Can you orbit the earth in any direction

What happens if you fire up the rockets, accelerating to a speed of 10 kilometres per second? Instead of following the curvature of the Earth, your spacecraft will follow a path that takes it far away from Earth.

As your spacecraft pulls away from Earth, it will start slowing down, both vertically and horizontally due to the conservation of angular momentum. Eventually it will reach a peak altitude apogee and fall back towards the Earth, accelerating as it does.

The process now reverses, with the spacecraft picking up speed until it reaches a minimum altitude perigee. The process then repeats, with the spacecraft tracing an ellipse around the Earth. What happens if you fire up the rockets again, accelerating to a speed of 11 kilometres per second?

Now things get interesting. Your spacecraft will travel away from the Earth and be slowed by gravity, but the gravitational pull of the Earth drops so rapidly that it will never stop you entirely. Your spacecraft will leave the vicinity of the Earth, to wander through our solar system.

Weather and TV satellites seem to hover above the equator. These satellites are in geostationary orbits. As one orbits further from the Earth, the speed required to stay in orbit decreases and the time required to complete an orbit increases.

At almost 36,km in altitude, an orbit takes a full day to circle the Earth. As the Earth spins on its axis once a day too, these satellites appear fixed in place from our spinning Earth-bound perspective. Go even further from the Earth and orbits take even longer. The moon is a natural satellite ,km from Earth and takes just over 27 days to complete a single orbit. It is high in the sky—tens of thousands of miles from the ground.

The other orbits the Earth quickly and passes over each of the poles many times in one day. This satellite is only a couple hundred miles from the ground. It all has to do with what each satellite is designed to accomplish. The goal of the GOES-R series is to keep a continual watch on one area of the world—the western hemisphere. By orbiting at the same speed the Earth rotates, it stays over one place.

This is called a geosynchronous orbit. That's why a geostationary orbit must be so high. It has to go out far enough so that it can travel slowly enough to go around Earth only once per day. In the cartoon to the left, the satellite passes nearly directly over the North and South Poles. In our animation, it goes around twice in one day.

In reality, the satellite may orbit Earth once every hour-and-a-half or so, going around many times per day. Putting the images from the three satellites together, it takes only six hours to get pictures of just about every square inch of Earth. This information is used to help scientists understand weather, climate, oceans, volcanoes, and vegetation patterns around the world. In addition, the information helps in search and rescue and in spotting forest fires. Suppose two satellites are to be launched to the same altitude.

However, one is to go into a polar orbit and one is to orbit the equator. Can you guess which satellite will take the most fuel to reach its orbit? At the equator, Earth itself is rotating from west to east at kilometers per hour miles per hour! If the satellite is launched in the same direction as Earth is rotating, it gets quite a boost. If it is launched toward the north or south, it doesn't get to take advantage of this boost.