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Space

European Rosetta Space Craft About To Rendezvous With Comet 62

Posted by timothy
from the rosetta-about-to-meet-stone dept.
Taco Cowboy (5327) writes After a long 10-year journey spanning some four (4) billion kilometers, Rosetta, an interplanetary space craft from the ESA (European Space Agency), is on its final approach to comet Comet 67P (or comet Churyumov-Gerasimenko). The last in a series of 10 thruster firings over the past few months has slowed Rosetta to the pace of a person walking, about two miles per hour relative to the speed of its target at a distance of about 60 miles. Photographs have already revealed a surprisingly irregular shape for the 2.5-mile-wide comet, possibly an amalgamation of two icy bodies or a result of uneven weathering during previous flybys. From a distance, the blurry blob initially looked somewhat like a rubber duck. As the details came into the focus, it now more resembles a knob of ginger flying through space. Wednesday marks a big moment for space exploration: After a few thruster rockets fire for a little over six minutes, Rosetta will be in position to make the first-ever rendezvous with that comet nickname 'Rubber Duck.' 'This burn, expected to start at 11 a.m. central European time, will tip Rosetta into the first leg of a series of triangular paths around the comet, according to the Paris-based European Space Agency, or ESA, which oversees the mission. Each leg will be about 100 kilometers (62 miles) long, and it will take Rosetta between three to four days to complete each leg. There will be a live streaming webcast of Rosetta's Aug. 6 orbital arrival starting at 8 a.m. GMT via a transmission from ESA's spacecraft operations centre in Darmstadt, Germany. Also at the BBC.
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European Rosetta Space Craft About To Rendezvous With Comet

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  • by Anonymous Coward

    6.4 billion kilometers (4 Billion miles)

  • by Trapezium Artist (919330) on Wednesday August 06, 2014 @12:39AM (#47611901)

    Our live webcast will be at www.esa.int starting at 10:00 CEST / 08:00 UT. Should be some cool new pictures of the comet to see.

    (Disclaimer: I'll be one of the speakers :-)

  • by able1234au (995975) on Wednesday August 06, 2014 @01:04AM (#47611949)

    Two miles per hour is much slower than i can get my Kerbal space ships. Of course, in that you are flying by the seat of your pants and another space ship is just a few clicks away. Still, it gives you a bit of an appreciation of what they have achieved with Rosetta.

    • by Anonymous Coward

      They're using MechJeb so it's really not that impressive.

  • by atom1c (2868995) on Wednesday August 06, 2014 @02:02AM (#47612075)

    The URL is http://www.livestream.com/euro... [livestream.com]

    I'm actually surprised that the post/summary doesn't include it (except for the incidental embedded version in the one article linked).

  • by Bryan Ischo (893) * on Wednesday August 06, 2014 @02:41AM (#47612165) Homepage

    I have always wondered why the photographs that come back from space are so grainy/blurry and have poor color reproduction. Why aren't the images clearer? Why don't we get to see movies instead of just crummy looking stills?

    There *must* be a reason that they can't make photos that come from space exploration better or include full color videos so that we can see what these things would look like if we were really there.

    I can only posit that either the radiation hardening necessary for space exploration somehow precludes the use of large CCD/CMOS sensors, or the bandwidth limitation of sending data from that far out makes anything other than tiny images with low resolution possible, and makes video impossible.

    But still I can't help wondering why, if they can spend tens of millions to put these things up there, they can't produce better images for whatever millions are left over for on board equipment.

    • by ghighi (1416473)
      I imagine that, given the price of sending any payload to space, fitting a real color, high res sensor of little scientific value must not be a priority. That being said we had some pretty bad ass shot from curiosity havn't we?
    • by Calinous (985536) on Wednesday August 06, 2014 @03:24AM (#47612273)

      There are severe limits on sending antenna size and power use on the craft. They use a 2.2 meters diameter dish (seven feet), with 850W electric power from solar panels to transmit from a distance about one hundred thousand times greater than geostationary TV satellites.
            It's like the difference between whispering at someone's ear (half and inch away) and shouting for someone a mile away. I can't think of a car analogy on five orders of magnitude, but I'm sure someone will be more inspired

      • by allcoolnameswheretak (1102727) on Wednesday August 06, 2014 @06:39AM (#47612787)

        It's like the difference between silently swearing at the idiot in the car right in front of you and honking in a traffic jam at some idiot a mile away.

      • There are severe limits on sending antenna size and power use on the craft. They use a 2.2 meters diameter dish (seven feet), with 850W electric power from solar panels to transmit from a distance about one hundred thousand times greater than geostationary TV satellites. It's like the difference between whispering at someone's ear (half and inch away) and shouting for someone a mile away. I can't think of a car analogy on five orders of magnitude, but I'm sure someone will be more inspired

        ... and it's a digital signal from a digital camera, so none of that should affect image quality.

        • by Calinous (985536)

          No, it only affects available bandwidth - the bytes per second and the bytes per watt (or maybe watts per bit?). Also, until now pictures were taken from astronomical distances and without the help of a huge optical apparatus, which would directly affect the apparent quality of the image.

          • No, it only affects available bandwidth - the bytes per second and the bytes per watt (or maybe watts per bit?).

            Exactly! So all that stuff about antenna size and signal power is irrelevant nonsense. A weak or noisy signal is not going to give them a grainy or blurry picture. It's going to give them a "Signal Lost" error message, and if it's important, the team will request a retransmission at a better bit rate. The image quality is solely dependent on the camera and optics (which are quite good, judging from the images I've seen. They are neither grainy nor blurry, but are crisp and sharp).

            • by Calinous (985536)

              If you can't send a 10MB image, but because of the restrictions in bandwidth you are limited to a 10kB image, you'll get a grainy, blurry image.

              • Wow! Rosetta must be in a really peculiar part of space indeed if noise can be mis-interpreted as signal, flipping bits in such a way as to fool the the error correction coding, finding only those pieces of the data stream that are part of the image telemetry, working its way backwards through the compression algorithm (which has its own error detection protocols) so as to affect only the specific pixels required to blur the image.
    • by Anonymous Coward on Wednesday August 06, 2014 @03:56AM (#47612357)

      In Rosetta's case, the OSIRIS cameras (one narrow angle, one wide angle) have a resolution 2048x2048. You have to remember Rosetta was launched in 2004, and I would guess the spacecraft hardware was finalized sometime before 2000. 4MP is actually a pretty good resolution for a digital camera from that era - for example the first consumer 4MP camera was the SONY DSC-S85 from 2001. OSIRIS has a whole load of filters it can use (see http://www.planetary.org/explore/resource-library/data/rosetta-osiris.html) which are mostly designed for science (e.g. looking for specific molecules), but do include separate RGB filters on the narrow angle camera, so colour images should be possible.

      • It has come up before when people compare technology to today's standards. This thing was launched 10 years ago, and designed years before that, and even then they are not going to use cutting edge stuff but rather time tested stuff that will not fail, because it won't actually be used for 10+ years. Try designing for that. Sure your iPhone might have a 10MP camera in it, but it only came out recently, and I don't know about you, but mine stopped working after 3 months.

        Could you imagine spending the amount

        • by Tablizer (95088)

          The early comet images I see on space.com look pretty damned good, actually. I'm sure with time they'll get more images and process and stitch them together better and we'll get some really nice big detailed screen wall-paper images.

          Distance, power, and the harsh radioactive conditions of space do put a lot of constraints on imaging. Movies require a lot of mostly redundant images, which tax-payers don't want to pay for. It's rational to spend the money to image new things in new places rather than spend it

      • That's totally correct. As far as I know, all detailed design for Osiris (including the power supply I designed while working at INTA) was carried out within the period 1998-2001 (with all the specs done long before that). The flight hardware test campaign was successfully completed sometime in 2001. This would be the equivalent to moving from development to production in the consumer world. One of the requirements for the power supply I designed was for it to operate in sync with the CCD electronics to mi
    • Also, in addition to the bandwidth and generation of equipment involved, consider the range from Rosetta to the comet when the photos were taken.

      One of the photos includes a |---2km---| scale marker. That means the camera is a bit further out than a studio photographer and distance reduces both the image size and amount of light reaching the camera.

      Also, the amount of light at the comet location is lower than in a photographic studio, so longer exposures are needed which increase the effect of craft shake

    • by iktos (166530) *

      If we were really there, the comet would look black, black, black and more black. And the shadows would be slightly, but probably imperceptibly, darker. The images are extremely enhanced to exagerrate the tiny variations of deep black.

      The question of colour is interesting. Space probe cameras don't have RGB sensors, they're monochrome with lots and lots of switchable filters for specific purposes, like seeing seeing specific gases like nitrogen monohydride or a mineral like orthopyroxene, and many are in UV

    • What grainy/blurry images? All of the images I've seen have been crystal clear, apart from the one where the comet is outgassing. Your guess about bandwidth limitations and video is probably correct.
  • by coastwalker (307620) <(moc.liamtoh) (ta) (reklawtsaoca)> on Wednesday August 06, 2014 @04:57AM (#47612509) Homepage

    The live broadcast has been fairly interesting so far, they actually allowed a scientist pointing at a water spectrum graph to be broadcast. This is almost like being back in the 70's when they treated the audience as if they had done high school and were actually interested.

    I do hope they put some of this up on Youtube

    • by gstoddart (321705)

      they actually allowed a scientist pointing at a water spectrum graph to be broadcast. This is almost like being back in the 70's when they treated the audience as if they had done high school and were actually interested

      I wonder if this is a general difference in science reporting between Europe and North America?

      Don't worry, I'm sure FOX will ignore all of the complicated sciency bits.

  • Where is Rosetta? (Score:3, Interesting)

    by skastrik (971221) on Wednesday August 06, 2014 @04:59AM (#47612515) Journal
    Here it is ... http://sci.esa.int/where_is_ro... [esa.int]
    Roughly 23 light minutes away.
  • Is the probe sponsored by the company that makes the language learning software?

  • I said Rosetta, this here's the Rubber Duck, and we ain't gonna pay no toll. So we crashed the gate, doing 98 (m/s), said let them truckers roll, 10-4.

    http://youtu.be/0gu2_ALY7oA#t=... [youtu.be]

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