What are Cacique and
DanzanteThese are the official names for the White Sands Ground Terminal (WSGT) and Second TDRSS Ground Terminal (STGT), respectively.
Where are the ground
terminals locatedThey are 16.6 miles north of Las Cruces, New Mexico.
What function do the ground
terminals serveThe ground terminals provide the operational control center for the Tracking and Data Relay Satellites and ground equipment required for providing customer telecommunications services. The ground terminals also provide the interface to NASA Communications (NASCOM) for the transport of customer data to the customer specified destination.
Do the ground terminals
provide any customer data processing functionsNo. However, the ground terminals will provide a data quality monitoring function based on customer specified parameters of data type and/or format. The ground terminals will also provide data formatting necessary for transport.
Does the customer interface
directly with the ground terminal systems or ground terminal operators to
schedule service or interact with the customer spacecraftNo. The customer interface is with the scheduling group, which communicates directly with the ground terminal systems and its operators. However, it is possible for customers to monitor status.
How does the data get from
the ground terminal to the customerOnce the data is received at the ground terminal from the customer spacecraft, it is routed via commercial domestic communication satellites (i.e., via NASCOM) back to GSFC and then on to the customer designated data collection point.
Can Data be recorded at the
ground terminal for line outage protection or for playback at a later timeYes. All customer events are recorded at the ground terminal and a playback of a tape can be scheduled within 48 hours of the original event.
Are there any differences
between the two ground terminalsYes. There are some minor differences between the two due to the fact that Cacique (WSGT) is an upgrade of the original TDRSS ground terminal designed and built in the late 1970's. However, none of the differences affect how a customer interacts with or receives data.
What happens if a ground
terminal experiences a failureIt depends on the type of failure experienced. It is unlikely that a single failure would totally disable the ground terminal. It is less unlikely that a failure in a single subsystem will occur. The ground terminal design is built to be robust and all elements in a communications string are redundant with the redundant equipment operating in a hot standby mode. In the event of a detected failure, the system under computer control will detect the failure and switch from the failed equipment to the redundant equipment, resulting in a minimal disruption to the ongoing service.
How long does a failover to
the hot standby equipment takeWithin the SGLT, a failover takes no longer than 10 seconds for the worst case and significantly less for component failover within the SGLT.