translunar injection from a circular Earth park orbit

[Steve Simpkin]

While not directly related, this reminds me of a HP-25 program by Paul Lutus that "performs that calculations required to describe how an object (spacecraft) would move about in relation to two bodies (planets) of chosen sizes".

The program that Paul Lutus submitted to Popular Electronics magazine (Space Flight) really fired my imagination with what could be done with a programmable calculator. I had been saving for almost two years and was already planning to buying my HP-25 in June 1977 on my 16th birthday. This article in Popular Electronics (which came out in May) just added to the fever. After I bought my HP-25 I ended up playing with Paul's program for hours plotting the orbits around various sized planets.

https://www.hpmuseum.org/forum/thread-4710.html