How fast does a space craft have to travel to acheive orbit? 17k?

Answer 1

Wow, there sure are a lot of people confusing the meaning of "escape velocity."

The various values given for escape velocity are correct. But you DO NOT need to reach escape velocity to go into orbit. In fact, the velocity required for (circular) orbit is smaller than escape velocity, by a factor of sqrt(2). Many people seem to think you need to "escape first" before you can get into orbit. That's completely false.

But that doesn't answer your question.

Your guess is basically correct: If you can get just above the atmosphere and go a little faster than 17k miles per hour, you'll be in orbit. The orbital speed "at" the surface of the earth is in fact about 17,685 mph.

If you go faster than that (but still less than escape velocity), you will still go into orbit; but (strangely enough) your orbit will be slower. That's because your extra initial speed will throw you farther away from the earth; and as you rise, you'll slow down. So the orbital speed at a comfortable 200 miles above the surface, is about 17,255 mph. In terms of energy expenditure, the orbits which are closer to the earth (and faster) actually cost less energy.

If you go at escape velocity (or faster), you will not be able to maintain an orbit at all; your speed will fling you completely away from the earth.

Answer 2

The space shuttle doesn't go out of the earth's orbit. If it did, it wouldn't be able to return. In fact, all the space shuttle does is reach to low earth orbit (about 185 miles), or a little higher on a mission to the IST (240 Miles) not even the geosynchronous orbit occupied by television satellites. Speed is between 17-18,000 mph

Answer 3

A low earth satellite must travel at about 18000 mph to remain in orbit, but orbital velocity ... Escape velocity from low earth orbit is about 25000 mph

Escape velocity is the speed a body must attain in order to break free of the gravitational hold of the larger body. Escape velocity depends on the mass of the larger body and the distance of the smaller body from the larger body's center. The escape velocity from the Earth is about 11.3 kilometers (7 miles) per second.

Orbital velocity is the speed needed to maintain that balance between gravity's pull on the satellite and the momentum of the satellite's motion. At an altitude of 242 kilometers (150 miles), this is approximately 17,000 miles per hour, or a little less than full escape velocity.

Answer 4

Orbital velocity depends on how far above Earth they're going, but 17,500 is generally the right speed for low Earth Orbit (from about 150-300 miles.)

Answer 5

To travel a circular orbit around the Earth, a spacecraft needs a given speed. So the minimum speed for it to achieve orbit is the one required by the smallest orbit possible, that is just a bit larger than Earth itself.
This speed is actually given by :
v = sqrt( 2 G Mearth / Rearth), where G = 6.67 10^-11.
v = 11.19 kilometers per second
In miles per hour, v = 25130 mph.

Answer 6

The near circular Orbital velocity at the 380 km (236 miles) altitude of the International Space Station is 7.68 km/s, 27,648 km/h, 17,180 mph, or roughly equivalent to Mach 23 at sea level.

Answer 7

In order for a space craft to attain orbit it must first escape Earth's gravity and must attain a velocity of 7 miles per second.

Answer 8

That depends on the altitude of the orbit, the most common altitude for NASA satellites requires a speed of about 17,500 MPH.

Answer 9

11 200 meters/second is the escape velocity of earth.

Which is a little more than 10 times the muzzle velocity of a rifle bullet.

Answer 10

Earth's Escape velocity is, I believe, around 25,000mph = 40,000kph.