Low-cost satellite communication system

A communication system comprising:

• a plurality of remote terminal units, each including
• a transmitter that transmits a transmission message to a satellite having a service area and a high-gain antenna with a field of view that sweeps the service area during a sweep period, such that:
• the transmitter is within the field of view for an illumination period that is substantially less than the sweep period, and
• the transmission message has a message duration that is less than the illumination period;
• and,
• a ground station that receives retransmission messages corresponding to the transmission message of at least a first terminal unit of the plurality of remote terminal units when the transmitter of the first terminal unit is within the field of view,
• wherein
• a DSSS code of a plurality of DSSS codes is allocated to each of the plurality of remote terminal units, and
• the transmitter of each of the plurality of remote terminal units is configured to transmit in accordance with the DSSS code allocated to the each of the plurality of remote terminal units.

A communication system comprising:

• a base station that receives an information bandwidth that includes a plurality of transmission messages, the base station including:
• a plurality of DSSS correlators for demodulating at least two of the plurality of transmission messages based on a predetermined DSSS code, each correlator of the plurality of DSSS correlators using the predetermined DSSS code,
• wherein
• a first message of the at least two of the plurality of transmission messages has a first start time, and an end time,
• a second message of the at least two of the plurality of transmission messages has a second start time that is between the first start time and the end time,
• at least one of the first start time and the second start time is independent of the base station, and
• the base station is configured to distinguish between the first and second message based on a distinction between the first and second start times.

A satellite system comprising:

• a spacecraft control system that is configured to control a behavior of the satellite system,
• a receiver that is configured to receive communications from a base station for subsequent retransmission to a plurality of remote terminal units,
• a transmitter that is configured to transmit communications from the plurality of remote terminal units to the base station, and
• a satellite terminal unit, operably coupled to the receiver, the transmitter, and the spacecraft control system, that is configured to:
• monitor the communications from the base station for messages that are addressed to the spacecraft control system,
• communicate the communications that are addressed to the spacecraft control system to the spacecraft control system, and
• communicate messages from the spacecraft control system to the base station via the transmitter.