Have you tried power cycling the modem? That means unplugging it, waiting at least 30 seconds, then plugging it back in, then waiting a couple of minutes and trying again.
If you have, but you still can't connect, there's likely a problem, as you've surmised, as even if there is an alignment issue with the dish, or some other reception issue, you should still be able to connect to the System Control Center. The reps are normally on M-F from approximately 8AM to 5PM EST, though once in a while there is one on during the weekends and/or evenings. Even though you can't connect, it would still be a good idea to leave the modem plugged in so that the reps can attempt to run remote diagnostics on it.
Normally I wouldn't suggest this, but being that it's the weekend you may even want to try direct messaging HughesNet through their Facebook page. I don't know if you'll have luck, but you may. :)
