1 Intro to Orbital Mechanics Flashcards
What is Kepler’s 1st Law?
Law of Ellipses
What is Kepler’s 2nd Law?
Law of Equal Areas
What is Kepler’s 3rd Law?
Law of Harmonics
What is Newton’s 1st law?
Law of Inertia
What is Newton’s 2nd law?
Law of Changing Momentum
What is Newton’s 3rd law?
Reaction
Force of Attraction is directly proportional to…
…the product of their masses.
Force of Attraction is inversely proportional to…
…the square of the distance between them.
The point at which an Earth orbiting object is CLOSEST to the Earth is known as…
…Perigee.
The point at which an Earth orbiting object is FURTHEST AWAY to the Earth is known as…
…Apogee.
How many Keplerian Classical Orbit Elements are there to understand an determine a satellite’s orbit?
6
In KCOEs. The size of the orbit is given by…
Semi Major Axis
In KCOEs. The shape is given by…
…Eccentricity
In KCOEs. The tilt of an orbit is given by…
…Inclination
In KCOEs. The twist of an orbit is given by…
…right ascension of the ascending node
In KCOEs. The rotation of the orbit is given by…
…the Argument of Perigee.
In KCOEs. The satellite’s position on orbit is given by…
…True Anomaly
Describe a LEO orbit (altitude and period)
~150 km to 2000 km
~90 mins
Describe a Polar Orbit.
A polar orbit is one which passes over the North and South Poles on each revolution
What is an advantage of a Polar Orbit?
Over a period of time, the satellite can observe the entire planet
Describe a Sun-Synchronous Orbit
Enables a satellite to pass over a given point on the Earths surface at the same local mean solar time.
Describe a MEO orbit (altitude and period)
~2000 km to 35862 km
~11hrs 58 mins
Describe a Semi-Synchronous Orbit
SemiSOs have an orbital period equal to half of the average rotational period of the body being orbited.
And orbit in the same direction as the rotational body it is orbiting.
What are the two kinds of HEOs?
Molniya
Tundra
Describe a Molniya HEO (altitude, period and inclination)
~600 km to ~40,000km
~11 hrs 58 mins
~63.4 deg
Provides long loiter time over the hemisphere of interest
Describe a Tundra HEO (altitude and period)
~25,000 km to ~46,000 km
~23 hrs 56 mins
Describe a Geosynchronous Orbit (GEO) (altitude and period)
35,863 km
23 hrs and 56 mins
Orbits at the same period as the Earth and appears to ‘hang’ over the same point on the Earths surface
Describe a Geostationary Orbit (GSO) (altitude and period)
35,862 km
23 hrs 56 mins
Specifically orbits in-line with the Earths equator
