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原始链接: https://news.ycombinator.com/item?id=40081348

标题：美国宇航局深空网络和航海者号任务的迷人历史这部名为“[暮色中更安静](https://www。imdb。com/title/tt17658964/)”的有趣纪录片探讨了 NASA 航行者计划的历史，并对参与其持续维护的一组精选人员进行了采访。 Growing up as a science enthusiast in Australia during the 1970s and 1980s, the speaker was captivated by references to NASA's Mars landing and the Australian tracking stations mentioned in Jeff Wayne's musical adaptation of "War of the Worlds" (1978)。 In the late 1960s, plans for NASA's Viking missions to Mars began, leading to successful landings in 1976。 However, contrary to the documentarian's depiction, the Parkes Observatory in Australia, featured in the film, predates NASA's deep space communication facility, DSS-43。 The speaker shared his childhood fascination with amateur radio communication, leading him to pursue obtaining a ham radio license, joining the U。S。 Navy or Army for a Sigint role, transitioning to the private Sigint industry, and eventually mastering the technical aspects of high frequency communications。 Angles and dimensions were discussed, including the difference between degrees, minutes, and seconds, and the comparison of the size of celestial bodies like Mars, the moon, and Saturn, and the required preciseness for directing communications to distant spacecraft。 Additionally, discussions surrounding the limitations of communication signals expanding outward from Earth and reaching extraterrestrial objects were explored。 In conclusion, this engaging documentary sheds light on both the historical significance of the Voyager mission and the importance of continued investment in maintaining the infrastructure necessary for interplanetary exploration。 By understanding the complexities of high frequency communication systems and the challenges faced in managing them, audiences gain newfound appreciation for humanity's achievements in space exploration。

I thought I'd noticed this documentary on HN a few weeks ago, but I'll re-add it here.

"It's Quieter in the Twilight": https://www.imdb.com/title/tt17658964/

Interesting piece on a bit of the history of the Voyagers, as well as recent interviews with the handful of remaining folks dealing with Voyager today (well, as of 2021/2022).

As a science (and science fiction) nerd kid growing up in Australia in the 1970/80s I got a kick out of tracking station 43 mention in Epilogue 2 of Jeff Wayne's Musical Version of War of the Worlds (1978)...

[NASA unmanned landing craft just touches down on mars] [Houston Control]: "What's that flare? See it? A green flare, coming from Mars, kind of a green mist behind it. It's getting closer. You see it, Bermuda? Come in, Bermuda! Houston, come in! What's going on? Tracking station 43, Canberra, come in, Canberra! Tracking station 63, can you hear me, Madrid? Can anybody hear me? Come in, come in!" [instrumental music suddenly stops]

https://www.youtube.com/playlist?list=PLPHEbh7cnr561iJqxno3q...

The Viking missions to mars had started planning in the late 1960s and Viking 1 and 2 landed on Mars in 1976 so the inclusion of a NASA Mars landing in Epilogue 2 was pretty neat.

I agree it's a good watch, however they're different antennas.

The radio telescope at Parkes was built prior to DSS-43 that is the article's subject, they're located approx. 4 hours drive apart.

I would get my ham license and do everything I could with that hobby, especially digital.

While doing that I’d either enlist in the US Navy or US Army and work my way into a SIGINT job. Once you’re in a SIGINT job, you’ll be far too busy with radio for ham. This would be a fast track into SIGINT.

After that I’d use my military career to get into the private sector SIGINT world, as there’s a well-worn path there.

It’s hard for me to understand the arc seconds and degrees. Is there some kind of illustration available that shows the transmission from earth as a megaphone cone expanding out into to space?

1 degree = 60 arcminutes, 1 arcminute = 60 arcseconds

One arcminute is about the resolution of the human eye. That is, if two points are less than 1 arcminute apart on the your field of view, they appear as one point.

The moon is 30 arc minutes (1/2 degree) on your field of view, that's why one can see the details of the surface with the naked eye.

18 arcseconds is about the size of Saturn (without the rings) as seen from the earth. It means it is just precise enough to shoot through the rings of Saturn. You can't see this without magnification, like with a small telescope or a good pair of binoculars.

Draw an equilateral triangle. The internal angle at a corner is 1/6 of a circle, 1.0471975511965 radians.

That can be divided by 60 into degrees, which are 0.0174532925199 radians

Those can be divided by 60 into minutes, which are 0.0002908882086 radians

Those can be divided by 60 into seconds, which are 0.00000484813681109 radians

Those can be divided by 60 into thirds, which are 8.08022801849E−8 radians

I think going any further is likely to be meaningless in a modern context, but fourths and fifths were used in the past.

https://en.m.wikipedia.org/wiki/Degree_(angle)

The angle is about 9x10^-5 radians. If you were to take a meter stick (or a yard stick) and stick a piece of paper under one end, that's the precision within which it can point the dish. (While the earth is spinning, and going around the sun!) The actual width of the beam is about 5 times that angle.

Well, the area taken by a cone with angle "a" at the distance "r" is pi * r^2 * sin(a)^2.

For an arcsec, the square sin is ~85e-9. At the distance of the Moon, that means the signal occupies ~400km^2. At the distance of the Sun, ~5 billions of km^2 (5Mm^2).

The signal intensity is inversely proportional to that area.

For example, if the screw/servo controlling one axis of the dish is turned by a minimum adjustment, how many hundreds or thousands of miles does it throw the cone’s target at the distance of the probe? What’s the remaining margin for error at these scales?

Successful space travel and rocket science being a contemporary of war and violence is only strange if you find toys to be fascinating objects. And didn't a human land on the Moon because of a cold war between two superpowers?

What's strange is acknowledgement of the possibility of scarce resources necessitating conflict is considered invalid criticism that needs to be silenced or given negative reviews by the majority opinion. But that's not really surprising when things like ascetic religion were created as a reaction to what is popularly called criminal or antisocial mental models of the world.

It’s a Dish of Theseus, though. The electronics have been replaced, and the dish has been widened. I wonder how much of it is actually 50 years old besides the superstructure.

We, as a species, need the Deep Space Network(DSN) in order to keep communicating with everything man made that’s out there exploring our neighborhood.

This should be a global effort and I’ve read many articles about the lack of funding for the DSN. It’s getting more and more difficult to “juggle” and do proper time sharing in order to keep communicating with all the existing (and coming) spacecraft.

More resources and funding should be put together, by all space agencies (NASA, ESA, JAXA, ISRO…) so as to continue having means of communicating with all these space probes.

https://eyes.nasa.gov/dsn/dsn.html

If the global free market doesn't want to spend capital in space stuff, then space is probably not worth it. Capitalism is an effective filter for economics and resource allocation. Soviet Union styled failed management occurs otherwise.

I love how it's automatically "the Soviet Union" any time someone suggests that we might go against what the free market wants.

As an aside, the "free market" doesn't actually exist, something people with even a basic financial and civics education should trivially realize.

>Capitalism is an effective filter for economics and resource allocation

It really isn't a good filter for anything except "makes money quickly". Plenty of science returns zero economic benefits for years, even decades, but that doesn't mean it's useless.

> It really isn't a good filter for anything except "makes money quickly".

How do you figure? We stand in a nation built on giant economic long shots and in the only one that managed to put humans on the moon in a joint government commercial venture.

I'm using an open source product to write this to you. Running on an open source operating system. Also on an open source hardware device. Where's the "quick money" in any of this?

> but that doesn't mean it's useless.

It doesn't mean it's useful either. You can't use a simple "expectation factor" divorced from all other reality to decide how to spend tax money.

Our motivation for putting humans on the moon was an international dick-measuring contest. While the space race certainly created jobs and advanced science and technology, none of that was the primary reason we went up there.

>Where's the "quick money" in any of this?

Where's the capitalism in open source? Yes, yes, Red Hat, Microsoft etc all have their hands in it, but the very idea is anticapitalist.

>You can't use a simple "expectation factor" divorced from all other reality to decide how to spend tax money.

It's a bit more complicated than that, but plenty of countries outside the US spend money on things without tangible economic benefit.

Money has to come somewhere. Hence market is a way. Competition is also needed so you produce better and better.

There is no capitalism as such it is a communism or. We have mix system always. War, love, gov, politics, … even old communist found relative autonomy and over determination (and once on that no point to say ultimate we believe communism or capitalism will determine as things keep on going, end never comes).

Btw totalitarianism is the worry. Once you are in especially media (india starting china and Russia telling) good luck. That is the worry. Not politics, market, war, … alone.

Multi dimensional life and sometimes believe me one guy can do a lot. Rip, steve.

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