[HN Gopher] China on Mars: Zhurong rover returns first pictures
___________________________________________________________________
China on Mars: Zhurong rover returns first pictures
Author : leemailll
Score : 221 points
Date : 2021-05-19 12:21 UTC (10 hours ago)
(HTM) web link (www.bbc.com)
(TXT) w3m dump (www.bbc.com)
| aphextron wrote:
| I thought this looked familiar https://youtu.be/0L01FxuRBZY?t=11
| spaetzleesser wrote:
| Does anybody know how these are reported in chinese media? NASA
| makes a huge effort to publish their stuff in the western world
| and you don't hear much about china. Is it the opposite from
| inside China?
| markus_zhang wrote:
| As a Chinese I know that the government doesn't publicize such
| things very often, even in Chinese. Medias are not really
| professional enough to do these kinds of reports either. Most
| reporters simply do not have enough science and tech background
| to even ask good questions. If you know Chinese and listen to
| the live reports you can feel it.
|
| Things might turn around for the next decade when more young
| people who are motivated by these missions get into the fields
| (both R&D and media). But again I won't expect a lot of English
| reports. There will be some in the English channels such as
| CGTV.
| Dah00n wrote:
| I don't think you can get an unbiased reply on this topic on HN
| unfortunately (or any other SoMe site). You can look at
| CNSA.gov.cn yourself though and make up your own mind :)
|
| English site: http://www.cnsa.gov.cn/english/index.html
| HDMI_Cable wrote:
| > (or any other SoMe site)
|
| What does SoMe mean?
| the-dude wrote:
| My guess : Social Media.
| spicyramen wrote:
| I never heard this either. Please just use social media
| tablespoon wrote:
| > I never heard this either. Please just use social media
|
| I agree. It's also impossible to Google, since that
| acronym is also a common word.
| Dah00n wrote:
| Sorry about that. Social media :)
| HDMI_Cable wrote:
| Oh no problem. I thought it was a place name, like SoCal
| for Southern California or Soho.
| canada2us wrote:
| There is a YouTube channel from New China News Agency. It's the
| Reuters in China. You can find quite a few videos on the Mars
| rover.
|
| https://www.youtube.com/c/ChinaViewTV/videos
| qiqing wrote:
| My dad sends me articles about it on WeChat all the time, but I
| have difficulty reading it since my Chinese reading
| comprehension is barely at a 3rd grade level. They do make a
| big deal about it and it gets lots of coverage.
| dumb1224 wrote:
| There are a lot of posts indeed circulating on my Wechat
| timeline so it is quite well covered.
|
| Out of interest what is 3rd grade level Chinese reading? I'm
| curious to know what kind of grading is that?
| simonh wrote:
| They were very low key about it right up until it landed, then
| once they were sure it was ok they hit the domestic media
| pretty hard. Scenes of mission controllers hugging (somewhat
| awkwardly), group shots of the mission team with dramatic
| backdrop images, etc.
|
| I can understand they were concerned about the risk of a
| problem, landing anything on Mars is hard. ESA has failed twice
| now, and historically about half of all missions to Mars have
| crapped out. It's a genuinely impressive achievement, for all
| the sour grapes about stealing US tech, actually implementing
| this stuff and following through like this is no cakewalk.
|
| I suspect this will be pointed to as the moment China pulled
| ahead of Russia in space technology. Yes Russia has more
| achievements under it's belt, but most of that was over a
| generation ago. In terms of current capabilities I think this
| is really significant.
| DiogenesKynikos wrote:
| Here are a few videos from Chinese media, well before the
| landing. You can judge for yourself:
|
| * January 2021: https://youtu.be/HaZOfZYOLgU
|
| * February 2021: https://youtu.be/rBhVaihkDvc
| evidencebased wrote:
| The launch of the Tianhe core module was live streamed on
| Tiktok and possibly other outlets. Not sure about this one
| though.
| ch4s3 wrote:
| Good for them. It's great to see space exploration picking up
| outside of our efforts in the US. I would be great if we could
| cooperate more upfront, but the more people around the world that
| know how to land a payload on another planet the better. That
| kind of applied science and engineering is really valuable.
| mygoodaccount wrote:
| I expect this post won't garner the same attention here. I wonder
| why that might be.
| sho_hn wrote:
| While I know what you mean (and it's true to some extent), I
| think the media strategy and of course lang sphere barrier are
| factors. With the American Mars landing it's a big live event
| with the landing time known down to the second in advance,
| designed to generate a lot of momentous excitement. The Chinese
| space programme tends to release information more sparingly and
| after the fact.
|
| I'd actually love to know more about this from a good English
| source (unfortunately I haven't taken the time to study
| Mandarin), really. Especially the engineering - it's been a
| while since we had two distinct tech stacks on the Red Planet,
| it'd be cool to compare and contrast.
| jacquesm wrote:
| Part of that is because a lot of space activity in the West
| is competing for public funding and so you get a huge amount
| of publicity around any event to ensure that the public sees
| where its money goes. A plan economy doesn't really have that
| problem, publicity is an afterthought and if it has value
| that is more on the international stage (so when it is
| successful) then nationally, where it is welcome but not a
| necessity.
|
| So that's why you'll see the accent on success rather than on
| activity.
| Dah00n wrote:
| The official site of CNSA is available in English:
|
| http://www.cnsa.gov.cn/english/index.html
| BelenusMordred wrote:
| Another pic: https://imgur.com/Vct0PXV
|
| It's an interesting design, in someways the ramp is a deceptively
| simple concept but I'm not sure if it's safer than the US
| approach.
|
| Some other neat things are:
|
| Solar panels, they are a specially designed to electrically repel
| Martian dust, in theory there should be a decent power gain from
| this and it will likely be used in future missions. While other
| rovers fortuitously found solar was self cleaning on Mars, power
| is still a knife-edge engineering problem for rovers.
|
| Ground penetrating radar, can see down 100m, a lot further than
| anyone else has ever investigated, should yield some interesting
| data. Like most other missions they are very interested in prior
| and current water on the planet.
|
| Coverage, they are planning a few hundred metres over 3 months,
| the rover itself can do 200m in a day though if needed, very
| unlikely that will happen but it is in a flat area of Mars. The
| landing zone was so huge that there'll be some tough choices
| about what is the most productive area to explore for planetary
| science.
|
| The speed of entry, Zhurong came in at about half the speed of
| Perseverance, this makes life a lot easier. It takes a lot longer
| to bleed off that velocity in orbit but seems like other nations
| attempting a landing will follow this path.
|
| I'd be interested to know about their uplink, remember hearing
| they might be using an ESA orbiter but not sure about that, the
| orbiter they have is not that great for a connection due to it's
| altitude.
|
| Technical info is surprisingly hard to find, even in publications
| like nature or science mags normally focused more on the details.
| tectonic wrote:
| Do you have a reference for the electrically-repelling solar
| panels? They sound fascinating.
| toothpickguy wrote:
| Not original commenter, but here are some relevant papers
| that should have publicly available pdfs if you search for
| them on Google Scholar:
|
| Landis, G. A. (1998). Mars dust-removal technology. Journal
| of Propulsion and Power, 14(1), 126-128.
|
| Kawamoto, H., & Shibata, T. (2015). Electrostatic cleaning
| system for removal of sand from solar panels. Journal of
| Electrostatics, 73, 65-70.
|
| Saravanan, V. S., & Darvekar, S. K. (2018). Solar
| Photovoltaic panels cleaning methods: A Review. Int. J. Pure
| Appl. Math, 118, 1-17.
| samcheng wrote:
| Reading the last names of the authors of these publications
| is refreshing, particularly in contrast to the often
| nationalistic comments that have peppered discussion of
| this rover.
|
| Maybe the future is brighter than we think!
| bgee wrote:
| Care to elaborate why you think the comments on this
| rover are nationalistic? Or, do you feel the same way
| about comments regarding NASA or JAXA achievements?
|
| Disclaimer: I'm a China/Chinese national.
| tectonic wrote:
| I haven't been able to find any evidence supporting this
| claim.
|
| https://www.nytimes.com/2021/05/14/science/china-mars.html
| says, for example:
|
| > Days after the touchdown, the rover will roll off the
| lander. Like Spirit and Opportunity, Zhurong will be powered
| by solar panels, which are retractable so that it can
| periodically shake off any accumulated dust.
|
| I'd love to learn more.
| giantrobot wrote:
| I don't think the technical data being hard to find is that
| surprising. China has a pattern of not talking about their
| space missions unless they go well. Since they control their
| press the party only ever gets good press. It's also worth
| noting that the CNSA is _not_ a civilian agency like NASA or
| the ESA. It 's a military agency and treats programs as if
| they're secret military projects.
| neither_color wrote:
| >China has a pattern of not talking about their space
| missions unless they go well
|
| Not only space. This is the reason it always feels like the
| west is collapsing while Chinese hegemony is inevitable.
| Western news outlets publish hyper-critical editorials about
| western governments that wouldn't be allowed on state run
| media in the east.
| pasabagi wrote:
| This is totally simplistic. If you think western
| journalists are incentivised to criticize basic societal
| norms and systemic problems, I have a bridge to sell you.
| I'm also not sure where you're getting these 'hyper-
| critical' editorials from - where I come from, nearly 150
| thousand people just died in a pandemic, and the media has
| barely said a critical word.
|
| Obviously, in China, they are allowed to criticize even
| less, but _westerners do not read chinese news_.
|
| What's more, nor does anybody else.
|
| So the image of China doing very well is not for a lack of
| bad press. If you read publications about China over the
| last decade or so, it's a constant slew of doomsaying, and
| negativity, mostly about problems that turned out to be
| very surmountable or insubstantial.
|
| The image of China becoming more and more hegemonic is
| simple: look at their economic growth. Look at the size of
| the nation. Look at their intellectual culture. China being
| a very powerful country is a return to a historical norm,
| and is a totally reasonable development given how big their
| population is, how skilled it is, and its values.
|
| Meanwhile, the west is seen as falling apart because it is
| having a massive identity crisis which involved things like
| the leader of the free world bragging about how big his
| nukes were on Twitter.
|
| I'm not frankly particularly enthusiastic about China as a
| world power - I'm not a fan of confucianism, for example,
| and CCP spokespeople talk like politicians from dystopian
| sci-fi, but I think it's profoundly wrong to think China is
| deceiving the world with its masterful press controls. Far
| from it - the direct censorship and press controls are very
| blunt mechanisms most states have given up on because _they
| don 't work_ and if you're good at media, _you don 't need
| them anyway_.
| cromwellian wrote:
| China was never really a world power, even at its height.
| Look back at Western history: Alexander the Great, the
| Roman Empire, the British Empire, or the Mongols, or
| further back, the Xiongnu. Han China mostly stayed
| confined to its own self imposed borders, with the
| exception of the acquisition of Xinjiang and the Tibetan
| plateau, and some voyages by Zheng He.
|
| I guess what I'm saying is, if China becomes a hegemonic
| power, it won't be militarily, it'll be economically,
| sort of like monopolies/oligopolies today, and those
| kinds of powers can be resisted much more easily by soft
| power methods.
|
| The economic growth argument fails to impress it. Every
| nation that goes through an agrarian->industrial
| conversion experiences huge economic growth until they
| transition to a developed service sector economy.
|
| Much is made about Chinese infrastructure building, but
| did you ever look at what was done by FDR under the New
| Deal? 1 million kilometers of roads built. 10,000
| bridges. 40,000 schools. etc. The Tennessee Valley
| Authority built tens of thousands of miles of electric
| grid. Or take progress in the Space Program of China. It
| looks impressive, but Von Braun founded the US rocket
| program in 1945, and NASA was founded in 1958. 11 years
| later, there were men standing on the moon.
|
| Things only look fast now, because developed Western
| economies have settled into long term 2-3% service
| oriented economy growth. With China's declining birth
| rate, rising cost of living and wages, it too will
| experience a slowdown.
| hnnnnnnng wrote:
| Go read the book manufacturing consent.
| seryoiupfurds wrote:
| Case in point, would that book have been published if all
| publishers were ideologically controlled by the state?
| qiqing wrote:
| Here's a video from Chinese TV in Feb before the landing that
| someone else posted in this thread:
| https://www.youtube.com/watch?v=rBhVaihkDvc
|
| I realize it doesn't have English subtitles, so I'll
| summarize some highlights of what's in there:
|
| * interviews with scientists and engineers working on the
| project
|
| * trajectory of the spacecraft and lots of talk about the
| challenges of reducing velocity for landing
|
| * historical overview and context for why Mars exploration is
| important for science
|
| * what to expect in the future landing and when it'll happen
|
| It's pretty similar to video programs that NASA produces. Not
| sure what information you're expecting that isn't out there,
| but I think you're attributing to secrecy what is more easily
| attributable to people not translating open public reports
| into English.
| mturmon wrote:
| Here's a technical review of the (engineering, not science)
| imaging system for Perseverance, published in November 2000
| before a touchdown in February 2021:
|
| https://link.springer.com/article/10.1007/s11214-020-00765-
| 9
|
| Here's the process for how the landing site was selected:
|
| https://mars.nasa.gov/mars2020/mission/science/for-
| scientist...
|
| I think this is more open than the Zhurong information has
| been, but I'd be happy to learn more.
| eunos wrote:
| CNSA is under MIIT (Ministry of Industry and Information
| Technology) not PLA.
| vkou wrote:
| > It's also worth noting that the CNSA is not a civilian
| agency like NASA or the ESA
|
| Given how many classified Shuttle missions[1] took place over
| the decades it was in service, and how the Hubble Space
| Telescope was likely a clone of a spy satellite, I don't
| think it's fair to say that NASA is entirely a civilian
| agency.
|
| [1] https://www.space.com/34522-secret-shuttle-missions.html
| justicezyx wrote:
| > CNSA is not a cilivllian agency
|
| Look at Wikipedia: CNSA is under the jurisdiction Ministry of
| Industry and Information Technology (Gong Xin Bu ), which
| itself is a civilian department, at least not less so than US
| department of energy.
|
| What's the proof for your claim that CNSA is not a civilian
| agency?
| lacksconfidence wrote:
| I am no expert in china, I don't know what exactly it
| means. But if my country had a "State Administration for
| Science, Technology and Industry for National Defense", and
| the national space adminstration reported to them, i would
| assume the national defense was military.
| mytailorisrich wrote:
| > _It 's an interesting design, in som eways the ramp is a
| deceptively simple concept but I'm not sure if it's safer than
| the US approach._
|
| It's the 'standard' way as far as I know (see Path
| Finder/Sojourner for instance).
|
| The 'sky crane' system used by the US is fairly new and, I
| guess, much more complex to pull off and more expensive. I
| think it was developed partly because the payload had become
| too big/heavy for the previous airbag system.
| someperson wrote:
| The ramp approach was used by the 1997 Sojourner rover:
| https://flickr.com/photos/rhubarble/268583624
| pkaye wrote:
| > It's an interesting design, in someways the ramp is a
| deceptively simple concept but I'm not sure if it's safer than
| the US approach.
|
| I think its closer to the Sojourner rover approach. It works
| fine for lower weight rovers but at higher weight you need a
| rocketpack or something.
| rtkwe wrote:
| The rocket backpack seems like it would allow you to land more
| weight than the lander an ramp method because you don't have a
| much superfluous structure on the rocket lander section of the
| craft. Zhurong is only about as big as Spirit and Opportunity
| that the US landed back in 2003 using big airbags, larger
| rovers can't do that so you get into more complex things like
| the sky crane.
| cromwellian wrote:
| The main problem with Zhurong is they brought their orbiter
| along with them. Since they can only launch 6000kg to trans-
| martian orbit, packaging the rover and orbiter together
| limits your rover.
|
| NASA launched its orbiters on separate missions, which means
| both the Orbiter and Rovers can be bigger without needing a
| ginormous launcher.
| danielvf wrote:
| Although the US rover program has made Mars look easy, it's been
| fiendishly failure prone for other space agencys
|
| Outside of one Russian lander working for 120 seconds after
| touchdown before failing, no nation outside the US has ever
| gotten a lander to work on Mars before.
|
| Have a look at the list of mars missions and see just how many
| failures there are:
|
| https://en.wikipedia.org/wiki/List_of_missions_to_Mars
| mlacks wrote:
| Has there been any discussion on "nations" on mars? I just always
| assumed Mars would have colonies like ISS spread around.
|
| I wonder if anyone is planning on marking territory
| bryananderson wrote:
| The Outer Space Treaty prohibits the claiming of territory in
| space or on other planetary bodies. This treaty is signed by
| all of the major spacefaring states. If states begin to extract
| resources or establish permanent habitation beyond scientific
| expeditions such as the ISS, the terms of this treaty will not
| be tenable. There is no magic solution to prevent states from
| being self-interested and claiming resources for themselves,
| but hopefully the resolution will be a new treaty which
| provides a framework for peaceful, fair, and sustainable
| development of space. Some self-enrichment can be allowed while
| also ensuring that some of the benefits flow to all of
| humanity. The alternative, if no such agreement can be reached
| between the spacefaring powers, is a free-for-all in which
| states withdraw from the OST and do whatever they want. This
| seems likely to lead to monopolization of the solar system's
| resources by a few states. It also seems likely to lead to
| confrontation between the spacefaring powers.
| mc32 wrote:
| they may need a treaty to resolve issues between private
| companies as well and not only nations give we are seeing
| more private enterprise enter spa(ce)tial frontier.
| coldcode wrote:
| What is the map projection called in that map from NASA?
| tantalor wrote:
| It basically looks like equirectangular and modified with
| pointy poles.
|
| https://en.wikipedia.org/wiki/Equirectangular_projection
|
| Maybe it is just regular equirectangular but the lines are
| drawn weird.
| DiogenesKynikos wrote:
| It's a completely standard Cartesian projection (x = longitude,
| y = latitude), but with nonsense graticules plotted on top. I
| think BBC took a NASA image of Mars and added their own
| graticules and landing-site labels. Compare the BBC image with
| these two NASA images:
|
| * BBC:
| https://ichef.bbci.co.uk/news/976/cpsprodpb/825B/production/...
|
| * NASA base map of Mars:
| https://astrobiology.nasa.gov/uploads/filer_public_thumbnail...
|
| * NASA landing sites:
| https://mars.nasa.gov/resources/24729/map-of-nasas-mars-land...
___________________________________________________________________
(page generated 2021-05-19 23:02 UTC)