Why can’t I access Computational Fluid Dynamics meshes via a NASA FTP URL? Is the server down?

I am trying to access some CFD meshes uploaded on the NASA archive. They are accessible publicly and available at the following FTP URL:

ftp://cmb24.larc.nasa.gov/outgoing/Vassberg_2D_NACA0012

However, I tried using FileZilla, and it seems the server is offline. Since I am not familiar with FTP URLs, I was wondering whether anyone could help me on this.