Roles of NASA and OTC stations

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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. This is clarified by the following twelve key points.

1. 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.
2. CRO – principal 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.
3. CRO - other roles 
(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, and reflecting laser beams from the Moon; (2) The FPQ-6 radar, the most accurate radar of its time, tracked almost everything that the US launched including manned-space flights, deep space missions, and scientific, defence and communication satellites and, in addition, participated in research projects involving sounding rockets, water vapour clouds in space, wedge-tailed eagles, and orbiting balloons – and, it is rumoured, racehorses orbiting the Carnarvon Racecourse; (3) The Solar Particle Alert Network (SPAN) observatory monitored solar flares and recorded ‘signals’ from the planet Jupiter.
4. 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. Later a troposcatter link to Geraldton was installed to increase ground communication reliability but it only functioned well in cloudy weather – rare in the region.
5. 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, OTC-1, affectionately known as the ‘sugar scoop’.
6. A starring role for OTC 
The OTC role was intended to be solely for two-way relay of data and voice between CRO and the United States via the Pacific satellite. However, the first of the three satellites went adrift and presented OTC and the ABC with the opportunity to make the first Australian overseas live television broadcast from Australia to the outside world. On 25 November 1966 "Down Under Comes Up Live" was transmitted from Carnarvon to Goonhilly (England) taking advantage of the failed satellite as it drifted over the Indian Ocean. The other two satellites went into successful synchronous orbits; one over the Atlantic, the other over the Pacific. (see for a more human account under 'Early Satellite Broadcasts to/from Britain' >> 'Australia to UK By Satellite, 1966')
7. Increased demand for satellite 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 viewable from Western Australia.
8. The Apollo 11 Moon walk, 20 July 1969, - the separate roles of CRO and OTC 
CRO gave backup support to Apollo-11 for the latter part of the Moon walk. It received direct TV signals of the walk when the Moon rose about 30 minutes after the walk commenced. But contrary to popular myth, OTC-2 did not receive direct signals from any Apollo mission - ever. The Moon walk TV signals were received by Honeysuckle Creek Tracking Station, ACT, and by Parkes Radio Telescope, NSW, and were relayed up to the Pacific Communications Satellite via the Moree OTC station, NSW, and back down again to Carnarvon OTC-1 and along a co-axial cable to Perth. The transmission was significant however as the first live TV transmission to WA audiences from outside the state.
But what is not so commonly known is that the first TV transmission into Western Australia was even earlier on 5 July 1966 when TV pictures of fuel behaviour in the Apollo-2 launch rocket were transmitted to the USB antenna at the NASA Space Tracking Station further down Browns Range - though not broadcast beyond there.
9. CRO closure 
Before April 1975 the OTC earth station did not track NASA spacecraft nor did it ever receive signals directly from the moon. It merely acted as a relay station for CRO.
10. 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 Halley’s Comet when OTC-2 was the prime Giotto deep space control centre – Mar ‘86
11. OTC closure 
In 1987 the Gnangara OTC Earth Station opened near Perth, consequently the Carnarvon OTC Earth station was closed.

12. Both Carnarvon stations, CRO and OTC, were casualties of a communications revolution.


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