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Sunspot
http://planetary.org/news/2005/voyager-upd...ation_0524.html

Voyager 1, the most distant human-made object in space, has crossed the termination shock, the last major threshold in the solar system, team members announced today at the annual American Geophysical Union (AGU) meeting in New Orleans, Louisiana.
spaceffm
Do You think it is possible to see a picture towards the sun wikthout magnifictaion?
Is Voyager still this functionial?
djellison
QUOTE (spaceffm @ Jun 4 2005, 01:45 AM)
Is Voyager still this functionial?
*


No, basically smile.gif

Doug
edstrick
The instruments on the scan platforms have been turned off. The last camera use was the look back across the solar system that caught the "pale blue dot". The ultraviolet spectrometer was in use as a poor-man's ultraviolet astronomy spectroscopy satellite for some years, but was finally retired. Heaters on the instruments and scan platform gear-boxes are off so they've all cooled to various near-cryogenic temperature levels, far outside their design survivability ranges. Thermal contraction of materials has probably broken solder joints and the like.

The voyagers probably have not enough power to run anything on the scan platforms now, anyway, even if they weren't probably broken by the cooldown.
PhilCo126
I thought it would last untill 2015 before the first VOYAGER spacecraft will be in interstellar space ...
ljk4-1
QUOTE (PhilCo126 @ Nov 13 2005, 12:48 PM)
I thought it would last untill 2015 before the first VOYAGER spacecraft will be in interstellar space ...
*


I went to the official NASA/JPL Web site on the Voyagers and found this:

http://voyager.jpl.nasa.gov/mission/weekly-reports/index.htm

And if you go to the home Voyager page, they have links to the latest science data from the probes from this year. Go here and look on the left column under Latest Browse Data:

http://voyager.jpl.nasa.gov/

This page has a rundown of what the Voyagers will be doing through the year 2020, when it is thought they will finally be unable to power even a single instrument:

http://voyager.jpl.nasa.gov/spacecraft/spacecraftlife.html
The Messenger
QUOTE (ljk4-1 @ Nov 14 2005, 08:52 AM)
I went to the official NASA/JPL Web site on the Voyagers and found this...

I pulled up some of data, the increase in cosmic ray count is an eye opener, at least doubling, if not more over the last two years. I am also intregued by the the fact that the plutonium powered system is producing more energy than expected. Over the short term, this can be written off as better-than-expected aging of the thermalcouples; but the trend looks like it is gnawing away at three sigma limits.

Wouldn't it be a hoot if radioactive half-lifes turn out to vary as a function of AU? Could the increase in cosmic rays be effecting the decay rate?
deglr6328
3-Sigma limits of what? Has anyone ever even studied thermoelectric junction degradation rate fluctuations over a period of 30 years?
mike
I wouldn't complain if the increase in cosmic rays (or something else out there) was somehow recharging the power supply (employ a more scientific-sounding explanation if you like)..
ljk4-1
http://voyager.jpl.nasa.gov/mission/weekly-reports/index.htm

Voyager Mission Operations Status Report # 2005-11-11, Week Ending November 11, 2005

Command Transmission & Verification Operations

Voyager 1 command operations consisted of the uplink of a command loss timer reset on 11/08 [DOY 312/1625z]. The spacecraft received the command.

There were no Voyager 2 command operations due to the extended downtime of DSS-43.

Sequence Generation Operations

Continue sequence development of CCSL B131.

Data Return Operations

Voyager 1 Data Processing and Operations:

There were 83.2 hours of DSN scheduled support for Voyager 1 of which 28.1 hours were large aperture coverage. There was one schedule change made on 11/09 [DOY 313] when 3.5 hours of DSS-65 support was released to support MUSC. The total actual support for the period was 79.7 hours of which 28.1 hours were large aperture coverage. There were no significant outages during the period

Science instrument performance was nominal for all activities during this period. One frame of GS-4 data was recorded this week. A second frame of GS-4 data was recorded on day 309. The EDR backlog is 9 days.

Voyager 2 Data Processing and Operations:

There were 54.5 hours of DSN scheduled support for Voyager 2 of which 0 hours were large aperture coverage. There was one schedule change made on 11/09 [DOY 313] when 2.5 hours of DSS-45 support was released to support MUSC. The total actual support for the period was 52.0 hours of which 0 hours were large aperture coverage.

There was one significant outage of 0.7 hours on 11/08 [DOY 312] due to a sub-reflector problem at DSS-45 [DR C104604].

Science instrument performance was nominal for all activities during this period. One frame of GS-4 data was recorded this week. The EDR backlog is 8 days.

Flight System Performance

Voyager 1 performance was nominal during this report period. Activities included a PMPCAL and switching to Band Low Power on 11/9 (DOY 313/314).

Voyager 2 performance was nominal during this report period.

PROPELLANT/POWER CONSUMABLES STATUS AS OF THIS REPORT

Spacecraft
Consumption

One Week (Gm)
Propellant

Remaining (Kg)
Output

(Watts)
Margin

(Watts)

1
50.34*
28.58
292.9
35

2
7.87
30.49
294.5
41


*MAGROL 05-308/21:45

RANGE, VELOCITY AND ROUND TRIP LIGHT TIME AS OF 11/11/2005

Voyager 1
Voyager 2

Distance from the Sun (Km)
14,558,000,000
11,671,000,000

Distance from the Sun (Mi)
9,046,000,000
7,252,000,000

Distance from the Earth (Km)
14,669,000,000
11,736,000,000

Distance from the Earth (Mi)
9,115,000,000
7,292,000,000

Total Distance Traveled Since Launch (Km)
17,312,000,000
16,308,000,000

Total Distance Traveled Since Launch (Mi)
10,757,000,000
10,134,000,000

Velocity Relative to Sun (Km/sec)
17.162
15.610

Velocity Relative to Sun (Mi/hr)
38,390
34,919

Velocity Relative to Earth (Km/sec)
40.552
41.500

Velocity Relative to Earth (Mi/hr)
90,711
92,832

Round Trip Light Time (hh:mm:ss)
27:10:20
21:44:54
Rob Pinnegar
QUOTE (ljk4-1 @ Jan 11 2006, 04:32 PM)
Distance from the Sun (Mi)
9,046,000,000
7,252,000,000


Looks like Voyager 1 will pass 100 AU pretty soon. Not a scientifically important point, but significant in its own way.
ljk4-1
Voyager Mission Status 11/18/2005 and 11/25/2005:

http://voyager.jpl.nasa.gov/mission/weekly-reports/index.htm

Feature video in the main Voyager page:

http://voyager.jpl.nasa.gov/index.html

'Voyager enters the Heliosheath' by the Voyager Project Scientist, Dr. Ed Stone.
ljk4-1
COSMIC RAY MYSTERY SOLVED
-------------------------

When Voyager 1 finally crossed the "termination shock" at the edge of
interstellar space in December 2004, space physicists anticipated the
long-sought discovery of the source of anomalous cosmic rays. These cosmic
rays, among the most energetic particle radiation in the solar system, are
thought to be produced at the termination shock - the boundary at the edge
of the solar system where the million-mile-per-hour solar wind abruptly
slows. A mystery unfolded instead when Voyager data showed 20 years of
predictions to be wrong.

...

The paper, "An Explanation of the Voyager Paradox: Particle Acceleration at a
Blunt Termination Shock," is available in the February 17 issue of the Geophysical
Research Letters.

http://spaceflightnow.com/news/n0602/19voyager/
ljk4-1
Astrophysics, abstract
astro-ph/0603318

From: Merav Opher [view email]

Date: Mon, 13 Mar 2006 19:30:59 GMT (539kb)

Effects of a Local Interstellar Magnetic Field on Voyager 1 and 2 Observations

Authors: Merav Opher, Edward C. Stone, Paulett C. Liewer

Comments: 12 pages, 5 figures

Journal-ref: Astrophysical Journal Letters v.640, 71, 2006

We show that that an interstellar magnetic field can produce a north/south asymmetry in solar wind termination shock. Using Voyager 1 and 2 measurements, we suggest that the angle $\alpha$ between the interstellar wind velocity and magnetic field is $30^{\circ} < \alpha < 60^{\circ}$. The distortion of the shock is such that termination shock particles could stream outward along the spiral interplanetary magnetic field connecting Voyager 1 to the shock when the spacecraft was within $\sim 2~AU$ of the shock. The shock distortion is larger in the southern hemisphere, and Voyager 2 could be connected to the shock when it is within $\sim 5~AU$ of the shock, but with particles from the shock streaming inward along the field. Tighter constraints on the interstellar magnetic field should be possible when Voyager 2 crosses the shock in the next several years.

http://fr.arxiv.org/abs/astro-ph/0603318
dilo
From updated solar wind speed diagram, Voyager-2 experienced a repentine increase (more than 100 Km/s) at the end of February/beginning of March.
In my understanding, transition through termination shock should produce a dramatic wind speed decrease, so this is not the case... Anyway still intriguing, because even if in the past Voyager-2 already observed speed close to 500 Km/s, now increase seems more repentine and appear associated to one of the largest ions density spikes ever observed by the spacecraft...
Any suggestion?
Rem31
QUOTE (dilo @ Mar 17 2006, 12:32 AM) *
From updated solar wind speed diagram, Voyager-2 experienced a repentine increase (more than 100 Km/s) at the end of February/beginning of March.
In my understanding, transition through termination shock should produce a dramatic wind speed decrease, so this is not the case... Anyway still intriguing, because even if in the past Voyager-2 already observed speed close to 500 Km/s, now increase seems more repentine and appear associated to one of the largest ions density spikes ever observed by the spacecraft...
Any suggestion?

How bright is the light of the sun at the place where the pioneers and the voyagers are at (this) moment? Or is it completely dark there now ,please can you tell me that? Thanks.
Rob Pinnegar
QUOTE (Rem31 @ Mar 24 2006, 08:13 PM) *
How bright is the light of the sun at the place where the pioneers and the voyagers are at (this) moment? Or is it completely dark there now ,please can you tell me that? Thanks.

Well, the apparent brightness of the Sun varies as the inverse square of your distance from the Sun. Right now Voyager 1 is about a hundred times farther from the Sun than we are. So that means that, as seen from Voyager 1, the Sun is about one ten-thousandth as bright as what we are used to.

That's still about 500 times brighter than a full Moon, though. So although the Sun would look like a star from Voyager 1, it would be a really, really bright star.
dilo
Something is definitely happening around Voyager-2!
Last nucleon data shows that, after 10 months of caothic behavior, density dropped to very low levels; in the meantime, wind speed stopped the regular descent (after the step-up previously noticed) and started to go up and down on a hourly scale (density and velocity seems to have a complementary behaviour...).
I do not recall what exactly happened to Voyager-1 density data (any help?), but I strongly suspect termination shock is very close... or already passed!
dilo
Based on Solar System Simulator, Voyager-2 is only 79.6AU from Sun: considering also the unfavorable heading direction, is too early for a termination shock encounter (but not impossible, it depends also from solar activity!).
Meanwhile, it is interesting to highlight that Voyager-1 is now only 130million Km from the 100 AU milestone! Should happens at mid August... I have to prepare some champagle bottle rolleyes.gif
Bob Shaw
QUOTE (Rob Pinnegar @ Mar 25 2006, 07:40 PM) *
Well, the apparent brightness of the Sun varies as the inverse square of your distance from the Sun. Right now Voyager 1 is about a hundred times farther from the Sun than we are. So that means that, as seen from Voyager 1, the Sun is about one ten-thousandth as bright as what we are used to.

That's still about 500 times brighter than a full Moon, though. So although the Sun would look like a star from Voyager 1, it would be a really, really bright star.


Rob:

Any idea how far from the Sun the human eye can still see colour rather than using monochrome 'night' vision?

Bob Shaw
Myran
QUOTE
Dilo wrote: .....but I strongly suspect termination shock is very close... or already passed!


What you retold makes me wonder if that might be the case, and Voyager 2 might have reached the heliopause. Thank you or the heads up.
ljk4-1
Podcast Advisory May 23, 2006

Voyager: Still Going Strong After Nearly 30 Years

NASA's twin Voyager spacecraft are beaming back new information about the final frontier of our solar system, including evidence of "potholes" in the turbulent zone near the edge.

A podcast, featuring an interview with Voyager Project Scientist Dr. Ed Stone of Caltech, is online at http://www.jpl.nasa.gov/multimedia/podcast/voyager-20060523/ . The interview includes information about the latest findings, as well as highlights from the past 29 years of the Voyagers' journeys through space.

More information on the Voyager spacecraft is available at http://voyager.jpl.nasa.gov/ and www.nasa.gov/voyager .

Voyager 1 and 2 launched in 1977 on a mission to study the outer planets of our solar system, and they are now on their way to becoming the first spacecraft to leave our solar system.

Additional JPL podcasts are at http://www.jpl.nasa.gov/multimedia/indexPod.cfm .
climber
[quote name='ljk4-1' date='May 23 2006, 10:56 PM' post='55471']
Voyager 1 and 2 launched in 1977 on a mission to study the outer planets of our solar system, and they are now on their way to becoming the first spacecraft to leave our solar system.


I thought Pioneer 10 & 11 were considered been the first.
By the way, Ed Stone was already there at last encounter with Neptune back in 1989. He's got to have faith in what he does to carry out the VIM (is that correct Voyager Insterstellar Mission ?) since it's apparently look less rewarding after "The Grand Tour". Hat off Mister Stone.
dilo
Climber, Pioneer didn't reached the heliopause because they are slower.
This is clear looking to distances from Sun, calculated by Solar System Simulator and ranked in descending order:
Voyager-1: 99.2 AU
Pioneer-10: 90.6 AU
Voyager-2: 79.7 AU
Pioneer-11: 69.9 AU
(hey, they are almost equally spaced in this moment!)
In particular, Pioneer-10 was surpassed by Voyager-1 several years ago and, anyway, now is inactive...

Thanks, ljk4-1 for the interview highlight. The words of Dr. Ed Stone confirm that Voyager entered in a new region as I suspected, but still to reach the heliopause which should be 5 AU ahead!
ljk4-1
Voyager 2 Detects Odd Shape of Solar System's Edge

http://www.space.com/scienceastronomy/0605...here_shape.html

Voyager 2 could pass beyond the outermost layer of our solar system, called the
"termination shock," sometime within the next year, NASA scientists announced at
a media teleconference today.
climber
[quote name='dilo' date='May 24 2006, 12:20 AM' post='55486']
Climber, Pioneer didn't reached the heliopause because they are slower.
This is clear looking to distances from Sun, calculated by Solar System Simulator and ranked in descending order:
Voyager-1: 99.2 AU
Pioneer-10: 90.6 AU
Voyager-2: 79.7 AU
Pioneer-11: 69.9 AU
(hey, they are almost equally spaced in this moment!)
In particular, Pioneer-10 was surpassed by Voyager-1 several years ago and, anyway, now is inactive...


Thanks Dilo. Doesn't show very well in the numbers anyway.
Pioneer 10 deserve to has been the first one to be launched with an interstellar "destination" (as a by product), and Pionner 11 the second... and they will.
PhilCo126
The greatest traveller of all times ! wink.gif
Analyst
Do you have a link to the press kit? Or a press kit etc. of any of the other encounters?

Analyst
SigurRosFan
QUOTE (dilo @ May 15 2006, 11:47 PM) *
Based on Solar System Simulator, Voyager-2 is only 79.6AU from Sun: considering also the unfavorable heading direction, is too early for a termination shock encounter (but not impossible, it depends also from solar activity!).
Meanwhile, it is interesting to highlight that Voyager-1 is now only 130million Km from the 100 AU milestone! Should happens at mid August... I have to prepare some champagle bottle rolleyes.gif

Yes, it should happens on August 17, 2006!

- http://voyager.jpl.nasa.gov/science/Vgrlocations.pdf
ljk4-1
Voyager Data May Reveal Trajectory Of Solar System

Newport Beach CA (SPX) Jun 01, 2006

Nearly 30 years after launch, the two Voyager spacecraft are still operational and returning useful data. In their early years they produced some of the first close up images of the large outer planets.

http://www.spacedaily.com/reports/Voyager_...lar_System.html
ljk4-1
PHYSICS NEWS UPDATE

The American Institute of Physics Bulletin of Physics News

Number 778 May 26, 2006 by Phillip F. Schewe, Ben Stein,
and Davide Castelvecchi www.aip.org/pnu

THE MISSHAPEN SOLAR SYSTEM. Having traveled far beyond the planets
in their 28.5-year journey, the two Voyager spacecraft are providing
new information on the heliosphere, the teardrop-shaped bubble that
separates the solar system from interstellar space. At this week's
Joint Assembly Meeting in Baltimore of the American Geophysical
Union (AGU) and several other geophysics-related societies, Ed Stone
of Caltech reported that the heliosphere is deformed, according to
Voyager observations, with the teardrop's rounded edge bulging at
the top (the northern hemisphere of the solar system) and squashed
at the bottom (the southern hemisphere). (See pictures and movies at
http://www.nasa.gov/vision/universe/solars...er_2006agu.html
) As Rob Decker of Johns Hopkins University Applied Physics
Laboratory explained, the asymmetry is due to a magnetic field from
interstellar space pushing on the southern hemisphere. The field is
about 1/100,000 the strength of Earth's field but its effects can be
felt for billions of miles, since it is acting over a large area on
the very dilute gas at the solar system's edge.

The interstellar field even squashes an important spherical zone
inside the heliosphere, called the termination shock. Analogous to
the circle that forms when water splatters on a sink, the
termination shock represents the boundary at which the rapidly
traveling solar wind (the stream of charged gas from the sun) slows
down abruptly and piles up. Voyager 2's measurements indicate that
the southern part of the termination sphere might be a billion miles
closer to the sun than the northern part. Moreover, forces from the
solar wind cause the termination shock to breathe in and out roughly
every dozen years. Voyager 1 has already ventured beyond the
termination shock, to the heliosheath, the region where solar wind
and interstellar gas mix. So in a way, the end of the solar system
is not clearly defined. Stone guesses it could be another 10 years
(3-4 billion miles) before the two spacecraft pass through the
heliopause (the very outermost boundary of the heliosphere) and
enter purely interstellar space. The spacecraft have about another
15 years of power left in them. (Session SH02 at meeting; see
http://www.agu.org/meetings/ja06/?content=search)



QUOTE (Analyst @ May 27 2006, 02:39 AM) *
Do you have a link to the press kit? Or a press kit etc. of any of the other encounters?

Analyst


There is the Voyager Neptune Travel Guide online:

http://ntrs.nasa.gov/archive/nasa/casi.ntr..._1990004096.pdf

Other online Voyager documents from NASA can be found here by
scrolling all the way down (the spacecraft are listed in alphabetical order):

http://www.geocities.com/bobandrepont/unmannedpdf.htm
ljk4-1
Voyager Reports March 3, 2006 to March 24, 2006 Available

http://voyager.jpl.nasa.gov/mission/weekly-reports/index.htm
MCS
There's a new story at science.nasa.gov about some of the things Voyager 1 has found within the heliosheath. Magnetic turbulence, a slower than expected solar wind, and unexpected anomalous cosmic ray intensities are the main things mentioned. I hope this helps make the case for continued funding.
dilo
This is not exactly a new: Voyager 2 entered the heliosheath on August 30, 2007.
http://voyager.jpl.nasa.gov/news/voyager_squashed.html
However, incredibly, I completely ignored the event on this page and only now I "discovered" it by looking to these eloquent plots:
http://web.mit.edu/space/www/voyager/voyag...plot_recent.gif
(in the past, I was looking more often to these data but in recent months I'm more and more busy mad.gif ).
Looking to this Forum section, it seems nobody noticed it... cannot believe anyone missed it like me! blink.gif

Addendum: based on Solar System Simulator, cross occurred at 83.7 AU from sun, about 10 AU closer than Voyager-1!
dilo
Further infos: As you know, contrary to his brother, Voyager 2 has a working Plasma Science instrument that can directly measure the velocity, density and temperature of the solar wind.
I downloaded hourly data from this plasma science page. Following plots shows trend of measured proton speed, thermal speed (temperature) and density (second plot is a temporal enlargement covering the transition (window is 0.1 years or 36.5 days large):
Click to view attachment Click to view attachment
As mentioned in the article, Voyager-2 had at least five shock crossings over a couple of days; perhaps they are the density peaks visible in second plot. QUESTION: why there is a so large hiatus (11 days) in the data immediately after this event??? Too strange for a coincidence!
They also found a much lower temperature beyond the shock than was predicted; anyway, based on following scatter plots (referred to data in the narrow temporal window of second plot above) there is a good correlation (almost inverse-square) between these twoparameters:
Click to view attachment

Any comment is welcomed!
scalbers
I saw a nice talk that Ed Stone gave on this topic three days ago. It will be interesting to follow along for a decade or so to see what the magnetic field looks like when Voyager gets completely into the interstellar medium.
brellis
(edit: of course this is old news to UMSF thread readers!)

The solar system is 'dented' as reported in this CNN Article.

I'm curious about how they refer to 'north' and 'south', and whether the motion of the Sun through the Milky Way impacts the escape velocities of the Voyagers.

(2nd edit: I thought I had asked the velocity question somewhere before, and found that dmuller provided insight in this post over in the New Horizons thread.

thank you dmuller!)
Paolo
In the latest issue of Astronomy & Astrophysics
Imaging the heliosheath using HSTOF energetic neutral atoms and Voyager 1 ion data
Fran Ontanaya
You may want to look at Voyager 2 wind speed data:

http://web.mit.edu/afs/athena/org/s/space/...yager_data.html

There was a nice spike last month, from ~225 km/s to ~325 km/s, the fastest speed since it crossed the termination shock.
PhilCo126
http://www.nature.com/nature/videoarchive/voyager/
Paolo
The latest issue of Astronomy & Astrophystics (v491 n1) has some articles about heliospheric science, including results from Voyager, Ulysses, Cassini, Nozomi etc.
dilo
Grazie, Paolo. Very interesting!
Enceladus75
I'm curious to know what science instruments are still functional on each Voyager. I'm aware that the cameras are now permanently turned off Voyager 2 has some more capability at measuring fields and particles over Voyager 1, but what instruments are actually still operational?

And for how long are they expected to remain operational?
Fran Ontanaya
About lifetime:

http://voyager.jpl.nasa.gov/spacecraft/spacecraftlife.html

dilo
and about instruments (from wikipedia):
As of the present date, the Voyager 2 and Voyager 1 scan platforms, including all of the platform instruments, have been powered down. The ultraviolet spectrometer (UVS) on Voyager 1 was active until 2003, when it too was deactivated. Gyro operations will end in 2010 for Voyager 2 and 2011 for Voyager 1. Gyro operations are used to rotate the probe 360 degrees six times a year to measure the magnetic field of the spacecraft, which is then subtracted from the magnetometer science data.
Enceladus75
Thanks guys. So it seems like both Voyagers will still have most of the fields and particles instruments active for the next decade or so.
dilo
Yes.
More precisely, with the exception of the Voyager 1 Plasma Science instrument (which is turned off to accommodate UVS observations), all instruments are working well and are capable of continuing operations at least until 2020. However, due to termination of gyro operations about 7 years from now, it will be impossible to calibrate the magnetometer instrument and, more important, spacecrafts could loose orientation anticipating communications blackout with Earth... so, let's cross our fingers!
Barnard
QUOTE (ljk4-1 @ Jun 9 2006, 03:59 AM) *
Voyager Reports March 3, 2006 to March 24, 2006 Available

http://voyager.jpl.nasa.gov/mission/weekly-reports/index.htm


I had a look at this page today and it seems the last report was made on the 31st of July? Is there a problem with the probes?
remcook
They always update these pages in batches with some time delay. No worries.
ZLD
Voyager 1 Sees Solar Wind Decline; Edges Closer to Interstellar Space (2010-12-13)

http://solarsystem.nasa.gov/news/display.cfm?News_ID=36121
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