The Eq. 4.43 is in Battin's An Introduction to the Mathematics and Methods of Astrodynamics where he does not derive it. The derivation is outlined in his earlier book Astronautical Guidance (1964) on ...

It is one of the Lagrange Planetary Equations. A very similar form is given by Archie E. Roy (The Foundations of Astrodynamics, 1965 at page 175 and Orbital Motion, 1978 at page 184). Be careful in ...

Assume the velocity increment is at the perigee and along the velocity then the new velocity is $V$, calcualate the semimajor axis from the vis viva equation: $V^2 = \mu (2/r - 1/a)$ The apogee ...

First U S satellite Explorer 1, launched February 1, 1958 and reentered in 1970. While the batteries lasted 4 months it was used to discover the Van Allen radiation belts. From Wikipedia:

Probably units and the format of eq (7) are the problem. After looking at the referenced website by Nakka, I used the questions information given to get $\dot m= 1.187 kg/s$ (using a rounded off r=...

When true anomaly is between 0 and $\pi$ the formula for E is fine, but above $\pi$ you have to adjust the Arctan value to get E in the right quadrant. It looks like just add 2$\pi$ to a negative ...

I would say it is a good reference. It is not a book, but rather a 33 page paper (one page is distribution page so no real information). I got a copy of the pdf from dtic.mil. A quick search shows the ...

The equation shows that the cross-sectional area of the nozzle depends on the local pressure $P$ and values that are constant. So, he expects you to differentiate with respect to $P$, set the result ...

Universal gas constant R' is correct. Sutton uses $C_p$ for molar specific heat and $c_p$ for mass specific heat. See table of symbols at end of chapter (I have the 7th ed.).

Check out http://www.johnstonsarchive.net/astro/nearstar.html which list planets and stars to 25.1 ly but last update in 2018. Also, http://www.johnstonsarchive.net/astro/nearstarmap.html I found this ...