each user has their own key, do not give the key to others your key will insure that you can view and send messages all messages will be sent to a server on the planet, for record-keeping this server version will not be able to handle plain-text communications platforms. It will not be compliant with the ground server based version. If you move from sector x to sector y, you have to get a new username, and a new user-id. The server/satellite will manage that. A username consists of the sector number, then your name. Optional numbers follow. Changing your name is only granted by the administrator. Users NEVER see others user-id, because that is what matters. you don't even need to see yours
you have one user in sector 1, USA a second user is in sector 9, china
Users will not be able to have live conversation, simply because of how the satellite travels. the satellite takes about 90 minutes or so, so you would use it for brief conversation or instructions.
Your computer or box will always be on, so you can get the messages.
Example:
satellite is over sector 1
user 1spam, with user-id:142b124fs sends message:
to: 9foo;from: 1spam;user-id:142b124fs;please tell me if you want me to send you cookies
satellite receives message, and tells user with user-id:142b124fs that message was sent.
satellite is over sector 9
satellite gets user 9foo's user-id, and it uses that to encode the message before sending.
when user 9foo receives the message, the box decodes the message, and replies to the server that the message was received.
The server deletes the message from the to-send list