Roles of NASA and OTC stations

The separate and different roles of the NASA Carnarvon Space Tracking Station (CRO) and the Carnarvon OTC Earth Station are often confused to the extent that CRO's vital role for the Apollo missions is often attributed to OTC. The following key points should set the record right.

CRO – establishment: 

conceived by NASA in 1961 as a replacement for the Muchea (Perth) station. CRO was surveyed 1962, constructed in ’63 at the southern end of Browns Range, and opened ’64.

CRO – role: 

to provide critical support for the Manned Spaceflight Network (MSFN) missions of Gemini and Apollo which led to men walking on the moon from July ‘69 to December ’72; followed by the Skylab missions.

CRO - other facilities: 

(1) The Satellite and Tracking Data Acquisition Network (STADAN) RARR supported almost a hundred different satellites in a scientific analysis of the near space environment and the Earth’s weather patterns and its land and marine resources; (2) The FPQ-6 radar, the most accurate radar of its time, tracked everything that the US ever launched and included deep space missions, defence satellites, sounding rockets, water vapour clouds in space, balloons and wedge-tailed eagles for CSIRO research – and, it is rumoured, horses at the Carnarvon Races; and (3) The Solar Particle Alert Network (SPAN) observatory monitored solar flares, recorded ‘signals’ from the planet Jupiter, and reflected laser beams from the moon.

CRO – ground communications: 

At first only marginally reliable, CRO nearly missed its first mission (April’64) due to a lightning strike near Gascoyne Junction. PMG technicians worked frantically to improvise an alternative route along an obsolete section of a PMG pole-top phone line from Mullewa to Northampton, and then patched it through to the postmistress at Hamelin Pool. She gallantly read the data figures – for over two hours – down the line to the Carnarvon Telephone exchange. A troposcatter link to Geraldton was installed to increase ground communication reliability but this only functioned well in cloudy weather – rare in the region.

NASA – communications upgrade: 

Requiring a much more reliable communications network for the critical support from CRO, NASA contracted Intelsat to launch three communications satellites. To link with these, NASA also contracted OTC to build an ‘earth station’ at Carnarvon at the northern end of Browns Range. This was opened in October ’66; a 12.6m Cassegrain horn antenna affectionately known as the ‘sugar scoop’.

Communications upgrade implemented: 

The communications satellites were launched by Intelsat. The first went adrift; the other two went into successful synchronous orbits, one over the Atlantic, the other over the Pacific. OTC’s role was solely the two-way relay of data and voice between CRO and the United States via the Pacific satellite, apart from a starring part in the first Australian overseas live television broadcast – Down Under Comes Up Live - from Carnarvon to Goonhilly (England) on 24/25 November ’66, which took advantage of the failed satellite as it drifted over the Indian Ocean.

Increased demand for stellite communications: 

A need for improved communications for Apollo and a developing demand for commercial satellite communication from Perth led to the construction of OTC 2 at Carnarvon in mid-1969, a 32m parabolic dish connected by coaxial cable to Perth. OTC 1 was now released for maintenance and operations on the Intelsat network for tracking, telemetry, and command - monitoring the various communication satellites near Australia.

The separate roles of CRO and OTC for the Apollo 11 Moon walk - 20 July 1969: 

CRO was suporting Apollo 11 for the latter part of the Moon walk and direct TV signals of the walk were received by them when the Moon ose about 30 minutes after the walk commenced. But contrary to popular myth OTC-2 did not receive direct signals from any Apollo mission - ever. OTC-2 did however transmit the Moon walk TV indirectly to audiences in Perth. These were received by Honeysuckle Creek Tracking Station, ACT, and by Parkes Radio Telescope, NSW, and relayed up to the Pacific Communications Satellite via the Moree OTC station, NSW, and back down again to the Carnarvon OTC and along a co-axial cable to Perth. It was significant however as the first live TV transmission in WA from outside the state.

CRO closure: 

Until April 1975 the OTC earth station did not track NASA spacecraft nor did they receive signals directly from the moon. They merely acted as a relay station for CRO.

OTC continuation: 

Intelsat still needed OTC for commercial satellite communication. In addition, OTC was contracted to support the European Space Agency (ESA). It now had an additional role as a ‘space tracking station’ in the full sense, notably supporting the Galaxy communications satellite rescue shortly after launch – Sep ’84; a NASA shuttle recovery of the Palapa & Westar communications satellites – Nov ’84; and the ESA Giotto rendezvous with Haley’s Comet when OTC was the prime deep space control centre – Mar ‘86

OTC closure: 

In 1987 the Gnangarra Earth Station opened near Perth and the Carnarvon OTC station was closed.

All Carnarvon stations, both CRO and OTC, were the victims of a communications revolution.