1. Sun – Earth System Questions
Understanding Orbits
Sun – Earth System
Questions
1. Why are the suns rays shown as parallel when reaching the earth?
2. Does the earth have the axis tilted all year long?
3. Does the orbit shown spend any time in the eclipse?
SSE-120

2. Questions 1. What is the estimated inclination for the orbit shown?
Understanding Orbits
Questions
1. What is the estimated inclination for the orbit shown?
2. What would inclination be for the spacecraft velocity going in the opposite direction?
3. Will the inclination change with increase in altitude?
4. Will the inclination change if the orbit were elliptical?
SSE-120

3. Questions Earth’s rotation around the sun
Understanding Orbits
Earth’s rotation around the sun
Questions
1. Does the eclipse of the earth change with seasons?
2. If there are no disturbing perturbations to the orbit, draw a terminator orbit for each season.
3. Does the terminator orbit differ for each season?
SSE-120

4. Launching a spacecraft
Understanding Orbits
Launching a spacecraft
Questions
1. Does the eclipse of the earth change with orbit altitude?
2. Will they eclipse time of the spacecraft change with an increase in altitude?
3. Does an eclipse occur with a GEO spacecraft?
SSE-120

5. Questions What is the inclination on orbit A? B? C? D? E?
Understanding Orbits
Questions
What is the inclination on orbit A? B? C? D? E?
SSE-120

6. A spacecraft in a terminator orbit
Understanding Orbits
A spacecraft in a terminator orbit
Questions
1. Does the eclipse of a terminator orbit change with orbit altitude?
2. Will the eclipse time of this spacecraft change with an increase in altitude?
3. Does an eclipse occur with a Molniya orbiting spacecraft?
SSE-120
SSE-120

7. Questions 1. Where is the eclipse in this diagram?
Understanding Orbits
Questions
1. Where is the eclipse in this diagram?
2. What would you consider to determine if this orbit experiences an eclipse over a year?
SSE-120
SSE-120

8. A spacecraft in a noon-midnight orbit
Understanding Orbits
A spacecraft in a noon-midnight orbit
Questions
1. Does the eclipse of this orbit change with a change in altitude?
2. Will the eclipse time of this spacecraft change with an increase in altitude?
SSE-120

9. Understanding Orbits
Questions
What would be the eclipse time if a spacecraft could orbit at zero altitude?
What is the eclipse time for an altitude of 750 km for the noon-midnight orbit?
What would be the maximum eclipse time for a 750 km altitude orbit if the inclination was 90 degrees?
SSE-120