Orbit and Ground Path

Orbital Plane and Ground Path

While in free orbit (only the gravitational force is acting on the shuttle), the actual path of the space shuttle orbiter is circular on an imaginary plane which slices through the center of the earth. The shuttle revolves around the earth once every 90 minutes. During that 90 minutes, the earth is also rotating.

Use the object movie below to investigate the inclination of the orbital plane and its corresponding ground path. The ground path is the location on the earth where the shuttle is directly overhead. This object movie shows three synchronized frames. The upper left frame shows the orbit of the space shuttle orbiter from a point in space directly above where the inclining orbit crosses the equator (as shown in a previous simulation). The upper right frame shows a view which travels directly above the space shuttle. The lower frame shows the ground path of the given orbit paths. To use the movie, place the cursor on the movie and drag to the right. The time lapse for each frame is 4 minutes.

Questions:

1) Does the orbiter follow leave the same ground path on every orbit?

2) Which direction does the ground path shift on each subsequent orbit?

3) How long does it take the shuttle orbiter to revolve once? How much does the earth rotate during that amount of time?

4) How much does the second ground path shift as compared to the first orbit (in degrees)?

5) What time of year is the mission taking place (hint: look at the geometry of the nightline)?

6) At what inclination would the shuttle show no curving ground path? At what inclination would show the largest curve?

Science Simulations | Mission Control