NASA Deep Space Network

[skeeterm5]

I always take a quick look at Nasa DSN when ever I pick up my iPad, and I am looking for Voyager 1 and 2.

It always makes me pause in wonder when I reflect on the journey that have made. Right now it says V2 is 18.46bn km away and the round trip time for light of 1.43 days - think about that for a moment - mind boggling.

Is it just me that smiles when I see them connected?

S

[Beati Dogu]

That reminds me of this well timed clip:

https://youtu.be/2WoDQBhJCVQ

This is the launch in August 1977 of Voyager 2, which despite the name, launched two weeks before Voyager 1, as it was taking a longer path and would arrive second.

[realjv]

There is something incredibly beautiful about the Voyager missions which I think stand as NASAs greatest achievement.

[Gullwings]

In the vastness of space, the voyager mission will probably outlast humanity

[Eric Mc]

Not to mention Pioneers 10 and 11 and the New Horizon space probe. All those probes are heading off into interstellar space. Not only will they survive the end of humanity, they may very well survive to the end of the universe.

[Zirconia]

I like DSN as well, what I also like is the bit rates used. Amazing what data is cut down to but still useful and that was (is) 60/70 tech. The talking to it is all a great insight as it is for all the missions.

I get twitter alerts for Voyager 1 and 2. Nothing serious, just how far it is, odd snippet of happenings. (unofficial account but part of a team dealing with it)

https://twitter.com/NSFVoyager2

[Condi]

When will Voyager get to the point at which signals are simply too weak to be received? Or will we end up putting a receiver on the moon/into space to boost the signals down to earth?

[Leithen]

Condi said:

When will Voyager get to the point at which signals are simply too weak to be received? Or will we end up putting a receiver on the moon/into space to boost the signals down to earth?

Possibly 2036 according to this.

[Eric Mc]

Condi said:

When will Voyager get to the point at which signals are simply too weak to be received? Or will we end up putting a receiver on the moon/into space to boost the signals down to earth?

A receiver on the moon would do little to assist a signal coming from the distance both Voyagers are now at.

[keo]

I watched a good documentary on Voyager on amazon prime. I can’t remember if it was called Furthest or farthest though. Sure it is easily findable if someone is interested.

[Condi]

Eric Mc said:

A receiver on the moon would do little to assist a signal coming from the distance both Voyagers are now at.

Is the signal not significantly disrupted or weakened by going through the atmosphere?

[Beati Dogu]

keo said:

I watched a good documentary on Voyager on amazon prime. I can’t remember if it was called Furthest or farthest though. Sure it is easily findable if someone is interested.

“The Farthest“

Here's the trailer:
https://youtu.be/znTdk_de_K8

[Zirconia]

Condi said:

Eric Mc said:

A receiver on the moon would do little to assist a signal coming from the distance both Voyagers are now at.

Is the signal not significantly disrupted or weakened by going through the atmosphere?

When we did link budgets for tv work (not often), the distance to the satellite was used but the killer for Ku (a particular frequency range) is the atmosphere, water in its various forms. Space programs use a frequency less afflicted by our damp air (x band I think). And big dishes with some serious cryogenic cooling at the receivers and being in quiet area's (electronic quiet). Some web sites used to have the link budget calculators to test it out.

Sat there watching your carrier vanish in a rain storm wakes you up a tad. Woe betide anyone getting the sun down the bottle and not planning for it.

You will also have some info as to the part of the world you are in (with regards the wet stuff) and how much atmosphere you are going through, it varies of course.

Edit, there are many bands BTW, they will be chosen to suit.

Edited by Zirconia on Sunday 7th June 21:23

[Krikkit]

Zirconia said:

Space programs use a frequency less afflicted by our damp air (x band I think). And big dishes with some serious cryogenic cooling at the receivers and being in quiet area's (electronic quiet).

S and X band for voyager, so pretty durable.

Eventually the chance of the photons reaching the receivers will drop so low as to be none at all.

[Terminator X]

How do we keep contact from so far away? Does it just keep beaming a signal regardless of distance?

TX.

Edit - don't they suffer from broken parts with potential to make them scrap metal?

[anonymous-user]

Interesting videos (series of 3) here on DSS43 NASA Canberra Deep Space dish by Dave Jones of the EEVblog:

https://www.youtube.com/watch?v=FzRP1qdwPKw

Quite technical in places but the details leave one a bit mind blown about something we tend to take rather for granted in this day and age

Edited by anonymous-user on Monday 8th June 00:02

[Eric Mc]

Condi said:

Is the signal not significantly disrupted or weakened by going through the atmosphere?

No.

And even if it was, the signal from the moon would also have to pass through the earth's atmosphere.

[Eric Mc]

Terminator X said:

How do we keep contact from so far away? Does it just keep beaming a signal regardless of distance?

TX.

Edit - don't they suffer from broken parts with potential to make them scrap metal?

Yes and yes.

Most of the equipment on the Voyagers has been turned off, to save on power. Some items did fail during the mission although they were able to work around the problems (like a jammed scan platform or a sticking tape recorder).

[anonymous-user]

Eric Mc said:

Condi said:

Is the signal not significantly disrupted or weakened by going through the atmosphere?

No.

And even if it was, the signal from the moon would also have to pass through the earth's atmosphere.

There is signifcant discussion in the video i linked about the Signal to Noise ratio of the signals and the things that affect that SNR, and some of the clever tricks to boost it to enable faster data rates!

[anonymous-user]

During that video they show the link to Voyager 2 at around -160 dBm. That might not mean much to non electronics / radio engineers, but that signal is tiny, how tiny? Well dBm is decibels relative to 1 milliWatt (1000th of a Watt) and -160dB is pretty much a ratio of 1 in 100,000,000 (1e-8), so in terms of the signal power that the antenna is recieving that is 1 / 100,000,000,000 of a single watt, despite having a 70m diameter antenna to gather the RF energy!