chapters 7 of your Understanding Space textbook!!!

1.Defined the following items in the heliocentric-ecliptic coordinate frame:

1. Origin:
2. Fundamental plane:
3. Principal direction:

2. Why can't we include all the appropriate gravitational forces for an interplanetary trajectory in a single equation of motion and solve it directly?

Your answer should be no longer than one or two short sentences.

3. What does a planet's sphere of influence (SOI) represent?

4. what two factors determine the size of a planet's SOI?

1.

2.

5. What are the three regions used in the patched-conic approximation of an interplanetary trajectory and what coordinate frame does each use?

Region 1: Name: Coordinate frame: Region 2: Name: Coordinate frame: Region 3: Name: Coordinate frame:

6. What "head start" does a spacecraft have in achieving the large velocities needed to travel around the Sun?

7. Why do we escape from Earth (or any planet) on a hyperbolic trajectory versus a parabolic trajectory?

8.

9. In a couple of short sentences explain how we can use gravity assist to get "free V" for interplanetary transfers.

10. Can a flyby of the Sun be used to help us change a spacecraft's interplanetary trajectory?

Yes or No

11. For a spacecraft in a circular, polar orbit with an altitude of 800 km, find its time of flight between the equator and the North Pole.

Express your answer in seconds. Please just enter the numeric portion of your answer (leave off the 'sec').