Back in 1980 after leaving the Army, I was hired to work for SBS as a Satellite Controller and ground station technician at their Satellite Control Center (SCC).  The Clarksburg Telemetry, Tracking and Command (TT&C) ground station in Maryland was nearing completion and was under acceptance testing in preparation for the first launch of a SBS satellite. Over 14 years of operation the station facilities grew to include added functionality, Carrier System Monitor (CSM) area, Central Reference Station (CRS),  Video Support Center (VSC) for uplink monitoring and assistance and finely a Launch Control Facility. The station power was supported by an uninterpretable power system including 500 KW diesel and turbine generators,  battery backup and an automated transfer system to switch from commercial power to the backup systems. Office space was available for management, the engineering staff and a facilities engineer who maintain the heating, air conditioning and humidity control systems.  Each shift was staffed to support 24 hour operations of all of these functional areas and also maintain or repair the equipment.

SBS TT&C ground station early 80's

This picture shows the 3 NEC 7.8 meter Ku-Band limited motion antennas we used for control of the SBS satellites. Also shown is a mobile ground station parked between 2 of the fixed antennas that we used for video demonstrations and remote onsite testing. The NEC antennas moved in the X and Y axises using jack screws driven by electric motors.  Once the antenna was pointed at the satellite it was capable of tracking using a modified program track system. The antenna drive speed was 0.01 degree per second, and the range of movement was limited to a section of the satellite ark assigned to the SBS satellites for on orbit operations. These antennas were linear polarized and the feed assembly  could be rotated for horizontal or vertical polarization. Electric heating elements were imbedded in the individual panels of the dish and are used to prevent accumulation of snow or ice on the dish surface. During on station operations of the satellites, data is collected and process as telemetry, time stamped X & Y angle data measurements are taken to process tracking and used in orbit determination,  range tones are transmitted and received , and commands are sent to the satellite.

The SCC section of the Operations area shows the racks to the left that held the HP 1000 E series mainframe computers used for satellite and ground systems  command,  control, and data processing. The baseband processing, voice communications network and time translation  equipment was located in the center. With the modems and interfaces to dedicated data and voice lines to the right.  Status changes and alarm conditions were sent to the event status printers located next to the two computer control terminals.

SBS SCC computers and Baseband racks

(This was state of the art in high tech at the time).  This room had raised floors to allow cabling and airflow to cool the racks of equipment. The three cabinets to the right in the picture are an EdPac system used to control humidity and maintain the rack temperature between 65 and 68 degrees to optimize equipment performance and eliminate the potential of static shocks. For fire protection the room was designed with a halon system that would seal the room, release the halon into the room to extinguish the fire and then evacuate any smoke and/or halon gas from the room in less than 2 minutes.

Satellite control and monitoring was preformed at this console that accommodated 2 flight controllers and a operations engineer. The monitors on top of the console provided a visual status of the RF equipment for each antenna, the transmit and receive path configurations, the IF equipment used in the paths in addition to computer status alarms.

The right half of the console was setup for commanding operations and the left side to allowed other satellites to be monitored simultaneously. Satellite simulators were used for launch preparation and to provide training of new engineers and controllers without interference with ongoing operations.

Pre-command checks

The 4 racks seen in the background of this picture contain the NEC RF equipment. Frequency conversion was accomplished using up and down converters that had a shared synthesizer to simplified link frequency selection. Each link had an attenuator to set it’s operating  level and provide an adjustment to raise or lower the output as needed. The transmit rack housed the IPA and HPA’s used to achieve the required transmit output power levels needed to meet the required link margins.

In the next picture the racks to the left support IF conversion and Antenna control equipment. The IF section has FM and Phase modulators for the transmit side and receivers with demodulators on the receive side.  IF input and output switch matrix hardware allowed computer or manual configuration of the up and down links at the 70MHz level.  The antenna control panels used by the operations team to manually point the antenna, change polarization from Horizontal to Vertical with minor angle adjustments, select program, modified program or step tracking, in addition to operations of the de-icing system. SCC expanded to full capacity

The Carrier System Monitor (CSM) equipment was initially installed by COMSAT General Corp.

CSM initial installation nearing completion

This system was used to monitor the traffic over the full 500 MHz frequency bandwidth of the satellite.  It contained all test equipment required to analyzed each link and track transmitted power, frequency, bandwidth, type of modulation and data error rates for each user on the satellite. We preformed acceptance testing on each of the 3 systems.

The fully operational system was optimized so one person could operate all 3 systems, monitoring 3 satellites at the same time. The CSM provided the capability to monitor traffic 24 hours a day and also supported network activation and customer network support.  These activities included daily carrier/traffic analysis, printouts used in network monitoring, status reporting, trending and to support information requested by the customer billing office.

CSM in full operations

The racks in the back to the left in the picture above (not completely shown) is the Video Support Center area.  As SBS started to lease out more space on the satellite for full time and occasional use video transmission services, 4 racks of video support equipment were added. Color-bar generators were used to provide test patterns along with all video test equipment needed to test the quality of the video up and down links.  As the satellite links started to be encrypted VideoCypher units were also installed and maintained as part of our support.

As an upgrade RF equipment installation started on the third antenna after the second satellite was launched.

Installation of LM-3 RF racks.

The Central Reference Station was installed to provide timing for networks. Using a ultra-stable timing source, the system would transmit a TDMA carrier into each of the 10 channels of the satellite providing a common reference. This would allow a more dynamic and flexible network configuration so any station could transmit on only one channel while receiving on more than one channel using this reference signal.

Additional RF racks being completed for the CRS

In preparation for our third satellite additional RF equipment and a fourth antenna was installed for backup.

Four operational LM Antennas

In the mid 80′s an addition was built to expand the SCC to support up to 6 satellites and preform Launch and checkout operations. This added 2 floors with a new SCC on the first floor, the Mission Control Center (MCC) launch operations facility on the second floor and 2 Improved Limited Motion (ILM’s) Azimuth – Elevation tracking Antennas made by TIW.

Expantion of building completed.

The new SCC had areas supporting control, new HP A900 computers and processing equipment, data analysis, and offices for the Operations manager and engineers.

New Satellite Control console

The new console used new HP 100 terminals equipped with touchscreen technology. Security monitors and remote control cameras were installed to view the equipment and the facility grounds.

The computer system controlled graphics generators connected to a video switch for easy switching of telemetry displays, security cameras, graphs, and video feeds. New Cisco switches and roughers were installed along with dial back modems for network configuration and remote access.

The offices had access to monitors and the video switch to monitor data and operations.

The Mission directors console in the MCC had monitors that were connected to a video switch used to select displays of satellite telemetry, plots, launch site video feeds, or signal strength test equipment. The voice network could access any of 8 channels ranging from remote tracking stations to the launch site in addition to telephone lines and operations networks. There were corded handsets and headsets available for each work area.

The engineering support consoles, had the same features for each subsystem engineer.

For support of additional backup power requirements a new 500 KW turbine generator  was added during the expansion.

This TT&C station was used by SBS, and in 1985 became part of MCI.  By 1990 this facility was sold to COMSAT.  COMSAT moved their control center to Clarksburg and integrated both operations to control 8 satellites form this site. Eventually COMSAT converted the station into a Tele-port as the satellites reached the end of their operational life and now it is owned and operated by Lockheed .