Apollo 11 Moon landing

On July 21, 1969, at 12.56 pm, Australian Eastern Standard Time (AEST), mankind took its ‘one big leap’ and 600 million people watched Neil Armstrong walking on the Moon.

Our radio telescope in Parkes famously supported receiving television signals on that important day. While many claim that the Parkes telescope was the only station transmitting the signal, the 26-meter antenna at NASA’s Honeysuckle Creek space monitoring station near Canberra was the primary station assigned to receive the original TV pictures from the Moon and Neil Armstrong’s first steps on the lunar surface.

Eight and a half minutes after the first groundbreaking images were transmitted all over the world, NASA used the television signal obtained by the larger 64-meter Parkes radio telescope to supply the images for the next two hours and 12 minutes of live coverage as the Apollo 11 astronauts explored the Moon surface.

While the signals were received successfully by the Parkes telescope, the opportunity didn’t go without a hitch. Around 6.17 am AEST the lunar module had landed. Before the Moonwalk, astronauts Neil Armstrong and Buzz Aldrin were expected to rest but Neil Armstrong was keen to get moving. The astronauts gradually got into their suits and rose above Parkes as they got beyond the Surface.

As a series of powerful wind gusts – 110 km per hour – struck, the telescope was completely tipped over, waiting for the Moon to rise. We shuddered the control room, then jammed back the telescope against its gears on the zenith axis. Luckily, the wind slowed, and Buzz Aldrin turned the TV camera on just as the Moon came into the field of view of the telescope.

During this time the key signal was being taken from Honeysuckle Creek. Eight minutes later the Moon was in the field-of-view of the Parkes main detector and NASA switched to Parkes. The weather remained poor, and the telescope was running well outside its safety limits.

The signals Parkes has received were sent to Sydney. From there the television signal was separated. To international telecast, one signal went to the Australian Broadcasting Commission, the other to Houston.

The international signal had to travel from Sydney to Houston half way around the world, adding a delay. So Australian viewers have seen the landmark first move of Neil Armstrong 0.3 seconds ahead of the rest of the world.

The Australian film, ‘The Dish’ about the Parkes telescope, is great entertainment, but not entirely accurate in history. In fact, there were lots of CSIRO staff involved, at Parkes and elsewhere.

At the control desk was Parkes staffer Neil ‘Fox’ Mason, directing the telescope. Despite being at the core of the action, he was not able to turn around and see the photos come in. Then, he had to control the tracking of the telescope, should the wind pick up again. And on the Dish none have ever played cricket.

https://www.csiro.au/en/Research/Astronomy/Spacecraft-tracking/Apollo-11-Moon-landing

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