Forgot your password?
typodupeerror
China Space Science

Details of Chinese Spacecraft's Asteroid Encounter 89

Posted by Soulskill
from the veni-vidi-vici dept.
the_newsbeagle writes "Chinese aerospace engineers have revealed, for the first time, details about their Chang'e-2 spacecraft's encounter with the asteroid Toutatis last month. They have plenty to boast: The asteroid flyby wasn't part of the original flight plan, but engineers adapted the mission and navigated the satellite through deep space (PDF). Exactly how close Chang'e-2 came to Toutatis is still unclear. The article states that the first reports 'placed the flyby range at 3.2 km, which was astonishingly—even recklessly—tight. Passing within a few kilometers of an asteroid only 2 to 3 km in diameter at a speed of 10,730 meters per second could be described as either superb shooting or a near disaster.' If the Chinese spacecraft did pass that near, it could provide a "scientific bonanza" with data about the asteroid's mass and composition."
This discussion has been archived. No new comments can be posted.

Details of Chinese Spacecraft's Asteroid Encounter

Comments Filter:
  • China! China! ... (Score:5, Insightful)

    by tqk (413719) <s.keeling@mail.com> on Friday February 01, 2013 @05:31PM (#42766253)

    Passing within a few kilometers of an asteroid only 2 to 3 km in diameter at a speed of 10,730 meters per second could be described as either superb shooting or a near disaster.

    I'm not often a "Yay, China!" kind of guy, but I do admit that's pretty cool; ballsy even. I'm happy for the engineers who stuck their necks out to try it. Pretty neat!

    • by imsabbel (611519)

      I wonder if they were actually able to take pictures or something. I mean, there is no way that the thing was ever designed for such tracking rates...

      • by tqk (413719)

        ... there is no way that the thing was ever designed for such tracking rates

        If you're playing with something like space, you need to design in the exponential. Eleven klicks per sec. is pretty slow compared to a lot of stuff that's flying around out there.

        • by imsabbel (611519)

          Tracking rate. At 1000 degree/s tracking rate if you want to keep the target stable in focus at closest appoach. I doubt that thing has gyros to give it that much rotational momentum...

          • by tqk (413719)

            ... there is no way that the thing was ever designed for such tracking rates

            If you're playing with something like space, you need to design in the exponential. Eleven klicks per sec. is pretty slow compared to a lot of stuff that's flying around out there.

            At 1000 degree/s tracking rate if you want to keep the target stable in focus at closest appoach. I doubt that thing has gyros to give it that much rotational momentum...

            We've sent out stuff that are damned near blasting past planets, yet they manage to handle the flyby easily even at the velocity at which they're moving.

            Cosmic particles go quite a bit faster than that mere "stuff."

    • by Ryanrule (1657199)

      Problem with china is, you stick your neck out and fail, your head is promptly removed.

      • by tqk (413719)

        Problem with china is, you stick your neck out and fail, your head is promptly removed.

        That's Japan. "It was a good death." -- The Last Samurai.

    • What's wrong with China? I'm hoping my country, Australia, starts aligning more with China and less with the USA. They're less threatening in my world view.
      • by tqk (413719)

        What's wrong with China?

        There's nothing wrong with China. The Chinese, on the other hand ... Ca. four billion people who treat each other like shit, all of who treat everyone who's not Chinese like shit. Bravo. What a stupid culture, Yeah, great, your civilizatiion's four thousand years old. Big deal. What've you done with that other than bury pottery armies and oppress your own people (and other people)?

        • people who treat each other like shit : China Y / USA Y
          all of who treat everyone who's not [LOCAL] like shit : China Y / USA Y
          What a stupid culture : China Y / USA Y
          great, your civilizatiion's four thousand years old : China Y / USA N
          bury pottery armies : China Y / USA N
          oppress your own people (and other people)? : China Y / USA N

          |/flamebait
          Ahem... Seems they beat you on Culture and artifacts. /flamebait
          • by tqk (413719)

            oppress your own people (and other people)? : China Y / USA N

            You got that one wrong. China Y / USA Y.

        • by tqk (413719)

          Yeah, great, your civilization's four thousand years old. Big deal. What've you done with that other than bury pottery armies and oppress your own people (and other people)?

          Okay, they've done some fantastic things with food, including pasta/noodles, admitted. And rocketry, and gunpowder, and weaponry (lots of weaponry), ... Still, ...

          The Korean War pretty much sucked in every way. Ditto The Cultural Revolution, the Red Guard, and everything related to Mao. Ditto VietNam, Tibet, ... Tsianenman Square ...

          Tell me when to stop. :-P

    • I'd love to have a video of THAT flyby.

      10+ kilometers/second (36000k/h) with those kinds of tolerances must look like being on a bullet aimed at a bull's eye right up until the end.

    • by tqk (413719)

      ... I do admit that's pretty cool; ballsy even.

      For the girls/females/women out there, ovaries are ballsy-ish, yes? I didn't intend that epithet to exclude you, just so's you know. Had to say that (for whatever reason, I'm not entirely sure). Carry on; kthxbye. Tooduls!!!111 :-)

  • by Anonymous Coward

    We (the U.S.) actually landed on one, and a staunch documentary about it starred Bruce W.

  • Did anyone notice in the article where it said the probe may have been close enough for the asteroid to alter its flight path? While this may sound amazing, I just hope the Chinese were smart enough to realize that the encounter would also change the orbit of the asteroid ever so slightly. I would suggest that we closely observe the orbit of Toutatis in the future to make sure this "ever so slight" orbital change doesn't aim it toward earths' big red bulls-eye on subsequent orbits. I also noticed other post
    • by koxkoxkox (879667)

      And when launching the probe, they changed the orbit of the Earth ! Why is it that no one showed us the calculations proving it is safe ?!

    • A satellite can change the orbit of an asteroid; one play to deflect them is a 'gravity tractor' that uses ion engines to station keep some distance from the asteroid, and its gravitational pull alters its orbit.

      However, that technique (which is what I presume you were thinking of) depends on the probe spending months near the asteroid. This flyby was on a timescale of ~1s. Chang'e 2 has a mass of ~2500kg, so we are talking an effect that is likely to be tiny compared to other influences such as solar light

  • by spasm (79260) on Friday February 01, 2013 @10:59PM (#42768809) Homepage

    For once, the phrase "photos or it didn't happen" seems about right, if only to encourage the Chinese to publish their data sooner rather than later. Excellent achievement though!

    • by Audin (17719)

      Uh. Didn't actually read the article did you? Or maybe you were using lynx and didn't note the [image] on top?

    • Please note that them hanging on to their data is hardly out of order. It routine for principal investigators to be able to hang on to data from expensive space missions for a set amount of time - its a funding thing, basically.
  • by EmperorOfCanada (1332175) on Friday February 01, 2013 @11:24PM (#42768937)
    Taking chances, dancing near the fire, I love them. This is science done right. I am glad they didn't listen to some risk adverse nitwit who would rather have a useless "successful" mission than a risky useful mission. This why we have curiosity tramping around on mars with a computer with 2G of storage on it. It probably was the only computer to be able to pass all the bureaucratic tests as opposed to some simple physics tests. But if it fails not a single stone could be cast at the guy who picked it.
    • by thrich81 (1357561) on Saturday February 02, 2013 @04:47AM (#42770089)

      Holy (bleep), did you see the landing sequence of Curiosity? -- that's dancing near the fire! The reason it worked is because of all of those "bureaucratic tests", and there is now a laboratory on Mars which no other nation or agency could have put there. Kudos to the Chinese for the Chang'e-2 mission, but NASA is still so far ahead of anyone else in robot exploration of the solar system, measured by current, operating, successful missions (Cassini, Messenger, Curiosity, New Horizons, etc, etc), that there is really no comparison.

    • by sysrammer (446839)

      When Curiosity was in the planning stages, 2gb for a comp was a major improvement. At some point they had to freeze the specs. If they had tried to keep up with Moore's Law, I doubt we'd have a functioning vehicle.

      As far as bureaucracy goes, I hate it as much as the next person, maybe more. I wish humanity could come up with something better to ensure the success of complex projects.

  • in high resolution glory:
    http://159.226.88.59:7779/CE1OutENGWeb/ [159.226.88.59]
    It is hosted on some weird IP address... I know... You need to register to download too. NASA tend to release everything on their website, and you don't tend to need to register.

  • Splat!

"Never ascribe to malice that which is caused by greed and ignorance." -- Cal Keegan

Working...