The original Project Mercury station at Muchea, near Perth, was mostly built from off the shelf and military equipment, progressing to a much more substantial installation for the Gemini Program at Carnarvon. These stations were good for earth orbit passes, but the long tracks and distances to the moon were a different matter, and a sophisticated system was developed from the Deep Space technology used by the Jet Propulsion Laboratory. It became known as the Unified S Band, or USB, system.

             The Mercury and Gemini missions were designed for the passes over the station to be controlled from the station beneath, and a specially trained team of flight controllers were deployed to each site before a mission, Carnarvon’s medical team supplemented by Royal Australian Air Force doctors. With the arrival of Apollo, the stations in Australia at Honeysuckle Creek and Carnarvon became just a communications point between the Mission Control Centre at Houston, Texas, and the spacecraft, relaying voice and commands from the Control Centre, and receiving voice, telemetry, and video from the spacecraft for transmission back to the Control Centre by undersea cables or satellite. Normally no NASA personnel were present on site for the missions.

             Honeysuckle Creek's operations were divided into clearly defined areas, both electronically and physically. At the front end was the Antenna, located as accurately as the surveying methods of the time allowed. Under the main antenna was a room containing the Power Transmitters, sensitive Receivers, and the Cryogenically Cooled Parametric Amplifiers. A hydraulic Servo System drove the antenna.

             A large room in the operations building, facing the antenna, was known as the USB Section.  It had the only window in the operations area, to see the antenna, and contained the servo console and computers to control the antenna, the receivers to amplify the signal, the sub-carrier data demodulators, station time standard, and the ranging system.

             Next was the Telemetry Section with all the signal processing and recording equipment for the data from the astronauts and spacecraft, followed by the Computer Section.

             A Communications Section handled all the voice and teletype traffic, and the data signals in and out of the station, including a microwave link across to Tidbinbilla.

             An Operations Section tied all these separate areas together and organised the mission activities, tests, and interfacing with Mission Control Centre at Houston. They worked from a special console next to the computer section.

             A Facilities Section provided all the power. As it all had to be 110 volt, 60 Hertz mains for the American equipment, and reliability and remoteness were also factors, all power was generated by Caterpiller diesel engines on site. There was a small management and administration section, which included a logistics area, or store, for parts and equipment.


             Lets explain what all these operational sections do, beginning with  what we called the front end, the USB Section, and its prime responsibility, the signal to and from the spacecraft. All the uplink and down link signals were modulated onto a single carrier. Lets look at the uplink first.


            The uplink was less complicated than the downlink and consisted of Voice, Commands, and the Ranging code. Both Honeysuckle Creek and Tidbinbilla could transmit two uplinks simultaneously for either to backup in case of failure of the link in use, or to transmit to two spacecraft within the antenna beamwidth at the same time.


            Speech was regarded as the prime uplink signal, and simply stated, provided a telephone link between the Capsule Communicator (Capcom) at Houston, usually one of the astronauts, and the astronauts in the spacecraft. A Communication Technician (Comtec) at Honeysuckle Creek monitored all the traffic and checked the best channel was being used. The baseband voice signal was analog with a frequency response of 300 to 2,550 Hz modulated on to a 30 kHz subcarrier, summed with the other uplink signals, and phase modulated onto the carrier. 


            Commands consisted of instructions to the spacecraft, primarily to relieve the astronauts of irksome chores. Examples were antenna switching for the optimum signal strength at the ground station, recorder control for transferring information stored on magnetic tape from the spacecraft to the ground, and the more important navigational data to update the command module/lunar module computers.

            Commands were loaded into the station's Univac 642B Command Computer by high speed data lines from Houston. These were transmitted with a digital code of 57 bits at a rate of 4.8 kilobits per second.

             Commands could be called up for transmission  to the spacecraft at a designated time, or be sent in real time. Instructions to transmit a command were initiated in Houston, and the 642B computer recalled the required command from memory and transmitted it to the spacecraft, where a digital word was returned with the telemetry stream back to the computer. If no return word was received by the computer, it would retransmit the command a pre-determined number of times before raising an alarm. Commands could also be sent manually from the Operations console in the event of data communication problems with Houston.

            A command would leave the computer in a 30 bit parallel code, was converted to a serial phase shifted keyed (PSK) waveform consisting of a 2 kHz data signal combined with a 1 kHz reference. This baseband command signal was first frequency modulated on a 70 kHz carrier before being summed with the other uplink signals and phase modulated onto the carrier.



            Ranging was a code transmitted to the spacecraft and returned for time comparison with the original code. The pseudo random noise range code, generated by a dedicated ranging system, was a combination of 5 codes to form a 5.4 second period code of 5,456,682 bits, which gave a maximum unambiguous range of 500,000 miles (804,650 km), or twice the distance to the moon.

            Ranging was initiated manually by the Ranging Technician after the station was locked onto the signal from the spacecraft, and once acquired by the code, was updated by doppler only. Resolution within the Ranging System was +/‑ 3 feet (1 metre), but system jitter and ground instabilities gave an overall accuracy of +/‑ 50 feet (15.2 metres).

            The range code was summed with the other uplink signals and phase modulated onto the carrier.


The Uplink:

            As stated earlier, there were two uplinks, the final modulation process used phase modulation with relatively narrow deviation to ensure a phase stable carrier component arrived at the spacecraft, as the spacecraft transmission carrier was derived from the received carrier through a transponder. The total RMS phase deviation on the uplink carrier was kept at about 1 radian.

            The command sub-carrier of 70 kHz and voice sub-carrier of 30 kHz were combined in a sub-carrier oscillator system, and delivered to the exciter as normal modulation, phase modulated on the S Band carrier.

            The Power Amplifier used a klystron and delivered a continuously variable CW output of 1 to 20 kilowatts. The bandwidth of 10 MHz was wide enough to accommodate both uplink frequencies. 500 milliwatts drive was required to produce the full 20 kilowatts output into the antenna.



            The 26 metre diameter parabolic dish antenna used what was known as an XY mount, which meant the antenna could tilt in two directions, north to south, and east to west. Combining the movements, almost the whole sky could be covered, only a small section known as the "keyhole" in the east and west direction was blind.

Beamwidth: 0.43° +/‑ 0.05°.

Pointing accuracy: 40 seconds of arc.

Maximum tracking rate: 3° per second.

Polarisation: Right Hand Circular, or left hand Circular, remotely switchable.

Gain:  51db up,  53db down.

Acceleration: 5° per second ²

            A small 2 metre dish located at the apex of the quad legs was known as the Acquisition Antenna. It was only used for relatively strong signals from fast moving earth orbiting spacecraft to initially locate the signal from the spacecraft and steer the Main Antenna  onto the target. It was also used for tracking aircraft during simulations and tests, where there were no predicts. Once we even tried using a person standing outside the window pointing at the aircraft with their arm!

             Located on a nearby mountain ridge was a tower, known as a Collimation Tower, with special equipment and antennae to simulate a spacecraft, so the main antenna could be pointed at it to run tests on all the transmitting, receiving and processing equipment. Before every pass all the equipment was checked out on the Collimation Tower. If a problem appeared while tracking a spacecraft, the station could quickly check out all its systems by going to the tower and running tests to confirm whether the problem was in the station or in the spacecraft.

             Due to the narrow beam width of the antenna, it had to be extremely accurately pointed at the target. To achieve this, computers at the Goddard Space Flight Centre (GSFC) calculated the spacecraft's position and trajectory from previous tracking data and the result was modified for Honeysuckle Creek's location before being fed to the station down the NASCOM communication lines at least 30 minutes before the spacecraft was due. These were known as predicts.

            A Univac 1218 Computer received these predicts and produced a paper tape for a special processor called an Antenna Position Programmer (APP) which interfaced directly with the Antenna Servo System to drive the dish. Once the spacecraft had been acquired using the computer instructions to point the antenna, the normal procedure was to switch the antenna drive from Program to Autotrack follow the spacecraft's signal. For deep space work the antenna remained in program track due to the low level signals, and could be offset to maximise the signal, if required.

             Once the station had locked onto the signal, another special processor called a Tracking Data Processor, (TDP) accepted the ranging data, the speed of the spacecraft relative to the station from the doppler, and the antenna angles relative to the station's geographical location, and coded this information for transmission to Goddard. It was coded in both high speed data at 2,400 bits per second and in teletype code onto paper tape.



             The spacecraft downlink S Band signals could be received at the antenna at levels varying from -150 to -90 dbm. The signals bounced off the parabolic aluminium dish surface to the Hyperbole Focus where the feed system was split into four parts, giving a Common Monopulse Tracking System of left or right circular polarisation, remotely selected.

             The sum output of the Monopulse Comparator was fed into a Cryogenic Parametric Amplifier (Cooled Paramp) with a low system temperature. This Paramp output was split 5 ways, 4 to independent phase locked Receivers, switchable between  1 kHz to 12 Hz, allowing the receivers to track down to a level of ‑160 dbm.

             The "X" and "Y" outputs of the Monopulse Comparator were fed to a triple channel Warm Paramp, then to Tracking Receivers whose reference was derived from the original sum channel. The remaining channel of the warm Paramp was used as a backup for the main cryogenic Paramp.

             The function of the Diplexer (together with the band pass and reject filters) was to combine the uplink and down link frequencies, giving a rejection of 180 db in the receive spectrum.


            The S band frequency from the Cooled Paramp was converted down to an IF of 50 MHz, then reconverted to a 10 MHz reference frequency. Phase detection at this frequency drove programmable local oscillators and multiplier chains for the phase‑locked operation. The outputs from the Receivers, of 50 MHz and 10 MHz were composite signals which were fed into the Subcarrier Data Demodulator System (SDDS) where the various channels of information were stripped off and patched to the appropriate areas.

Subcarrier Data Demodulators:

            The Subcarrier Data Demodulators accepted the composite signals from the Honeysuckle Creek, Tidbinbilla, and Parkes Receivers. They contained the voice, telemetry, biomedical, and television signals and broke them down into a Pulse Code Modulated (PCM) bit stream, Voice and Biomedical data. These were patched in both PM or FM modes as dictated by operational requirements.

             The Television signals, which were frequency modulated directly on the carrier in the spacecraft, entered via the 50 MHz FM channel and were completely demodulated and fed to the television processing equipment.


            The voice from the demodulators was fed to the Communications Technician (Comtec) who monitored and switched for the best signal source. The voice was recorded on analog reel to reel magnetic tape recorders as well as being sent in real time to Mission Control at Houston via Telecom circuits. OTC then passed it over to the USA via undersea cable or satellite.


            The telemetry PCM bit stream was routed to 4 Decommutators in the Telemetry Area. The rates were variable, normally high at 51.2 kilobits and low at 1.6 kilobits/ second. The telemetry data was recorded onto reel to reel magnetic tape data recorders.

             The prime function of the PCM Decommutators was to present all the decoded data to the Telemetry Univac 642B Computer in 30 bit parallel form for transmission to Houston. They also allowed station personnel to monitor selected data on indicators or chart recorders.

             The PCM telemetry could be broken down into 6,400 words of information on the spacecraft antenna direction, physical condition of the astronauts in the CSM, quantities of consumables, engineering data, etc.


            The Biomedical information was in two distinct paths. One was used for the Command Module when the data came via Pulse Code Modulated (PCM) telemetry. The other path was used while the astronauts were in the LM, or in their spacesuits during the lunar walks. The LM biomedical data was routed down separate analog FM telemetry channels to special processing equipment which converted the analog information to digital for the computer. Both sets of information, together with the other PCM data were presented to the Univac 642B computer for transmission to line.


            As the data lines between the station and Mission Control Centre in Houston had limited capability for data transmission in those days, all the telemetry was presented to the Telemetry Univac 642B Computer, where only data selected by the Flight Controllers in Houston was transmitted to line. The output from the computer of 30 bit parallel words was converted to a serial bit stream at 4.8 kilobits a second and transmitted to line.

             Both Command and Telemetry Computers were identical and interchangeable and had 20 input and 20 output channels, 64k memory and duplex magnetic tapes, each with 4 tape transports.  Between them was an Expanded Memory Unit (EMU) of 128k.

            Programs used during the mission were sent from Goddard Space Flight Centre in Maryland, USA, on magnetic tape and paper tape to be loaded into the computer at pre-determined times. The magnetic tape units held the mission operational programs were also used for fault analysis as well as storing data.


            The Television signal from the spacecraft in the later Apollo missions was the American standard of 525 lines/60 field frame sequential colour television, and it also contained information on the television camera temperature or battery voltage. This television signal from the demodulators was presented to a matrix switch which selected the best signal from Honeysuckle Creek, Tidbinbilla, and Parkes. The voice and telemetry subcarriers were filtered out with a subcarrier cancellation device which eliminated the subcarriers by a locally generated subcarrier locked to the incoming signal and 180° out of phase with it.

             The signal was cleaned up and processed in a standard television processing amplifier before the vertical interval test (VIT) signals, multiburst, and gray scale were inserted on line 16 and 17 of the vertical blanking period.

             The television signals were recorded on Ampex VR 660 and VR 1100 video recorders. The composite processed television signal from the Honeysuckle Creek and/or Tidbinbilla stations were monitored on a modified Conrac colour monitor and transmitted to the specially prepared video centre in Sydney. The Parkes signal was sent directly to Sydney where NASA operators selected the best signal for transmission direct to Houston.

             Ed von Renouard, the Television technician at Honeysuckle Creek in the Apollo flights offers the following comments on the Apollo television system:

            "The RCA Scan Converter for Apollo 11 operated on the optical conversion principle, that is the narrow band slow scan television (SSTV) down link picture from the Lunar Module at high resolution (800 lines)and 10 frames per second was displayed on a black and white 10 inch monitor and scanned at the US (EIA) TV standard of 525 lines and 60 frames per second by a Vidicon camera, from where the 10 original frames per second were recorded on a magnetic disc whilst simultaneously going out live to Sydney and Houston, and were then replayed five times from the disc to make up the 60 frames per second. This replaying delay, incidentally, is the reason why the pictures seen by the public were so smeared and ghostly when the astronauts moved.

            The original idea of mounting the television camera upside down in the MESA (Modular Equipment Storage Area) was to simplify its removal by the astronaut. When the astronaut removed the camera to plant it on the lunar surface it would be right way up. A few weeks before the Apollo 11 mission someone at NASA spotted the camera would be upside down in the MESA so a modification to install a toggle switch connected to the deflection coils of the camera by means of a relay inverted the picture by the simple expedient of reversing the vertical scans.

            Every fifteen minutes during the whole period of the moon walk and the subsequent three hours of video and telemetry down link  until we lost the signal we had to change the ½ inch magnetic tapes on the Ampex 1400 instrumentation recorders which recorded the telemetry from the spacecraft and the astronauts, and also the slow scan television at a speed of 120 inches per second. The converted commercial standard television was recorded on an Ampex VR1100 four-head video recorder using a 2 inch tape which decided to choose this mission to develop an intractable and elusive fault. It started to overheat and blow fuses so I had to place a fan blowing on it to keep it cool until the end of the mission.

            In later Apollo missions with full commercial standard television from the moon, Ampex VR660 helical scan two‑head video recorders using 2 inch tape were used with a Wollensak ½ inch helical scan recorder as a backup - more than ten years before helical scan VCR's became available to the general public.

            For Apollo 13 the scan converter was no longer used, because a more powerful transmitter on the Lunar Module allowed EIA standard frame sequential television to be down linked from the moon. The colour was produced by means of a red, green, and blue colour wheel rotating at 20 frames per second in front of a black and white Westinghouse television camera used by the astronauts, which was then electronically converted at Honeysuckle and the other tracking stations to the standard commercial broadcast signal, colour synchronised to the green field, before it was sent to line.

            By Apollo 15 the television system was properly installed without "kluges' and modifications, and from then on worked very well, though still using the colour wheel."  

 Time Standard.

            All the activities of the missions revolved around time, and Honeysuckle Creek had a dual time standard which provided multiple readouts, pulses and various coded times for time tagging all data produced on the station. Three main forms of time were displayed around the operational areas:

 Universal Time UT also known as Greenwich Mean Time, GMT, or Zulu time, was used by everyone in the mission as a common time reference. The stations had digital readouts, and analog 24 hour dial clocks with two hour hands to show both Universal Time and local time.

 Ground Elapsed Time, or GET was also used by all the mission people as a planning and event time. The Flight Plan for the whole mission was planned months before using a time that began from zero at lift off.  The GET clock started as a minus count before the mission, ending as the familiar "Three - Two - One - We have lift off," and the moment the spacecraft left the ground this clock would count through zero and begin counting up, and continue counting in hours until the end of the mission. We all knew exactly where we were in the mission from the GET.

                          Horizon Time was used only by the station, and gave us a reference for events on the station for every pass. For earth orbit passes for instance, it would begin at H‑30, or 30 minutes before the spacecraft was due to appear on the horizon, and count down to zero when all the signals should appear in the equipment, then count up until 10 minutes after the end of the pass, when it would be reset ready for the next pass.

            Accurate time was essential, and various methods were used to keep the station time within 10 mseconds of Universal Time. WWV, or WWVH were used for a coarse check, but for a vernier adjustment down to +/- 10 mseconds, 100 kHz Loran C  navigational signals were used. The North West Pacific Loran C chain was the nearest, with delays calculated for the seven hops from, say, Iwo Jima, the master station. The prime frequency source was a Hewlett Packard Cesium beam frequency standard giving a stability of around 1 x 10 - 10.

Operations Console:

            The central co-ordinating operational position tied the station together, and provided an interface with external organisations. The console had lamp and meter displays giving station configuration and equipment status to the operators.

            The console had facilities for the station to communicate with the spacecraft in case of a communication failure with Houston, which was actually used on a number of occasions. The console could also send commands to the spacecraft in case of data communications failures, and control the Telemetry and Command computer configurations.



             There was a vast communications link up for the Apollo 11 mission just in Australia alone, involving the Post Office (now Telstra), OverseasTelecommunications Commission, (now part of Telstra) The Australian Broadcasting Commission, and the Australian Federation of Commercial Television Stations.

            The NASA Switching Center in the Canberra suburb of Deakin provided a central communications point for the ACT tracking stations, using computers to assemble the signals destined for the USA, and unscrambling the signals from the USA to the stations.

The Post Master General's (PMG's) Department.

            The PMG, now called Telstra, provided circuits to carry television, voice, telemetry, and command data between Honeysuckle Creek and the overseas terminals where the Overseas Telecommunications Commission (OTC) took over. It also provided lines from Carnarvon and Bassendean in Perth from the Indian Ocean Ship right across Australia for transmission to Houston via OTC connections. The whole range of facilities of the Post Office were used ‑ coaxial cable, microwave radio, and open wires. Alternate circuits, sometimes even triplicated, were used in case of a failure.

             The open wire system across the Nullarbor Plain was backed up by a radio link from Perth to Melbourne. Western Australia was unable to see Apollo 11 live because at that time there was no broadband link across the nation. Experts had checked and double checked all the security aspects of the relays.

             10,000 miles (16,000 km) of trunk circuits were used for over a week. Just the television relay network over the eastern states covered 5,000 miles (8,046 km), all looked after by more than 100 engineers and technicians working around the clock. These links were being carried free of charge by the PMG as the Apollo 11 relays were regarded as programs of national importance.


 The Overseas Telecommunications Commission (OTC).

            The television signals from Honeysuckle Creek and Parkes were fed down PMG bearers to the OTC terminal at Paddington in Sydney, where it was selected for the best quality signal by NASA personnel and split, one for the local networks was sent to the ABC at Gore Hill, where it was converted from the American standard of 525 lines to the Australian standard of 625 for distribution to the local networks for an estimated 10 million viewers. The second split was sent to the OTC satellite communications station at Moree, New South Wales, for transmission to Houston via the Intelsat III Pacific Communications satellite.

            At various times during the mission OTC received telecasts from the United States for distribution to the local television networks. The "Voice of Apollo" sound programs were sent from the United States using the Compac cable system, the Moree satellite earth station, or the Seacom cable which terminated at Cairns.

             The NASA ships and aircraft stationed around Australia used the OTC facilities to relay their signals back to Houston, particularly during the earth orbit and landing phases.



            The Manned Spacecraft Center is located in Houston, Texas, a city honouring Sam Houston, Commander in Chief of the Texan army and twice President of the Republic of Texas between 1836 and 1844. Texan and a past President of the United States, Lyndon B. Johnson was instrumental in selecting Houston as the site for the nerve centre of all the NASA manned missions.

            The Manned Spacecraft Center grew from the Space Task Group originally formed at Langley Field, Virginia, in November, 1958. Built on land donated by Rice University, the Manned Spacecraft Center, now called the Johnson Space Center, is a thriving community dedicated to exploring the space environment. The tracking stations around the world were under control of the Goddard Space Flight Center in Greenbelt, Maryland, but during the operational phases of a mission, were connected to the Mission Control Center.

            The Manned Spacecraft Center had the management responsibility for the design and development of spacecraft for manned space flights and planning and execution of space flight missions under the overall direction of the Office of Manned Space Flight, NASA Headquarters in Washington, DC.  It controlled the mission from launch through to recovery from Building 30, which had three elements:

            1. The Mission Operations Wing contained the systems and equipment required to        support and control the manned missions. It was made up of five basic systems:

             2. The Operations Support Wing contained the offices, laboratories, and                                   technical support areas.

             3. The Lobby Wing, an interconnecting building contained additional office space,            and dormitory facilities.  


 There were two identical Mission Control Centers and Staff Support Rooms, on the second and third floors of the Mission Operations Wing of Building 30.

            The Mission Operations Control Room (MOCR) located in the Mission Operations Wing of Building 30 was the principle command and decision area for each mission, and was the “Houston” frequently referred to in the book. The centre of a complex world wide communications network to tracking stations, ships, and aircraft,  it had 17 main areas of responsibilities shown in the diagram opposite.

Main management and operating positions:

1.  Director of Flight Operations - had the overall responsibility for the missions.

2.  Mission Director from NASA Headquarters.

3.  The Department of Defense Representative - controlled the recovery forces.

4.  The Public Affairs Officer - was responsible for providing information on the mission to     the public. The television and radio voice of Mission Control.

5.  The Flight Director - the team leader, was responsible to the Mission Director for detailed             control of  the mission from launch to splashdown and assumed the duties of the          Mission Director in his absence.

6. Operations and Procedures Officer - was responsible to the Flight Director for the            detailed implementation of the Mission Control Center/Ground Operational Support     Systems mission control procedures.

7.  The Assistant Flight Director - was responsible to the Flight Director for detailed control             of the mission and assumed the duties of the Flight Director in his absence.

8.  Flight Activities Officer - kept track of crew activities in relation to mission time lines.

9.  Network Controller - had detailed operational control of the world wide Ground    Operational Support System, which included the tracking stations.

10.  Flight Surgeons - directed all operational medical activities and crew’s medical status.

11.  Spacecraft Communicator - or Capcom, an astronaut who provided all the voice             communications between the ground and the spacecraft.

12.  Vehicle Systems Engineers - monitored the performance of all electrical, mechanical,      communications, environmental and life support systems on the spacecraft.

13. Booster Systems Engineer - monitored the 3 Saturn V stages during the launch phase.

            During lunar surface activities an Experimental Officer directed scientific activities and     relayed information from the science teams from this console.

14. Retrofire Officer -  Kept track of abort and return to earth options.

15. Flight Dynamics Officer - monitored the flight parameters, on board propulsion systems, and planned major spacecraft manoeuvres. Recommended whether to “Go” or “Abort” a mission.

16. Guidance Officer - monitored the spacecraft computers, the Inertial Guidance and             Navigation Systems, and the abort guidance system.

17. The Maintenance and Operations Supervisor - was responsible for the performance and status of the Mission Control Center equipment.

            Backing the above front line operators were six Staff Support Rooms (SSR):

1.  Flight Dynamics - to monitor all aspects of powered flight concerning crew safety and        orbital insertion, evaluate and recommend modification of trajectories to meet mission       objectives.

2.  Vehicle Systems - to monitor detailed status of trends of flight systems and components of the spacecraft, and overcoming in-flight equipment failures.

3.  Life Systems - to monitor physiological and environmental information from the       spacecraft.

4.  Flight Crew - to co-ordinate non medical flight crew activities and any scientific       experiments attempted during the flight.

5.  Networks - to schedule, monitor, and direct network activities and readiness checks.

6.  Operations and Procedures - to provide detailed technical and administrative support.