive moves the entire local space that the ship sits in. There is no speed limit on how fast space itself could move.

Answer 6

It takes a while to get out of the atmosphere becuase of the gravity...earth is trying really hard to pull it back but after it's out it has more "freedom", so it maybe goes a little faster....