PC 2 Study Guide

Question 1

Orbital perturbations are called perturbations due to their deviations from the standard what?

Answer 1

Motion

Question 2

The largest perturbing force present for near earth objects is the mass and shape of the ______

Answer 2

Earth

Question 3

The _____ perturbation is the largest central body effect, caused by the oblate-ness of the Earth

Answer 3

J2

Question 4

_______ and ______ are the two COEs most affected by the J2 effect

Answer 4

RAAN

Argument of perigee

Question 5

Gravity wells have the greatest effect on satellites in the ____ orbit

Answer 5

GEO

Question 6

________ are caused by any celestial body which effects a satellite gravitationally that is not earth.

Answer 6

3rd Body Effect

Question 7

Third body effects allows for the existence of

Answer 7

Lagrange Points

Question 8

Third body effects have the highest effect on satellites in the_____ orbit

Answer 8

GEO

Question 9

Lagrange points are five locations where a small third body will ______ it’s relative position with two larger bodies as they orbit one another

Answer 9

Maintain

Question 10

_________ affects an objects semi major axis and eccentricity.

Answer 10

Atmospheric drag

Question 11

RAAN is also known as

Answer 11

Nodal regression

Question 12

Argument of perigee is also known as

Answer 12

Apsidal rotation

Question 13

_______ is the change in RAAN caused by the J2 effect

Answer 13

Nodal regression

Question 14

During nodal regression, prograde orbits will precess _______ and retrograde orbits will precess ______

Answer 14

West

East

Question 15

Nodal regression is not present when inclination equals

Answer 15

90 degrees

Question 16

The larger the ________, the smaller the effects of Nodal Regression

Answer 16

Semi-major axis

Question 17

Apsidal Rotation causes ________ to change over time.

Answer 17

Argument of perigee

Question 18

Satellites, in an orbit inclined at 63.4 degrees will not experience ________, keeping the Argument of Perigee stationary.

Answer 18

Apsidal rotation

Question 19

Due to Earth’s mass asymmetry, there are two points along the equator called ______

Answer 19

Gravity wells

Question 20

Atmospheric drag will have the greatest effect on satellites with ____ mass and ____ surface area

Answer 20

Low mass

High surface area

Question 21

Ground tracks are “ traces” over the Earth of the area located directly ________ the orbiting satellite.

Answer 21

Below

Question 22

Earth’s rotation provides a ________ to any satellite, launched into a prograde orbit.

Answer 22

Initial velocity/velocity boost

Question 23

Launch ______ will determine the RAAN of the final orbit

Answer 23

Time

Question 24

Earths _____ and _____ are the largest perturbing force present for near earth objects

Answer 24

Mass and shape

Question 25

What causes nodal regression and apsidal rotation?

Answer 25

The “oblate-ness” of Earth (J2 effect)

Question 26

Apsidal rotation will cause an orbit with i < 63.4 or i > 116.6 to rotate its argument of perigee in what direction?

Answer 26

Same direction of spacecraft motion

Question 27

For a direct launch, a space launch complex must be_______ the desired inclination:

A. Greater than inclination= ___ opportunities

B._____ inclination =___ opportunity

C. ____ inclination= __ opportunities

Answer 27

Less than or equal to

A. 0 opportunities

B. Equal, 1 opportunity

C. Less than, 2 opportunities

Question 28

What two locations on earth will pull GEO satellites toward their location over time?

Answer 28

77E and 135W

Question 29

Third body effects on satellites in GEO are primarily caused by what celestial body?

Answer 29

Moon

Question 30

How many Sun/Earth Lagrange points are there?

Answer 30

5

Question 31

Atmospheric drag will eventually cause a satellite to do what

Answer 31

Re-enter the atmosphere

Question 32

Solar radiation has the greatest effect on satellites in what orbit?

Answer 32

GEO

Question 33

What COEs affect the way a ground track appears on a map?

Tip: think TOSS

Answer 33

• Semi Major Axis
• Inclination
• Eccentricity
• Argument of Perigee

Question 34

Launches from what location on earth deliver the greatest velocity boost?

Answer 34

Equator

Question 35

Launching directly east will result in what?

Answer 35

Inclination matching the latitude of the launch location

Question 36

What launch consideration will affect the RAAN of your orbit?

Answer 36

Timing of launch

Question 37

Look over ground track maps.

Answer 37

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