The project will consist of a microcontroller which will be the main "brains" of the system, a RockBlock Naked which will handle the satellite communications, a GPS unit to find position and ideally a display/input component to allow messages to be read/sent if there isn't a PC or phone available to connect to the unit via Wifi or Bluetooth. There will also be a web app written using the Meteor framework that records and displays messages and position, this will also forward messages to the SMS network using the Twilio API.
Below is the system design diagram:
Here's my video where I (try to) explain the basics.
I got this message On video "This video is unavailable with Safety Mode enabled. To view this video, you will need to disable Safety Mode." ??!!