If you're wondering why there wasn't nitrogen mixed in, it's because the additional systems+tanks for handling nitrogen would've added more weight to the spacec

If you're wondering why there wasn't nitrogen mixed in, it's because the additional systems+tanks for handling nitrogen would've added more weight to the spacecraft. This video goes in to a bit more detail: https://www.youtube.com/watch?v=FvA7N_j_8os https://www.youtube.com/watch?v=FvA7N_j_8os