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“This video details planetary motion or orbital mechanics. It explains Kepler’s and Newton’s Laws plus terminology including perigee, apogee, eccentricity, orbital inclination, launch window, etc.”
NEW VERSION with improved video & sound:
Public domain film from the US National Archives, slightly cropped to remove uneven edges, with the aspect ratio corrected, and mild video noise reduction applied.
The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization (the resulting sound, though not perfect, is far less noisy than the original).
Reupload of a previously uploaded film, in one piece instead of multiple parts, and with improved sound.
for all the math, see The Orbital Mechanics of Flight Mechanics, 1973
This video primarily deals with Earth orbit navigation. For interplanetary navigation, also see:
The Evolution of Deep Space Navigation: 1962-1989
“The navigation of a spacecraft is the process of determining the current position and the predicted flight path of the vehicle and correcting the flight path so that it stays within acceptable limits of the desired trajectory. Spacecraft navigation is a complex process involving the collection of data containing information about the position and velocity of the vehicle (and other pertinent quantities as well), followed by the processing of these data to yield estimates of the vehicle’s position and velocity as functions of time. Further computation is then needed to plan corrections for the trajectory dispersions away from the desired flight path that inevitably occur. The computational process requires accurate modeling of the motions of the vehicle and the observational data.
A number of robotic spacecraft have traveled throughout the solar system, collecting in-situ and remote scientific observations. In nearly all cases the ability to determine and control the flight path of the vehicle has been critical to mission success…
All planetary missions involve an approach to at least one celestial body. That body may be simply flown past (or impacted in some fashion), or engines on board the vehicle may be fired to slow it down and place it into orbit around the body. In either case, measurements are acquired as the spacecraft approaches its target, and a spacecraft orbit is determined based on these data. This orbit determination process is repeated as additional measurements are acquired. Trajectory-correction maneuvers (TCMs) are performed several times during the approach, if the predicted encounter conditions are not within some tolerance of the desired conditions. When the last allowable TCM has been performed, typically several days before encounter, the delivery conditions are fixed and cannot be improved further. However, the collection of additional measurements and the generation of subsequent orbit determination solutions allow the trajectory to be predicted more accurately near encounter than it can be controlled. This allows the timing of spacecraft sequences and the pointing of instruments to be adjusted shortly before encounter to optimize the return of scientific data. Measurements that are collected around closest approach are received too late to either modify the encounter conditions or update instrument pointing, but are useful for deducing, after the fact, what the true encounter conditions were, to allow a best reconstructed orbit for science data correlation purposes…”
In orbital mechanics, the Hohmann transfer orbit /ˈhoʊ.mʌn/ is an elliptical orbit used to transfer between two circular orbits of different radii in the same plane.
The orbital maneuver to perform the Hohmann transfer uses two engine impulses, one to move a spacecraft onto the transfer orbit and a second to move off it. This maneuver was named after Walter Hohmann, the German scientist who published a description of it in his 1925 book Die Erreichbarkeit der Himmelskörper (The Accessibility of Celestial Bodies). Hohmann was influenced in part by the German science fiction author Kurd Lasswitz and his 1897 book Two Planets…
