Since an HTTP 502 error indicates an internal server error, one of the following may be happening.
- A DDoS attack may be temporary rendering the server offline, or partially disabled.
- The server may be undergoing maitance
- Something else happened to the server
In any case, the issue should be resolved shortly. Unfortunately, I don’t really have more information then that, although Admin may have more info once he comes online.
If this is really bothering you, you can backup your website, and create a new hosting account (This should move you to a new IP address, hopefully one that is not having issues). Just make sure to move your domain over as well!