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Space Science

Voyager Keeps on Trucking 51

Posted by michael from the to-boldly-go dept.
spagiola writes "CNN has a brief story about Voyager I continuing on past Pluto, and about the problems of keeping in touch with it as it keeps heading further away. They've activated a spare sun sensor and star tracker. I wonder: would it make sense to send out another probe after it, to relay messages to/from it?"
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Voyager Keeps on Trucking More

Voyager Keeps on Trucking

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  • They should learn lessons, but use money elsewhere (Score:2, Insightful)

    by Anonymous Coward
    Although it would be an interesting experiment to extend our communications reach with relay probes, the scientific data provided by Voyager isn't worth it when the money should go to more important things like the Pluto mission. The Voyager mission is basically down to exploring the Kuiper belt and testing the length of time the back-up systems that NASA wisely installed will last. Hopefully the extreme survivability of Voyager will encourage aerospace and spacecraft engineers to use more redundancy, as the trend lately has been towards less to cut costs.

    Thanks,

    Travis
    forkspoon@hotmail.com

    • Re:They should learn lessons, but use money elsewh (Score:4, Insightful)

      by CheshireCatCO ( 185193 ) on Thursday April 18, 2002 @10:45AM (#3365515) Homepage
      The cost of checking in with Voyager every now and again is minimal. Far, far less than the costs of building even New Horizons, let alone another Voyager-class mission. And since Voyager is heading for the the heliopause and quite probably will get through it before it dies off or we lose contact, that will be a great scientific benefit. Right now, we don't really know where the heliopause is, exactly. To miss this chance to encounter it would be foolish, especially since our next chance wouldn't come for at least 20 more years, if we launched a mission right now.

      • Re:They should learn lessons, but use money elsewh (Score:5, Interesting)

        by alfredw ( 318652 ) <alfNO@SPAMfreealf.com> on Thursday April 18, 2002 @12:19PM (#3366361) Homepage
        ... especially since our next chance wouldn't come for at least 20 more years, if we launched a mission right now.

        Not even. Voyager 2 used four gravity assists off of the giant planets to build up speed. Even IF we launched today, we couldn't get to Uranus or Neptune with conventional rockets. The configuration of the planets that allowed the multiple-assist grand tour of the solar system (giving the two Voyager probes more delta-V than we can with today's (or even tomorrow's) technology) only occurs once every ~180 years.

        To quote a NASA mission scientist on Voyager, "the last time this was possible, Jefferson was President. And boy, did he blow it."

        • It's not quite that bad. If you do a couple of gravity assists off of Earth and Venus (and you can do that no matter what year you launch) and snag Jupiter on your way out, you can get a pretty good velocity up. A big reason the Voyager alignment was so special is that they actually got to go to all 4 giant planets. If Neptune had been on the opposite side of the Sun from Jupiter, gravity assist or not, we'd have been sunk. Pioneers 10 and 11 didn't use the outer 3 giant planets, and they're doing a pretty good clip, too.

          Still, you're right that we'd be short some of that Voyager delta-v! If memory serves (which is does at its own conviences, the punk), Voyagers overtook their Pioneer cousins a while ago.
          • If memory serves (which is does at its own conviences, the punk), Voyagers overtook their Pioneer cousins a while ago.

            Your memory is doing just fine :)

            The most distant spacecraft right now is Voyager 2, followed by Voyager 1, and then the Pioneers 10 and 11 (not sure which order).

            The Pioneers, of course, were just test probes to make a rough estimate of what the Voyagers could expect. Went to Jupiter and Saturn. Discovered the Jupiter-Io flux tube (which resulted in a major Voyager redesign) and proved that it was possible to get through the asteroid belt (which was a big question at the time).

            Good ships, all of them!

          • Sorry, i'm confused. How do you slingshot around Venus when you're going out of the solar system? Seems like that would be counter-productive unless you can manage to slingshot around the sun too, which seems pretty weird.
    • Sounds like a perfect application for the USNA Shoestring satellite guys: [slashdot.org]

  • What?!? (Score:4, Funny)

    by Servo5678 ( 468237 ) on Thursday April 18, 2002 @11:19AM (#3365830)
    What are you talking about? The series finale aired last June. It's called "Endgame" and...

    Oh, you meant the probe... my mistake...

  • Suppose that a probe could be placed halfway between Voyager and Earth. To get the same signal/noise ratio that we get on the ground (atmospheric effects ignored), that probe would need a receiving antenna about half the diameter of the ones we use here.

    The Deep Space Network has some 70 meter dish antennas. Can you imagine trying to get a 35-meter dish antenna even so far as low-earth orbit, let alone on a solar-escape trajectory? Get real. I wish the editors would do a little thinking before posting.

    • Re:Relaying is silly (Score:3, Insightful)

      by tzanger ( 1575 )

      Can you imagine trying to get a 35-meter dish antenna even so far as low-earth orbit, let alone on a solar-escape trajectory? Get real.

      I see no such problem. Perhaps it is you who should take a little time to think before posting; The concept of a sectored parabolic dish that expands when it deploys is not a new concept. If you do that now you're down to an 18m long component. If you're willing to send it up and have a crew assemble it instead of have it self-deploy en route to its destination you can get that number down MUCH smaller.

      • Perhaps it is you who should take a little time to think before posting; The concept of a sectored parabolic dish that expands when it deploys is not a new concept. If you do that now you're down to an 18m long component. If you're willing to send it up and have a crew assemble it instead of have it self-deploy en route to its destination you can get that number down MUCH smaller.
        For the cost of getting it into orbit and assembled you could probably re-construct the entire Deep Space Network from the ground up and put together a number of big radiotelescope arrays and interferometers as well. With that you could not only track Voyager to several times its present distance, but you could communicate with every other functioning bird in space and do a hell of a lot of radioastronomy and SETI work too.

        Compare that to a very expensive, single-purpose mission. Just because something might be feasible (notice that we've never done anything of the sort before) doesn't mean that it makes any sense to try to do it.

    • Re:Relaying is silly (Score:3, Informative)

      by zardor ( 452852 )
      The Japenese Halca [nasda.go.jp] satellite, launched in 1997 had an 8 meter deployable dish, and it was supposed to be superceeded by something bigger (but funding got a bit tight of course)
      The "Trumpet" SigInt (Signals Intellegence) satellites, of which the NSA has launched 4 or so, have an absolutly HUGE dish. See Pic here [fas.org] Size is said to be in the region of 150-200 meters in diameter, in a very high orbit (either Moylina, or Geosync)
      (Of course, it needs to be that size to pick up your keystrokes and monitor radiation from orbit.)

      Karma cap reached, so mod somebody else up.
      • With a dish that big one spec of space debris would make the dish unusable.

        Actually I am surprised we don't see that happen more often with our shuttles and satellites that we send up.
        • The disk isn't that vunerable, mainly due to three reasons:
          1. Its in a fairly clean orbit, most of the manmade space junk is in low orbits.
          2. The dish is made up of a light mesh, so its mostly 'empty space', the actual 'cross section target area' is relativly small.
          3. At the frequencies that this disk is listening, you don't need a solid dish, so if a passing asteroid punches a 10 foot hole through it, it will still work. (although your signal strength and 'aiming sharpness' will be slightly degraded).

  • Useless information (Score:5, Interesting)

    by Mr.Intel ( 165870 ) <mrintel173@@@yahoo...com> on Thursday April 18, 2002 @11:54AM (#3366145) Homepage Journal
    Here is some useless information about the Voyager spacecraft...

    From the article:" Voyager 1 was launched on Sept. 5, 1977 and completed flyby exploration of both Jupiter and Saturn. The spacecraft now is rising above the ecliptic plane -- the plane in which most of the planets orbit the sun -- at an angle of about 35 degrees at a rate of about 520 million kilometers (about 320 million miles) a year.

    Voyager 2 was launched on Aug. 20, 1977 and also completed visits to Jupiter and Saturn and then went on to explore Uranus and Neptune, completing the reconnaissance of the giant outer planets. The spacecraft is now diving below the ecliptic plane at an angle of about 48 degrees and a rate of about 470 million kilometers (about 290 million miles) a year.

    So Voyager 1 is travelling at 320,000,000 miles per year. That is about 3090 m/s or 0.0103C. Not too shabby! Voyager 2 is at 290,000,000 miles per year or 2800 m/s or 0.0093C.

    I wonder what the fastest man made object is? Hmmm let's see, this [sunblock99.org.uk] page says that the Ulysses probe was the fastest at 15 km/sec. That's 15,000 m/s or 0.05C! Then this [nauts.com] page claims the Pioneer 10 was the fastest at 51,810 km/hour. That's 14,391.67 m/s or 0.04797C. So it looks like Ulysses wins. If you can find anything else to add to the list, please do!
    • Thanks for the info. (no sarcasm here) I was actually wondering about the article.

      The article says:
      "Voyager I was launched in 1977 to study and photograph the giant planets in the outer solar system...."

      and then later says:
      "A robotic twin of Voyager I left Earth in 1975 as well. Voyager II is heading in the opposite direction of Voyager I and traveling at a slightly slower speed."

      That confused the hell outta me. (Why would they name it "II" if it left 2 years earlier than "I"???)

      As for the fastest man-made object, Deep Space 1 would have it I believe with its ion drive (53,100 kilometers per hour):
      http://www.space.com/scienceastronomy/sola rsystem/ deepspace_propulsion_000816.html

      • My guess... (Score:2, Insightful)

        by niftyeric ( 467236 )
        Maybe they started building Voyager II after Voyager I, but finished Voyager II first and launched it first.

      • Re:Actually, not so useless... (Score:5, Informative)

        by Mr.Intel ( 165870 ) <mrintel173@@@yahoo...com> on Thursday April 18, 2002 @02:13PM (#3367694) Homepage Journal
        As for the fastest man-made object, Deep Space 1 would have it I believe with its ion drive (53,100 kilometers per hour): http://www.space.com/scienceastronomy/solarsystem/ deepspace_propulsion_000816.html

        That was just an estimate of capability. For actual speeds, check the official website out here [nasa.gov]. Also look at the log archives of the different staff members. Here [nasa.gov] you will see that as of July 29, 2001 it was travelling at 16.5 km/s! That's 16,500 m/s or 0.055C. So you are correct, it is the fastest man-made object so far.

        • I dont know what you ppl are talking about!!!!

          0.05C!!!!! *Are you MAD*?

          One-Twentieth the speed of light????????

          I was so astounded on seeing this, that I did the math myself.

          I dont know how can so many people commit this simple mistake.

          As far as I know, 16.5 km/s is just equal to 0.000055C. (Speed of light=300000km/s)

          It will not be in our lifetimes that we acheive speeds of OneTwentieth the speed of light.
      • Both Voyagers were launched in 1977, the article made a typo (notice the "as well" in there). Voyager II did leave a few months earlier, but it took a slower route, so it got to the outer planets after its older brother. The trade-off to being the second child and travelling slower is that it got to say a big "Howdy!" to Uranus and Neptune, in a glorious mission extension.
      • Why would they name it "II" if it left 2 years earlier than "I"??

        IIRC "2" was launched first and arrived at Jupiter second because it was in a longer transfer orbit.
    • well according to NASA
      http://vraptor.jpl.nasa.gov/voyager/pressrel/vgr 21 7.html

      Voyager 1's speed is 17.4 km/s
      Voyager 2's speed is 15.9 km/s

      http://spaceprojects.arc.nasa.gov/Space_Projects /p ioneer/PNStat.html

      Pioneer 10's speed is 12.24 km/s
      Pioneer 11's speed is 12 km/sec

      And by my calcualtions that makes their speed relative to c (~300,000,000 m/s) to be:
      V1: 0.000058 c
      V2: 0.000053 c
      P10: 0.0000408 c
      P11: 0.00004

      so it looks like you math was a bit off. Oh and incidentelly, 320,000,000 miles per year is about 16,000 m/s not 3090 m/s; and it looks like you used 300,000 m/s for c, not 300,000,000. Oops.
    • I'm afraid the speed of light is ~300,000 km/s, not m/s, so that 15km/s is .00005C, not .05C.

  • I'm gonna watch it again! (Score:2, Insightful)

    by whee ( 36911 )
    Even if it were technically feasible, it'd just add another possible point of failure. Trying to fix a problem in Voyager would be interesting if everything had to be relayed, and even more interesting if the relay itself had problems. If the information Voyager gathers is really that useful, they'll find a way to keep in contact.
    • I suppose they could always place a satellite in orbit around jupiter or something. The satellite would then be able to communicate and store data that it could relay next time earth is in the right trajectory.

      Now if only they could come up with sub-space communication these problems would be negligible. Though until then it is dreaming in front of the TV and using conventional radio frequencies to do the work.

    • Why would you want to relay the signal? You are in the vacuum of space where signals don't slow down or are interfered with. A relay would only create a greater chance of error.

      The fastest way between two points is a straight line.
  • http://slashdot.org/article.pl?sid=02/04/10/151825 3&mode=thread

  • that future probes consider <focus_paranoia>nuclear</focus_paranoia > reactors for long term power needs when solar panels no longer provide sufficient means?

    I know they got a bad rap after a Russian satellite equipped with a nuclear reactor crashed down into Canada a few years ago, but it seems like they'd be a good idea for interstellar probes of this kind.

  • Here is an article about voyager reaching the end of uor galaxy, the point where solar "rays" theoretically stop and interstellar space begins. http://vraptor.jpl.nasa.gov/voyager/vgrhelio_pr.ht ml

  • Some day... (Score:1, Interesting)

    by yzquxnet ( 133355 )
    Some day, in a museum some place, the voyager 1 probe will sit on display. (The actual one that is out there now). At some point we will have the capability to go out and actually retrieve the probe. Assuming something doesn't hit the probe and we have some means of locating it I don't see why it wouldn't be possible.
  • I would bet if anything is going to be picked up by other intelligent species in the galaxy (that originated from us), it is going to be Voyager I. We cannot be certain they watch the same electromagnetic frequencies we have been transmitting for the last 50+ years. We can, however, figure if someone is watching their skies like we do, they would eventually see this sucker whipping through deep-space all alone and emitting radio signals.

    We should send out another one some day that sends signals in ALL directions, like a beacon. Sure, it might get us blowed up good by some bad-assed ID4 type ETs but it might also put us in contact with the Vulcan type MFs.

    Just a rambling thought I guess.
    • We can, however, figure if someone is watching their skies like we do, they would eventually see this sucker whipping through deep-space all alone and emitting radio signals.

      You, my friend, have a common misconception of the volume of empty space out there. We can't see shit, metaphorically speaking. Given the distances involved in comparison with (1) the size of voyager and (2) the speed of voyager I really think it would be akin to releasing a dandilion seed on the continent of africa and hoping someone on the other side sees it one day.

      Check the numbers for the sizes and distances of the sun, the earth, and pluto.. then boil it down to scales we can see. If the sun was a basketball - how far away would the earth be from it, and how large would it be? What about pluto? Now, how far away from those objects is the next closest star?

      Given those distances and sizes, how big would voyager be and how fast is it moving?

      it boggles the mind, it does! :-)

    • (* We should send out another one some day that sends signals in ALL directions, like a beacon. *)

      It would be much more cost effective to send a strong signal from *earth* than send a weak one from just outside our sun.

      However, the last time native americans were friendly with the odd visitors, they got slammed. So perhaps we should keep our planetary trap shut.

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