You probably don't need satellite internet. Satellite internet is extremely expensive and slow, and is only truly required in regions without cell reception, such as the south pole.
You need cellular internet, which may be purchased from AT&T, Sprint and many other cell providers. You will need to purchase a cellular modem (or a computer with one built in) for your carrier of choice. Cellular plans start at around $60/month.
Also consider WiMax from a provider like Clear, if the regions you will be traveling to are set up for it.