I started development of this software, OITS, in April 2017 on a holiday near the little town of Cheadle, in the county of Staffordshire, UK.
I started from the very basics, deriving the theory during the holiday and continuing shortly thereafter, and then immersed myself in the implementation of the equations I had derived.
In the space of a few months I had developed the code and also had attached a GUI (Graphical-User Interface) to it, which also involved some quite time-consuming programming skills. I eventually had something reasonably easy to use as well as extremely powerful on my DELL laptop computer.
Pivotal to the success of OITS was my discovery that the MATLAB version of the Non-Linear Programming solver NOMAD was an ideal tool to supplement my development, allowing rapid and extremely accurate convergence to optimal solutions.
I knew I was onto something when I found it solved the Cassini interplanetary trajectory Earth-Venus-DSM-Venus-Earth-Jupiter-Saturn, with ease.
I subsequently exploited OITS in the study of missions to the first interstellar object to be discovered, 1I/'Oumuamua, in other words Project Lyra.
If you have MATLAB, go to the github repository here:
It's genuinely a fun and powerful tool to use. enjoy!