Voyager Spacecraft Celebrate 30th Anniversary

Raver32 writes to mention that 30 years after the original launch of Voyager 2, both Voyager spacecraft are still going strong. Flying away from us some billions of miles from our solar system's edge they continue to be a wealth of information more than 25 years after their original mission concluded. Voyager 1 currently is the farthest human-made object at a distance from the sun of about 9.7 billion miles (15.6 billion kilometers). Voyager 2 is about 7.8 billion miles (12.6 billion kilometers).

Comments

Too bad...

[Kagura]

A little off-topic and out of left field, but it's too bad these probes are three-axis stabilized, which means they cannot help us figure out exactly what is going on with the Pioneer anomaly. The anomaly even featured as an Unsolved Problem of Physics on Wikipedia.

Re:Too bad...

[nutshell42]

I kinda hope there's not a trivial explanation (i.e. not a measurement error, non-uniform radiation pressure etc.)

Our current model for how the universe works is way off ( >90% of the universe are dark matter and dark energy) and any clues on when and how reality deviates from theory should be quite interesting.

Remarkable Spacecraft

[decipher_saint]

Both Voyager I & II are amazing pieces of technology. Still giving us valuable information about the universe in which we live. So, kudos NASA but particularly to the development and current project teams at JPL.

Re:Remarkable Spacecraft

[Iskender]

Let's not forget what makes these probes possible: nuclear power, more specifically RTGs. No, I'm not trying to glorify nuclear, but we simply don't have the technology to make something equally robust at anything approaching a reasonable price and launch weight. So for the moment, RTGs it is for outer solar system probes, and nuclear reactors should be given consideration if they make more valuable science possible (remember, the Russians already used some of those in space AND had them fail, so they won't be the end of us).

Re:Remarkable Spacecraft

[niktemadur]

The two Voyagers, as well the two Pioneer probes, are barely on the edge of the heliopause (around 85 AUs from the Sun). It is speculated that the Oort Cloud begins around 750 AUs from the Sun. As it's taken 30 years to travel 85 AUs, it'll be approximately 250 years before the probes enter the proposed inner boundary of the Oort Cloud.
A quick footnote: Voyager 1, thanks to the particular trajectory chosen for it, is a bit further away than the other three probes, around 100 AUs away from the Sun.

Now here's the clincher: Voyagers' batteries are supposed to last another 15-20 years at most. As for the Pioneers, the last signal from Pioneer 10 was registered in 2003, from Pioneer 11 in 2005. On blueprint, they still have a bit of juice left, but their distances from Earth are so great that there's no current instrument that can pick up their incredibly weak signal.

Anyhow, by the time the Voyagers and Pioneers reach the Oort Cloud, they'll have been stone cold dead for centuries.

These spacecraft fascinate me more today than back in their prime-time heyday. Most people think that when Voyager 2 flew by Neptune, the planetary team moved out of JPL and that was that. Yet the current team moved in and the really hardcore adventure really kicked into gear. These things just kept going and sailed right off the edge!

Re:Remarkable Spacecraft

[StarfishOne]

I once read that the strength of this incredibly weak signal was not the problem. After doing a search, I discovered that it is indeed the decaying (pun intended) power supply and not the communication signal that will become the problem when it comes to communicating with those probes in decades/centuries to come:

"* Barring any serious spacecraft subsystem failures, the Voyagers may survive until the early twenty-first century (~ 2020), when diminishing power and hydrazine levels will prevent further operation. Were it not for these dwindling consumables and the possibility of losing lock on the faint Sun, our tracking antennas could continue to "talk" with the Voyagers for another century or two!"

http://voyager.jpl.nasa.gov/mission/didyouknow.htm l

Re:Remarkable Spacecraft

[niktemadur]

It seems that you're absolutely right. I did some further reading since I posted, and here's what I came up with:

Pioneer 11, for example, had a constant power supply of 144W upon arrival to Jupiter, but by the time it got to Saturn, that figure had decreased to 100W. By the time they lost contact with it, the figure must have been much lower, and still they lost the signal only because its' antenna's alignment with Earth had been lost. BTW, there's a typo in my original post, as last contact with Pioneer 11 was not in 2005, but in 1995.
Pioneer 10, however, with the same specs as Pioneer 11, never lost telemetry, so the final verdict is that its' batteries simply petered out. Which is to say, signal strength did finally cross the threshold, due to the dying juice supply.

Compare this with the Voyagers, which upon launch generated 420W of power, and I think your point becomes apparent.

Then of course, in all four craft, some instruments were switched off after the planetary tours, to divert crucial power supply to the absolutely essential components of the following phase of the mission.

One final thought: how low does transmitter strength have to go before it fades away, from that distance? Something like one of those gizmos you hook up to an iPod so you can listen to it in your car radio?

Re:Remarkable Spacecraft

[StarfishOne]

I'm not a specialist when it comes to transmitters and receivers, but I found a few more bits of information that you might find interesting:

"After launch, Pioneer 10 was capable of transmitting data at a maximum data rate of 2408 bits per second. Now the data rate is 16 bits per second. Reducing the bit rate compensates for the reduced signal strength; it is like speaking more slowly to enunciate more clearly. The signal strength from the craft's main transmitter is now about 7.8 watts; by the time it reaches the DSN antennas, the signal has diminished to less than a billionth of a trillionth (10-21) of a watt."

http://www.newscientist.com/article/mg13318105.500 -pioneer-the-persistent-probe-pioneer-10-the-first spacecraft-to-head-for-jupiter-proved-that-probes- could-reach-the-outerplanets-of-our-solar-system-t wenty-years-on-it-is-sending-us-messagesfrominters tellar-space.html

Deep space tracking station - http://personal.ee.surrey.ac.uk/Personal/D.Jefferi es/tidbin.html

"Successfully sending a DSN signal into Voyager-2's receiver is like throwing a baseball across thousands of miles of ocean into a porthole of a moving cruise ship."

http://www.spacetoday.org/SolSys/DeepSpaceNetwork/ DeepSpaceNetwork.html

I just cannot praise the people who made and make this project possible enough. The facts are jaw dropping!

IMHO

[StarfishOne]

The Voyagers belong somewhere in the top of the list with the most amazing machines ever developed by humans.

Every time I see the "Interesting Facts about the Voyager Mission" page [1] and "Fast Facts" page [2] at NASA's JPL, I am just amazed that this was achieved with technology from the early '70s!

I often find myself wishing that I was born earlier and that I was part of the team of man and women who pushed so many of our frontiers so much further then ever before.

*raises glass*

To the Voyagers! [3]

[1] http://voyager.jpl.nasa.gov/mission/didyouknow.htm l
[2] http://voyager.jpl.nasa.gov/mission/fastfacts.html
[3] Voyager 1 will celebrate it's 30th anniversary on september 5th, so let's celebrate both achievements ;)

Re:IMHO

[ConceptJunkie]

And the amazing thing was that Voyager was not initially supposed to go to Uranus or Neptune, or that the NASA boffins managed to re-engineer the thing from over a billion miles away to take better pictures.

Re:Ping?

[Arceliar]

Actually, my math was way off on that, it'd be like 28 hours to ping it, but you get the point. It'd take a while.

The really amazing thing

[edwardpickman]

The distance actually can be measured in light hours and I'll probably live to see it go into a light day distant and some on the forum may see it hit two light days, young teens with long lives. Puts interstellar travel into perspective.

technology from the 70s was quite good enough

[swschrad]

and isn't it curious how we can still find ways to play Edison cylinders, decode stone heiroglyphs, communicate at the edge of the solar wind with a handful of transistors ruggedized and wired in very conservative circuits...

and we can't find a drive to read a 5-1/4 inch floppy in? can't play a Betamax tape?

good enough is good enough, you don't have to spend a billion on a whole new infrastructure to get one project done.

Re:technology from the 70s was quite good enough

[jd]

Well, some hieroglyphs. There are a good few hundred languages from the days of writing on stone or in clay that cannot be deciphered and quite likely never will be. I find the study of ancient languages fascinating, as they were never intended to be DRMed - uhh, unreadable, but they have become so. At the present time, nobody has successfully used computers to assist in decoding such languages except in the limited sense of counting sign combinations. This seems like a superb application, but it is also an unsolved application. Nobody, nobody at all, knows how.

When it comes to old technologies, some things are superb and some things have proven a disaster. Floppies didn't start with the 5.25" - the 8" was older and is even less readable. Long before floppies, you had core memory. Good for 100+ years! But in less than half that time, I doubt there are many systems that could actually read the damn thing without wiping it. (Core was destructive on read, so you had to perform a write for every read into the correct address space.)

On ancient technology, more than one archaeological site has been utterly destroyed - partially or totally unmapped and unstudied - because some country or other wanted to build a dam. Water is important, sure, but you can collect water in any number of ways, and even if the dam is imperative, it'll take years to decades to build. Allowing scientists a few months to collect irreplaceable data isn't going to kill anyone or anything. Denying them does kill our chances of understanding the past. We only have one history, once it's gone, it's gone. It is, sadly, very easy to destroy and politicians have done much to destroy it.

Farthest Man Made Object? I duno....

[Tmack]

Voyager 1 currently is the farthest human-made object at a distance from the sun of about 9.7 billion miles (15.6 billion kilometers). Voyager 2 is about 7.8 billion miles (12.6 billion kilometers).

I think theres Another contender for that title...

Tm

Re:Farthest Man Made Object? I duno....

[Anonymous Coward]

Two actually... this one has more confirmation that it actually was launched, and had a better chance of escaping earth.

tm

Re:Farthest Man Made Object? I duno....

[pjt33]

That's without even raising the question of what constitutes an object. If photons or neutrinos count...

Re:Interstellar space

[m.dillon]

Its always possible to spec very reliable parts, as well as over-engineer equipment to handle degredation. It just costs a lot more for those sorts components verses the mass-produced junk you see in most consumer electronics. The market is there, its just a lot smaller.

There's still computing equipment out in the field going strong that I designed 20 years ago. They were 68000 based computers with dynamic ram, with everything overengineered by 2x (including running the cpu at 1/2 the clock frequency in production that it was tested at during burn-in, specing resistors for far more current then they were expected to handle, refreshing the ram at 2x the required rate, specing capacitors for almost 2x the voltage they were expected to handle, and throwing a dozen zeners all over the motherboard to protect all the regulated voltage busses). Virtually unbreakable. One even operated for over two weeks completely submerged when a station got flooded before corrosion shorted it out. Some scraping and A good washing in a washing machine (no heat), and after careful drying and replacing a fuse it was ready to go again!

-Matt

Mission Planning Engineer on Voyager 2; Re:IMHO

[Anonymous Coward]

I was Mission Planning Engineer on Voyager 2, after the Saturn flyby, and in preparation for the Uranus flyby.

I mentioned this on emails that I sent to my friends today. I also mentioned it on an email that I sent to the principal of Balir IB Magnet High School in Pasadena, where in summer school earlier this month I gave a final exam question based on my Voyager 2 experience.

59. Uranus (19.6 AU from the sun), at 14 Earth masses,
is the lightest of the outer planets. Uniquely among
the planets, it orbits the Sun on its side; its axial
tilt is over ninety degrees to the ecliptic. It has a
much colder core than the other gas giants, and
radiates very little heat into space. Uranus has
twenty-seven known satellites), the largest ones being
Titania, Oberon, Umbriel, Ariel and Miranda.
        I was the Mission Planning Engineer responsible
for designing how many photographs the Voyager 2
spacecraft took of Miranda, as it flew past Uranus and
its moons.
        If we estimate the length of time it takes light
to travel from the Sun to the Earth as 8 minutes, how
long does it take for light to travel from the Sun to
Uranus?

I saw the Principal today. He's awaiting enrollment numbers from the school district, to determine if he'll have the budget to hire me full time as of Labor Day. If not, a rival high school's acting principal wants me immediately to teach Physics.

-- Prof. Jonathan Vos Post

I was 17

[p51d007]

and beginning my senior year of high school when those were launched. For those of you too young..........we had PONG and THAT was it! No cell phone, no internet, no video games. Telephones had these things called rotary dials. You couldn't call someone in another city, sometimes, without going through the operator. There were only THREE kinds of gasoline. Leaded (for the older cars), diesel, & unleaded. We didn't have the 5-6 types of unleaded, JUST ONE. Cars costs an average of 5-8 thousand dollars BRAND NEW. Of course, they fell apart, looked like boxes, and were noisy. For music, there were a couple of FM radio stations, most cars had AM, some had FM, and if it was REALLY fancy, it had (get this) an 8 TRACK TAPE player. Oh, we walked up hill 10 miles to school in the snow every day...both ways....LOL

Re:I liked the part....

[TheRaven64]

It has so far travelled around 0.001 light years. At its current rate, it will have to travel for a at least sixty millennia before it's closer to any other start than ours (assuming one was launched in the direction of Proxima). It would have to go near another star and sling-shot off in a different direction before there could be any doubt as to which solar system launched it. Once you know that, you just need to pick the planet with all of the crap in orbit.

If we discover some form of faster than light (or even near-C) travel in the next 120 millennia, then we will get to the nearest stars long before it does. If we don't, then either we've wiped ourselves out or such a form of travel isn't possible at all (120,000 years is a really long time for technology; it only took 4,000 to go from horse taming to mobile phones and space shuttles). If we've wiped ourselves out without developing interstellar travel, then it will probably be tens of millions of years before the probe goes anywhere near an inhabited system (if it ever does), by which time there is unlikely much evidence that we ever inhabited this planet. In this case, it's quite possible that the probes to be our last memorial. I wonder if anyone will ever see them...

Re:I liked the part....

[Opportunist]

No matter whether we're still alive (well, humanity, not you and me), should this craft be caught by some alien it can have some serious impact for their culture.

Imagine we noticed something artificial flying by. We needn't even be able to catch and examine it, just imagine the Hubble telescope picks up some item that is without a doubt artificial. Even after millenia of interstellar travel, a probe is still not an asteroid. It will be heavily damaged and probably look barely like the probe that was launched, but it will no less be clearly evident that some intelligence shaped it.

How would we react if we found something like that? Most certainly it would be an answer to the eternal question whether we're alone in the universe. Not only statistically (with so many stars and so many planets it's near impossible that we're really alone), but we would have hard proof that there is or at least was some other civilisation that was at the very least so advanced that they could create spaceship.

I'm fairly sure that this would increase our own interest in space. It would most certainly mean better funding for space exploration, maybe it would also mean a lot of fear of an "alien invasion", as ridiculous as it may be (when Voyager reaches any other solar system, we will either already be there or no longer alive, it is likely that the same applies for other civilisations). But the impact would be there, and I'm fairly sure that it would be large. No matter if the civilisation that created the probe still exists or not.

And I can remember...

[SIGBUS]

...when one of the "upcoming events" that was in FidoNet's FidoNews was "August 24 1989: Voyager 2 passes Neptune." Scary to think it was that long ago - it seems like only yesterday.

Re:From a time when NASA actually "worked"

[shutdown -p now]

Everyone knows Gagarin, but who knows Korolyov?

In the USSR, every kid knew about both. Times are different now, of course...