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China lands Chang'e-4 on far side of Moon
- soheil 8y agoNice
- jackconnor 8y agoThe way they used the L2 point to lasso a relay satellite so they could transmit information from the rover on the far side is stunning too. This was really brilliant, China's space program has really become something.
- stcredzero 8y agoThe way they used the L2 point to lasso a relay satellite So confusing to put it that way. No one has caught anything with a rope or a cable, as far as I know. Basically, they are orbiting a relay satellite around the L2 Lagrange point so that the relay has line of sight with both the landing point and Earth. Obviously, if it just sat at L2, the moon would be in between the relay and the Earth. Orbiting around Lagrange points has been known about for a long time. If you want to cite something more recent and innovative pertaining to Lagrange points, astronomers, rocket scientists, and engineers have been working on fuel saving chaotic trajectories through the Lagrange points. Arguably, the fact that they are the first to implement the L2 halo does win the Chinese space agency some innovation points.
- auslander 8y ago> No one has caught anything with a rope or a cable, as far as I know Soo good to have an expert here, thanks!
- FigmentEngine 8y agoactually things can and have been caught. Space tethers have been succesful https://en.m.wikipedia.org/wiki/Space_tether_missions#TSS-1R_mission https://en.m.wikipedia.org/wiki/Space_tether_missions#TSS-1R...
- vidarh 8y agoYes, but not in this instance.
- stcredzero 8y agoactually things can and have been caught. Space tethers have been succesful Indeed, so a choice of words that indicates this was going on in this instance is all the more confusing.
- turbinerneiter 8y agoIsn't there a solar telescope around sun-earth L1?
- mkl 8y agoYes, more than one, in fact: https://en.wikipedia.org/wiki/Lagrangian_point#Spacecraft_at_Sun%E2%80%93Earth_L1 https://en.wikipedia.org/wiki/Lagrangian_point#Spacecraft_at...
- jackconnor 8y agoIf you read John Varley's Titan series or Neal Stephenson books like Seveneves they regularly call LaGrange points "L2", "L4", etc. I called it a lasso because, if you look at the diagram, it literally looks like a lasso.
- stcredzero 8y agoIf you read John Varley's Titan series or Neal Stephenson books like Seveneves they regularly call LaGrange points "L2", "L4", etc. Never got around to Titan. I really liked Seveneves. I think Sonar Taxlaw is the most perfect woman, next to my wife. Nothing wrong with referring to L2, L4, L5... I called it a lasso because, if you look at the diagram, it literally looks like a lasso. Arrgh! That would be like when my grade school teacher called the LEM the "moonwalker" because it looked like it could walk around on the moon.
- deleted 8y ago[deleted]
- 789body 8y agoThis comment threw me for a loop - "L2" and "lasso" triggered the pattern recognition in my head for "regression regularization" and it took a moment to realize the topic was still orbital dynamics. Come to think of it, saying "Lagrangian" wouldn't have prevented my confusion - not that there's anything wrong with the terminology in OP. I'm reminded of a passage in Cryptonomicon, which I've been rereading: "Newton wrote a *different* book, *also* called *Principia Mathematica*, which isn't *really* about mathematics at all; it's about what we would todaycall physics." "Then why did he call it Principia Mathematica?" "Because the distinction between mathematics and physics wasn't especially clear in Newton's day--" "Or maybe even in zis day," Rudy said.
- stcredzero 8y agoThis comment threw me for a loop - "L2" and "lasso" triggered the pattern recognition in my head for "regression regularization" and it took a moment to realize the topic was still orbital dynamics. Yeah. It's not the most apt choice of words.
- 789body 8y agoIt's a fine choice of words. It's just a coincidence.
- stcredzero 8y agoNo one is capturing anything with a rope or cable. It's a rotten choice of words.
- szappetx 8y agoFor what it's worth, I'm from Texas where I see actual lassos somewhat regularly, and I perfectly understood the phrasing here. Maybe it's just a regional difference in how the word "lasso" is understood.
- tome 8y agoOff topic: That quotation is a bit strange because the full title is "Philosophiæ Naturalis Principia Mathematica", or "Mathematical Principles of Natural Philosophy", which describes exactly what it is ("Natural Philosphy" basically being "science"). https://en.wikipedia.org/wiki/Philosophi%C3%A6_Naturalis_Principia_Mathematica https://en.wikipedia.org/wiki/Philosophi%C3%A6_Naturalis_Pri...
- phendrenad2 8y agoI know you don't mean to be patronizing, but this reads as patronizing.
- dang 8y ago"Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith." https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html
- SCAQTony 8y agoIt is known as radio repeating. Radio stations use them to boost their signals into new territories. Cell towers too. Radio repeating: "[It's]...a combination of a radio receiver and a radio transmitter that receives a signal and retransmits it, so that two-way radio signals can cover longer distances. A repeater sited at a high elevation can allow two mobile stations, otherwise out of line-of-sight propagation range of each other, to communicate. Repeaters are found in professional, commercial, and government mobile radio systems and also in amateur radio. ..."
- mediocrejoker 8y agoAlthough radio receivers on earth don't orbit la grange points.
- mturmon 8y agoThe use of a relay is something less than "stunning" and "brilliant". The use of relay satellites when ground stations do not have line-of-sight to the primary spacecraft (or, when you have reduced bandwidth or other restrictive conditions) is standard practice. This concept is used to relay telemetry from Mars landers, for instance.
- jackconnor 8y agoYou realize the words "stunning" and "brilliant" are subjective, right? Your "standard practice" here is both incredible AND the first time ever done in this scenario to achieve something brand new in space travel. Not sure why you need to tell people not to like things, but it's a really bad habit you should break.
- mturmon 8y agoI do like the notion of using a relay. In 1999, JPL lost Mars Polar Lander, and didn't have telemetry to know why. One of the major lessons learned from this loss was to always have telemetry of Entry, Descent, and Landing (EDL). This telemetry is usually provided by a relay. So despite the fact that we both like it, using relays is not new. (See sec. 5.1 of [1]: "The omission of EDL telemetry was justifiable from a project perspective. However, the loss of MPL without yielding any clues as to the cause of the loss jeopardized the potential for success of future Mars landers. Therefore, the decision was not justifiable in the context of MPL as one element of the ongoing Mars exploration program.") I like that they put it in an orbit about the Earth-Moon L2 point. I think it's the first such satellite there. [1] https://spaceflight.nasa.gov/spacenews/releases/2000/mpl/mpl_report_1.pdf https://spaceflight.nasa.gov/spacenews/releases/2000/mpl/mpl...
- mhandley 8y agoThis nicely explains the relay's orbit and the trajectory they took to get there: http://www.planetary.org/blogs/guest-blogs/2018/20180615-queqiao-orbit-explainer.html http://www.planetary.org/blogs/guest-blogs/2018/20180615-que...
- 8bitsrule 8y agoAlso interesting is the 'Dutch NCLE' project, which hitched a ride with the relay orbiter to study how hard it will be to do 'low-frequency' radio astronomy (esp. below 30MHz) from behind the moon. That may turn out to have more science value than establishing that the far side is old (just joshing ... a bit).
- A2017U1 8y agoCopying earlier comment: Wikipedia seems to say the rover mission duration is 3 months, yet the previous rover traveled for a year and transmitted a bit longer. The Chinese seemed quite coy about it failing last time (as with many things) so perhaps underpromising in this case? This all preparation for China's planned permanent radio telescope on the far side which would be a huge boon for astronomers by escaping Earth's EM interference. Also out left field is the 3kg "self sustaining" biosphere of silkworms and plants with a camera inside. Interested to see how long it survives.
- taneq 8y ago> Also out left field is the 3kg "self sustaining" biosphere of silkworms and plants with a camera inside. Interested to see how long it survives. Aw man, that's how you get giant mutant moonworms.
- stcredzero 8y agoThey should've added those to Iron Sky
- hyperpallium 8y agoWhere's that? I couldn't fimd it in the linked article. Sounds like Elon Musk's original idea for a greenhouse on Mars, to inspire via realtime cam. Is there any indication they'll have a public cam for it?
- taneq 8y agoIt wasn't in TFA, but here's a source: https://www.bbc.com/news/science-environment-46724727 https://www.bbc.com/news/science-environment-46724727 > The lander carries a 3kg (6.6lb) container with potato and arabidopsis plant seeds - as well as silkworm eggs - to perform biological studies. The "lunar mini biosphere" experiment was designed by 28 Chinese universities. (Source for the silkworms, at least. I must confess that giant mutant moonworms are only conjecture... for now...)
- arduanika 8y ago"...and if the dam breaks open many years too soon..." Perhaps interesting to note the origin of this name for spacecraft. The legend "Chang'e flies to the moon" (嫦娥奔月) lies behind the Mid-Autumn Festival (featuring mooncakes, as it were). Point is, the names of Chinese space missions are every bit as carefully steeped in tradition as, say, Mercury/Gemini/Apollo.
- tanilama 8y agoThe story behind Chang'e is also interesting. Essentially, she is the wife of a legendary hero, Hou Yi(后羿), who saved the mankind from dying of drought due to the presence of nine Suns, by shooting all but one of them down. Chang'e stole the Immortal Pill, and eat it alone without her husband knowing. After she ate it, her body became to float and she flied to the moon, to live there alone forever as her punishment, with only one rabbit being her companion. Sounds familiar? Yep I believe if you are a Naruto fan, you can make a lot of connections.
- dempseye 8y agoThe trisolarian plot in Cixin Liu's The Three Body Problem also seems to have borrowed from this myth.
- sthomas1618 8y agoHaving read (and enjoyed) that trilogy, I'm not making the connection. Which part?
- nitrogen 8y agoThere is a 3-star system that causes periodic droughts on a planet in the system based on which star(s) the planet's semi-stable orbit crosses.
- headsupftw 8y agoIn the novel, the three-body civilization would go extinct if there are two or three suns in the sky.
- datumy 8y agoamazing communication system.
- deleted 8y ago[deleted]
- golfer 8y agoFrom the NYT article [0] on the topic: "We Chinese people have done something that the Americans have not dared try.” -- someone associated with the Chinese space agency Why so insecure? Not a good look. [0] https://www.nytimes.com/2019/01/02/world/asia/china-change-4-moon.html https://www.nytimes.com/2019/01/02/world/asia/china-change-4...
- datumy 8y agoIt sounds like a flamebait from NYT. I would not bite.
- colordrops 8y agoAgreed. This professor didn't even work on the mission.
- seppin 8y agoWelcome to any discussion about China.
- XorNot 8y agoI'm pretty happy if China wants to throw shade at the US over space program accomplishments. I'd prefer a measuring contest over space accomplishments then building more earth-bound weapons systems.
- joejerryronnie 8y agoAnd how long before the space program accomplishments start looking just a little like space-based weapons systems. I’m sure Chinese military leadership can extrapolate as well as the Pentagon can.
- ageofwant 8y agoAs soon as possible. Man being man, we only seem to be able to accomplish things under threat of violence.
- 8y ago
- skilled 8y agoCan someone explain how are these types of devices safe from hackers? I mean, it talks back to the space agency, right? Just curious is all. Haven't seen anything related to this question.
- abhishekjha 8y agoWouldn’t the spread spectrum help in preventing any kind of interception?
- ggm 8y agoFeels like a state actor risk in the main. I can't think of a state actor without significant volumes of more attackable assets in earth orbit, and that's without considering their options for eg A one time cipher stream or other serious protection of the uplink signal. I doubt it's using open comms and a diginotarencrypt certificate.
- Rebelgecko 8y agoA lot of satellites and probes "back in the day" more or less depended on security through obscurity. You would need to know what frequency (or frequencies) to use, and how to encode the commands. Your ground station also needs a bigass antenna, and a good idea of where to point it. Now most if not all satellites use encryption and/or authentication for command and control, but I wouldn't be surprised if some space programs don't bother. With something like the New Horizons, why waste precious CPU cycles with encryption/decryption when it takes such a tremendous effort to communicate with it. The Deep Space Network costs something upwards of $1,000/hour, and requires huge dishes and lots of land.
- skilled 8y agoAwesome, great to know. Didn't know about the DSN so going to read upon that.
- ohitsdom 8y agoFor others that might not have seen it, there's a cool live dashboard of the DSN so you can see which spacecraft are currently transmitting: https://eyes.nasa.gov/dsn/dsn.html https://eyes.nasa.gov/dsn/dsn.html
- jetison_out_to_ 8y agoNoticed this is the same day as NASA got the Ultima-Thule photos. Was this announced today to overshadow it, like how Uber announced their IPO basically a day after Lyft's? Want to avoid going off about conspiracy theories or who's more patriotic, just curious how the announcements actually lined up. This (wikipedia-sourced) AP wire from Oct 22, 2015 when the Pluto flyby happened said they had re-pointed the probe for this flyby, scheduled for Jan 1, 2019, which it did exactly that. So we knew at least 3 years ago the exact date of Ultima-Thule -- spacework requires very good precision*. http://apnews.excite.com/article/20151022/us-sci--pluto-next_stop-3b1bf3f8fc.html http://apnews.excite.com/article/20151022/us-sci--pluto-next... The Chang'e 4 wikipedia page says it was launched Dec 7, 2018, only about a month ago. So I get launches are well-planned in advance so wheels have been spinning a long time there too, but even so, they clearly must have known the two events would occur right around the same time, the Chinese one just a day or two after the American one. Is this what a space race feels like?
- adventured 8y ago> Is this what a space race feels like? No. New Horizons capturing Ultima Thule is not a large enough event to warrant the Chinese feeling like they need to compete with it. Spectator wise, it's a nice event for anyone that likes astronomy. It will be ignored by most of the people on the planet, just as the Chinese landing on the far side of the moon will be. These are not seminal moments in space history.
- deleted 8y ago[deleted]
- isostatic 8y agoNew Horizons was the most read story on bbc yesterday morning. China’s landing is today. It’s no Sputnik or Gagarin or Apollo, but experts at Nasa as "a first for humanity and an impressive accomplishment".
- computerex 8y ago> These are not seminal moments in space history. Intercepting a 20 km object in the Kuiper Belt, the farthest body ever explored by mankind, isn't seminal? This also happens to be the first encounter with a planetesimal. It gives us a unique window into planetary formation. This is a very huge accomplishment.
- deleted 8y ago[deleted]
- dbcooper 8y agoHopefully they find some carbon in the crust. Only traces have been found so far on the moon.
- computerex 8y agoSorry for my ignorance, but what's the significance of carbon in the crust?
- thecanman 8y agoMost important building block of life
- computerex 8y agoUnfortunately the likelihood of life on Moon is next to nothing (if that's what you are implying by carbon). Remember, we have some ~900 lbs of moon rock we brought back with Apollo that we have studied. By all accounts the moon is just a dead ball of dust. There isn't even tectonic activity. The little water is trapped as frozen ice in rocks. No atmosphere means constant bombardment by radiation and temperature differentials are in hundreds of degrees. It's as inhospitable as it gets.
- BattyMilk 8y agoApologies in advance for the (hopefully not) stupid questions from a layperson... How constant is the L2 point for the relay satellite's orbit? If I understand correctly, this is the "balance" point between the earth and sun's gravity. Does the moon's gravity affect this? If so the L2 point will shift as the moon moves towards and away from this point? As the moon orbits the earth, presumably the relay satellite would stay put and not follow the moon in its orbit. This would mean that communication from the lander and rover to the satellite is only possible when the moon is in a particular position (between the earth and the sun), correct?
- juloo 8y agoIt's the L2 point in the earth-moon system, it is different from the earth-sun L2 point. And yes, the satellite follow the moon in its orbit, the point in the L2 point.
- mkl 8y agoThe L2 point that the satellite is orbiting is a Lagrange point [1], a place where the gravity (edit: and centrifugal forces) of the Earth and the moon balance. L2 follows the moon as the moon orbits, because the moon is what makes it exist. [1] https://en.wikipedia.org/wiki/Lagrangian_point https://en.wikipedia.org/wiki/Lagrangian_point
- 0nce 8y agoLagrange points are found near any couple of large bodies. They are points where a smaller object will maintain its position relative to the large orbiting bodies. The Chinese relay satellite is orbiting the L2 point of the Earth-Moon system. That is beyond the Moon on a line which goes from Earth to Moon. Hence, this L2 point orbits the Earth like the Moon does, and the whole system orbits the Sun as well. Now if the spacecraft would be exactly at that point, the Moon would be blocking communications between the probe and Earth antennas. So instead, it follows a halo orbit which is quite stable around that point, but goes over the Moon horizon so that there is always a direct line of sight between Earth and the spacecraft. Not a stupid question at all !
- 8y ago
- erikb 8y agoAnd until now nobody is complaining how this moon landing was fake because Jim Bridenstine used a 3D simulation instead of a photo. I'm impressed.
- ForrestN 8y agoTo what extent is this impressive feat and the global praise of it contributing to the repressive, genocidal government's hold on power?
- valgor 8y agoI was really surprised to see an article on HN about China that wasn't full of ignorant hate and racism in both the article and in the comments, but then down and the very bottom is your sole lonely comment. Stay true, freedom fighter.
- ForrestN 8y agoYes—you clearly misjudged HN culture! Asking a question with a whiff of human rights concerns in the face of scientific neatness generally gets the sort of mild, banal techno-libertarian backlash those of us who've been here a while expect. "Don't bother my fascination with worries about concentration camps! That's... racist!"
- ryanqian 8y agoGood point :)
- ForrestN 8y agoOr not :(
- tikumo 8y agoThe dark side of the moon, perhaps the perfect place for a big telescope?
- deleted 8y ago[deleted]
- GraemeL 8y agoThe far side of the moon isn't dark. It has the same day/night cycle that causes the phases of the moon visible from Earth. On the other hand, it is shielded from radio emissions from Earth and might be a good place for a radio-telescope.
- aflag 8y agoSurely it's darker than the earth facing side. I'm no rocket scientist, but I reckon at least some of the light the sun sends our way gets reflected. From experience, a moonless night sure feels darker than when the full moon is up.
- GraemeL 8y agoYou're probably correct, but I also have know idea how much of a difference it would make. One other advantage would also be the lack of atmospheric scattering, but they have made huge strides with adaptive optics so it might not be worth the extra cost of getting all the components to the Moon and assembling them. You would also be limited by how close you could point the telescope to the Sun when it's in the sky. I think Hubble isn't allowed to point closer than 50 degrees for fear of damaging its optics/sensors.
- KineticLensman 8y agoThe amount of reflected Earthlight would depend on your location on the Moon's nearside and the phase of the Earth. The corollary of one side of the Moon always facing the Earth is that the Earth hangs in about the same place in the sky for any given point on the Moon's surface. Over a period of (earth) days the Earth's position would slightly but visibly oscillate due to libration [0]. This might slightly vary the incoming Earthlight (analogous to the Moon's illumination at the horizon vs. at the Zenith). A much bigger effect, however, would be due to the phase of the Earth. As the Moon orbits it will sometimes be between the Earth and the Sun, sometimes further away. On the sun-side, the Earth would be more 'full' and thus there would be more light to reflect. This would significantly vary the incoming light. [0] https://en.wikipedia.org/wiki/Libration https://en.wikipedia.org/wiki/Libration
- deleted 8y ago[deleted]
- Proven 8y agoOn the side we can't see from here? I suspect foul play!
- dandare 8y agoHow much lighter is the lander compared to Apollo moon lander? I mean, how far are the Chinese from sending people to the moon? The Russians landed a Lunokhod too but were very far from sending people to the moon.
- eps 8y agoRussians were on a verge of manned mission, but the program stalled with Korolev's death and then scrapped altogether for non-technical reasons, primarily because of the regime change.
- computerex 8y agoNo they weren't. What's your source? Their solution (N1) had inherent flaws that would have taken a long time to work out.
- eps 8y agoDocumentary on the subject that interviewed people from the project. What's your source for the "would have taken a long time" bit? Edit - ok, read up on it and N1 was not indeed flightworthy. There is however little information on the nature of technical issues and how long they would've taken to resolve. The program collapsed first and foremost because of the politics and personnel/finance issues.
- computerex 8y agoThe N1 used closed loop cycles, which was something new at the time and was a lot harder to get right. Also the n1 had some 30 engines that all had to operate perfectly so the inherent risk of failure was higher. The rocket was never even man rated.
- avmich 8y agoUSA rocketry school tradition of counting engines by chambers makes R-7 a rocket which uses 32 engines at liftoff 4 main chambers for each of 4 RD-107 and 1 RD-108 (20 chambers) and 12 steering chambers (each with about 3 tons of thrust, about as much as a chamber of British Gamma-8 engine) - more than N-1. Yet R-7 is a pretty reliable rocket overall. Also Falcon Heavy has 27 engines, which not too many complain about. No, engines didn't need to operate perfectly. N-1 has less gross liftoff mass (GLOM) than Saturn-5, yet N-1 had higher liftoff trust. That's partially because it was supposed to complete the mission with up to 4 engines out during flight.
- DoreenMichele 8y agoChina releases photos from first-ever mission to land on the dark side of the moon https://www.businessinsider.com/photos-dark-side-moon-china-change-4-landing-2019-1 https://www.businessinsider.com/photos-dark-side-moon-china-...
- betterworldb 8y agoIs there a way around the paywall for business insider?
- DoreenMichele 8y agoThe photos were originally published here: http://www.cnsa.gov.cn/n6758823/n6758838/c6805034/content.html http://www.cnsa.gov.cn/n6758823/n6758838/c6805034/content.ht... It's the original source. I chose to post the BI article because the original source is in Chinese.
- Accacin 8y agoI believe they have an English version of the page: http://www.cnsa.gov.cn/english/n6465652/n6465653/c6805049/content.html http://www.cnsa.gov.cn/english/n6465652/n6465653/c6805049/co...
- paraditedc 8y agoI don't blame you, but next time you go to a foreign website, you can look out for icons that resemble national flags or EN. There is usually an English version of the website available for important government websites (as with this case, the button is on the top right corner).
- DoreenMichele 8y agoThanks. I'll keep that in mind. I have lousy eyesight. It's easy for me to miss details like that.
- Serthys 8y ago
- m3nu 8y agoTheir logo has similarities to a certain sci-fi TV show.. https://www.space.com/22743-china-national-space-administration.html https://www.space.com/22743-china-national-space-administrat...
- rsynnott 8y agoI mean, https://en.wikipedia.org/wiki/Air_Force_Space_Command#/media/File:Air_Force_Space_Command_Logo.svg https://en.wikipedia.org/wiki/Air_Force_Space_Command#/media...
- m3nu 8y agoI mean http://memory-alpha.wikia.com/wiki/Starfleet http://memory-alpha.wikia.com/wiki/Starfleet, "Seal of Starfleet in the alternate reality"
- 99052882514569 8y agoI mean, https://en.wikipedia.org/wiki/Roscosmos#/media/File:Roscosmos_logo_en.svg https://en.wikipedia.org/wiki/Roscosmos#/media/File:Roscosmo...
- maloneyg 8y agoDamn..it is an impressive accomplishment by China.
- deleted 8y ago[deleted]
- dbrgn 8y agoA great day for listening to Pink Floyd!
- vermontdevil 8y agoAwesome. Too bad US freezes China out in working with NASA on space exploration. I think we all should partner up despite our political differences.
- Retra 8y agoDo you know why NASA doesn't partner up with China? Because it sounds like you think those political differences are insignificant.
- balabaster 8y agoThey should be... sadly, the political reality often gets in the way of idealism.
- Rebelgecko 8y agoIt's currently illegal for NASA to work with China. There's been a line in the NASA appropriations bills for the last 5 years or so saying none of the money they're receiving can be used bilaterally or in cooperation with China
- Retra 8y agoThat describes the mechanism, not the rational.
- cuspycode 8y agoHow about working with Taiwan? I think they too have a space program, although I have no idea how big it is.
- avmich 8y ago"The 'One China' policy is not a card on the bargaining table," said Paul Haenle, a former China director at the U.S. National Security Council. "It is the table itself."
- headsupftw 8y ago
- sizzzzlerz 8y agoDoes China have an equivalent to NASA's Deep Space Network tracking stations? By deploying large antennae in the US, Spain, and Australia, the US was able to maintain 24/7 contact with the space missions. Granted, this isn't a manned mission but I'd still think that they'd want to have continuous comms to their lander.
- ptero 8y agoThere is little value in the continuous comms to the unmanned missions. You generally want good tracking during maneuvers (which is where things go wrong), but outside of those motion is highly predictable. And the comms to the unmanned missions are mostly for forensics (outside of active science or other active payload functions) -- if a problem arises that the automation on board cannot solve it is highly unlikely that a difference between real-time and an hour later warning would matter.
- Rooster61 8y agoI'd agree with you for anything outside the Earth's SoI, but the Moon is somewhat unique in that we DO have the ability to try to correct things in near-real time. It's one thing to have to wait 16 minutes to grab telemetry and issue commands to something on Mars, but having only a few seconds lag seems like something mission designers/operators would take full advantage of. The idea of actively controlling a rover rather than having it perform pre-programmed routines seems highly desirable.
- ptero 8y ago> The idea of actively controlling a rover rather than having it perform pre-programmed routines seems highly desirable. Rover, probably (which I considered payload functions). For delivery vehicle during passive parts of the trajectory the value is doubtful. Plus, the standard way of getting a ground station outside a country's land footprint is to put one on a ship. That's what Soviet Union did and I suspect this is what China is doing now.
- 8y ago
- dopylitty 8y agoThe headline should be "China claims to successfully land..." Given the government and business tendency in China to make claims that later turn out to be fabricated nothing they announce should be taken as true without independent verification.
- Symmetry 8y agoHow clever of them to have faked a rover failure with Chang'e 3 then, so that we'd believe them now if they report that the rover works. But seriously, we haven't seen any indications of the CNSA faking anything. China isn't a person, it's a whole big country. The fact that Bernie Madoff defrauded a huge number of people doesn't mean that you can't trust NASA.
- Symmetry 8y agoI don't want to sing the praises of CNSA's openness here. They have a history of keeping things secret until they work out, like the Soviets did. And probably there are failures we'll never hear about. But if they say they landed a probe on the far side of the Moon then there isn't reason to doubt them.
- microdrum 8y agoSeconded. That is the proper contextualization for news out of CH.
- SmellyGeekBoy 8y agoSwitzerland?
- philwelch 8y agoThis isn't really impressive enough to be worth the risk of lying about, and anything that was impressive enough would be worth verifying so you couldn't lie about it anyway. If they're going to lie about something, it would be something they would have total information control over in the first place, like, "no, of course we didn't try to launch a rocket on this date".
- anewguy9000 8y agopics or it didnt happen!
- sbarre 8y agohttp://www.cnsa.gov.cn/english/n6465652/n6465653/c6805049/content.html http://www.cnsa.gov.cn/english/n6465652/n6465653/c6805049/co...
- billfruit 8y agoIt is kind of surprising that the Chinese choose mystical names for their space probes, rather than names of revolutionary origin (I guess Long March, is an exception).
- philwelch 8y agoAfter the Cultural Revolution, the PRC seemingly decided that turning their backs on centuries of culture might not have been the best move. And by culture I mean the subset of "Chinese" culture they deem compatible with their planned future society; cultural and religious "fringe" groups are still brutally repressed.
- openloop 8y agoGratz.
- metabagel 8y agoBut did they find a Nazi moon base? http://ironsky.net/ http://ironsky.net/
- peter303 8y agoIsrael and India may be sending landers to the Moon too. India has sent orbiters to the Moon and Mars. https://en.m.wikipedia.org/wiki/Mars_Orbiter_Mission_2 https://en.m.wikipedia.org/wiki/Mars_Orbiter_Mission_2 https://en.m.wikipedia.org/wiki/Chandrayaan-2 https://en.m.wikipedia.org/wiki/Chandrayaan-2 An Israeli group got pretty far with an entry in the lunar lander XPrize. But the prize reached its deadline dates and expired. I hear they may be shopping for a deep space launch vehicle.
- m000z0rz 8y agoI think the Israeli group is SpaceIL, currently scheduled to launch (alongside a satellite) on a Falcon 9 in February. https://spaceflightnow.com/launch-schedule/ https://spaceflightnow.com/launch-schedule/
- TheForumTroll 8y agoWho better to build Moon settlements than the Israeli.
- ams6110 8y agoFTA: "In addition to its value as a scientific exploration target, the Moon’s quiet, airless far side makes it one of the best places in the inner solar system for science applications like radio astronomy." It what way is any part of the moon not "quiet and airless" ?
- ColinWright 8y agoThe near side is bathed in radio (and other) waves from the Earth. It's not "radio quiet". Also, the Earth "leaks" a surprisingly large amount of air, especially when it's a full Moon and the solar wind is carrying outer reaches of the atmosphere with it. The amounts are small, but scientific instruments are - by design - quite sensitive.
- hnbroseph 8y agore "airless", the moon does have some semblance of atmosphere, but i think it's neither constrained to the near side nor in general particularly notable.
- godelski 8y agoThe sun is really loud. [0] But in all seriousness, it produces a lot of radio signals. So it is completely accurate to call it loud. The moon doesn't have a magnetic core so it doesn't produce its own noise like Earth does. [0] https://youtu.be/Rvvsw21PgIk?t=17 https://youtu.be/Rvvsw21PgIk?t=17
- black-tea 8y agoThe sun shines on the "dark side" just as much as it shines on the near side.
- En_gr_Student 8y agoThink about what you just said, in context of why one side is light and one is dark. Where does the light come from?