Talk:Astrodynamics

Kepler's Laws
I don't like starting off by saying what Kepler's Laws are "caused by". That material should be presented after Keplers laws have been derived from Newton's laws. Maybe in an aside "Kepler's Laws Revisited" or something like that. If we're going to start off with Kepler's laws, some statement needs to be made that they were empirically determined. --D'Arby 23:09, 13 November 2005 (UTC)

Naming policy
We need to decide which pages belong to this Astrodynamics book, and rename those pages to start with "Astrodynamics/" in their name, so that there is no confusion. --Kernigh 01:56, 29 March 2006 (UTC)


 * Looking through the TOC, I dont think there are any naming convention problems with this book anymore. I have removed the tag. --Whiteknight (talk) (projects) 18:29, 15 February 2007 (UTC)

Derivative notation?
I already posted this in the Motion Constants chapter, but I figured I should mention it again on the main discussion page:

Is there any particular reason why the "prime" notation is being used instead of "dot" notation for derivatives, i.e. $$r'$$ as opposed to $$\dot{r}$$?

Dot notation (aka Newton notation) is generally used for time derivatives and it is consistently used in probably all of the texts I have on the topic of this book (Bate,Mueller&White, etc). It is also slightly more aesthetic, but that is just my opinion

http://en.wikipedia.org/wiki/Notation_for_differentiation

Jaxcp3 (discuss • contribs) 21:23, 3 July 2013 (UTC)

Structure of the book.
I have noticed that this book is not really worked and it's structure is a bit messy. I wanted to discuss a possible structure to the book.

I think the best way to structure this is to build it from basic laws and mathematical shapes then adding new information as we go on. So, it feels less overwhelming and more like a like building blocks. Then at the end of each section repeating the key information in a sort of reference manual type of way (not the teaching but referencing part so we have both).

Please state if anyone has other ideas, agrees or disagrees with my ideas.

Introduction


 * 1) Fundamental laws - discussing the law - adding their derivation (from the motion constants)
 * 2) Fundamental laws - moving newtons laws of motion and gravity to the start
 * 3) Fundamental laws - adding a section to the discussion of physical phenomena that can occur and specifying where they will be discussed (gravity including a bit with relativity, adding aerodynamic drag, solar radiation, ect)
 * 4) Fundamental laws -  adding a section about ellipses and their mathematical properties and nature
 * 5) Removing "the earth" and putting it's content else where ideally under planet which could list key properties
 * 6) Fundamental laws - adding a section about angular momentum conservation and explain what it is.
 * 7) Time - adding key time frames such as the Gregorian and the time at which the J2000 reference frame was defined at
 * 8) Coordinate Systems - expanding on earth centred and fixed, adding J200 frame and the ICRF, adding geographical (geocentric and geodetic)
 * 9) Planets - adding the main description of planets, such as their standard gravitational parameter, J2 perturbation, and mentioning some key data between ideal and real life.
 * 10) possibly adding a topic about constellation of satellites.

Therefore the introduction would look something like this


 * 1) Fundamental law and physical phenomena
 * 2) Time systems
 * 3) Coordinate systems and reference frames
 * 4) Planets
 * 5) Satellite constellations

Basic orbits


 * 1) N-body problem - I would prefer this to start with an idealised 2 body problem mentioning how it works then going to a N body
 * 2) N-body problem - adding the special cases where the N body problem (like 3 body) has stable systems
 * 3) I would rearrange the motion constants with orbital basics
 * 4) Orbit basics - I would add the simplest known orbit a circular orbit, how circular motion and Newtons law of gravity come together to give this orbit. Also we can show the speed required to travel at the surface if we needed to be in orbit and how the planets rotational speed at the same point is different.
 * 5) Orbit basics - introduction to the elliptical orbit based on a simple ellipse and then applying the basic physical laws and the equations derived in the N-Body problem, Which is a perfect time to introduce 2D Keplerian orbital elements and their anomaly angles.
 * 6) At this point combine the Keplerian elements and frame with the orbital basics to demonstrate the 3D planes
 * 7) Orbit basics - Introduction of the vis viva equations now after we explained the elliptical orbit and Keplerian elements. (or maybe just before we introduce the Keplerian elements)
 * 8) Orbit basics - introduction to the parabolic and hyperbolic equations.
 * 9) Now introducing more of the constants and energy and mathematics to the concepts shown and discussed.
 * 10) I would remove the orbital determination from this section (and possibly make it into it's own section as it can be quite larger with errors and optimization methods). Also move it after we have covered positions and velocities.

Therefore the basic orbits section would look like this:


 * 1) N body
 * 2) Orbital basics
 * 3) Motion constants

The rest

I partly feel like section 3 is also basic and should be added into section 2 as sub categories. but I may be wrong.

Orbital manuvers can be added into section 3 (inclination change, apogee change, also Hohmann and bi-elliptical orbits can be added) All of these under impulsive and then maybe adding finite burns.

I'm fine with the perturbations but adding a introduction to it like what was discussed in the introduction section (solar radiation, J2, ect)

I feel trajectories should be split up. a interplanetary trajectory can easily include Lambert's problem, finite burns, Hohmann transfer, beta hyper planes, optimal control such as direct transcripts and Hamiltonians) easily a book on their own about each topic.

Anyone have any opinions and ideas about this. (also sorry for the spelling mistakes it's quite late) W.Kalin (discuss • contribs) 22:33, 18 September 2023 (UTC)


 * I agree with this proposal. Although this book has a coherent structure, it is not good enough for such a complicated topic ALazyEditor (discuss • contribs) 07:03, 14 July 2024 (UTC)