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Space

Comet-Chasing Probe Wakes Up On Monday 67

Posted by Soulskill
from the looking-forward-to-pretty-pictures dept.
Hugh Pickens DOT Com writes "Jason Major reports that after nearly a decade of soaring through the inner solar system, flying past Mars and Earth several times and even briefly visiting a couple of asteroids for a gravity assist, the European Space Agency's comet-chasing spacecraft, Rosetta, is due to 'wake up' on January 20 after 957 days of hibernation. The probe is awakening to prepare for its upcoming and highly-anticipated rendezvous with comet 67P/Churyumov-Gerasimenko in August. The spacecraft was designed to be put in hibernation for the coldest part of the journey that took it close to the orbit of Jupiter, because even with massive solar panels the size of a basketball court, Rosetta would not have enough power to complete its mission without this energy-saving strategy. Once Rosetta enters orbit around the comet — the first time a spacecraft has ever done so — it will map its surface and, three months later in November, deploy the 220-lb (100-kg) Philae lander that will intimately investigate the surface of the nucleus using a suite of advanced science instruments. 'It's the first time we've made a rendezvous with a comet — that's never been done before — and it's going to be the first time we've escorted a comet past its closest approach to the Sun,' says ESA project scientist Matt Taylor."
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Comet-Chasing Probe Wakes Up On Monday

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  • units (Score:5, Insightful)

    by rossdee (243626) on Sunday January 19, 2014 @09:46AM (#46004637)

    "massive solar panels the size of a basketball court,"

    can we please have proper units for measuring things in space?

    • Re:units (Score:5, Insightful)

      by bahco (522962) on Sunday January 19, 2014 @09:52AM (#46004645) Homepage Journal

      "massive solar panels the size of a basketball court,"

      can we please have proper units for measuring things in space?

      And confuse half of the american audience? Basketball courts they know, meters they don't.

      • by kencurry (471519)

        "massive solar panels the size of a basketball court,"

        can we please have proper units for measuring things in space?

        And confuse half of the american audience? Basketball courts they know, meters they don't.

        FTFA "...have a total span of about 32 metres tip to tip." Or 105 feet; a basketball court is 94 feet long.

        On behalf of the USA, you're welcome.

    • by Anonymous Coward

      the solar panels are over 2 x the size of 1/2 of an american basketball court.

    • Re:units (Score:4, Informative)

      by xaxa (988988) on Sunday January 19, 2014 @10:29AM (#46004763)

      The page on the ESA website [esa.int] says there are two panels, each 32 m^2.

      I'm not familiar with basketball courts, but I assume they're quite a lot bigger than that.

      • Hence the probe had to hibernate.

      • by Optali (809880)

        They forgot to say "The size of a basketball court for hamsters", it's the favourite sport at ESA, you should see new power forward, maaan! the critter is awesome, MVP for two consecutive seasons:

        https://encrypted-tbn0.gstatic... [gstatic.com]

    • by tomhath (637240)
      You're correct, since this is an ESA project the proper units would be soccer fields. Unfortunately that doesn't seem to be a standard measurement; I suppose it's about 9% of a smallish field - if that helps
      • by Anonymous Coward

        Err, since it's an ESA project it would be "football fields". "Soccer" is not a word frequently encountered in Europe, except from the lips of the more impressionable of Britain's youth, few if any of whom actually understand the rules of American Football but a distressing number of whom use American terminology for the game they themselves actually play.

        Balls to them and their habit of playing football on my lawn!

        • "Soccer" is not a word frequently encountered in Europe, except from the lips of the more impressionable of Britain's youth

          And Saturday morning Sky Sports coverage [wikipedia.org].

        • by Optali (809880)

          Spot on mate!!!
          FOOTBALL is the name of the #1 sport on the planet, played by 11 vs 11 guys with spike in their shoes a _round_ ball and some guys in black that nobody cares about... and hooligans wrecking havoc in the town.

          This sport that USians call "football" where an undefined number of guys stay for hours deciding how to place themselves and were everybody is covered in cushions should be called more appropriately "Fluffyball" or "sissy-rugby".

    • by JoshuaZ (1134087)
      It is approximately one millionth of the surface area of all the pages in the Library of Congress.
    • by Optali (809880)

      How much is that in FIFA approved football fields?

  • by Anonymous Coward

    ...flying past Mars and Earth several times...

    That sounds like a sleepy driver to me!

    Unless....are they using ethanol to fuel this thing?! Does MADS (Mother Against Drunk Space exploration) know about this?

  • Wake Up (Score:5, Funny)

    by ketomax (2859503) on Sunday January 19, 2014 @10:01AM (#46004671)

    is due to 'wake up' on January 20 after 957 days of hibernation

    If successful, this will be a new record for the onboard Windows XP.

  • by eclectro (227083) on Sunday January 19, 2014 @10:10AM (#46004689)

    You know that ice that's in the corner of the parking lot covered in black dirt and is the last piece of ice to melt? That's what's that probe is going to find.

  • Why didn't they just use an RTG? http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator [wikipedia.org]

    • Re:RTG? (Score:5, Informative)

      by hey! (33014) on Sunday January 19, 2014 @11:01AM (#46004913) Homepage Journal

      I presume because a large solar array with some battery backup meets their power needs over the mission for less money than an RTG, and they only need to operate for a short period out near the outer limits of what is feasible for photovoltaics (roughly the orbit of Jupiter).

      The solar panels will produce 850 watts at the rendezvous point -- roughly the same as the Cassini probe's RTG at launch. Those panels will produce prodigious amounts of power at the spacecraft's action-packed perihelion, which may be useful. For example a huge power budget would allow faster transmission of data [wikipedia.org].

      The drawback I see is reliability. The spacecraft's systems have to be kept dormant for a long time when it's out near its aphelion.

  • The 12-year Journey (Score:5, Informative)

    by martyb (196687) on Sunday January 19, 2014 @10:13AM (#46004703)

    For the curious, here's a video showing Rosetta's path: Rosetta's Twelve-Year Journey to Land on a Comet - ESA Space Science HD Video [youtube.com]

    • Re: (Score:2, Interesting)

      by Anonymous Coward

      Nice. We can also see that the submitter claim "briefly visiting a couple of asteroids for a gravity assist" is bunk. The asteroid flybys didn't change the orbit in any useful amount -- only the planet flybys did.

      • You are correct.

        It should have read:

        " flying past Mars and Earth several times for a gravity assist and even briefly visiting a couple of asteroids"

        • by cusco (717999)

          Really SlashDot, I'm disappointed. I expected to see this observation making up half of the discussion thread, instead just a bunch of whining about the size of a basketball court. Sigh.

          Actually, it's an incredibly cool accomplishment. This has already been one of the most productive deep space probes in years, and now the show really starts.

  • by Bayoudegradeable (1003768) on Sunday January 19, 2014 @10:22AM (#46004729)
    Saying a probe wakes up on Monday assumes no glitches. Wouldn't it be best to say "should/expected to/might" wake up Monday?
    • by Anonymous Coward

      If you had to qualify statements with modifiers like that, you'd never get anything said.

  • Poor space probe, I sympathise with it. What a day to wake up on!

    • by terryk29 (2756467)

      ESA: "Rosetta will prepare for its upcoming rendezvous with comet 67P/Churyumov-Gerasimenko"

      Probe: Groan, mumble. "Whatever... where's my coffee?"

  • by hackertourist (2202674) <<ln.tensmx> <ta> <tsiruotrekcah>> on Sunday January 19, 2014 @10:33AM (#46004779)

    I remember staying up late to watch Giotto's close approach to Halley. That we're now planning to *land* on a comet, is very impressive.

  • by seven of five (578993) on Sunday January 19, 2014 @11:06AM (#46004939) Homepage
    All These Worlds are Yours Except 67P Churyumov-Gerasimenko.
    Attempt No Landings There.
  • by burnttoy (754394) on Sunday January 19, 2014 @11:12AM (#46004969) Homepage Journal

    http://www.nasa.gov/images/content/468180main_2_Lutetia_and_Saturn_946-710.jpg [nasa.gov]

    With Saturn hanging in the background. Stunning. It's worth it already!

    • by monkeyhybrid (1677192) on Sunday January 19, 2014 @11:47AM (#46005165)

      Wow, I don't remember seeing that pic before (must be from the 2010 flyby) but it's just about to become my desktop wallpaper. Thanks!

      On a side note, for anyone who's not looked at the night sky before through a telescope, you can see Saturn somewhat like it is in that image, with an entry level (ish) telescope from your back yard. I first saw Saturn through an old TAL-1 newtonian that can be bought for as little as £100 here in the UK and on a good night you'll get a sharper view of Saturn than shown in that image. Or you could pop along to your local astro meet (there's bound to be one near you) and have a look at some of these objects through varying sizes and designs of telescopes.

      Seeing Saturn for the first time through a telescope is, in my experience and from what others frequently say too, jaw dropping amazing. Then take a look at Jupiter with the same telescope and you should be able to make out Jupiter's bands and some of its moons, maybe even the great red spot if you time it right. We've all seen them in photos but there's nothing quite like the knowledge that your eye is at the receiving end of actual photons being reflected by the planets, or being emitted from galaxies.

  • orbital parameters (Score:5, Informative)

    by terryk29 (2756467) on Sunday January 19, 2014 @01:03PM (#46005739)

    I dug around ESA's pages and finally found details on the orbital parameters: on Comet Rendezvous [esa.int], under "Comet mapping and characterisation (August 2014)" (halfway down) it says: "...the spacecraft is inserted into orbit around the nucleus at a distance of about 25 kilometres. Their [sic] relative speed is now down to a few centimetres per second. "

    That slow orbital speed (OK, slow compared to what we're used to dealing with) is due to the small mass of the comet (again, compared to things like the Earth or Moon), which Wikipedia [wikipedia.org] gives as about 3e12 kg. Checking the math, the equation for circular orbital velocity v[circ] = sqrt(GM/R) ~= sqrt( (7e-11)(3e12) / 25e3 ) = 0.09 m/s = 9 cm/s, cool. (Even if the quoted 25 km is to the surface rather than the centre, using that figure for R is OK since the comet's radius is only about 2 km.)

    FWIW, at the surface, escape velocity sqrt(2)*v[circ] = sqrt( 2(7e-11)(3e12) / 2e3 ) = 0.5 m/s. You could easily jump off of that comet!

    • by Muad'Dave (255648)

      ... Their [sic] relative speed ...

      Why the [sic]? 'Their' is the correct word. It certainly wouldn't be 'there', and when talking about relative speed there have to be two objects, hence the plural - 'its' would not be correct either.

  • ...decides it hasn't recovered from the weekend yet, calls in sick, goes back to sleep and rolls in on Tuesday at about 09:30.

  • briefly visiting a couple of asteroids for a gravity assist

    Gravity assist for whom, the probe or the asteroids?

  • Can Hugh Pickens DOT Com not get his own website to post stuff on ?
  • Jabin jay Trapp... I am excited that we have virtually any space exploration
  • I was following the webcast [esa.int], a few minutes ago they received the signal from Rosetta, so the wakeup has succeeded, if a bit behind schedule.

    (unfortunately I can't see a way to rewind, so you'll have to wait for the video to become available on the archive section of the webcast page)

  • I also woke up this Monday, what's the big deal?

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