Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 


Forgot your password?
Close
typodupeerror
×
Space

Rosetta Probe Awakens, Prepares To Chase Comet 72

Posted by Soulskill from the cue-benny-hill-music dept.
sciencehabit writes "The European comet-chasing probe Rosetta is up and running again today after it successfully roused itself from a 2½-year sleep and signaled anxious controllers on the ground. The spacecraft had been put into hibernation during the most distant part of its 10-year journey in pursuit of comet 67 P/Churyumov-Gerasimenko because sunlight was too dim to keep its solar-powered systems running. Dozing in a slow stabilizing spin, Rosetta could not receive signals from the ground, so there was a risk that some problem might prevent it from responding to its preset alarm call at 10:00 GMT. Even then, there were many processes to go through before news reached Earth: The spacecraft's heaters would need to warm up its systems, its startrackers get a fix, boosters halt the spin, solar arrays turn towards the sun, and, finally, its communications antenna would need to point at Earth. It was not till 18:18 GMT that the signal was picked up by NASA's ground stations at Goldstone, California, and Canberra in Australia, and transmitted to the European Space Agency's (ESA's) control center at Darmstadt in Germany."
This discussion has been archived. No new comments can be posted.

Rosetta Probe Awakens, Prepares To Chase Comet More

Rosetta Probe Awakens, Prepares To Chase Comet

Comments Filter:

  • Everything about this mission is a miracle (Score:5, Informative)

    by Anonymous Coward on Tuesday January 21, 2014 @02:46PM (#46027859)

    The spacecraft wasn't designed to operate that far out in space and it wasn't designed to handle the comet it's chasing. That anything about the mission is going well at all since they blew their initial launch window and had to retarget [spacedaily.com] is a miracle.

  • Not to diminish... (Score:3, Interesting)

    by jomama717 ( 779243 ) <jomama717@gmail.com> on Tuesday January 21, 2014 @02:46PM (#46027861) Journal
    ...but IMHO the curiosity landing makes anything like this that I read about seem like a cake walk. Still in complete awe of the team(s) that pulled that off.

    Excited to see what Rosetta sends back!

    • eh? (Score:4, Interesting)

      by schneidafunk ( 795759 ) on Tuesday January 21, 2014 @02:52PM (#46027965)

      Landing on a high-speed small comet versus a giant planet, seems more difficult to me.

      • Re:eh? (Score:4, Interesting)

        by dpilot ( 134227 ) on Tuesday January 21, 2014 @03:12PM (#46028197) Homepage Journal

        Speed is relative, so is velocity. Rosetta is going to rendesvous with the comet, and go into orbit around it. At that point the speed and velocity will both be quite slow. I'm guessing that the biggest problem for the lander will be not bouncing off or floating away - there's next to no gravity.

        • Yea, they're using a harpoon. Wild stuff! Personally I think this is going to be more difficult than the curiosity landing. The accuracy must be much higher for the comet rendezvous.

          • Re: (Score:2)

            by gmhowell ( 26755 )

            Yea, they're using a harpoon.

            This sounds more like something Wile E. Coyote dreamed up every day...

            I mean that in a good way.

      • Landing on a high-speed small comet versus a giant planet, seems more difficult to me.

        Both targets will be/were travelling at close to relatively zero at landing time.

        The lack of gravity and atmosphere might make the comet easier.

        • Re:eh? (Score:4, Funny)

          by Anonymous Coward on Tuesday January 21, 2014 @03:35PM (#46028437)

          Both targets will be/were travelling at close to relatively zero at landing time.

          That's how I would design a lander too.

        • Re: (Score:3)

          by Rich0 ( 548339 )

          The lack of gravity and atmosphere might make the comet easier.

          Well, lack of atmosphere means that you need more propellant to equalize velocity. To land on a body with an atmosphere you have to just carry shielding and hit it at the right angle and the friction does the rest. The problem is that this gets you to terminal velocity and not zero velocity, and you don't want to hit the ground at terminal velocity.

          If you're going to intercept a body without an atmosphere you have to equalize speed with only the use of propellant, so that is a lot more mass to carry. How

          • To land on a body with an atmosphere you have to just carry shielding and hit it at the right angle and the friction does the rest.

            Except Mars has such an incredibly thin atmosphere that a parachute needs to be impossibly large for a soft landing. The gravity is too high for a rocket-powered landing like on the moon. Not to mention that same thin atmosphere being thick enough that you also need a tough heat shield.

            • Re: (Score:2)

              by Rich0 ( 548339 )

              To land on a body with an atmosphere you have to just carry shielding and hit it at the right angle and the friction does the rest.

              Except Mars has such an incredibly thin atmosphere that a parachute needs to be impossibly large for a soft landing. The gravity is too high for a rocket-powered landing like on the moon. Not to mention that same thin atmosphere being thick enough that you also need a tough heat shield.

              Actually, the atmosphere gets you 99% of the way. As I said in my post, an atmosphere only gets you to terminal velocity, so you usually still have some slowing down to do.

              Compared to interplanetary velocity, terminal velocity is barely moving at all. On Mars it just happens to still be high enough to smash the probe. If you had to decelerate the probe completely to rest using only propellant (such as to land on one of Mars's moons) you'd need a lot more propellant. Actually, Mars's moons have the advan

              • the atmosphere gets you 99% of the way.

                It can, but it's not "free". You need a lot of heavy equipment to use that thin atmosphere to slow down. Landing on something without an atmosphere, and with low gravity, might only take a tiny fraction as much weight in fuel.

        • Re: (Score:2)

          by sjames ( 1099 )

          Or harder. There is so little gravity the lander could bounce off.

      • Landing on a high-speed small comet versus a giant planet, seems more difficult to me.

        No, no -- the planet is MUCH, much easier than the small comet -- trust me on this.

        Oh! You meant in one piece.

  • First Glitch (Score:5, Funny)

    by Freshly Exhumed ( 105597 ) on Tuesday January 21, 2014 @02:48PM (#46027873) Homepage

    On wakeup an error in the MAKE COFFEE subroutine was discovered that has resulted in Rosetta being a bit grouchy.

  • I have a new appreciation for this (Score:3)

    by scorp1us ( 235526 ) on Tuesday January 21, 2014 @02:49PM (#46027897) Journal

    After playing Kerbal Space Program [jttp] and doing a simple docking in Kerbin orbit. I also managed one in Mun orbit. And to think what they are doing with this comet is just amazing.

    • Compared to a planet, a comet is tiny. You essentially need a perfect intercept to minimize the delta-v required to enter comet orbit. Then they have to stick the landing and keep the probe from flying off the surface.

      Gotta love KSP! I should look into modding in a tiny body like a comet just to test with. Someone on Reddit used Gilly as a comparable body for a "test run".

      • Re: (Score:3)

        by edremy ( 36408 )
        The most annoying thing about trying to land on a comet is that you can't timewarp past 1x anywhere close to it, and the gravity is so low it takes forever to actually land, or have your Kerbal come down after jumping.

        (Would be cool if they'd add a couple to KSP. I bet there's a mod that does)

  • The Path of Rosetta since launch (Score:5, Informative)

    by idji ( 984038 ) on Tuesday January 21, 2014 @03:23PM (#46028301)
    Here is a beautiful interactive 3D simulation of how Rosetta got to where it is now. Where is Rosetta? [esa.int]. Video [esa.int]
    The choreography of the Earth, Mars, Earth, Earth slingshots is just amazing.
    Here is the complex orbits to come of Rosetta around the comet Orbit around Comet [esa.int]

  • It took 8 hours and 18 minutes to warm up its systems, get a location fix, halt the spin, turn towards the sun, and, finally, point its communications antenna at Earth. Bah, I do that in 15 minutes *every* morning.

    • But Rosetta did it without coffee ;-)

      • Re: (Score:2)

        by gmhowell ( 26755 )

        But Rosetta did it without coffee ;-)

        True, but given that GP is a /. poster, I'm guessing he fits in more masturbation in his wake up routine than Rosetta.

  • Now that's more like it! Forget the asteroid-mining bullshitters and the nutters who think one day we're going to colonise Mars, (much as I'd love that to be one day possible...it just ain't).

    This is real science, real exploration, with a real goal to further mankind's scientific knowledge, requiring efforts lasting years.
    Oh, and (in the scheme of things), very little money.

    Hats off to them. Can't wait to see if the lander makes it. Now THAT would be impressive.
    Kinda like getting Woody Allen's VW to not

    • Re: (Score:2)

      by Isaac-1 ( 233099 )

      As I see it a Mars Outpost like the Outpost we have operated at the south pole for the last half century is possible in the foreseeable future (50-100 years), but a Mars Colony that did not require a constant lifeline of supplies just to survive is something best left to the sci-fi writers talking about the year 3,000.

  • If you worked in this particular mission control group, how could you possibly resist setting all the clocks forward about 2 minutes on the day in question?

    I know, with clock synchronization and everybody having a cell phone, this is likely a lot harder than it used to be, but, that just means the reaction is that much more worth it.

    • Re: (Score:1)

      by Soft ( 266615 )

      If you worked in this particular mission control group, how could you possibly resist setting all the clocks forward about 2 minutes on the day in question?

      Hold that thought, think of the tense wait... Then consider that the signal was actually received 18 minutes later than expected [esa.int].

  • There appears to be conflict as the first works spoken.

    Good morning:

    http://www.slate.com/blogs/bad... [slate.com]

    Hello world:

    http://www.independent.co.uk/n... [independent.co.uk]

  • The original comet rendezvous-er [thespacereview.com] is coming back to Earth [planetary.org] 35 years later. I hope we do more than just wave as it goes by.

    • Re: (Score:1)

      by Soft ( 266615 )
      Not to diminish ICE's accomplishments, but it didn't do rendezvous, only flybys. Rosetta will place itself in orbit then drop a lander on its target comet.

Slashdot Top Deals

What is research but a blind date with knowledge? -- Will Harvey

Close