The Chandra X-ray Center announces the retirement of the unencrypted and anonymous Chandra Data Archive public FTP area on November 01, 2020. The secure, HTTPS version of the FTP area is already available at the following URL:
https://cxc.cfa.harvard.edu/cdaftp/The internal structure of the HTTPS area remains unchanged. All users of the old FTP service are encouraged to update their scripts to use the new interface.
The effects of this change on CIAO and DS9 are described
here.