PC 2 Study Guide Flashcards
Assignment 2 + Study Guide
Orbital perturbations are called perturbations due to their deviations from the standard what?
Motion
The largest perturbing force present for near earth objects is the mass and shape of the ______
Earth
The _____ perturbation is the largest central body effect, caused by the oblate-ness of the Earth
J2
_______ and ______ are the two COEs most affected by the J2 effect
RAAN
Argument of perigee
Gravity wells have the greatest effect on satellites in the ____ orbit
GEO
________ are caused by any celestial body which effects a satellite gravitationally that is not earth.
3rd Body Effect
Third body effects allows for the existence of
Lagrange Points
Third body effects have the highest effect on satellites in the_____ orbit
GEO
Lagrange points are five locations where a small third body will ______ it’s relative position with two larger bodies as they orbit one another
Maintain
_________ affects an objects semi major axis and eccentricity.
Atmospheric drag
RAAN is also known as
Nodal regression
Argument of perigee is also known as
Apsidal rotation
_______ is the change in RAAN caused by the J2 effect
Nodal regression
During nodal regression, prograde orbits will precess _______ and retrograde orbits will precess ______
West
East
Nodal regression is not present when inclination equals
90 degrees
The larger the ________, the smaller the effects of Nodal Regression
Semi-major axis
Apsidal Rotation causes ________ to change over time.
Argument of perigee
Satellites, in an orbit inclined at 63.4 degrees will not experience ________, keeping the Argument of Perigee stationary.
Apsidal rotation
Due to Earth’s mass asymmetry, there are two points along the equator called ______
Gravity wells
Atmospheric drag will have the greatest effect on satellites with ____ mass and ____ surface area
Low mass
High surface area
Ground tracks are “ traces” over the Earth of the area located directly ________ the orbiting satellite.
Below
Earth’s rotation provides a ________ to any satellite, launched into a prograde orbit.
Initial velocity/velocity boost
Launch ______ will determine the RAAN of the final orbit
Time
Earths _____ and _____ are the largest perturbing force present for near earth objects
Mass and shape
What causes nodal regression and apsidal rotation?
The “oblate-ness” of Earth (J2 effect)
Apsidal rotation will cause an orbit with i < 63.4 or i > 116.6 to rotate its argument of perigee in what direction?
Same direction of spacecraft motion
For a direct launch, a space launch complex must be_______ the desired inclination:
A. Greater than inclination= ___ opportunities
B._____ inclination =___ opportunity
C. ____ inclination= __ opportunities
Less than or equal to
A. 0 opportunities
B. Equal, 1 opportunity
C. Less than, 2 opportunities
What two locations on earth will pull GEO satellites toward their location over time?
77E and 105W
Third body effects on satellites in GEO are primarily caused by what celestial body?
Moon
How many Sun/Earth Lagrange points are there?
5
Atmospheric drag will eventually cause a satellite to do what
Re-enter the atmosphere
Solar radiation has the greatest effect on satellites in what orbit?
GEO
What COEs affect the way a ground track appears on a map?
Tip: think TOSS
- Semi Major Axis
- Inclination
- Eccentricity
- Argument of Perigee
Launches from what location on earth deliver the greatest velocity boost?
Equator
Launching directly east will result in what?
Inclination matching the latitude of the launch location
What launch consideration will affect the RAAN of your orbit?
Timing of launch
Look over ground track maps.
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