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General => General Technical Chat => Topic started by: edy on January 04, 2019, 06:53:00 pm

Title: China just landed a probe on the far side of the moon!
Post by: edy on January 04, 2019, 06:53:00 pm
https://spacenews.com/change-4-makes-historic-first-landing-on-the-far-side-of-the-moon/ (https://spacenews.com/change-4-makes-historic-first-landing-on-the-far-side-of-the-moon/)

(https://spacenews.com/wp-content/uploads/2018/08/change-4-rover-casc-aug2018-1-879x485.jpg)

The Chang'e-4 probe landed in the Von Kármán crater and is shielded from radio noise coming from Earth, making it ideal to explore external radio signals.... which begs the question, how do they communicate with the probe? It turns out the Chinese have another satellite in orbit around the moon named Queqiao (‘Magpie bridge’ from Chinese mythology) which relays signals.

I find it fascinating and also surprised that it didn't make bigger news here, at least in the West (or have I been living under a rock?). These missions (more Moon landings are planned by China this year) should be heralded as advancing scientific knowledge for all mankind... unless landing on the moon is considered passé. And to those threads saying we never landed on the moon... I guess China is faking it also. Who can prove them wrong? They landed on the FAR side of the moon... :-DD

MORE LINKS:

https://www.space.com/42895-landing-site-chang-e-4-mission.html (https://www.space.com/42895-landing-site-chang-e-4-mission.html)
https://www.bbc.com/news/science-environment-46760729 (https://www.bbc.com/news/science-environment-46760729)
https://en.wikipedia.org/wiki/Chang'e_4 (https://en.wikipedia.org/wiki/Chang'e_4)
https://www.theguardian.com/world/2019/jan/04/china-change-4-moon-rover-jade-rabbit-2-sets-off (https://www.theguardian.com/world/2019/jan/04/china-change-4-moon-rover-jade-rabbit-2-sets-off)
https://nssdc.gsfc.nasa.gov/planetary/lunar/cnsa_moon_future.html (https://nssdc.gsfc.nasa.gov/planetary/lunar/cnsa_moon_future.html)
Title: Re: China just landed a probe on the far side of the moon!
Post by: soldar on January 04, 2019, 08:49:45 pm
Note: https://en.wikipedia.org/wiki/Chang%27e

And I love Moon Cakes!
Title: Re: China just landed a probe on the far side of the moon!
Post by: chris_leyson on January 04, 2019, 08:56:58 pm
Should produce some interesting science. Apparently the Von Kármán crater is within the South Pole–Aitken basin which is one of the largest impact craters in the solor system, 13km deep.

The low frequency spectrometer, LFS, on the lander has three orthogonal antennas and works from 100kHz to 40MHz. Queqiao is also carrying a low frequency spectrometer on board, the NCLE (Netherlands Chinese Low-Frequency Explorer) developed by ASTRON and uses three 5m long orthogonal antennas. Queqiao is in an L2 Lagragian orbit about 65,000km from the moon and that is the first time a satellite has been put into that orbit.

Also as part of the mission two micro satellites were put into lunar orbit, Longjiang-1 and Longjiang-2. Longjiang-1 failed to reach luna orbit . Longjiang-2, aka DSLWP-B, was developed by students at the Harbin Institute of Technology (HIT) in the Heilongjiang Province, northeast China. Despite having a mass of just 47 kg, the tiny satellite managed to use its own propulsion to slow down and enter lunar orbit while the relay satellite continued past the Moon to its special destination. During its time in orbit Longjiang-2 has used a student-developed camera to take images of the Moon, Mars, the Sun and other objects. UHF tests have seen data transmitted by Longjiang-2 and received and decoded by radio operators on Earth.

Quote
I find it fascinating and also surprised that it didn't make bigger news here, at least in the West (or have I been living under a rock?)
Nope, you haven't been living under a rock, good information is hard to find but it's improving.

https://directory.eoportal.org/web/eoportal/satellite-missions/c-missions/chang-e-4 (https://directory.eoportal.org/web/eoportal/satellite-missions/c-missions/chang-e-4)
https://www.nasaspaceflight.com/2019/01/china-returning-moon-change-4-mission/ (https://www.nasaspaceflight.com/2019/01/china-returning-moon-change-4-mission/)
http://www.moondaily.com/reports/Dutch_Radio_Antenna_To_Depart_For_The_Moon_On_Chinese_Mission_999.html (http://www.moondaily.com/reports/Dutch_Radio_Antenna_To_Depart_For_The_Moon_On_Chinese_Mission_999.html)


Title: Re: China just landed a probe on the far side of the moon!
Post by: rdl on January 05, 2019, 12:46:17 am
Although not going to the far side, India's ISRO has a mission to the Moon planned for this year. Also, some of the landers originally intended for the Google Lunar X Prize may finally get to the Moon this year.
Title: Re: China just landed a probe on the far side of the moon!
Post by: donotdespisethesnake on January 05, 2019, 08:49:16 am
I find it fascinating and also surprised that it didn't make bigger news here, at least in the West (or have I been living under a rock?). These missions (more Moon landings are planned by China this year) should be heralded as advancing scientific knowledge for all mankind... unless landing on the moon is considered passé.

Two things: landers on the Moon are passé, and the Chinese typically don't release the science data.

But, putting a Chinese flag on the Moon is big news for Chinese leadership I guess.
Title: Re: China just landed a probe on the far side of the moon!
Post by: mrpackethead on January 05, 2019, 10:15:55 am
https://www.youtube.com/watch?v=gmHrHQEmp2Q (https://www.youtube.com/watch?v=gmHrHQEmp2Q)
Title: Re: China just landed a probe on the far side of the moon!
Post by: soldar on January 05, 2019, 11:11:52 am
I find it fascinating and also surprised that it didn't make bigger news here, at least in the West (or have I been living under a rock?).
Western countries are very self-centered. We believe we are the best in everything and we are not interested in any news that challenges that. Cite any accomplishment by China and you will often hear things like "all they do is copy cheap stuff, they have no initiative or imagination". In the meanwhile China is progressing like no country in history has done before. A country where just a few decades ago people were literally starving to death and they have brought millions and millions out of poverty and into the middle class. China is quietly building itself up as a world power and they are very quietly investing and buying up much of Africa and South America. Rich western countries, rather than think maybe we should put a little more effort into competing we just dismiss China as wannabes but China is not going to go away. China today is the biggest market for cell phones, computers, automobiles, etc. Pretending they don't exist and locking your country out of commerce with them will only result in disaster for your own country.

I am old enough to remember when western countries disparaged Japan's products as being cheap and of inferior quality. They laughed at Japan and called them imitators and makers of cheap copies. Just ask western car and electronics manufacturers how that worked out for them.

China has put stuff on Luna and it shows they have the capacity, the money, the means, the know-how. Poo-pooing the feat just to make ourselves feel good is shortsighted and will backfire. We need to get off our butts and look at ways to be more productive and less whinny.
Title: Re: China just landed a probe on the far side of the moon!
Post by: A Hellene on January 05, 2019, 11:59:33 am
So...

Is, finally, that damned thing (https://www.eevblog.com/forum/chat/is-the-moon-real/msg2068477/#msg2068477) made of kasseri (https://en.wikipedia.org/wiki/Kasseri) or not?
We should not be kept in the dark anymore... :P

-George
Title: Re: China just landed a probe on the far side of the moon!
Post by: EEVblog on January 05, 2019, 01:06:30 pm
I find it fascinating and also surprised that it didn't make bigger news here, at least in the West (or have I been living under a rock?).

The problem is that China is so secretive about it, it's hard to get any info at all, and they don't seem to feed much to the western media.
Title: Re: China just landed a probe on the far side of the moon!
Post by: soldar on January 05, 2019, 02:03:29 pm
The problem is that China is so secretive about it, it's hard to get any info at all, and they don't seem to feed much to the western media.
I totally disagree with that. The Chinese Lunar Exploration Program is well known and has a Wikipedia page (https://en.wikipedia.org/wiki/Chinese_Lunar_Exploration_Program) where you can read all about it, past, present and future.

The Chinese Government is not secretive at all but, on the contrary, are presenting it as a great achievement.

It is western media who give low precedence to news from China; well, from non-western countries in general. Big news from Asia, Africa or South America are relegated below much less important news that originates in western countries and even a lot of that western "news" is "manufactured".  "Professor of XYZ University says women suffer discrimination" is given higher priority than "hundreds drown trying to get away from civil war and reach safety". That's the way it works because that is what we ask for.

I follow news from China much more closely than your average westerner because my wife is Chinese and most of the times I tell her "did you hear about this that happened in China and is in today's news?" she responds "that's old, it was in the news three days ago".   Western news agencies keep those news of "lesser importance" in wait and to be used for filling in.  https://www.reuters.com/places/china (https://www.reuters.com/places/china)

Again, the volume of news from different origins says more about us than about the Chinese.

I would say the same about Russia, Middle East, etc. There are perfectly good news sources out there Russia Today, Al Jazeera, etc. but we dismiss them as not in line with our interests and way of seeing things.  We are more interested in knowing that Sandra Bullock got a pimple on her nose and what she did about it.

Title: Re: China just landed a probe on the far side of the moon!
Post by: VK3DRB on January 06, 2019, 12:07:29 am
And yet almost no Chinese in the PRC would have ever heard of Pink Floyd's Dark Side of the Moon. If they had, they would have known that there is no dark side of the moon, really. As of a matter of fact, it's all dark.
Title: Re: China just landed a probe on the far side of the moon!
Post by: raptor1956 on January 06, 2019, 12:22:10 am
The problem is that China is so secretive about it, it's hard to get any info at all, and they don't seem to feed much to the western media.
I totally disagree with that. The Chinese Lunar Exploration Program is well known and has a Wikipedia page (https://en.wikipedia.org/wiki/Chinese_Lunar_Exploration_Program) where you can read all about it, past, present and future.

The Chinese Government is not secretive at all but, on the contrary, are presenting it as a great achievement.

It is western media who give low precedence to news from China; well, from non-western countries in general. Big news from Asia, Africa or South America are relegated below much less important news that originates in western countries and even a lot of that western "news" is "manufactured".  "Professor of XYZ University says women suffer discrimination" is given higher priority than "hundreds drown trying to get away from civil war and reach safety". That's the way it works because that is what we ask for.

I follow news from China much more closely than your average westerner because my wife is Chinese and most of the times I tell her "did you hear about this that happened in China and is in today's news?" she responds "that's old, it was in the news three days ago".   Western news agencies keep those news of "lesser importance" in wait and to be used for filling in.  https://www.reuters.com/places/china (https://www.reuters.com/places/china)

Again, the volume of news from different origins says more about us than about the Chinese.

I would say the same about Russia, Middle East, etc. There are perfectly good news sources out there Russia Today, Al Jazeera, etc. but we dismiss them as not in line with our interests and way of seeing things.  We are more interested in knowing that Sandra Bullock got a pimple on her nose and what she did about it.

OK, so the Chinese are very open and we've just misjudged them -- so can you point me to a source for video from the Chinese lander?  Got a source for the images and video they are collecting?  And what about the science -- where can I get updates on the science they are producing?


Brian
Title: Re: China just landed a probe on the far side of the moon!
Post by: cdev on January 06, 2019, 04:25:49 am
It is a huge accomplishment.

Unfortunately, at least in many other areas, they are anything but "open".
 
They are a totalitarian state which is by definition secretive.

They have always been that way. Even before the PRC.

They have never had anything even remotely resembling democracy in mainland China.

Its a complicated situation.
Title: Re: China just landed a probe on the far side of the moon!
Post by: EEVblog on January 06, 2019, 05:19:01 am
The problem is that China is so secretive about it, it's hard to get any info at all, and they don't seem to feed much to the western media.
I totally disagree with that. The Chinese Lunar Exploration Program is well known and has a Wikipedia page (https://en.wikipedia.org/wiki/Chinese_Lunar_Exploration_Program) where you can read all about it, past, present and future.

The Chinese Government is not secretive at all but, on the contrary, are presenting it as a great achievement.

It is western media who give low precedence to news from China; well, from non-western countries in general. Big news from Asia, Africa or South America are relegated below much less important news that originates in western countries and even a lot of that western "news" is "manufactured".  "Professor of XYZ University says women suffer discrimination" is given higher priority than "hundreds drown trying to get away from civil war and reach safety". That's the way it works because that is what we ask for.

I follow news from China much more closely than your average westerner because my wife is Chinese and most of the times I tell her "did you hear about this that happened in China and is in today's news?" she responds "that's old, it was in the news three days ago".   Western news agencies keep those news of "lesser importance" in wait and to be used for filling in.  https://www.reuters.com/places/china (https://www.reuters.com/places/china)

Again, the volume of news from different origins says more about us than about the Chinese.

I would say the same about Russia, Middle East, etc. There are perfectly good news sources out there Russia Today, Al Jazeera, etc. but we dismiss them as not in line with our interests and way of seeing things.  We are more interested in knowing that Sandra Bullock got a pimple on her nose and what she did about it.

OK, so the Chinese are very open and we've just misjudged them -- so can you point me to a source for video from the Chinese lander?  Got a source for the images and video they are collecting?  And what about the science -- where can I get updates on the science they are producing?

What about hype videos leading up to it, chats with the scientists?, live coverage of the landing? etc
AFAIK they don't do anything even remotely close to what western agencies do in terms of public coverage.
Title: Re: China just landed a probe on the far side of the moon!
Post by: EEVblog on January 06, 2019, 05:21:07 am
There are perfectly good news sources out there Russia Today, Al Jazeera, etc. but we dismiss them as not in line with our interests and way of seeing things. 

You aren't speaking for me, I watch those sources just like any other news outlet.
Title: Re: China just landed a probe on the far side of the moon!
Post by: Rick Law on January 06, 2019, 06:53:42 am
I've been paying attention.  I knew they had a plan to do so, but I barely knew the probe landed until I caught the news article in SCMP (South China Morning Post) just hours before I got to this forum.

I think the reason they are not making loud noises is that there was a fear of failure and getting egg-on-face in public.  Now that the landing apparently succeeded, they may be making louder noises and more frequent noises about their future plans.

This is a good development for all man-kind.  I think they view it as "I've arrived (to the status of being an advance technology capable nation)."  This hopefully will ignite competition.  With competition, advancements will be made more frequent and at more speed.

Trump has voiced interest in Mars mission.  I think he might not have that Mars interest had it not been China's plans of Mar mission.  Regardless of whether China get there first or if USA get there first, we all will be richer in knowledge and technology driven by the winds of that competition.
Title: Re: China just landed a probe on the far side of the moon!
Post by: TheNewLab on January 06, 2019, 07:35:51 am

I think the reason they are not making loud noises is that there was a fear of failure and getting egg-on-face in public.  Now that the landing apparently succeeded, they may be making louder noises and more frequent noises about their future plans.

This is a good development for all man-kind.  I think they view it as "I've arrived (to the status of being an advance technology capable nation)."  This hopefully will ignite competition.  With competition, advancements will be made more frequent and at more speed.
Yes, keeping face is important. When the US demanded the return of the Spy plane that emergency landed back in the" otts" (xx00's), Bush was obnoxious about it, and so China, simply dismantled it completely and told the US to pick up the box crates. I understand they put all the screws and fasteners into another crate.

The US govt. did not get this. but my HK friend's did!

I knew they had launched a probe. They have plans to do the same for Mars. It appears we now have a space race! in a good way.
China wants a manned flight to the Mood, and are talking about a moon base.
The Eu wants to do their own manned space flight to somewhere. moon? Mars?
India the same
Turkey is building their own space launch pad for putting their people in space..
Has S. Korea, or Japan also talking about their own manned space flights.too?

I guess when politics and economy gets difficult on earth..Space becomes the new focus.

We may have half a dozen nations or more doing their own independent space exploration!
This is really great!
Title: Re: China just landed a probe on the far side of the moon!
Post by: TheNewLab on January 06, 2019, 07:38:23 am
..to the Mood..   :palm:
Well, I guess mood is really important in space :-//

 :popcorn: I need another Guinness..
Title: Re: China just landed a probe on the far side of the moon!
Post by: TheNewLab on January 06, 2019, 08:03:16 am
The problem is that China is so secretive about it, it's hard to get any info at all, and they don't seem to feed much to the western media.
I totally disagree with that. The Chinese Lunar Exploration Program is well known and has a Wikipedia page (https://en.wikipedia.org/wiki/Chinese_Lunar_Exploration_Program) where you can read all about it, past, present and future.

The Chinese Government is not secretive at all but, on the contrary, are presenting it as a great achievement.

It is western media who give low precedence to news from China; [by].. non-western countries

I would say the same about Russia, Middle East, etc. There are perfectly good news sources out there Russia Today, Al Jazeera, etc.... we dismiss them ...[peroid].  We are more interested in knowing that Sandra Bullock got a pimple on her nose and what she did about it.

Solder, I so agree, and agree, and agree.
However, China promote as great achievements and makes public,except for the details, until certain. Russia does this...and other nations.
Tthe USA  goes on and on and on about what we are, what we want to, and so often what we plan to, but never do... Welcome to the empire and Emerald City....  Only not so emerald.
I quit, disturbed by, US news when American TV stations suddenly changed all of their TV news sets the day we started bomping Iraq. Months of Scott Ritter saying there "are NO!! WMD's here" repeatedly reporting, UNSCOM (sp?) have covered all Iraq, had carte blanche to do surprise inspections anywhere. Then, I one day all the news stations just ignored what they had been covering for months and war joined the bandwagon.

Truth is, by watching and reading international sources I still get more than enough US news..

May I add? 24, NHK, and DW (not "America") the Hurriet, and some of those independent, non-mainstream..typically non-profit investigative sources?
So many US top, Pulitzer Prize journalists have left their major papers & have gone outside of the USA to independent organizations to report..
AH!! I just learned that all the US "fake news" talk, actually started with Putin and Russia, which is very old strategy to create doubt and make citizen's except the propaganda they want you to believe.
The Road to Unfreedom Timothy Snyder (c) 2018

Enough, me.  :blah:  :blah:  :blah:
Title: Re: China just landed a probe on the far side of the moon!
Post by: EEVblog on January 06, 2019, 09:47:05 am
Can you please leave the politics off the forum.
Title: Re: China just landed a probe on the far side of the moon!
Post by: EEVblog on January 06, 2019, 09:49:48 am
Yes. China is usually not shy to put these things on media if it knows the success rate is near 100%, such as launching a manned mission with all proven technology. After all, no one has ever landed on the back of the moon.

Technically, landing on the far side of the moon shouldn't be any more difficult than then ear side, right?
The far side would have a signal trip delay time, as it has to go through the repeater at the legrange point, but the descent would be automated in either case.
Title: Re: China just landed a probe on the far side of the moon!
Post by: EEVblog on January 06, 2019, 09:54:38 am
(https://ichef.bbci.co.uk/news/660/cpsprodpb/5BFA/production/_105064532_mediaitem105064528.jpg)

(https://s4.reutersmedia.net/resources/r/?m=02&d=20190105&t=2&i=1342353146&r=LYNXNPEF0409Z&w=940)
Title: Re: China just landed a probe on the far side of the moon!
Post by: coppercone2 on January 06, 2019, 09:58:43 am
I find it fascinating and also surprised that it didn't make bigger news here, at least in the West (or have I been living under a rock?).

The problem is that China is so secretive about it, it's hard to get any info at all, and they don't seem to feed much to the western media.

i dont think we should allow for a lunar gap.
Title: Re: China just landed a probe on the far side of the moon!
Post by: EEVblog on January 06, 2019, 09:58:50 am
I love these images from the Change'3 mission:

(https://static.gbtimes.com/uploads/old/2016/09/28/change3-yutu-moon.jpg)

(https://static.gbtimes.com/uploads/old/2015/10/29/yutu-chang-e-3-cas.jpg)
Title: Re: China just landed a probe on the far side of the moon!
Post by: coppercone2 on January 06, 2019, 10:03:39 am
it looks kinda like a hot dog stand
Title: Re: China just landed a probe on the far side of the moon!
Post by: coppercone2 on January 06, 2019, 10:12:29 am
does anyone think it would be cute and amusing if there was a russian, japanese and american ones near the same location so you can't take a picture of one without seeing the other ones, like a crowded moon scenario?
Title: Re: China just landed a probe on the far side of the moon!
Post by: soldar on January 06, 2019, 11:00:36 am
It is a huge accomplishment.

Unfortunately, at least in many other areas, they are anything but "open".
 
They are a totalitarian state which is by definition secretive.

They have always been that way. Even before the PRC.

They have never had anything even remotely resembling democracy in mainland China.

Its a complicated situation.
It's a complicated situation. I had prepared a long reply to your post but then I saw this
Can you please leave the politics off the forum.
and I thought it is better to err on the side of caution. If being married has taught me anything it is that it is always better to err on the side of caution. :)
Title: Re: China just landed a probe on the far side of the moon!
Post by: rdl on January 06, 2019, 12:19:14 pm
I think the real trick was putting their relay satellite (Queqiao) at the Earth-Moon L2 point. I'm not sure anyone else has ever done that.

Yes. China is usually not shy to put these things on media if it knows the success rate is near 100%, such as launching a manned mission with all proven technology. After all, no one has ever landed on the back of the moon.

Technically, landing on the far side of the moon shouldn't be any more difficult than then ear side, right?
The far side would have a signal trip delay time, as it has to go through the repeater at the legrange point, but the descent would be automated in either case.
Title: Re: China just landed a probe on the far side of the moon!
Post by: EEVblog on January 06, 2019, 01:29:26 pm
I think the real trick was putting their relay satellite (Queqiao) at the Earth-Moon L2 point. I'm not sure anyone else has ever done that.

There are two others it seems:

https://en.wikipedia.org/wiki/List_of_objects_at_Lagrangian_points#L2_2

L2 is unstable and needs to be corrected every 23 days:
https://wmap.gsfc.nasa.gov/mission/observatory_l2.html
Title: Re: China just landed a probe on the far side of the moon!
Post by: cdev on January 06, 2019, 01:31:17 pm
The wheel design on the rover is an interesting one. These designs keep improving and borrowing from one another so even though we have independent efforts to explore the Moon, Mars and other planets there still is a total effect that is much more than the sum of it's parts.

The idea of a radio observatory on the dark side of the Moon where the Earth's radio signals and even it's light are not present, is really interesting to me. 

Maybe one of the most interesting things that I think we could achieve short term in space.

It would be smart for all the Earth's countries to pool their efforts to build a really powerful one. It would be an opportunity for people to propose things to best utilize the platform. Cubesats have been pretty successful at getting schools and other organizations all around the world involved in space. A shared Moon observatory could take that a step farther.

Stanley Kubrick's incredible "2001: A Space Odyssey" of course is the film that does the best job of depicting a human presence on the Moon in the future.

Showing us all how science fictions films should be done, he really did his homework on what that future might look like putting that film really in a class by itself as far as its special effects - something that right there I think did a lot for our planet's collective science literacy.

I cant think of another science fiction film that has done anywhere near as well. Can anybody here think of one? Its especially impressive given the embryonic state of computer graphics at the time.

Still, he did a really good job of guessing what would be happening in his future world, using the very best resources and advice available to him at that time. He was a real master of the art.

It contains its great scenes of the huge space station which in the movie appears to be a shared international project, although the bases on the Moon seem to be built by nations.

Clearly, Kubrick also put a lot of thought into the subtleties of politics in space in the future world he created. Really, its a masterpiece in every possible way. It still takes my breath away to see it. I've watched it dozens of times.


-----

Also, when I've found stuff on the Chinese space missions, like their live spacewalk a few years ago, I have to admit I was literally crying with joy. I would really like to see much more cooperation between the world's countries in space.

China's use of the Soyuz capsule makes sense as it has a good safety record and it also means their SVs should be compatible/interoperable with the ISS.







 
Title: Re: China just landed a probe on the far side of the moon!
Post by: EEVblog on January 06, 2019, 01:38:25 pm
The idea of a radio observatory on the dark side of the Moon where the Earth's radio signals and even it's light are not present, is really interesting to me. 

Some amazing science can be done on the far side of the moon, and I think this could/should be a real compelling reason to have an initial permanent scientific colony on the moon.

Quote
Maybe one of the most interesting things that I think we could achieve short term in space.

Trivial to do compared to the relative pipe dream of a colony on Mars.

Quote
The movie "2001: A Space Odyssey" of course is the film that does the best job of depicting a human presence on the Moon in the future.

I cannot wait for the Artemis movie to come out, this will be spectacular!
Title: Re: China just landed a probe on the far side of the moon!
Post by: coppercone2 on January 06, 2019, 06:31:42 pm
clearly you have not seen the adventures of pluto nash if you think the two thousand and one depiction of the moon is at all accurate.
Title: Re: China just landed a probe on the far side of the moon!
Post by: apis on January 06, 2019, 10:06:38 pm
It would be cool if the first moon base was an international project, but as things are developing it looks like it will most likely be Chinese. I hope they will let the rest of us come and visit. ^-^

https://www.youtube.com/watch?v=NtQkz0aRDe8 (https://www.youtube.com/watch?v=NtQkz0aRDe8)
Title: Re: China just landed a probe on the far side of the moon!
Post by: VK3DRB on January 07, 2019, 12:23:02 pm
Chang'e is a Chinese goddess. It seems a great irony these mission names are based on religious hocus pocus. Maybe the Chinese government copied NASA's moronic naming convention for its missions (Apollo, Mercury, Juno, Saturn, Thor). The names have nothing to do with common sense or science.

But the fact the Chinese got a probe in the far side and can relay data back to earth is a remarkable feat in anyone's language. For Apollo 8, there was a known roughly 50% chance it would end in disaster, and yet it the American media/govt televised it up front. The Chinese government said next to nothing in case Chang'e 3 failed. Therein lies one big difference between relative freedom in a democracy and thought control by a totalitarian state. So in one way the Chinese proletariat only got to enjoy part of the achievement.
Title: Re: China just landed a probe on the far side of the moon!
Post by: coppercone2 on January 07, 2019, 12:26:03 pm
would you rather see it named after communist officials... i think they did a bang on job on the name
Title: Re: China just landed a probe on the far side of the moon!
Post by: schmitt trigger on January 07, 2019, 06:42:06 pm

What will they find? 2001 Space Odyssey's Monolith?
 :-DD

Now seriously....radio telescope observation conditions, free from terrestrial noise, should be excellent.
Title: Re: China just landed a probe on the far side of the moon!
Post by: cdev on January 07, 2019, 06:44:18 pm
Despite the issues which have been discussed, I think its a very positive thing that they did this, I like the name and the mythical story behind it and think it makes sense, as it makes sense to all the Chinese Ive asked about it, and thats what counts as it is their accomplishment which they have every right to be very very proud of.

Its a very real accomplishment that speaks to how far they have come in a very short time.
as well as to all human progress and our shared potential.

So a toast! To the many scientists and workpeople who made it possible, to the Moon goddess Chang'e and her faithful white rabbit companion, and to many more successes in space for all the nations of the Earth and our human race.
Title: Re: China just landed a probe on the far side of the moon!
Post by: Rick Law on January 07, 2019, 07:45:19 pm
Yes. China is usually not shy to put these things on media if it knows the success rate is near 100%, such as launching a manned mission with all proven technology. After all, no one has ever landed on the back of the moon.

Technically, landing on the far side of the moon shouldn't be any more difficult than then ear side, right?
The far side would have a signal trip delay time, as it has to go through the repeater at the legrange point, but the descent would be automated in either case.

Not for the landing itself, but to find out how things went, they needed communication/relay satellite(s) since it happened on the dark side.

I think at least one of the relay satellite didn't work - the one build by HIT (Harbin(?) Institute of Technology) students.  But I couldn't find that article again to confirm...

Interesting things going on:

Chang’e 4 - That was the one that just landed - launcher was Long March 3B carrier rocket
Chang’e 5 - first sample-return (2kg lunar soil) mission with a moon rover and robotic arm to do the collection.  Planned launcher is/was Long March 5, but original date delayed due to the failure of the Long March 5 launcher.  Probably looking at some time in 2019 still.
Chang’e 6 - second sample-return mission, target launch 2020 also on Long March 5 if Chang’e 5 went according to plan.
Title: Re: China just landed a probe on the far side of the moon!
Post by: chris_leyson on January 07, 2019, 10:54:56 pm
This is the first serious attempt at low frequency radio astronomy outside of the ionosphere so we really don't know what we might hear. Karl Jansky at Bell Labs started it all off in 1931 whilst investigating sources of radio interference or static. He eventually categorized them into three types of static: nearby thunderstorms, distant thunderstorms, and a faint steady hiss of unknown origin. He spent over a year investigating the source of the third type of static and determined that the signal repeated on a cycle of 23 hours and 56 minutes, a sidereal day.
By comparing his observations with optical astronomical maps, Jansky concluded that the radiation was coming from the Milky Way and was strongest in the direction of the center of the galaxy. He published "Electrical disturbances apparently of extraterrestrial origin" in 1933, the astronomers didn't show much interest and Bell Labs wouldn't let him build a larger antenna, so that was it. He does however have a unit of spectral flux density named after him, 1Jy = 10-26W/(m2.Hz). So that's how radio astronomy got started, so when any science gets published the results will probably be in Janskys, they usually are.

Radboud University Radio Lab and ASTRON might be two useful sources when anything is published.

https://www.ru.nl/astrophysics/research/radboud-radio-lab-0/ (https://www.ru.nl/astrophysics/research/radboud-radio-lab-0/)
https://www.astron.nl/r-d-laboratory/ncle/netherlands-china-low-frequency-explorer-ncle (https://www.astron.nl/r-d-laboratory/ncle/netherlands-china-low-frequency-explorer-ncle)

BTW. Jansky's radio observations were done at 20.5MHz, so that's why went rabbiting on about Karl Jansky.

EDIT: According to the Earth Observation Portal website
"Two Chinese microsatellites, DSLWP -A and -B (Discovering the Sky at Longest Wavelengths Pathfinder), also referred to as Longjiang-1 and Longjiang-2, were launched with the Chang’e 4 relay mission to conduct astronomical observations from deep space (Selenocentric, elliptical orbit). The two microsatellites were developed by the Harbin Institute of Technology. Each microsatellite has a mass of 47 kg"
Longjiang-1 failed but Longjiang-2 reached orbit.

Also, according to the mission status on the eoportal website, "the three 5-meter antennas of the low-frequency radio spectrometer on the lander have fully spread out". Dated 5th January

https://directory.eoportal.org/web/eoportal/satellite-missions/c-missions/chang-e-4 (https://directory.eoportal.org/web/eoportal/satellite-missions/c-missions/chang-e-4)
Title: Re: China just landed a probe on the far side of the moon!
Post by: raptor1956 on January 08, 2019, 01:24:20 am
Those first sets of photos are very cool and I hope more are forthcoming.  The rover doesn't look to have much range and I doubt we'll see it venture more than a km from the landing spot, but, I hope I'm wrong and that things puts on some decent mileage. 

Is there a breakdown of the cameras and other scientific equipment on the rover and lander -- it would be nice to know what the potential is?


Brian
Title: Re: China just landed a probe on the far side of the moon!
Post by: raptor1956 on January 11, 2019, 09:20:35 pm
Well Scott Manley just linked a video of the landing -- very nice...

https://www.youtube.com/watch?v=tI_feE6r-Oc (https://www.youtube.com/watch?v=tI_feE6r-Oc)

It would be nice to see some data overlay for vertical and horizontal velocity, radar altitude, fuel quantity, thrust setting, etc, but the video is pretty decent.


Brian
Title: Re: China just landed a probe on the far side of the moon!
Post by: BrianHG on January 11, 2019, 09:39:53 pm
Industrializing the moon:
https://youtu.be/bGcvv3683Os
Title: Re: China just landed a probe on the far side of the moon!
Post by: Electro Detective on January 11, 2019, 11:17:56 pm

It looks a bit suss... 

OneHungLow backers planning to build factories up there to employ very cheaper 6 armed alien child labour?  >:D

Good news for us > Aneng multimeters "Made In Moon"  :-DMM 

cheaper by the dozen...   :clap:

Title: Re: China just landed a probe on the far side of the moon!
Post by: Mr. Scram on January 11, 2019, 11:21:31 pm

It looks a bit suss... 

OneHungLow backers planning to build factories up there to employ very cheaper 6 armed alien child labour?  >:D

Good news for us > Aneng multimeters "Made In Moon"  :-DMM 

cheaper by the dozen...   :clap:
What looks "suss"?
Title: Re: China just landed a probe on the far side of the moon!
Post by: apis on January 11, 2019, 11:23:50 pm
I have no idea if you can make a bomb out of only 3He. But they would have to mine it first. And I believe all space nations, like China, already have fusion bombs so it wouldn't really change anything. I hope China builds a moon base though, and that it makes the US so paranoid that they also want one. It might just be enough to start another space race. :)

cheaper by the dozen...   :clap:
You are going to be very disappointed if you think that is how it works.
Title: Re: China just landed a probe on the far side of the moon!
Post by: coppercone2 on January 11, 2019, 11:37:39 pm
how do you trigger the fusion reaction with a fission reaction?

don't you still need insane pressures?
Title: Re: China just landed a probe on the far side of the moon!
Post by: apis on January 11, 2019, 11:47:51 pm
The firs tone is mutual destruction and can only be used as a token force. The second is no more than an over powered conventional bomb.
But an opponent with nuclear weapons would still respond with fission-fusion bombs if they believed they were under attack, so you would end up with mutual destruction either way.
Title: Re: China just landed a probe on the far side of the moon!
Post by: coppercone2 on January 11, 2019, 11:55:05 pm
if you can make a pure fusion bomb (how?) won't it be very clean apart from neutron radiation causing some isotopes? Does it even make neutrons?

That decreases the whole 'radioactive zombie mutant cancer" problem that makes nuclear weapons distasteful and makes it more like a high explosive weapon.

Even if it made some neutron radiation, it should be safe to use in the atmosphere as a air defense weapon or ground shock weapon.

But how do you trigger a fusion reaction without a nuclear energy source? do you surround it by a grid of fusion reactors that are laser pumped or something?
Title: Re: China just landed a probe on the far side of the moon!
Post by: apis on January 12, 2019, 12:06:53 am
It's not only the radiation. They are not exactly precision weapons, they can wipe out entire cities which are inevitably full of civilians. So called weapons of mass destruction. Similar weapons that kill indiscriminately are also banned. Like chemical and biological weapons.

If they have both small yield and are very clean it might be considered a normal bomb, but in that case, you could also use a normal bomb for that, no?
Title: Re: China just landed a probe on the far side of the moon!
Post by: coppercone2 on January 12, 2019, 12:09:51 am
But an opponent with nuclear weapons would still respond with fission-fusion bombs if they believed they were under attack, so you would end up with mutual destruction either way.

Since it doesn't need a fission trigger, much lower yield can be achieved.
If a nuke has only yield of a few tens to a few hundreds tons, it will be a hard decision to retaliate back with real nukes.

how does it work without a fission trigger? Where do you get the activation energy from?
Title: Re: China just landed a probe on the far side of the moon!
Post by: coppercone2 on January 12, 2019, 12:23:19 am
i think you will get a hot spot that will change density and disrupt it unless its some how made very solid

i think you still want a sphere that has the entire surface fusion generating at the same time to ensure compression occurs and not some kind of blow out.

i think this is the basis of the tokamek or whatever. i don't think you will fit it in something smaller then a cruise ship.

i think a mechanical wave would need to be coincident on the entire surface. so sound is kind of out.

i don't know what 13.8MeV activation energy means in terms of stimulus though. A bomb would still need to go critical with internal energy transfer.
Title: Re: China just landed a probe on the far side of the moon!
Post by: coppercone2 on January 12, 2019, 12:45:03 am
i do wonder though if you can make a giant laser that can trigger even a small fusion reaction could be used for something like safe lunar blasting for project development. if you shoot it into a bore hole from far away.

So you don't need drilling machines or chemical explosives which are unsafe.
Title: Re: China just landed a probe on the far side of the moon!
Post by: apis on January 12, 2019, 01:19:40 am
Wouldn't that mean you had created a fusion power reactor?
Kind of like they are trying to do at the national ignition facility:
https://www.youtube.com/watch?v=yixhyPN0r3g (https://www.youtube.com/watch?v=yixhyPN0r3g)
Title: Re: China just landed a probe on the far side of the moon!
Post by: coppercone2 on January 12, 2019, 01:42:45 am
read the wikipedia article about pure fusion weapons

there are claims made. i think the weapon is easier because you dont need to save the heat etc. it would be nice for blasting on the moon you can move alot of material quickly.
Title: Re: China just landed a probe on the far side of the moon!
Post by: cdev on January 12, 2019, 05:11:12 am
A guy in Brooklyn was building a polywell, and he had it working. DIY nuclear fusion. Some people in Sydney at ANU are working on one too.

----

re weapons, a few years ago (2010) North Korea claimed to have detonated a hydrogen device as part of a peaceful power program that claimed to harness the "energy of the sun" on the day considered to be Kim Il Sung's (which means sun) birthday. (May 12) Everybody dismissed it but two independent experts in two separate fields, seismology and nuclear isotope detection both reported incidents that could possibly have been referring to the same event at the DPRK's nuclear test site, at the same time.

So there is a small but real chance something actually happened.
Title: Re: China just landed a probe on the far side of the moon!
Post by: cdev on January 12, 2019, 05:31:12 am
Well the polywell did glow with that unearthly light in photos I saw..
Title: Re: China just landed a probe on the far side of the moon!
Post by: coppercone2 on January 12, 2019, 05:35:45 am
if it even worked in a small scale it would be retarded not to blow it up in a big copper boiler as a cheap energy source, they wanted to do this with nukes for chirsts sake, the only big problem was radiation.

You use it to heat metal or melt salts or whatever to make steam or hot water. if it was in brooklyn he would have sold it to con-ed to heat apartments. thats the only thing someone would do with a nuclear generator in brooklyn, heating systems.

its BS. if a non radioactive cheap bomb worked it would be blown up in over sized water tanks with expansion baffles to heat water cheaply.

i will cut my underware up into little squares and eat it if some kind of useful fusion reactor came out of brooklyn
Title: Re: China just landed a probe on the far side of the moon!
Post by: coppercone2 on January 12, 2019, 05:44:57 am
how much would you save in nuclear regulation radiation release emergency response, litigation, regulations compliance, etc?

they would turn detroit into a optics factory and mass produce it. no one likes heavy radioactive isotopes. optics and grinding stuff is all freaking sand, its only expensive because we dont need it. economics of scale could make it disposable. you could hire a guy for 15$ an hour to watch over a machine grinding 10000 of them at a time in a factory that has 5000 of them.

zeiss is only expensive because no one wants it. world won't benefit from lens systems atm. unless its like boron nitride ceramics are basically a scam right now, all the tools used to make them suck in terms of output. if there was a use for them there would be a giant machine cranking out metrology grade glassware like rieces pieces.

someone would set up a row of like 50 different laps with different grits with ultrasonic cleaners and washing machines and laser measurements with robotic arms so your not grinding the same shit in the same goo for 3 days.

Grinding engineering is like in a barely alive state right now. You know with a surface grinder you can buy like 5 different wheels, buy 5 grinders and get a job done super quick. Instead you 'redress' the same grit wheel and mess with speeds and feeds so you can do the same job with 1 machine and 1 disk with some greybeard that figured out the tuning in his head. You can continuously sharpen a wheel and laser measure it while its running to speed things up, but none of it will make sense when you need to make a few military optics and some 4000$ cameras. No point in making cheap grinding wheels either.

Its not like they don't know how to make it super cheap, I don't think that there are even any real engineering problems, its just no demand. Same thing for laps and hones. If they had a tight spec you can make the machines to keep an aggressive precision machining speed going and get the stuff you need real fast.
Title: Re: China just landed a probe on the far side of the moon!
Post by: apis on January 12, 2019, 06:16:16 am
Well the polywell did glow with that unearthly light in photos I saw..
Creating fusion isn't that hard, you can do it DIY it in a garage. The trick is to get more energy out than you put in. Last thing I heard about polywells is they needed to build bigger and bigger test reactors to get more data. DARPA funded it for a while but apparently didn't find it promising enough to continue.

Same as with tokamaks basically, although it's tokamaks that gets all the money, probably because they are best understood and are the most promising. But even if someone manages to create sustained fusion (with net positive output), there are lots of unsolved problems, like how do you build a tokamak that can survive heavy neutron bombardment long enough for it to be economical.
Title: Re: China just landed a probe on the far side of the moon!
Post by: coppercone2 on January 12, 2019, 07:01:33 am
when it comes to fine finishing, did anyone here ever encounter 'sandpaper wizards' before?

some people can some how sort their used random grit sand paper in a way to do decent finishes all using various grades of the same worn paper. Then you get some kind of semi-used sand paper storage stack going.

same thing with used brillo pads.

all those tools that ware down end up being sorted by some kind of mastermind.. but you try to work in that kind of system and your scratching your head all pissed off (why not just spend 2$ on fucking different grits of sand paper instead of learning all that crazy shit)?\

thats what i mean with fine work. you get freaking masterminds figuring out how to save small sums of money at the expense of sanity/time. you end up with a nice finish but it takes 5 times longer, but some how you end up with a guy getting 600 grit finish using worn 60 grit.......

to me its like washing toilet paper. the worst part clueless people start doing it without thinking why? (like myself at first when it came to MOST angle grinder things, there is literally insane advice online about using grinders). then once in a while you get a snippet of truth and it feels like someone pulled a scab off your ear.

with trade stuff , you see some kind of hyper-greedy strategy being implemented and you think some professional might crucify you for doing the intermediate steps that cost a little bit..........

then your like dude, im not in a fucking russian prison cut the bullshit. you don't need to cook the french fries in ear wax and sebum in a old light bulb anymore.
Title: Re: China just landed a probe on the far side of the moon!
Post by: JPortici on January 15, 2019, 09:14:10 pm
And now on the news... china has planted the first plant on the moon. Wow. My eyes are filled with wonder :)

https://youtu.be/qaM80BjvLuA
Title: Re: China just landed a probe on the far side of the moon!
Post by: sainbablo on January 16, 2019, 04:16:10 pm
Can you please leave the politics off the forum.




It is  time for EEVblog  to create  a  separate page with suitable  heading to cater for posts  having  political over tones which
are  unavoidable and are relevant while  highlighting  impact of technological advances internationally.

sainbablo.
Title: Re: China just landed a probe on the far side of the moon!
Post by: cdev on January 17, 2019, 05:37:30 am
i will cut my underware up into little squares and eat it if some kind of useful fusion reactor came out of brooklyn

https://gizmodo.com/5570817/no-sleep-til-fusion (https://gizmodo.com/5570817/no-sleep-til-fusion)

https://scienceline.org/2010/06/amateur-fusioneer-hopes-to-build-polywell/ (https://scienceline.org/2010/06/amateur-fusioneer-hopes-to-build-polywell/)

"After I achieved fusion, I bought a kit to learn about electronics -- I still don't know everything I should."

https://www.youtube.com/watch?v=Jvkoklpubiw (https://www.youtube.com/watch?v=Jvkoklpubiw)

Here is his web page...

https://prometheusfusionperfection.com (https://prometheusfusionperfection.com)

Last I heard he was giving up.

 :--

But a group at a university in Sydney is working on a similar device...

 :-+
Title: Re: China just landed a probe on the far side of the moon!
Post by: apis on January 17, 2019, 08:11:29 am
Here is his web page...

https://prometheusfusionperfection.com (https://prometheusfusionperfection.com)

Last I heard he was giving up.

 :--
Wired is run by a bunch of fools. Yeah, he gave up (less than?) a year later after concluding it would cost him at lest $0.2 billion to continue. He didn't do anything except play around with some expensive toys (good for him), certainly not anything that hadn't already been done by Bussard.

A polywell is a very long shot at best but since the benefits would be enormous, just like the tokamak, it might be worth investigating. And the polywell has been investigated for over a decade now without much success.
https://en.wikipedia.org/wiki/Polywell

Would make more sense to put all that money into improving atomic energy concepts that have already been proven, like fission reactors for example.