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Moon China

Chinese Lunar Probe Lands Successfully 250

Posted by timothy
from the remote-control dept.
China's Chang'e 3 moon probe made its intended landing earlier today, setting down softly in the moon's Sinus Iridum, as reported by Reuters. From the article: "The Chang'e 3, a probe named after a lunar goddess in traditional Chinese mythology, is carrying the solar-powered Yutu, or Jade Rabbit buggy, which will dig and conduct geological surveys. ... China Central Television (CCTV) broadcast images of the probe's location on Saturday and a computer generated image of the probe on the surface of the moon on its website. The probe and the rover are expected to photograph each other tomorrow. ... The Bay of Rainbows was selected because it has yet to be studied, has ample sunlight and is convenient for remote communications with Earth, Xinhua said. The rover will be remotely controlled by Chinese control centers with support from a network of tracking and transmission stations around the world operated by the European Space Agency (ESA)."
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Chinese Lunar Probe Lands Successfully

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  • by tttonyyy (726776) on Saturday December 14, 2013 @02:34PM (#45690083) Homepage Journal

    Interestingly, this landing may affect NASA's Lunar Atmosphere and Dust Environment Explorer operation:

    http://www.space.com/23675-china-moon-lander-trouble-nasa-ladee.html [space.com]

    • When that happens, nobody will be able to say that the Chinese landing was a fake. Or, more likely, the conspiracy theorists will say that USA and China are colluding in secret to mutually corroborate their respective fakes.
    • by AJWM (19027) on Saturday December 14, 2013 @04:09PM (#45690673) Homepage

      Dust? Seriously?

      This is high vacuum we're talking about. Lunar dust is just tiny rocks, they get kicked up and immediately fall back to the surface. It's not as though the dust is going to float for days (or even minutes) in the (virtually non-existent) lunar atmosphere. (Sure sign of badly written SF or shot-in-a-studio movie footage: dust on the real Moon doesn't cloud, it sprays then drops.)

      Sure, the exhaust plume gases will stick around for a bit. That will give LADEE something to help calibrate its instruments against, since presumably the reaction products are known.

    • I believe that there is something to be said for an age where there are potential scheduling conflicts between lunar probes.

  • First (Score:5, Informative)

    by Dan East (318230) on Saturday December 14, 2013 @02:35PM (#45690089) Homepage Journal

    In case anyone cares, the first soft moon landing was on January 31, 1966 by the Soviet lander Lana-9. It still boggles my mind how they were able to achieve that without anything remotely resembling a modern computing device.

    • Re: (Score:3, Informative)

      by fisted (2295862)
      Sorry to break it to you but they did have turing-complete machines in '66, which do more than ``remotely resemble'' modern computing devices, as the fundamental principles didn't change.
      • Re: (Score:3, Informative)

        by Dan East (318230)

        Are you saying that Luna-9 was controlled by a Turing-complete computer? From what I can discover it only had a programmable timing device, which would trigger a fixed list of tasks after variable delays. Stuff like shutting off the main engines was done by a physical switch that detected when the lander was just above the surface. I stand by my comment that it was not controlled by anything remotely resembling a modern computer.

        • by hey! (33014)

          May have been. The Russians have always had a lot of great mathematicians, and they certainly understood the concepts. They had a significant computer industry, often copying western systems to be sure, but they were certainly could and did make their own designs going all the way back to the 50s.

          Anyhow, they wouldn't have needed to Turing complete machines. In many ways back in the 60s specialized circuits might have been simpler and more robust. By the mind 60s they had ballistic missiles with multiple,

          • by 0123456 (636235)

            Anyhow, they wouldn't have needed to Turing complete machines.

            They wouldn't have trusted it with a Turing-complete machine because it might have gained sentience and defected.

      • Re:First (Score:5, Interesting)

        by wjcofkc (964165) on Saturday December 14, 2013 @05:53PM (#45691235)
        Luna 9 did not have a computer. It was all careful launch timing and Newtonian mechanics to ensure it got where it needed to be and deployed what it needed to precisely when it needed to. The closest thing it had to a computer was a clock that made these things happen at precise intervals. From Wikipedia:

        The lander had a mass of 99 kilograms (220 lb). It used a landing bag to survive the impact speed of 22 kilometres per hour (14 mph).[2] It was a hermetically sealed container with radio equipment, a program timing device, heat control systems, scientific apparatus, power sources, and a television system.

        If the whole thing weighed 220 lbs., where would you even fit a meaningful 1966 computer? Never underestimate persistent human beings.
        • Re:First (Score:4, Informative)

          by DerekLyons (302214) <`fairwater' `at' `gmail.com'> on Saturday December 14, 2013 @08:13PM (#45691937) Homepage

          Luna 9 did not have a computer. It was all careful launch timing and Newtonian mechanics to ensure it got where it needed to be and deployed what it needed to precisely when it needed to. The closest thing it had to a computer was a clock that made these things happen at precise intervals.

          A certain amount of luck was involved too... a couple of feet more per second error, and that timer (pre-programmed on the ground before flight) could have been hopelessly out of sync with what was actually happening.
           

          If the whole thing weighed 220 lbs., where would you even fit a meaningful 1966 computer?

          SLBM guidance computers of the era weighed in at around forty to sixty pounds. Gemini's onboard guidance computer tipped the scales at a hair under sixty pounds. The Apollo guidance computer (directly descend from an SLBM system) weighed seventy pounds.
           
          Not that they had one, or the Soviets were that advanced of course, but not all meaningful computers available in the sixties were room sized behemoths weighing tons.

      • by gtall (79522)

        No, not Turing complete, their memories were FINITE. To be Turing complete means to simulate (at least) an infinitely long tape.

    • Re:First (Score:5, Informative)

      by Trepidity (597) <.delirium-slashdot. .at. .hackish.org.> on Saturday December 14, 2013 @02:47PM (#45690173)

      Nitpick: the name is Luna-9 [wikipedia.org].

      The first landing of any kind (a crash landing), was the Soviet Luna-2 in 1959. The U.S. then sent a series of crash-impact spacecraft in the early 1960s, the Ranger series, whose goal was to take photos during the final descent, along with testing out systems. Five of the nine Ranger missions successfully impacted the moon, and three of them managed to send back photos.

      Then as you note, Luna-9 was the first non-crash landing, in 1966.

      • Re:First (Score:5, Interesting)

        by david.given (6740) <dg AT cowlark DOT com> on Saturday December 14, 2013 @04:06PM (#45690649) Homepage Journal
        As an interesting addendum:

        Luna-9's pictures were sent back using one of the standard encodings used for wireless newspaper photography transmission. During the transmission, the Jodrell Bank radio telescope in the United Kingdom was listening in (well, wouldn't you?) and the astronomers there recognised the encoding, phoned someone at the Daily Express, and as a result the first pictures from the surface of the moon ever were printed in a British newspaper while the USSR was still wondering what to do with them.

        There is some speculation that the encoding scheme was picked deliberately to make sure this happened...

      • by arth1 (260657)

        Five of the nine Ranger missions successfully impacted the moon

        Does that mean that four of them missed?

        • by ballpoint (192660)

          Five of the nine Ranger missions successfully impacted the moon

          Does that mean that four of them missed?

          No, the other four impacted unsuccessfully.

        • Re:First (Score:4, Informative)

          by Trepidity (597) <.delirium-slashdot. .at. .hackish.org.> on Saturday December 14, 2013 @07:53PM (#45691859)

          Two of them actually did miss, and are now orbiting the sun in deep space. The other two didn't get far enough to miss.

          Ranger 1 and 2 were botched launches, which barely made it into space into unstable low-earth orbits, from which they burned up on reentry shortly thereafter.

          Ranger 3 did in fact miss the moon. It successfully launched to high-earth orbit, and then successfully boosted out of high-earth orbit towards the moon. But not quite towards the moon enough. It missed the moon by 22,000 miles and flew past it into deep space.

          Ranger 4 was the first successful mission. And then Ranger 5 missed again, this time by a much smaller amount, only 450 miles. The exit from high-earth orbit towards the moon appears to have been reasonably good this time, and any minor trajectory errors were supposed to be fixed in a mid-course corrective burn. But the craft lost power after exiting earth orbit, so was unable to make the mid-course correction, causing it to miss.

          More info in the usual place [wikipedia.org].

    • Re:First (Score:5, Interesting)

      by Thagg (9904) <thadbeier@gmail.com> on Saturday December 14, 2013 @02:54PM (#45690231) Journal

      Curiously, in my youth in the 60's, we referred to Luna-9 as a "hard landing", and the first "soft landing" was Surveyor 1 three months later. Now, it's clear that the Luna 9 lander really was a soft landing (similar to the landings of the Mars Pathfinder and Spirit/Opportunity rovers) and we were just ragging on the Soviets.

      • "hard landing" and "soft landing" is one way to think of it...

        a better way might be "controlled landing"...but even that could be nitpicked

        the difference is the level of control

        think of it as the difference between a plane landing vs an object dropping by parachute

        the implication is that if you're just doing it as a Cold War publicity stunt, you can get away with just flinging shit up there willy-nilly, whereas if you are actually trying to explore you use the landing sequence as an opportunity to iterative

    • by rasmusbr (2186518)

      In case anyone cares, the first soft moon landing was on January 31, 1966 by the Soviet lander Lana-9. It still boggles my mind how they were able to achieve that without anything remotely resembling a modern computing device.

      There were plenty of good analog designers available back then.

      They probably basically used one or several analog control systems to control the descent based on signals from a radar and one or several gyros. The landing sequence could have been terminated on landing by a simple mechanical switch.

      Come to think of it, the Moon is just about close enough that they could potentially have landed it by hand if the craft was sending back it's radar signal and gyro signals to Earth.

    • It still boggles my mind how they were able to achieve that without

      It was a radio transmitter packed into a cannon ball, just like Sputnik...not exactly 'space age' and certainly not requiring a modern computing device

      Techies today have kind of fetishized the command line, but there are other ways to program a machine.

      You can hurl a wad of electronics at a world and send pictures back or you can **EXPLORE**

      Guess which one this China mission is?

  • by Anonymous Coward on Saturday December 14, 2013 @02:38PM (#45690109)

    I'm happy that the ESA is willing to let the Chinese to use their transmission infrastructure. This way hopefully more science will be done.

  • Mars next! [wikipedia.org]

  • by mbone (558574) on Saturday December 14, 2013 @02:39PM (#45690123)

    There is a cool animated gif [postimg.org] of the descent imager pictures of the landing, and a false color image [twitter.com] of the surface.

  • by guanxi (216397) on Saturday December 14, 2013 @03:29PM (#45690383)

    I genuinely hope it is successful. The rise of China is one of the great humanitarian stories in history, lifting hundreds of millions from poverty. I expect the people of China to make great contributions to the world.

    However, it's still 2013 and China's government is still authoritarian, unaccountable and non-transparent, and the Chinese press is still restricted. If the mission failed, would they admit it, or release some photos anyway? (Could they get away with it? Could other governments or amateurs with telescopes see for themselves?)

    • by gerddie (173963) on Saturday December 14, 2013 @03:37PM (#45690445)

      If the mission failed, would they admit it, or release some photos anyway? (Could they get away with it?)

      No, because ESA [esa.int] helps during the whole mission.

    • by SuperKendall (25149) on Saturday December 14, 2013 @04:10PM (#45690679)

      The rise of China is one of the great humanitarian stories in history

      I think it's great the Chinese were successful at landing on the moon, but... greatest humanitarian stories in history??? Do you remember just how many TENS OF MILLIONS of people died [paulbogdanor.com] during the communist takeover and resulting purges? Or the famines?

      • by the gnat (153162) on Saturday December 14, 2013 @06:11PM (#45691323)

        greatest humanitarian stories in history??? Do you remember just how many TENS OF MILLIONS of people died [paulbogdanor.com] during the communist takeover and resulting purges? Or the famines?

        I think the GP was referring to the post-1980 era, which really was a great humanitarian story, especially compared to the 30 years preceding it. The Economist magazine uses phrases like this all the time, and there's never any question about what they're referring to.

      • by knarf (34928)

        The rise of China is one of the great humanitarian stories in history

        Don't you have that somewhat backward? China used to be pretty advanced compared to most other parts of the world for a long time. They lost this advance due to many reasons, eventually culminating in the wars which led to the communist takeover and the series of tragedies that followed (cultural revolution, etc). While the party in control of China still calls itself communist they don't have much in common with what Marx et al philosophi

    • Re: (Score:3, Informative)

      by ihtoit (3393327)

      (...Could other governments or amateurs with telescopes see for themselves?)

      No, because the probe is just too damn small.

      None of them can see it. The probe (or to borrow another local example, the Apollo 11 flag) is far too small to be seen with any telescope on Earth, or even the Hubble space telescope (which is in low Earth orbit).

      The Lunar Reconnaissance Orbiter (orbiting the Moon) took pictures of the Apollo 11 landing site, however. It showed a long shadow cast by the lower lander stage, but not the stage itself - again, it's just too small.

      You can approximate the angular size

      • by norite (552330)
        The HST isn't allowed to point anywhere near the moon; it's far too bright and it would damage the HST's sensitive instruments, so it's a moot point anyway.
  • by bradorsomething (527297) on Saturday December 14, 2013 @04:05PM (#45690643)
    It is only a matter of time until they wok on the moon.
  • Space is not the USA's!
  • Pity they couldn't have landed in Mare Tranquillitatis. Would have been fun to have the rover trundle over to the Eagle's descent stage to take some pictures of the flag and Neil and Buzz's footprints. Take that, whack-job conspiracy theorists.
  • Amazing success! (Score:3, Interesting)

    by Reliable Windmill (2932227) on Saturday December 14, 2013 @08:01PM (#45691899)
    Amazing! Congratulations to China, the whole world is proud of you! You will be at the forefront of space exploration, and if there is anyone who can establish a permanent base on the moon it is you. The 21st century belongs to China, no doubt!

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