A helical antenna is circular polarized to help with the spin drift while communicating with satellites.
I wrote an optimization program to design this antenna. I'm working on rewriting the program. I plan on publishing it under the GPL license when it is presentable. I used NEC2++ for the modeling. I used Python to talk with this and optimize the antenna. This is the structure my optimizer spit out. This is how NEC2++ would have seen it.
Here is the gain patter coming off of the antenna, which was estimated to be about a gain of 10.My friend Ron Brown drew this up for me and thought of how to build a quick and cheap prototype frame for the antenna. When I get all the antenna theory kinks out, I will build a sturdier frame so it can be mounted to track the satellites.
My friend K5ZY had an antenna analyzer, which we ran on the antenna. Our results are in the two graphs here. This shows it didn't resonate where I wanted it to, but where it did resonate, it did a very good job.