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SKY
2003-Jan-30, 07:46 PM
A few years ago I was speaking to my uncle who retired from JPL and we were discussing the Voyager project. He told me that Voyager 1 was somewhere in the Oort cloud and we were still recieving signals from it.

I was wondering if anybody knew if we were still recieving signals from Voyager 1 & 2, and if we are, are we able to gather any information concerning that area of space from the signals (besides the obvious...it's cold).

I think the fact that we were still recieving signals a few years ago is a great testament to our technology. /phpBB/images/smiles/icon_smile.gif

Glom
2003-Jan-30, 08:25 PM
Indeed we are. Check here (http://www.jpl.nasa.gov/voyager/). The JPL website is full of great things.

The Voyagers are on their way to the heliopause, the boundary between the solar system and beyond. It's position varied because it is defined at the point where interstellar gases and solar driven material meet (or something along those lines) and so depending on how strong the solar wind is, the heliopause can be further out.

When they get there, they will become the first Terran spacecraft to leave the Solar system.

Voyager has got to be JPL's crowning achievement.

SKY
2003-Jan-30, 08:43 PM
Glom-

Thanks for the link, that has alot of info to keep anybody busy reading for quite a while. Amazing...over 25 years and still ticking. Definitely a crowning achievement for JPL. Thanks again.

Glom
2003-Jan-30, 08:53 PM
It's the nuclear power they used.

A selective choice of fingers being demonstrated before the no-nukes crowd.

SKY
2003-Jan-30, 09:02 PM
Termination Shock

While the exact location of the termination shock is not known, it is now estimated to be located at about 90 10 Astronomical Units (AU). As of March 2002, Voyager 1 is at 84 AU and should reach 90 AU by the end of 2003



This is a quote from a piece in the above link. You can get to it by clicking on the "Fast Facts" link. I was just wondering, what exactly is "Termination Shock"

ToSeek
2003-Jan-30, 09:25 PM
And let's not forget about Pioneers 10 and 11 (http://spaceprojects.arc.nasa.gov/Space_Projects/pioneer/PNhome.html), which have about five years on the Voyagers. Pioneer 10, at least, is still ticking, though only barely. (The last time data was successfully received was last April, though the signal is still detectable.)

aurorae
2003-Jan-30, 09:37 PM
On 2003-01-30 16:25, ToSeek wrote:
And let's not forget about Pioneers 10 and 11 (http://spaceprojects.arc.nasa.gov/Space_Projects/pioneer/PNhome.html), which have about five years on the Voyagers. Pioneer 10, at least, is still ticking, though only barely. (The last time data was successfully received was last April, though the signal is still detectable.)


Pioneer 10 was last heard from in December.

http://spaceprojects.arc.nasa.gov/Space_Projects/pioneer/PNStat.html

which says:

There was one more Pioneer 10 contact on 5 December 2002. The Deep Space Station (DSS) near Madrid (DSS-63) found the signal but could not lock onto the receiver, and so no telemetry was received. The signal level was just under the threshold value. The uplink from DSS-14 at Goldstone, sent 4 December 2002, at a power level of 325 kw, confirmed that the spacecraft signal is still there (Round Trip Light Time = 22 hr 24 min).

A cool thing is the page also mentions:

ARICEBO

SETI Institute also acquired the same signal at Puerto Rico. SETI has been using Pioneer 10 as a reference signal.

SKY
2003-Jan-30, 09:52 PM
On 2003-01-30 16:25, ToSeek wrote:
And let's not forget about Pioneers 10 and 11 (http://spaceprojects.arc.nasa.gov/Space_Projects/pioneer/PNhome.html), which have about five years on the Voyagers. Pioneer 10, at least, is still ticking, though only barely. (The last time data was successfully received was last April, though the signal is still detectable.)



Thanks ToSeek. I do not know much about the Pioneer missions mainly because Voyager 1 was launched just one year after I was born so I grew up hearing alot about the Voyager mission, and my uncle liked to talk about it alot. I remember he gave my family and I a tour of JPL when I was very young, and I remember listening to "The Golden Record" and all I could remember of it was alot of nature sounds and a repeated recording of children saying "We are the children of the earth". I also remember I was in a daze staring at a moon rock they had locked in a glass case, I was so amazed that a piece of the moon was right in front of me. Man, I need to take another tour of that place.

Tim Thompson
2003-Jan-31, 10:39 PM
I've been at JPL for 22 years, in time to be here for Voyager II at Saturn, Uranus & Neptune. For the Uranus & Neptune encounters, I was helping out the Voyager Radio Science Team. We were trying to use radio emission from the planets to derive the strength & rotation period of the magnetuc fields. We had to stay up all night, but we scooped the magnetometer team (they have to wait for Voyager to reach the magnetic field, but when they get there, they get better results than we could). There was a brief period in the middle of the night when we were the only people on Earth who realized how far the magnetic fields were tilted from the spin axis. Cool.

During the early encounters (I was a guest on lab for at lest one Jupiter encounter), reporters & anonymous employees hung out together in the main cafeteria and watched the images come done in real time on closed circuit TV. But somewhere along the line, somebody realized the PR value. For the Uranus & Neptune encounters, the reporters & employees were rigorously segregated, the reporters managed by PR folks at all times.

As of March 2002 (according to the webpage), Voyager I was 84 AU out, and Voyager II was 65 AU out. That's farther than Pluto's apahelion distance of 48 AU. It's even farther out than the 50 AU edge of the dense Kuiper Belt (see Plan View of Kuiper Belt (http://www.ifa.hawaii.edu/~jewitt/kb/kb-plan.html)), but there are a few Kuiper Belt objects on the plan view that reach out to 150 AU and one beyond 200 AU (though the voyager orbits are inclined well above & below the Kuiper Belt).

So it's safe to say that the Voyagers are at Kuiper Belt distances & beyond. But the Oort cloud is proabably on the order of 50,000 AU out, so we are well short of that. What we really hope for is that the Voyagers will meet the heliopause (http://www.aip.org/enews/physnews/1998/split/pnu367-3.htm), the boundary between the solar magnetosphere and unadorned interstellar space. It was thought that they had spotted evidence of the approaching heliopause in 1993 (press release (http://www-pw.physics.uiowa.edu/plasma-wave/voyager/heliopr.html)), but so far as I know, neither voyager has reached it yet. If the heliopause is really as close as 90 AU, then Voyager I might break out some time soon.