Why is it impossible to get recent pictures from voyager 1 or 2 ?

reply to post by zedVSzardoz


I have to agree! Even if it turned out to be a black picture with the faintest dot of any star I want to see it too. So it drains Voyager of some power. What's the harm in that? It's not going to last forever anyways and it's not going to discover much once it reaches Interstellar space. So one last pic looking back at Earth or our Sun from one of our greatest achievements seems reasonable to me.

I just read that Voyager is suppose to begin to power down in 2020. Surely it can spare enough power for a few pictures. It is one of it's purposes after all.

Originally posted by Batfink420
I just read that Voyager is suppose to begin to power down in 2020. Surely it can spare enough power for a few pictures. It is one of it's purposes after all.

With respect, I'd much rather they spent their remaining power on doing useful science. Voyager is the furthest probe we have, and wasting a lot of energy to duplicate a shot that it already took would be almost criminal in my eyes.

Voyager should be kept alive as long as possible so we can learn about the environment of space that far out.

reply to post by exponent


I agree with you to some extent but once it reaches Interstellar space I'm not sure it's going to be doing much science. It's not going to discover any stars or planets or anything extraterrestrial. Won't it just be getting bombarded by cosmic rays and nothing else? I'm asking because I really don't know myself. It will reach that point long before it runs out of juice. Who knows, maybe we will see some pics yet. Voyager 2 is to start shutting down in 2025 so we still have plenty of time. Even so taking pictures was and is one of it's objectives.

Originally posted by Philosophile
If Voyager I is at the edge of our solar system, and our solar system is roughly 100 light years across, then shouldn't it take around 100 years for us to receive any signal from Voyager 1 to pick up any picture transmission? I'm JUST asking because I don't know either that's just my idea.

I think it's the galaxy that's 100 light years across....

Originally posted by wrkn4livn

Originally posted by Philosophile
If Voyager I is at the edge of our solar system, and our solar system is roughly 100 light years across, then shouldn't it take around 100 years for us to receive any signal from Voyager 1 to pick up any picture transmission? I'm JUST asking because I don't know either that's just my idea.

I think it's the galaxy that's 100 light years across....

The Galaxy is 100,000 light years across, not 100.

100 light years is both small and big -- depending on the scales you are talking about. For example, within 100 light years of us are about 2,000 stars. That's a lot of stars. That sounds big in comparison to the Earth (and it is -- in comparison to Earth).

However, lets look at it from a galactic perspective. We have been sending radio signals into space for about 100 years now with our early radio (and later TV) broadcasts. That means those radio waves have traveled a radius of 100 light years -- that's a bubble or sphere of radio waves that is 200 light years in diameter.

That sounds big, but take a look at that 200 light-year sphere relative to the galaxy in the artist's illustration in this article linked below (that tiny blue dot is the 200 light year sphere):

The Tiny Humanity Bubble

Remember -- that little blue dot in that article is NOT our solar system -- that dot much bigger than our solar system. That dot is only how far our earliest radio broadcasts have gone (at the speed of light) in 100 years. Our solar system is pretty damn insignificant in the grand scheme of things. It would take Voyager 1.75 MILLION years to go as far as those radio broadcasts have gone so far.

And this is only at the scale of our galaxy...there are hundreds of Billions of other galaxies in the universe -- making our solar system even far, far, far, far, far less significant to the universe than the tiniest dust speck is to us. We are smaller than miniscule.

Originally posted by Batfink420
reply to post by exponent

 

I agree with you to some extent but once it reaches Interstellar space I'm not sure it's going to be doing much science. It's not going to discover any stars or planets or anything extraterrestrial. Won't it just be getting bombarded by cosmic rays and nothing else? I'm asking because I really don't know myself. It will reach that point long before it runs out of juice. Who knows, maybe we will see some pics yet. Voyager 2 is to start shutting down in 2025 so we still have plenty of time. Even so taking pictures was and is one of it's objectives.

Hi there,
There's one important point here that may help understand the subject better.
The Voy probes have several sensors, one of which is tuned for visible-spectrum electromagnetic radiation.
But in the current (and last) phase of it's mission the most important data is gathered with OTHER sensors.
There's not much we could learn from a photo taken today by voyager, but we are learning A LOT thanks to those other sensors. For example we very recently discovered that there is a layer of "high-speed" transition between the solar system's heliosphere and the interstellar medium (the galactic atmosphere). And we were completely ignorant about this new structure until today.
On the other hand, using the camera would consume quite an amount of energy for little or no gain.

I completely understand your desire to actually SEE where voyager is, believe me I share that desire, but taking the former paragraph into account it's quite understandable why it wouldn't be convenient.

Cheers.

reply to post by Batfink420

I just read that Voyager is suppose to begin to power down in 2020. Surely it can spare enough power for a few pictures. It is one of it's purposes after all.

I don't think it's the power that is an issue. It uses a radioactive generator to provide power. The isotope used degrades slowly over time not based on power used. They don't expect the generator to provide enough power to operate the systems come 2020. They have been shutting down the biggest power hogs over the years. I think they had camera heaters running until several years ago.
The bigger problem I see is batteries and propellant.
Given the generators current output they may actually need the batteries to supplement the power needed to run the camera for several hours to get a time lapse. If the camera has the sensitivity needed to show the Earth a a single dot.
More importantly is the propellant needed to stabilize the camera for several hours for one lousy picture that will not show any detail of anything.
The radio antenna can be allowed to drift for awhile before propellant is used to bring it back on Earth. Not so for cameras.
Propellant is a fixed commodity. Once it's gone.....

Whats to come as is? Which way do the interstellar currents flow? Are there eddies of higher density? How fast are they?
What would a picture show us? One pixel for Earth and maybe 100 for the Sun. What's the point?

what exactly is voyager 'conserving power' for? is there a yet to be accomplished task ahead?

Originally posted by RoScoLaz
what exactly is voyager 'conserving power' for? is there a yet to be accomplished task ahead?

They still have important instruments that are operating, and they are still making big discoveries. Just yesterday (December 3), the Voyager team announced a new and unexpected discovery Voyager 1 made about the solar system out there:

Voyager 1 Spacecraft Enters New Realm at Solar System's Edge

It could be said that a yet-to-be-unaccomplished task is having the Voyager spacecraft pass outside the Heliosphere of the solar system (which is ONE definition -- but not the only definition -- of the edge of the solar system). There is a lot that science wants to know about the conditions out there, and Voyager still has instruments that can tell them that.


EDIT TO ADD:

Here is a web page on Voyagers' extended mission -- the "Interstellar Mission":

Voyager -- The Interstellar Mission

excerpt:

The mission objective of the Voyager Interstellar Mission (VIM) is to extend the NASA exploration of the solar system beyond the neighborhood of the outer planets to the outer limits of the Sun's sphere of influence, and possibly beyond. This extended mission is continuing to characterize the outer solar system environment and search for the heliopause boundary, the outer limits of the Sun's magnetic field and outward flow of the solar wind. Penetration of the heliopause boundary between the solar wind and the interstellar medium will allow measurements to be made of the interstellar fields, particles and waves unaffected by the solar wind.

Voyage had 470 watts at 30 volts at launch. Now it's down to 267 watts (Oct 2011).
The radio transmitter alone draws 23 watts. I can't find how much the computer(s) draws.

Just because they have 267wts doesn't mean you can use all of it. You must keep a margin in case one device develops a problem and draws more than its design. Example a motor when a gear sticks, can draw many times the origional plan.
If you max the load to the power available and one item fails and puts an extreme load on the power buss you could crash the computer.
Yes the computer will attempt to reboot but maybe they cannot change the boot ROM. Many of those loads may be turned ON by default. So the boot process will get to a point where the loads exceeds the generators output (again) and crash the computer. That means forever rebooting and loss of Voyager.

Here are a few things turned off and the year.

IRIS Flash-off Heater OFF (+31.8 W) - 1990
WA Camera OFF (+16.8 W) - 1990
NA Camera OFF (+18.0 W) 1990
PPS Supplemental Heater OFF (+2.8 W) - 1995
NA Optics Heater OFF (+2.6 W) - 1995
IRIS Standby A Supply OFF (+7.2 W) - 1995
WA Vidicon Heater OFF (+5.5 W) - 1998
NA Vidicon Heater OFF (+5.5 W) - 1998
IRIS Science Instrument OFF (+6.6 W) - 1998
WA Electronics Replacement Heater OFF (+10.5 W) - 2002
Azimuth Actuator Supplemental Heater OFF (+3.5 W) - 2003
Azimuth Coil Heater OFF (+4.4 W) - 2003
Scan Platform Slewing Power OFF (+2.4 W) - 2003
NA Electronics Replacement Heater OFF (+10.5 W) - 2005
Pyro Instrumentation Power OFF (+2.4 W) - 2007
PLS Science Instrument OFF (+4.2 W) - 2007
PLS Replacement Heater OFF (+4.3 W) - 2007
PRA Science Instrument OFF (+6.6W) -2008
IRIS Replacement Heater OFF (+7.8 W) - 2011

Notice the word 'vidicon', that's the camera(s).

Ok, I understand now why voyager is not taking pictures anymore. That makes sense.

Now, what about the rest of our assets in space, namely the rovers. Why don't we have live feeds from the cameras on them and our explorer probes?

I doubt they have similar issues as the voyager and pioneer probes.

Originally posted by zedVSzardoz
Ok, I understand now why voyager is not taking pictures anymore. That makes sense.

Now, what about the rest of our assets in space, namely the rovers. Why don't we have live feeds from the cameras on them and our explorer probes?

I doubt they have similar issues as the voyager and pioneer probes.

Hi there,
The main problem with a live-feed from mars is that we have a small window of communication (the rover sends it's data to the orbiters which in turn relay that data to earth, it's what they called DSN - Deep Space Network) and the bandwidth is also pretty small. That means that the amount of data they can send/receive is pretty limited.
So, even if it would be possible, it would substract a considerable amount of resources away from actual science use.

Don't worry though, be patient cause in a few years we will absolutely have that live-cam.
Hope it helped.
Cheers.

reply to post by zedVSzardoz

Why don't we have live feeds from the cameras on them and our explorer probes?

Several reasons.
1. They are not video cameras.
2. They are not color cameras. They use several shots with filters and stitch them together to give us a realistic color picture.
3. Transmission is slow. Remember dial up internet with high res pictures? It's close to that.

I doubt they have similar issues as the voyager and pioneer probes.

I'll bet they spend most of their time sitting and waiting for instructions or waiting to off load their data.

All that being said I too would love to see video of a drive across the surface of Mars. Not a bunch of stills but real HD video. Not gonna happen in my lifetime though.

Originally posted by samkent
reply to post by zedVSzardoz

 

Why don't we have live feeds from the cameras on them and our explorer probes?

Several reasons.
1. They are not video cameras.
2. They are not color cameras. They use several shots with filters and stitch them together to give us a realistic color picture.
3. Transmission is slow. Remember dial up internet with high res pictures? It's close to that.

Concerning point 2:
The "Mastcam" has an RGB Bayer filter (similar in concept to the filter on a consumer camera), so the raw images from Mastcam are in "color" (or at least the same kind of color as a consumer camera -- which isn't really "true color" either, but that's a different story altogether):

Both FFL Mastcams are color imagers. Integrated over each detector is an RGB Bayer pattern filter (GR/BG unit cell). A broadband (IR cutoff) filter through which RGB imaging will occur is included in one of the 8 filter positions within each camera's filter wheel.

Source

As for your other two points, you are correct. The field of view for the Mastcam is a narrow 15° ( at 34mm fvocal length). There is a 100 mm focal length Mastcam, and that filed of view is even at a more narrow angle -- just 5°. So yeah -- a single image is such a narrow field of view that it lacks much context. The images need to be stitched together to get a real contextual feel of what you are looking at.

And, yes -- the download time for each image can sometimes be several minutes to sometimes even an hour, depending on the amount of other data being transmitted back to Earth (via a relatively narrow bandwidth signal).

If NASA was going to do a final shot it would be when the tanks are almost dry as it would probably involve a lot of work such as reactivating the camera and aiming it back at us here on earth which probably would need a lot of energy to point the actual camera in the right direction and probably by then it would take a day to recieve a virtually black screen and at which point load of people here would scream conspiracy even though there was virtually sweet FA to show

Originally posted by Maxatoria
If NASA was going to do a final shot it would be when the tanks are almost dry as it would probably involve a lot of work such as reactivating the camera and aiming it back at us here on earth which probably would need a lot of energy to point the actual camera in the right direction and probably by then it would take a day to recieve a virtually black screen and at which point load of people here would scream conspiracy even though there was virtually sweet FA to show

And this is assuming that they even have the capability to turn it back on. It is entirely possible that they dont even have a way to turn it back on from a cold shutdown, so this whole thing may be completely irrelevant.

I do wish we had a way to get live video from the surface of Mars. The technology certainly exists to make it happen, but it would require one hell of a big investment in infrastructure, MANY billions more than what we've already invested in what we have there now.

Originally posted by Batfink420
I just read that Voyager is suppose to begin to power down in 2020. Surely it can spare enough power for a few pictures. It is one of it's purposes after all.

They have already been shutting various systems down. In just a few years, they will be shutting down the Data Tape Recorder and the gyro operations, which are fairly important systems on the Voyagers. I'd say the ability to snap photos ranks pretty low in their priorities. voyager.jpl.nasa.gov...

reply to post by Philosophile


Voyager 1 is about 100 AU from Earth I believe. An AU is the distance between the Earth and the Sun. Far from a light year, we're talking light minutes.