Today in History

Apollo 11 astronaut Buzz Aldrin walks on the surface of the moon, 1969, in a photograph taken by Neil Armstrong

Today in History: Apollo 11 Moon Walk

The CSIRO Observatory in Parkes, Australia, transmits the first pictures of the Apollo 11 Moon walk to the world.

Parkes is a rural town in the central west of New South Wales, located about 265km west of Sydney. The region was originally settled by pastoralists in 1865. Known as Bushmans when it was founded in 1871 following gold discoveries, the town was renamed Parkes in 1873, in honour of a visit by Governor Henry Parkes. However, the town’s greatest claim to fame is the role played by the Parkes Radio Telescope in the first Moon landing.

Parkes was the site of the first radio telescope to be built in Australia. Its completion in 1961 was the result of ten years of of negotiation between CSIRO Radiophysics Laboratory staff, the Australian Government and significant American Scientific institutions, Carnegie Corporation and the Rockefeller Foundation. Affectionately dubbed “The Dish”, the telescope comprised a disc some 210 feet (64 m) in diameter, constructed of mesh woven from high-tensile strength steel designed to withstand a range of pressures. The total cost of construction was 800,000 Australian pounds.

NASA first proposed that the Parkes radio telescope be incorporated into its worldwide tracking network in 1966, and in 1968 requested Parkes’s involvement in the Apollo 11 mission. On 16 July 1969, Apollo 11 was launched from Cape Kennedy, Florida. The Parkes telescope was crucial in transmitting the first pictures of the Moon landing, although it almost didn’t happen. At the time the astronauts were to leave the landing module, the moon was only in the view of the southern hemisphere. However, mission commander Neil Armstrong elected to forgo the astronauts’ scheduled six-hour rest period, and make the moon walk earlier, meaning the moon would not yet have risen over Parkes to get clear enough pictures. Fortunately, the astronauts took so long to prepare for the Moon walk that the Moon was just rising over Parkes.

The controllers at Parkes then faced another crisis. One of the reasons Parkes was chosen was that it had the weather conditions most conducive to gaining the best signal: ironically, as the Moon rose over Parkes, wind gusts of 110 km per hour gusts hit the radio telescope, threatening the integrity of the telescope structure as the dish was hammered back against its zenith axis gears. Nonetheless, tracking was able to begin just as the Moon rose into the Parkes radio telescope’s field of view. Being a larger telescope, it captured more signal and so produced better pictures. These pictures were transmitted on 21 July 1969, Australian time. The command centre at Houston switched to the Parkes feed, staying with that transmission for the remainder of the 21.5-hour broadcast.

The Return: On July 24, 1969, President Richard Nixon welcomes the quarantined Apollo 11 astronauts, Neil Armstrong, Michael Collins, and Buzz Aldrin, aboard the U.S.S. Hornet after the historic Apollo 11 lunar landing mission

In this way, the Parkes radio telescope, which still sits in the middle of a sheep paddock in rural New South Wales, became an integral part of the history of space exploration.

 

 

Extract from: referdex.com.au