Voyager 1 & 2

[djd1]

Voyager Mission Operations Status Report # 2005-10-07, Week Ending October 07, 2005

Command Transmission & Verification Operations

Voyager 1 command operations consisted of the uplink of a command loss timer reset on 10/05 [DOY 278/1730z]. The spacecraft received the command.

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

Sequence Generation Operations

Complete sequence development of CCSL A057. Begin sequence development of CCSL B131.

Data Return Operations

Voyager 1 Data Processing and Operations:

There were 73.4 hours of DSN scheduled support for Voyager 1 of which 14.7 hours were large aperture coverage. There were no real-time or schedule support changes or 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 274 from the AHELIO cyclic. The EDR backlog is 1 days.

Voyager 2 Data Processing and Operations:

There were 53.4 hours of DSN scheduled support for Voyager 2 of which 0 hours were large aperture coverage. There were no real-time or schedule support changes during the period.

There was one significant outage of 2.1 hours on 10/07 [DOY 280] due to rain at DSS-45 [DR C104544].

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 2 days.

Flight System Performance

Voyager 1 performance was nominal during this report period. Activities included a MAGROL followed by gyros OFF on 10/1 (DOY 274).

Voyager 2 performance was nominal during this report period.PROPELLANT/POWER CONSUMABLES STATUS AS OF THIS REPORT
Voyager 1

 

[rybanis]

The propellant is the important thing now, isn't it? If that runs out then the mission is done? <div class="Discussion_UserSignature"> </div>

 

[mikejz]

No, It's power, RTGs are continually dropping in power---Should have enought though to make it to 2020, with limited insturments.

 

[djd1]

The propellant is the important thing now, isn't it? If that runs out then the mission is done?
You still have to marvel at the outstanding achievments the engineers put into the construction of the voyagers

 

[djd1]

Voyager Mission Operations Status Report # 2005-10-14, Week Ending October 14, 2005

Command Transmission & Verification Operations

Voyager 1 command operations consisted of the uplink of CCSL A057, a command loss timer reset and MRO on 10/11 [DOY 284/1123z]. The spacecraft received all commands sent and the CCSL was verified.

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 82.8 hours of DSN scheduled support for Voyager 1 of which 32.1 hours were large aperture coverage. There were no real-time or schedule support changes during the period.

There was one significant outage of 1.3 hours on 10/10 [DOY 283] due to rain at DSS-65 [DR M103419].

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 281 from the AHELIO cyclic. The EDR backlog is 1 days.

Voyager 2 Data Processing and Operations:

There were 57.3 hours of DSN scheduled support for Voyager 2 of which 0 hours were large aperture coverage. There were no real-time or schedule support changes or 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. The EDR backlog is 1 days.

Flight System Performance

Voyager 1 performance was nominal during this report period. Activity included a PMPCAL on 10/11 (DOY 285).

Voyager 2 performance was nominal during this report period.

PROPELLANT/POWER CONSUMABLES STATUS AS OF THIS REPORT
Voyager1
Consumption/One week(Gm) 6.48Propellant

 

[dragon04]

I'm just amazed that both of these missions are still returning data and performing with 30 year old technology. <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[CalliArcale]

They're rugged. They've done an incredible job, and they continue to do useful science. It's too bad their cameras are done for; it would be neat to try for another Solar System Portrait (although I bet Earth is now too far away to show up at all). <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[mikejz]

On a related note, they use an RCA COSMAC processor, as did Viking and Galileo. In fact, the are still quite popular among Amsat, dispite the shortage of them.<br /><br />Fun fact, Galileo's design began prior to the Voyager flyby so some things, such as the radiation environment, were not built into the design.

 

[djd1]

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. Ac

 

[djd1]

<font color="yellow">I'm just amazed that both of these missions are still returning data and performing with 30 year old technology<br /><font color="white">Sure is a fantastic achievment, i could not agree with you more.<br /></font></font>

 

[djd1]

<font color="yellow">Thank you for the reminder of our old probes ! <br /><font color="white"> You are most welcome.</font></font>

 

[mikejz]

<font color="yellow">I'm just amazed that both of these missions are still returning data and performing with 30 year old technology</font><br /><br />*Cough*Shuttle*Cough*

 

[john_316]

I wonder what it would be like if they would have launched a Voyager or Pioneer upwards out of the Solar Systems towards Polaris. <br /><br />I wander what our star system would look like from that vantage point? If the disk could be clearly seen or what have you...<br /><br /><img src="/images/icons/smile.gif" /><br />

 

[siarad]

Early CMOS & Silicon on Sapphire, SOS which was more Radhard than Silicon on Silicon oxide & consumed lower power than the PMOS around at the time.<br />RCA managed to grow Sapphire in ribbons.<br />I've still got some including SOS RAM.<br />Viking may have used the earlier two-chip version

 

[ehs40]

i cant wait for the day they reach interstellar space that will be a major acomplishment by man and we will learn more about our universe in a short amonut of time when we recieve the data from those probes it will be great

 

[vt_hokie]

That is amazing! I wonder how long the craft will drift. I imagine the odds of colliding with another object are reasonably low, so it might be quite a long time!

 

[dragon04]

I don't know how feasible it would be, but I wonder if there's any thought at JPL about perhaps putting one of the Voyagers to sleep and using it later to relay data to New Horizons for retransmission to Earth.<br /><br />I don't know how an RTG works in depth. Is there any way to extend the life of one by putting a probe into "sleep mode"? <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[mikejz]

No, and RTG is really simple: Basically an RTG is a Peltier device where the heat source is via radioactive heating. The decline in power has to do with the decay of the Peltier device (I forget if it's from the heat or the radioactive particles).

 

[henryhallam]

Voager 1 &amp; 2

The decline in power has to do with the decay of the Peltier device (I forget if it's from the heat or the radioactive particles).
Actually the main cause of the reduction of power available is due to the radioactive source decaying. As it decays it produces heat which drives the RTG, but in the process the radioactive atoms are "consumed" (once an atom of Pu238 has decayed, it becomes a different atom and cannot decay again in the same way). The power loss follows an inverse exponential curve similar to this: http://www.geo.arizona.edu/palynology/g ... 4_half.gif (but with different numbers). So over time they have to turn off modules in the spacecraft in order to keep the load under the total power available. But turning EVERYTHING off wouldn't extend the life of the power supply.

At some point exhaustion of RCS gas will become a problem too.

 

[vogon13]

The half-life of the Pu in the Voyager RTGs is around 250,000 years. (IIRC)<br /><br />The germanium/iron junctions (IIRC) physical structure in the RTGs is damaged by the radiation of the Pu decaying.<br /><br />The RTG electrical ouput power is derived from heat, any daughter element of the original Pu with a short half-life will contribute to the heat flow.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[henryhallam]

Pu238 as used in the Voyager RTGs has a half life of 88 years so over the ~30 years since launch you can expect significant decay.<br /><br />It decays by alpha decay which is extremely easily shielded; no alpha particles escape the iridium capsule which contains the Pu. The silicon-germanium junctions in the Peltier devices are outside the capsule so they wouldn't get irradiated.<br /><br />The rest of the decay chain probably does generate some more penetrating radiation which may slowly degrade the junctions as you say, but I'm pretty certain the decay of the isotope is the limiting factor. <br /><br />There can't be very much radiation that gets through the shield or the RTGs wouldn't be safe to handle on the ground.

 

[brellis]

JPL News Release<br /><font color="orange"> PASADENA, Calif. - NASA's two venerable Voyager spacecraft are celebrating three decades of flight as they head toward interstellar space. Their ongoing odysseys mark an unprecedented and historic accomplishment.<br /><br />Voyager 2 launched on Aug. 20, 1977, and Voyager 1 launched on Sept. 5, 1977. They continue to return information from distances more than three times farther away than Pluto. </font><br /><br />List of Voyager discoveries <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[3488]

Thanks brellis.<br /><br />It is quite an oxymoron that they have outlived the Jupiter Galileo Orbiter & also likely to outlive the Saturn Cassini Orbiter.<br /><br />Does anyone know how long New Horizons is expected to operate after the Pluto system encounter??<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[CalliArcale]

Ah, brellis beat me to it. <img src="/images/icons/wink.gif" /> I was going to post about the 30th birthday of my favorite mission yesterday, when IT forcibly rebooted my PC to apply some patches. (Why they can't do it in the middle of the night is beyond me.)<br /><br />It remains to be seen how long Cassini will last, but of course Galileo had to contend with Jupiter's amazingly harsh environment. Plus, it wasn't in a safe disposal orbit already. Nobody cares where the Voyagers end up; there's no need to dispose of them before they fail completely. As far as Cassini's lifetime goes, my money is on it being disposed after the reaction wheels start to fail.<br /><br />New Horizons will probably last for decades as well, though given how fast it's traveling, signal strength may end up being its limiting factor. (There's a good chance that Pioneer 10 is still working, but its signal is now too weak for even Areceibo to talk to it.) That will probably also be the limiting factor for the Voyagers.<br /><br />The Voyagers are amazing. The things they discovered are astonishing, and even though Galileo and Cassini have conducted much more exhaustive surveys of Jupiter and Saturn, the Voyager data continues to be important, with new discoveries being made every year from the mountains of data they returned. Today, they mostly study the heliosheath, but you can still glean valuable science from their data about Jupiter and Saturn. Comparison of pictures taken by all the probes to visit Jupiter has revealed interesting things about Io, for instance -- it is phenomenally active, with volcanic activity constantly changing. And of course as Voyager 2 is still the only spacecraft to have visited Uranus and Neptune, its data for those worlds remain unparalleled.<br /><br />I love the Voyagers. <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[3488]

Hi CalliArcale,<br /><br />Very true indeed.<br /><br />AFAIK with Pioneer 10, yes the signal strength has dropped below the threshold for the DSN<br />to receive. <br />Another problem was that Pioneer 10 lost the ability to keep the HGA pointed at Earth. <br /><br />So really it was a double whammy.<br /><br />The Voyagers, they too are among my favourites. The discovery of the volcanoes on Io<br />as you correctly say, each mission since Voyager 1 has shown how Io's volcanoes <br />have changed activity patterns, & in a few cases, the vents have even moved!!!!!<br /><br />The difference in Io just between Voyager 1 & Voyager 2, was incredible. Pele's heart <br />shaped ejecta ring, turned circular. During Galileo's mission, it became more <br />elongated in a north - south direction & the Pluto bound New Horizons has very clearly <br />shown this trend continuing.<br /><br />Voyager 1 at Titan was a huge disappointment. A giant smoggy orange ball. Visually <br />unappealling, but the spectra & occultation data was compelling. <br /><br />Without it, there would have been no Huygens!!!!!!!<br /><br />Having said that, was the sacrifice of Voyager 1 at Titan worth it?<br /><br />Myself, I would rather them both gone onto Uranus & Neptune.<br /><br />Having said that though, Voyager 2 excelled at both Uranus & Neptune. <br /><br />Miranda, I remember that well. The day before, it was reported that Voyager 2 was to closely <br />encounter that smallish moon & the reporters dissing it as a cratered lump of ice,<br />undoubtably showing no interesting geology what so ever.<br /><br />24 hours later, lets say they were eating their words!!! <img src="/images/icons/laugh.gif" /><br /><br />I had known about the existance of the five major Uraninian moons since childhood, <br />but to see ALL five in detail like that, was a real thrill. Even now (you may have noticed, <br />I still talk about them on various other threads).<br /><br />Even the size order was uncertain. All what was <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>