To install from source, you will need to have Rust and maturin installed.

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
pip install maturin

git clone https://github.com/kjnapier/spacerocks
cd spacerocks
cd py_spacerocks
maturin develop --release

https://naif.jpl.nasa.gov/pub/naif/generic_kernels/pck/