# How do I calculate the Characteristic Energy for a rocket to Near Rectilinear Halo Orbit where the Deep Space Gateway is gonna orbit moon?

How do I calculate the Characteristic Energy for a rocket to Near Rectilinear Halo Orbit (NRHO) where the LOP-G or the Deep Space Gateway is going to be orbiting the moon? Or if someone already has a number, it would be appreciated!!

I am trying to find the payloads different rockets can take to the NRHO. I already have the c3 vs payload mass plots for the rockets I want. I just need the exact amount of c3 required to get there. I know it will be negative, since we are not leaving Earth SOI. Thank you for any and all help. Sources are appreciated.