Discussion:
The Dish
(too old to reply)
Arindam Banerjee
2021-01-29 01:07:17 UTC
Permalink
There is a dish in a place called Parkes, which I expect to visit in August.

It is actually a huge parabolic reflector, used as a radio telescope.

As per mainstream history, it was used to collect the TV signal from the Apollo 11 moon landing and transmit it to the world.

In 1969 Parkes thus enjoyed unprecedented attention from dignitaries.

But as per the film, disaster could have easily happened.

As a result of a power outage, the computers (then ancient) could not be restored to their earlier state. Apparently the backup generator did not start as the fuel lines had not been primed by the negligent clowns.

In the film they claimed that the system was running on UPS. A generator backup was thus there.

I am reasonably sure that in UPS you have a battery backup that kicks in seamlessly when the mains go off. So there is no chance of generator failure causing problems. Of course, the generator will start after a while and last till the mains come on.

But there was no word of battery backup, in the film.

Anyway, why did the moon landing was so timed as only Parkes could pick it up and not any US site? Surely it a 12 hour wait at most. They could easily have circled the moon for 12 hours.

The film made me nostalgic, thinking of the difficult first eight years of my career, when I was an Antenna Development Engineer, testing large antennas at the remote test site near Sohna. Then I was young, and could climb up the positioner easily to make adjustments to the antennas I was testing.
occam
2021-01-29 09:49:19 UTC
Permalink
Post by Arindam Banerjee
There is a dish in a place called Parkes, which I expect to visit in August.
It is actually a huge parabolic reflector, used as a radio telescope.
As per mainstream history, it was used to collect the TV signal from the Apollo 11 moon landing and transmit it to the world.
In 1969 Parkes thus enjoyed unprecedented attention from dignitaries.
But as per the film, disaster could have easily happened.
As a result of a power outage, the computers (then ancient) could not be restored to their earlier state. Apparently the backup generator did not start as the fuel lines had not been primed by the negligent clowns.
In the film they claimed that the system was running on UPS. A generator backup was thus there.
I am reasonably sure that in UPS you have a battery backup that kicks in seamlessly when the mains go off. So there is no chance of generator failure causing problems. Of course, the generator will start after a while and last till the mains come on.
But there was no word of battery backup, in the film.
Anyway, why did the moon landing was so timed as only Parkes could pick it up and not any US site? Surely it a 12 hour wait at most. They could easily have circled the moon for 12 hours.
The film made me nostalgic, thinking of the difficult first eight years of my career, when I was an Antenna Development Engineer, testing large antennas at the remote test site near Sohna. Then I was young, and could climb up the positioner easily to make adjustments to the antennas I was testing.
Thank you for the pointer. It looks like a very interesting film. I
believe the Parkes observatory also gets a scene of its own in the The
Right Stuff (1983). It is easy to pass judgement on computer / satellite
technologies of the era, with 20/20 hindsight. Yet they generated more
excitement at the time than most new technologies do today.
Peter Moylan
2021-01-29 10:21:25 UTC
Permalink
Post by Arindam Banerjee
There is a dish in a place called Parkes, which I expect to visit in August.
It is actually a huge parabolic reflector, used as a radio
telescope.
As per mainstream history, it was used to collect the TV signal from
the Apollo 11 moon landing and transmit it to the world.
Back in 1969 I got to walk on the Parkes dish. The operators tilted it
far enough that we could climb on to it, and then tilted it back as we
walked to the centre. This put us much further from the ground than I
had expected.

Close up, the dish surface looked like chicken wire. We had to walk on
the steel struts that held the chicken wire in place. I've always had
trouble with heights, but I managed to do the walk without looking down
too often.

Tourists aren't allowed to walk on the dish, but I was in a bunch of
recent graduates being given a week-long tour as part of a recruiting
drive by the CSIRO Division of Radio Astronomy. We were taken by bus to
a variety of astronomy sites. At some stage we went back to Sydney to
hear a talk by Fred Hoyle, who was visiting Australia at the time.
--
Peter Moylan Newcastle, NSW
occam
2021-01-29 11:05:58 UTC
Permalink
Post by Peter Moylan
Post by Arindam Banerjee
There is a dish in a place called Parkes, which I expect to visit in August.
It is actually a huge parabolic reflector, used as a radio
telescope.
As per mainstream history, it was used to collect the TV signal from
the Apollo 11 moon landing and transmit it to the world.
Back in 1969 I got to walk on the Parkes dish. The operators tilted it
far enough that we could climb on to it, and then tilted it back as we
walked to the centre. This put us much further from the ground than I
had expected.
Close up, the dish surface looked like chicken wire. We had to walk on
the steel struts that held the chicken wire in place. I've always had
trouble with heights, but I managed to do the walk without looking down
too often.
Tourists aren't allowed to walk on the dish, but I was in a bunch of
recent graduates being given a week-long tour as part of a recruiting
drive by the CSIRO Division of Radio Astronomy. We were taken by bus to
a variety of astronomy sites. At some stage we went back to Sydney to
hear a talk by Fred Hoyle, who was visiting Australia at the time.
A fact I was unaware of until now is the second Australian satellite
dish site - Honeysuckle Creek.

<https://www.abc.net.au/news/2019-07-18/the-dish-is-a-great-comedy-but-certainly-not-a-documentary/11318862>

From the perspective of someone planning a visit starting in Melbourn,
both look doable in one trip. "A two-dish course" is a likely pun, in
French.
Peter Moylan
2021-01-30 01:14:14 UTC
Permalink
Post by occam
Post by Peter Moylan
Back in 1969 I got to walk on the Parkes dish. The operators tilted
it far enough that we could climb on to it, and then tilted it back
as we walked to the centre. This put us much further from the
ground than I had expected.
[...]
Post by occam
A fact I was unaware of until now is the second Australian satellite
dish site - Honeysuckle Creek.
<https://www.abc.net.au/news/2019-07-18/the-dish-is-a-great-comedy-but-certainly-not-a-documentary/11318862>
By now there are radio-telescopes all over the world. A partial list of
those in Australia can be seen at

https://en.wikipedia.org/wiki/List_of_radio_telescopes#Australia

In the 1980s, or possibly it was the 1990s, I was part of a team that
developed a system for steering such dishes. We were, however, working
more with tracking telecommunications satellites than with
radio-astronomy. In astronomy, as we all know, there are databases to
tell you where to point your telescope. With telecommunications
satellites, the aim at the time was to keep the satellite in a known
orbit. This was true for geosynchronous satellites, and for
low-earth-orbit (LEO) satellites, and everything in between. With a
known orbit, you could steer your dish according to a pre-planned schedule.

But satellites drift away from their orbits, because of random
disturbances, so they must carry fuel for orbit corrections. When the
fuel runs out, the satellite becomes useless, even if it is still in
perfect condition.

Our system extended the useful life of satellites by tracking their
changes in orbit. Initially the dish searched in the vicinity of the
supposed orbit. Once it obtained a lock on the position, it built up a
software model of the orbit, and kept correcting that model as time
proceeded.

The system worked well, with a number of successful installations, until
some idiot in the military specified that our system had to be
"upgraded" to run under Windows. That seriously degraded its quality.
Post by occam
From the perspective of someone planning a visit starting in
Melbourn, both look doable in one trip. "A two-dish course" is a
likely pun, in French.
Melbourne to Canberra is an easy drive - about six hours, IIRC - with
freeway-standard roads all the way. Then Honeysuckle Creek is about an
hour from Canberra. Expect bad roads, because it's off the beaten track.
I believe camping is allowed there, but you need to bring all your
supplies including food. Of course you can always drive back to Canberra
if the food or water run out.

Canberra to Parkes is along less good roads, but it can be done in well
under four hours. There are plenty of motels in Parkes. Parkes back to
Melbourne is an eight-hour drive. Sydney is a bit closer - about 4-5 hours.

These days, of course, such a trip is complicated by having to get
permits to cross state borders, and a risk of a rule change at short
notice forcing you into quarantine. Just a month ago my wife and I had
to cancel a planned vacation in Tasmania because the risks were too high
of that sort of rule change.
--
Peter Moylan Newcastle, NSW
Lewis
2021-01-30 09:34:45 UTC
Permalink
Post by Peter Moylan
These days, of course, such a trip is complicated by having to get
permits to cross state borders, and a risk of a rule change at short
notice forcing you into quarantine. Just a month ago my wife and I had
to cancel a planned vacation in Tasmania because the risks were too high
of that sort of rule change.
I have a friend in Melbourne who has not been home for a little over a
month because he went to visit his family in Sydney before Christmas
and has not been allowed to leave NSW since.

Annoyingly, where he is has especially poor Internet, so there's been
very little contact. I have to rely on some other friends to update me
every now and then as he seems to only be able to get onto Facebook, and
that only once or twice a week.
--
Law of Probability Dispersal: Whatever hits the fan will not be
evenly distributed.
Peter Moylan
2021-01-30 12:27:53 UTC
Permalink
Post by Lewis
Post by Peter Moylan
These days, of course, such a trip is complicated by having to get
permits to cross state borders, and a risk of a rule change at
short notice forcing you into quarantine. Just a month ago my wife
and I had to cancel a planned vacation in Tasmania because the
risks were too high of that sort of rule change.
I have a friend in Melbourne who has not been home for a little over
a month because he went to visit his family in Sydney before
Christmas and has not been allowed to leave NSW since.
Yes, Sydney had a fresh covid outbreak recently, so Victoria banned
travel from Sydney and an area around Sydney. It wasn't the whole of
NSW, so I could have travelled to Melbourne subject only to a convincing
declaration that I hadn't been anywhere near Sydney in the recent past.
Of course, I would also have risked not being allowed back home again,
because these outbreaks are unpredictable.

For much of the past year, interstate travel has been banned in
Australia, although now and then some states open their borders to
travellers from "safe" regions.
Post by Lewis
Annoyingly, where he is has especially poor Internet, so there's
been very little contact. I have to rely on some other friends to
update me every now and then as he seems to only be able to get onto
Facebook, and that only once or twice a week.
--
Peter Moylan Newcastle, NSW
Kerr-Mudd,John
2021-01-30 14:48:11 UTC
Permalink
On Sat, 30 Jan 2021 12:27:53 GMT, Peter Moylan
Post by Peter Moylan
Post by Lewis
Post by Peter Moylan
These days, of course, such a trip is complicated by having to get
permits to cross state borders, and a risk of a rule change at
short notice forcing you into quarantine. Just a month ago my wife
and I had to cancel a planned vacation in Tasmania because the
risks were too high of that sort of rule change.
I have a friend in Melbourne who has not been home for a little over
a month because he went to visit his family in Sydney before
Christmas and has not been allowed to leave NSW since.
Yes, Sydney had a fresh covid outbreak recently, so Victoria banned
travel from Sydney and an area around Sydney. It wasn't the whole of
NSW, so I could have travelled to Melbourne subject only to a
convincing
Post by Peter Moylan
declaration that I hadn't been anywhere near Sydney in the recent past.
Of course, I would also have risked not being allowed back home again,
because these outbreaks are unpredictable.
For much of the past year, interstate travel has been banned in
Australia, although now and then some states open their borders to
travellers from "safe" regions.
Unless you're a high value sports person?
Post by Peter Moylan
Post by Lewis
Annoyingly, where he is has especially poor Internet, so there's
been very little contact. I have to rely on some other friends to
update me every now and then as he seems to only be able to get onto
Facebook, and that only once or twice a week.
--
Bah, and indeed, Humbug.
Peter Moylan
2021-01-30 22:16:25 UTC
Permalink
Post by Kerr-Mudd,John
On Sat, 30 Jan 2021 12:27:53 GMT, Peter Moylan
Post by Peter Moylan
Post by Lewis
Post by Peter Moylan
These days, of course, such a trip is complicated by having to
get permits to cross state borders, and a risk of a rule
change at short notice forcing you into quarantine. Just a
month ago my wife and I had to cancel a planned vacation in
Tasmania because the risks were too high of that sort of rule
change.
I have a friend in Melbourne who has not been home for a little
over a month because he went to visit his family in Sydney before
Christmas and has not been allowed to leave NSW since.
Yes, Sydney had a fresh covid outbreak recently, so Victoria banned
travel from Sydney and an area around Sydney. It wasn't the whole
of NSW, so I could have travelled to Melbourne subject only to a
convincing declaration that I hadn't been anywhere near Sydney in
the recent past. Of course, I would also have risked not being
allowed back home again, because these outbreaks are
unpredictable.
For much of the past year, interstate travel has been banned in
Australia, although now and then some states open their borders to
travellers from "safe" regions.
Unless you're a high value sports person?
Yes. Some of the Australian Open tennis players complained bitterly
about the quarantine rules. Then some of them tested positive for the
disease, and they had to eat their words. There has been some loss of
respect for tennis players here.

The football really annoys me. Football means money to the big media
companies, so there has been massive pressure to give all sorts of
exemptions to footballers to travel around the country. And football
players are exactly the sort of people who think rules don't apply to
them, so there's been lots of quarantine-breaking.

Our choir is not allowed to sing with more than five people. At the same
time, thirty thousand people in a sports arena can sing.
--
Peter Moylan Newcastle, NSW
Peter T. Daniels
2021-01-31 06:22:14 UTC
Permalink
Post by Peter Moylan
Post by Kerr-Mudd,John
On Sat, 30 Jan 2021 12:27:53 GMT, Peter Moylan
Post by Peter Moylan
Post by Lewis
Post by Peter Moylan
These days, of course, such a trip is complicated by having to
get permits to cross state borders, and a risk of a rule
change at short notice forcing you into quarantine. Just a
month ago my wife and I had to cancel a planned vacation in
Tasmania because the risks were too high of that sort of rule
change.
I have a friend in Melbourne who has not been home for a little
over a month because he went to visit his family in Sydney before
Christmas and has not been allowed to leave NSW since.
Yes, Sydney had a fresh covid outbreak recently, so Victoria banned
travel from Sydney and an area around Sydney. It wasn't the whole
of NSW, so I could have travelled to Melbourne subject only to a
convincing declaration that I hadn't been anywhere near Sydney in
the recent past. Of course, I would also have risked not being
allowed back home again, because these outbreaks are
unpredictable.
For much of the past year, interstate travel has been banned in
Australia, although now and then some states open their borders to
travellers from "safe" regions.
Unless you're a high value sports person?
Yes. Some of the Australian Open tennis players complained bitterly
about the quarantine rules. Then some of them tested positive for the
disease, and they had to eat their words. There has been some loss of
respect for tennis players here.
The football really annoys me. Football means money to the big media
companies, so there has been massive pressure to give all sorts of
exemptions to footballers to travel around the country. And football
players are exactly the sort of people who think rules don't apply to
them, so there's been lots of quarantine-breaking.
Our choir is not allowed to sing with more than five people. At the same
time, thirty thousand people in a sports arena can sing.
Some of our sports played limited seasons "in a bubble" -- in just one
or a few locations, with no outsiders allowed (baseball, basketball;
I don't know how hockey or soccer coped), but football was played in
stadiums around the country, mostly without spectators (both pro
and college), but last week for the semifinals Buffalo allowed some
6700 into its stadium -- alas it didn't make it to the Superbowl, the
first time in decades that it got that far. (Buffalo is at the other
end of New York State. Maybe you've heard of the one-time Buffalo
Bills star O. J. Simpson.)
Peter T. Daniels
2021-01-29 14:08:39 UTC
Permalink
Post by Peter Moylan
Post by Arindam Banerjee
There is a dish in a place called Parkes, which I expect to visit in August.
It is actually a huge parabolic reflector, used as a radio
telescope.
As per mainstream history, it was used to collect the TV signal from
the Apollo 11 moon landing and transmit it to the world.
Back in 1969 I got to walk on the Parkes dish. The operators tilted it
far enough that we could climb on to it, and then tilted it back as we
walked to the centre. This put us much further from the ground than I
had expected.
Close up, the dish surface looked like chicken wire. We had to walk on
the steel struts that held the chicken wire in place. I've always had
trouble with heights, but I managed to do the walk without looking down
too often.
Tourists aren't allowed to walk on the dish, but I was in a bunch of
recent graduates being given a week-long tour as part of a recruiting
drive by the CSIRO Division of Radio Astronomy. We were taken by bus to
a variety of astronomy sites. At some stage we went back to Sydney to
hear a talk by Fred Hoyle, who was visiting Australia at the time.
Even in 1969, wouldn't they have had to take relativistic physics into
account to establish and maintain contact with Apollo XI -- as well
as having had to do so for all previous space adventures?

There may have been some geosynchronous satellites by then, but
clearly not yet enough to blanket the earth with signal.

Telstar (1962) wasn't one.

https://en.wikipedia.org/wiki/Telstar

Hmm, I wonder why they put all the ground stations in a fairly
narrow band of Northern Hemisphere latitudbes, so that it only
functioned 20% of the time. I remember that first transatlantic
broadcast -- Walter Cronkite talked to Richard Dimbleby. (It says
Chet Huntley was there, too,)
charles
2021-01-29 15:42:03 UTC
Permalink
Post by Peter T. Daniels
Post by Peter Moylan
Post by Arindam Banerjee
There is a dish in a place called Parkes, which I expect to visit in August.
It is actually a huge parabolic reflector, used as a radio
telescope.
As per mainstream history, it was used to collect the TV signal from
the Apollo 11 moon landing and transmit it to the world.
Back in 1969 I got to walk on the Parkes dish. The operators tilted it
far enough that we could climb on to it, and then tilted it back as we
walked to the centre. This put us much further from the ground than I
had expected.
Close up, the dish surface looked like chicken wire. We had to walk on
the steel struts that held the chicken wire in place. I've always had
trouble with heights, but I managed to do the walk without looking down
too often.
Tourists aren't allowed to walk on the dish, but I was in a bunch of
recent graduates being given a week-long tour as part of a recruiting
drive by the CSIRO Division of Radio Astronomy. We were taken by bus to
a variety of astronomy sites. At some stage we went back to Sydney to
hear a talk by Fred Hoyle, who was visiting Australia at the time.
Even in 1969, wouldn't they have had to take relativistic physics into
account to establish and maintain contact with Apollo XI -- as well as
having had to do so for all previous space adventures?
There may have been some geosynchronous satellites by then, but clearly
not yet enough to blanket the earth with signal.
Telstar (1962) wasn't one.
https://en.wikipedia.org/wiki/Telstar
Hmm, I wonder why they put all the ground stations in a fairly narrow
band of Northern Hemisphere latitudbes, so that it only functioned 20%
of the time. I remember that first transatlantic broadcast -- Walter
Cronkite talked to Richard Dimbleby. (It says Chet Huntley was there,
too,)
Telstar was simply for transAtlantic use. There were 3 ground atations, 1
in the USA (Maine, I think) one in Brittany and one in Cornwall. That was
the technology of the time. By the time we got to Apollo there were more
satellites and more ground stations. The Tokyo Olympics in 1964 hastened
a transPacific satellite.
--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle
J. J. Lodder
2021-01-29 14:35:05 UTC
Permalink
Post by Peter Moylan
Post by Arindam Banerjee
There is a dish in a place called Parkes, which I expect to visit in August.
It is actually a huge parabolic reflector, used as a radio
telescope.
As per mainstream history, it was used to collect the TV signal from
the Apollo 11 moon landing and transmit it to the world.
Back in 1969 I got to walk on the Parkes dish. The operators tilted it
far enough that we could climb on to it, and then tilted it back as we
walked to the centre. This put us much further from the ground than I
had expected.
Close up, the dish surface looked like chicken wire. We had to walk on
the steel struts that held the chicken wire in place. I've always had
trouble with heights, but I managed to do the walk without looking down
too often.
Tourists aren't allowed to walk on the dish, but I was in a bunch of
recent graduates being given a week-long tour as part of a recruiting
drive by the CSIRO Division of Radio Astronomy. We were taken by bus to
a variety of astronomy sites. At some stage we went back to Sydney to
hear a talk by Fred Hoyle, who was visiting Australia at the time.
Would have been fun, I guess.
Any memory of what he talked about?

Jan
Peter Moylan
2021-01-30 00:46:16 UTC
Permalink
Post by Peter Moylan
Tourists aren't allowed to walk on the dish, but I was in a bunch
of recent graduates being given a week-long tour as part of a
recruiting drive by the CSIRO Division of Radio Astronomy. We were
taken by bus to a variety of astronomy sites. At some stage we went
back to Sydney to hear a talk by Fred Hoyle, who was visiting
Australia at the time.
Would have been fun, I guess. Any memory of what he talked about?
I think it was about the structure of the sun, but I might be confusing
that with someone else's talk, because at the time there were people
within CSIRO that were studying the sun.
--
Peter Moylan Newcastle, NSW
Stoat
2021-01-30 01:27:13 UTC
Permalink
[...]
. At some stage we went back to Sydney to
Post by J. J. Lodder
Post by Peter Moylan
hear a talk by Fred Hoyle, who was visiting Australia at the time.
Would have been fun, I guess.
Any memory of what he talked about?
Jan
I had the pleasure of attending a lecture course by Hoyle when I was an
undergraduate.
When he was there, he mostly seemed to tell stories about New York taxi
drivers.
He was away a lot of the time, and got his graduate student Narlikar to
give the lectures.
Narlikar's English was very difficult to understand. At the end of his
last lecture, he said
"Everything I have written on the blackboard is invariant under Indian
language".


--brian
--
Wellington
New Zealand
Arindam Banerjee
2021-01-30 06:20:27 UTC
Permalink
Post by Peter Moylan
[...]
. At some stage we went back to Sydney to
Post by J. J. Lodder
Post by Peter Moylan
hear a talk by Fred Hoyle, who was visiting Australia at the time.
Would have been fun, I guess.
Any memory of what he talked about?
Jan
I had the pleasure of attending a lecture course by Hoyle when I was an
undergraduate.
When he was there, he mostly seemed to tell stories about New York taxi
drivers.
He was away a lot of the time, and got his graduate student Narlikar to
give the lectures.
Narlikar's English was very difficult to understand. At the end of his
last lecture, he said
"Everything I have weritten on the blackboard is invariant under Indian
language".
What did you understand from that?
Post by Peter Moylan
--brian
--
Wellington
New Zealand
J. J. Lodder
2021-01-29 14:35:05 UTC
Permalink
Arindam Banerjee <***@gmail.com> wrote:
[-]
Post by Arindam Banerjee
In the film they claimed that the system was running on UPS. A generator
backup was thus there.
I am reasonably sure that in UPS you have a battery backup that kicks in
seamlessly when the mains go off. So there is no chance of generator
failure causing problems. Of course, the generator will start after a
while and last till the mains come on.
But there was no word of battery backup, in the film.
How would you start the generator without having a big battery at hand?
Post by Arindam Banerjee
Anyway, why did the moon landing was so timed as only Parkes could pick it
up and not any US site? Surely it a 12 hour wait at most. They could
easily have circled the moon for 12 hours.
You are mistaken about that. At the start of the moonwalk
the moon was to low above the horizon at Parkes,
so the signal went to California. (they had started a bit early)
Later on they switched to Parkes because it had better signal/noise.
Details at <https://en.wikipedia.org/wiki/Parkes_Observatory>

Jan
Peter Duncanson [BrE]
2021-02-02 00:02:57 UTC
Permalink
Post by J. J. Lodder
[-]
Post by Arindam Banerjee
In the film they claimed that the system was running on UPS. A generator
backup was thus there.
I am reasonably sure that in UPS you have a battery backup that kicks in
seamlessly when the mains go off. So there is no chance of generator
failure causing problems. Of course, the generator will start after a
while and last till the mains come on.
But there was no word of battery backup, in the film.
How would you start the generator without having a big battery at hand?
Post by Arindam Banerjee
Anyway, why did the moon landing was so timed as only Parkes could pick it
up and not any US site? Surely it a 12 hour wait at most. They could
easily have circled the moon for 12 hours.
You are mistaken about that. At the start of the moonwalk
the moon was to low above the horizon at Parkes,
so the signal went to California. (they had started a bit early)
Later on they switched to Parkes because it had better signal/noise.
Details at <https://en.wikipedia.org/wiki/Parkes_Observatory>
Jan
Also the landing occurred close to the scheduled time. The landing was
at 3:17 p.m. EST (20:17:40 UTC), which wss fine for US TV viewers.

A delay of 12 hours would have put the landing in the middle of the
night US time.
--
Peter Duncanson, UK
(in alt.usage.english)
J. J. Lodder
2021-02-02 10:41:39 UTC
Permalink
Post by Peter Duncanson [BrE]
Post by J. J. Lodder
[-]
Post by Arindam Banerjee
In the film they claimed that the system was running on UPS. A generator
backup was thus there.
I am reasonably sure that in UPS you have a battery backup that kicks in
seamlessly when the mains go off. So there is no chance of generator
failure causing problems. Of course, the generator will start after a
while and last till the mains come on.
But there was no word of battery backup, in the film.
How would you start the generator without having a big battery at hand?
Post by Arindam Banerjee
Anyway, why did the moon landing was so timed as only Parkes could pick it
up and not any US site? Surely it a 12 hour wait at most. They could
easily have circled the moon for 12 hours.
You are mistaken about that. At the start of the moonwalk
the moon was to low above the horizon at Parkes,
so the signal went to California. (they had started a bit early)
Later on they switched to Parkes because it had better signal/noise.
Details at <https://en.wikipedia.org/wiki/Parkes_Observatory>
Jan
Also the landing occurred close to the scheduled time. The landing was
at 3:17 p.m. EST (20:17:40 UTC), which wss fine for US TV viewers.
A delay of 12 hours would have put the landing in the middle of the
night US time.
And in the middle of the Atlantic instead of the Pacific,
with the likelyhood of worse weather conditions,

Jan

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