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Voyager 1 stops communicating with Earth

cnn.com

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Re: Voyager 1 stops communicating with Earth

#211

Post by jacquesm »

lagrange77 wrote: post #62
WJW wrote: post #41

Earlier quoted context omitted.

Signal processing algorithms can pull out a signal from well below the noise floor these days. Even the small and nondirectional antennas on your phone are good enough to receive GPS signals even all the way down at -125 dBm, which is WAY less than your phone receives in interference from random radio stations and faulty LED bulbs nearby. The tech used to receive Voyager signals is not really different, just more sen…

Interesting! Why faulty LED bulbs in particular, does it have to do with their PWM frequency?

Electromagnetic radiation power roughly equivalent to the amount of light they output. I wished I was kidding, some of them are so bad they should qualify as jammers.

Re: Voyager 1 stops communicating with Earth

#214

Post by maccam912 »

calamari4065 wrote: post #149
lordnacho wrote: post #26

How is it possible to still be able to get a signal from a spacecraft that's so far away? How can the antenna be directional enough while still being pointed right at the Earth? How do we remove the noise?

A ridiculously huge and powerful array of antennas spread across the planet. NASA has a dashboard online for the Deep Space Network and you can see live which spacecraft we're communicating with. The Voyagers are usually active any time I look.

How live is it? Voyager 1 seemed to be shown there just now.

Re: Voyager 1 stops communicating with Earth

#215

Post by WalterBright »

Rebelgecko wrote: post #136
anonymous_sorry wrote: post #93

> Initially designed to last five years NASA tech often seems to outlive its initial mission length by a massive margin. The Mars rovers spring to mind. It's incredibly impressive, and almost embarrassing! Surely this isn't accidental. Is the kit massively over-specced? Do the uncertainties and risks necessitate such a depth of redundancy that when stuff goes kinda smoothly the thing lasts 9 times longer than it was…

In addition to what other people mentioned (if you design something to have a 99.99% chance of lasting x years, it'll probably last some multiple of x), a lot of failures follow what's called a bathtub curve (visual depiction: https://en.m.wikipedia.org/wiki/Bathtub_curve#/media/File%3A... ). Once you can make something work for 1 day, you're past the most dangerous phase.

It's the same with people. If you can make it past gestation, birth, and age 10, you're pretty good to go until 80, when everything falls apart.

Re: Voyager 1 stops communicating with Earth

#216

Post by mardifoufs »

WalterBright wrote: post #200

Criminy. Why aren't we launching more of these probes? With Musk's cheap rockets, we could launch a fleet of them.

I think launching stuff with nuclear RTGs would probably be met with red tape :(. Even if they are basically impossible to destroy even with a failed launch. I'm sure it will happen again but sadly not as fast or as often as I wish we would.

Re: Voyager 1 stops communicating with Earth

#217

Post by CSMastermind »

WalterBright wrote: post #200

Criminy. Why aren't we launching more of these probes? With Musk's cheap rockets, we could launch a fleet of them.

If I remember correctly Voyager benefitted from a particular alignment of the planets to get multiple slingshot boosts from gravity wells.

Part of the appeal of the mission was that it will be a very long time before we could possibly do this again because the planets won't line up correctly and we have no technology to speed the probes up to the velocities that the voyager probes achieved.

Re: Voyager 1 stops communicating with Earth

#218

Post by pdonis »

Macha wrote: post #197
alain94040 wrote: post #192

Earlier quoted context omitted.

Why isn't it linear?

Best guess: You get particles orbiting the sun, until you pass a point where the sun's gravity is too weak to hold them, and from that point you basically only see things who's escape trajectory intersects with yours

> You get particles orbiting the sun

The particles hitting Voyager aren't orbiting the Sun; they're from the Sun, the solar wind. The heliopause is the point where they are stopped by the interstellar medium. That point is what Voyager passed as shown in the graph.

Re: Voyager 1 stops communicating with Earth

#219

Post by WalterBright »

MeImCounting wrote: post #212
WalterBright wrote: post #200

Criminy. Why aren't we launching more of these probes? With Musk's cheap rockets, we could launch a fleet of them.

Voyager took advantage of a specific alignment of planets that allowed it to make many consecutive gravity assists.

I know. But still, just flying around the solar system can be endlessly productive. Does anyone think we've learned all we can about the solar system?
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