Likelihood of Catch Voyager1/2 downlink?

[rwgast]

Im moding a newer r80t2 based RTL-SDR dongle, this includes a TCXO, better linear regulator, freight everywhere on power lines, EMC testing, and seperating the TCXO, broadband lna4all and dongle in separate copper clad enclosures. I will then stick all the blocks inside a bigger copper clad case. Ive used a sheilded USB cable and to insert it in to the enclosures I wrapped the rubber jacket tight with 22ga about a quarter inch up and then fluxed and soldered the wire around the rubber jacket until it started melting a little bit, making sure not to ruin the inner conductors. I then painted that with liquid electric tape. The idea was to make the best gasket I could at the USB entry point. So im hoping ive basically made a Faraday cage around every block and the a bigger feraday cage around all the blocks. So hopefully no frequency will get in to the dongle except from the antenna jack!

Next the plan is to connect the SDR to this

I would be replacing the LNB with a Helical wound antenna tuned to the voyager downlink, next the part im not sure about is I would need to stick a 10ghz xband down converter in the chain.

Voyager 1 is somewhere in interstellar space out of the solar system, would a dish this big work or am I shooting at an impossible idea?

 

[n2nov]

I don't know about the received signal strength on the VLA (very large array) or those 30 foot dishes that NASA uses, but I would think a 6 to 10 foot C-band TVRO dish would get a much smaller signal. I could pull out my notes from when I was a TVRO business owner (Satview/Plus in NYC) in the 80's and 90's, but I am sure the information would be available on Wikipedia or a good Google search.

 

[ElroyJetson]

Voyager's signal strength at earth is about -180 dBm at 2.3 or 8.4 GHz.

Is your equipment even sensitive enough to pull out that signal? My suspicion is that it takes more than a backyard dish can deliver.

 

[prcguy]

Last I heard NASA uses a 70m (230ft dia) dish to receive Voyager signals with super low noise amplifiers and low phase noise LOs in the downconverters, etc. All state of the art stuff.

A TV dongle receiver is at or near the bottom of the barrel in performance and your 10ft dish will have about 28 to 30dB less gain than NASAs high performance 70m dish. You might have been able to pick up Voyager in 1977 with your setup when it was real close, but its impossible now.
prcguy

 

[krokus]

You might have more luck picking up the Mars probes.

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[rwgast]

:\ Ok so whats something cool I could pick up out there shooting out instrumentation data with a 10 ft dish? I dont really care about NOAA or things like that, I think a yagi and OSCAR or funcube would be a good start but what is an actual achievable goal thats in deeper space, and isnt encrypted?

 

[krokus]

:\ Ok so whats something cool I could pick up out there shooting out instrumentation data with a 10 ft dish? I dont really care about NOAA or things like that, I think a yagi and OSCAR or funcube would be a good start but what is an actual achievable goal thats in deeper space, and isnt encrypted?

Mars Rover
Mars Orbiter
Rosetta

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[ElroyJetson]

Here's one for you: Attempt to locate a retired communications satellite in a parking orbit. And use it for your own communications needs. Believe it or not, you can do that. There are a few people who do this as their hobby. And a few more who use retired, parked comm satellites for their own purposes other than a hobby.

 

[prcguy]

You can't do that legally or easily.

Quote from you:
"So you're stating your intentions to violate the law on a public forum.

Interesting.

That's not something I would recommend doing just on general principles.

It's not like the FCC has a budget for enforcing much these days anyway...."

prcguy

Here's one for you: Attempt to locate a retired communications satellite in a parking orbit. And use it for your own communications needs. Believe it or not, you can do that. There are a few people who do this as their hobby. And a few more who use retired, parked comm satellites for their own purposes other than a hobby.

 

[ElroyJetson]

You might want to check on that. There ARE legal ways to utilize a retired satellite. I'm not saying you won't have to get a license, but it can be done legally.

It would usually require you to get the satellite owner/operator to agree to allow you to use the satellite and provide you with the appropriate information required to operate the transponders. Some WILL do that, others won't.

So the rest of your comment is irrelevant.

 

[rwgast]

I thought the mar rover was joke lol.

How do you find a retired sat? By parked do you mean geo stationary?

 

[rwgast]

The mars rover is not encrypted? I would just assume they wouldn't want just anyone playing with it, is the uplink encrypted?

 

[krokus]

How do you find a retired sat? By parked do you mean geo stationary?

There are some websites with info on the old birds. The bird's original orbit will be modified, so the parking depends on what type of orbit was originally used. A low-Earth, polar, or sun-synchronous, orbit bird will not be placed into a geostationary position. (They might be de-orbited.) A geostationary bird might be moved, and clustered with other retired birds.

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[krokus]

The mars rover is not encrypted? I would just assume they wouldn't want just anyone playing with it, is the uplink encrypted?

I have no idea. The protocols used are not going to be publicized, but might be available. Not very many people would have access to the equipment necessary to attempt hijacking the spacecraft, in the first place.

Since the rovers uplink to orbiter, and the orbiter relays to the Earth, you are more likely to hear the orbiter signals. I do not have the details on the signals, but they might be online.

http://www.amsat.org has a lot of resources.

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[kayn1n32008]

The mars rover is not encrypted? I would just assume they wouldn't want just anyone playing with it, is the uplink encrypted?

Memory is in short supply... as is electricity... encryption requires both. The technical know how to 'hijack' the rovers is likly very specialized, that encryption is not needed

 

[wtp]

who needs it un-encrypted?

if i had that setup i would be happy to just hear a peep.
i try a couple of times a week just to hear the ISS on a radio and i mean the packet without a program.
enjoy the noise !

 

[ElroyJetson]

If you do want to look for retired satellites, if they were in geostationary orbit, they will be moved out of that orbit into a slighly higher orbit, most likely. Which means they'd move SLOWLY across the sky. You might be able to pick it up for several days before it goes over the horizon.

Low earth orbit satellites might be parked higher OR lower than their operational orbit, but as I have been reading, retired geostationary satellites are typically sent to a higher orbit so that a new satellite being inserted into geostationary orbit will not be crossing the orbit of a retired satellite. Makes sense.

I would be very interested in bird tracking, actually. I don't have the setup for it but maybe some day that will change.

 

[prcguy]

All C and Ku sats are shut down at end of life or when they are moved across the sky, otherwise they would jam current satellites. You can't just access any satellite, even with permission from the owner, you need a license to uplink. That runs a couple of thousand $$ minimum for Ku and more for C band because coordination is required for C band. I'm not just making this up, I had to gather and handle coordination and licensing info for many uplink antennas, C through Ka band.

There have been a few rogue sats that were active when they moved across the sky when their control system was crippled and they completely jammed all satellites in the arc as they went by. I've lived through a few of those and there is not much you can do to get around the interference. Even the beacons are shut down on retired sats, so what are you going to pick up as they go by?

There have been a few Govt sats in the VHF range that were retired and re-purposed for civilian research but you usually need a difficult to get experimental license for that type operation.

For C and Ku band most spacecraft owners want all the info on your uplink antenna sometimes including pattern cuts and they want you to do cross pol testing before your allowed to uplink your programming. That means a backyard receive dish is not going to fly as an uplink antenna to legitimately access any C or Ku satellite.
prcguy

If you do want to look for retired satellites, if they were in geostationary orbit, they will be moved out of that orbit into a slighly higher orbit, most likely. Which means they'd move SLOWLY across the sky. You might be able to pick it up for several days before it goes over the horizon.

Low earth orbit satellites might be parked higher OR lower than their operational orbit, but as I have been reading, retired geostationary satellites are typically sent to a higher orbit so that a new satellite being inserted into geostationary orbit will not be crossing the orbit of a retired satellite. Makes sense.

I would be very interested in bird tracking, actually. I don't have the setup for it but maybe some day that will change.

 

[gtaman]

You might want to check on that. There ARE legal ways to utilize a retired satellite. I'm not saying you won't have to get a license, but it can be done legally.

It would usually require you to get the satellite owner/operator to agree to allow you to use the satellite and provide you with the appropriate information required to operate the transponders. Some WILL do that, others won't.

So the rest of your comment is irrelevant.

Nearly all satellites with a payload that can be used for voice communications are owned by the U.S DOD. They are illegal to use whatsoever for public use. Even though FLTSAT 8 can be easily accessed with even a coat hanger. You will be getting a knock on the door for using it. Other commercial companies only have data that can be used as long as you are authorized to use it. They don't have voice payloads on them. Plus they are not just carriers on them too. They require some sort of modulation that the average radio will not produce.

But by all means if you want to use FLTSAT or MILSTAR go ahead. But be warned they can pinpoint you in a heartbeat. And they will have some fun in court with you.

Whether you are government or civilian users. They don't play around. I have witnessed ECHOSTAR sending a hefty bill to the U.S ARMY. That was for knocking CNN off the air for 5 seconds due to transmitting on the wrong transponder.

 

[gtaman]

All C and Ku sats are shut down at end of life or when they are moved across the sky, otherwise they would jam current satellites. You can't just access any satellite, even with permission from the owner, you need a license to uplink. That runs a couple of thousand $$ minimum for Ku and more for C band because coordination is required for C band. I'm not just making this up, I had to gather and handle coordination and licensing info for many uplink antennas, C through Ka band.

There have been a few rogue sats that were active when they moved across the sky when their control system was crippled and they completely jammed all satellites in the arc as they went by. I've lived through a few of those and there is not much you can do to get around the interference. Even the beacons are shut down on retired sats, so what are you going to pick up as they go by?

There have been a few Govt sats in the VHF range that were retired and re-purposed for civilian research but you usually need a difficult to get experimental license for that type operation.

For C and Ku band most spacecraft owners want all the info on your uplink antenna sometimes including pattern cuts and they want you to do cross pol testing before your allowed to uplink your programming. That means a backyard receive dish is not going to fly as an uplink antenna to legitimately access any C or Ku satellite.
prcguy

It's hard to do a PEEK and PULL with an antenna that is stationary and not powered by an APU and ACU.