DONE--OEM 101.2 Flashcards
Central and Third Body Effects
Orbital perturbations are caused by deviations from what?
The standard two-body problem
What is the largest perturbing force present for near Earth objects?
The mass and shape of the Earth
What is the largest central body effect?
J2 effect
Which COEs are most affected by the J2 effect?
RAAN and Argument of Perigee
What causes the change in RAAN caused by the J2 effect?
Nodal Regression
Prograde orbits will precess which direction during Nodal Regression?
West
Retrograde orbits will precess which direction during Nodal Regression?
East
At what inclination is Nodal Regression greatest?
O°
At what inclination is Nodal Regression not present?
90°
The larger the ________, the smaller the effects of Nodal Regression.
Semi-major axis
Apsidal Rotation causes which COE to change over time?
Argument of Perigee
Orbiting satellites experience no Apsidal Rotation (Argument of Perigee is stationary) at what inclination?
63.4°
What are the two points along the equator caused by Earth’s mass asymmetry?
Gravity wells
Which orbit do gravity wells have the greatest effect?
GEO
Any celestial body that is not Earth causes what gravitational effects?
Third-Body Effects
What do Third-Body Effects allow for?
Five Lagrange Points
Third-Body Effects have the greatest effect in which orbit?
GEO
Atmospheric drag affects which COEs?
Semi-major axis and eccentricity
Atmospheric drag has the greatest effect on satellites with ____ mass and ____ surface area.
Lower / Higher
What does Earth’s rotation provide to satellites launched into prograde orbit?
Initial velocity
How many opportunities does a space launch complex have when its latitude is greater than the desired inclination?
0
How many opportunities does a space launch complex have when its latitude is equal to the desired inclination?
1
How many opportunities does a space launch complex have when its latitude is less than the desired inclination?
2
What determines the RAAN of the final orbit?
Launch time
What causes the largest perturbing force for near Earth objects?
Earth’s mass and shape
RAAN and Argument of Perigee are affected by which central body effect?
J2
What causes Nodal Regression and Apsidal Rotation?
The oblateness of Earth
Apsidal Rotation will cause an orbit with i116.6 to rotate its Argument of Perigee in which direction?
Same direction of spacecraft motion
Apsidal Rotation will cause an orbit with 63.4°< i <116.6 to rotate its Argument of Perigee in which direction?
Opposite direction of spacecraft motion
What two locations on Earth will pull GEO satellites towards their location over time?
75°E and 107°W
What is primarily responsible for Third-Body Effects on GEO satellites?
Moon
Which orbit does solar radiation affect the most?
GEO
Which reference frame is best for viewing ground tracks?
ECEF
Which COEs affect the ground track’s appearance?
Semi-major axis, Inclination, Eccentricity, and Argument of Perigee
Launches from what location on Earth deliver the greatest velocity boost?
Equator
Launching directly East results in what inclination?
Matches latitude of the launch location
What launch consideration affects the RAAN of the orbit?
Timing of the launch
