How fast does a spacecraft go?

Question

Can u please tell me how fast does a spacecraft go? If you answer can u also tell me the site

Answer 1

Props to the previous answerer for the website reference for the current record for fastest spacecraft. How fast a spacecraft goes and how fast (or slow) it CAN go are two different things, and it also depends on your frame of reference.

On Apollo flights, the spacecraft were boosted out of Earth orbit with enough energy to get to the moon in a reasonable amount of time, but Earth's gravity slowed it to about 5,000 kph (3,000 mph) until it got to the point at which the moon's gravity exceeded the pull of Earth, and the craft sped up again.

This was a result of a compromise between the extra fuel needed to get the craft there in a shorter time and the amount of consumables (oxygen, food and water) that could be carried along. They could have reached the moon in just a few hours, but it's easier to take along extra consumables than build a booster large enough to haul along all that fuel needed for a longer translunar injection (TLI) burn. On the other hand, they could have taken less fuel and settled for a less powerful burn, but the craft could have slowed down to a few miles an hour until it got past the Lagrange point, at which the moon's gravity would take over, making it impractical to take along enough consumables. The trip could have taken months or even years instead of a few days.

Answer 2

Well, dm_cork has a lot of really good information in her or his answer. I must disagree with a couple of things, however. First, escape velocity from Earth is not 1 km per second, it's more like 11 km/sec. And, the moon's velocity in its circuit around the earth is about 3200 km/hr, much less than 1km per second..so something travelling more slowly than 1 km per second can be in orbit. Finally, I don't think any of the Apollo spacecraft were launched OUT of Earth orbit: I'm pretty certain they all were in extremely elliptical orbits and would have orbited the Earth if the moon wasn't there. The first 4 flights to the moon (8, 10, 11, and 12) were in a "free return" orbit, meaning that they would have come back to earth simply by passing around the moon. The others were not in free return, but I THINK the would still have been in Earth orbit, just wouldn't have returned closely enough to re-enter the atmosphere. I may be wrong about the non-free returned trajectories, and if I am I certainly apologise.

As far as the fastest spacecraft, the New Horizons Pluto probe launched in 2006 is the fastest one ever launched. If I'm not mistaken it got to the distance of the moon in about 8 hours and to the orbit of Mars in about 30 days. Normal spacecraft take about 70 hours to get to the moon and 260 days to get to Mars. It was launched that fast because, to get to Pluto in a reasonable time takes a lot of initial velocity, even with a "gravity boost" here and there.

Answer 3

Well, it depends on what you mean by a spacecraft....

Satellites in orbit around the earth travel at a specific speed, depending on their height. The further out a satellite is, the slower it has to travel to keep in orbit. A geostationary satellite travels at roughly 10,000 km per hour (about 7000 miles per hour, I think). Nothing can get into orbit without travelling at about 1 km per second - this is called escape velocity.

Spacecraft that need to reach other planets need to set off on their trip at a higher speed, in order to break away from earth's gravity, and to overcome the sun's gravity as they travel further out. Because spacecraft don't travel under power (generally, they get several boosts but the rest of the time cruise), they slow down the further out of a gravitational field they climb (further away from a large body like the sun or the earth). So spacecraft have a variety of speeds, depending on where they're going and at what stage in the journey they're at.

I didn't get this answer from any site, I just know it cos I have a physics degree! But wikipedia will have pages no doubt on 1) earth satellites, 2) interplanetary spacecraft, and 3) the voyager probes, which covers the three main subdivisions of spacecraft journeys (being close to earth, between planets, and heading out of the solar system completely). Hope this helps.

Answer 4

It really depends... orbital speeds are normally on the order of 18,000mph or 7.6km/s I think. I'm just going off of memory. Some spacecraft going to the outer planets and out of the solar system like voyager 1 has a speed of 17.2 kilometers per second.

Answer 5

And the fastest manned spacecraft was Apollo 10, which reached a speed of 24,790 mph, shortly before beginning reentry into the earth's atmosphere.

Answer 6

Kevin, A spacecraft travels nearly at the speed of a sound.

Answer 7

Your getting a lot of bad answers here.

Escape velocity is about 17000 mph. The shuttle can go up to 24,000 mph We have sent out some unmanned probes that go much faster.

The speed of sound is about 700 mph, not even close. And going the speed of light does not make you go back in time. myth.

Answer 8

a spacecraft travels at the speed of light and sound.

Answer 9

Is this what you were looking for?

http://www.aerospaceweb.org/question/spacecraft/q0260.shtml

Answer 10

wouldn't it be cool if it went 186,000 miles per second. then we could go back it time