slow to connect to site

[milton123]

i've noticed (as have some of my users) that it often takes a few seconds (sometimes many seconds) to connect to one of my web sites even just to connect to a public directory listing (thus avoiding any WordPress effects) takes far longer than it should. ex:

seems like it's been happening for a couple of weeks now.

the site is hosted on nasa .

any idea what could be causing this?

Thnaks