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Voyager 1 is about to reach one light-day from Earth

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Re: Voyager 1 is about to reach one light-day from Earth

#171

Post by JumpCrisscross »

chistev wrote: post #144
JumpCrisscross wrote: post #77

Earlier quoted context omitted.

> With time dilation, the "now" on Voyager is out of sync with our now A couple minutes [1]. > we will have to face the problem of time keeping across the galaxy Not really. Barring relativistic travel, it’s not dissimilar from the problem seagoing voyagers faced on long trade routes. Ship time is set based on the convenience of the passengers and the route. [1] https://space.stackexchange.com/questions/56055/if-voya…

Why a couple minutes?

> Why a couple minutes?

…because that’s what the math says? Based on Voyager’s relative velocity it’s expected to be about 2 seconds younger than it would have been had it stayed on Earth.

Re: Voyager 1 is about to reach one light-day from Earth

#172

Post by namirez »

Sharlin wrote: post #17
chistev wrote: post #11

Wrote about the Voyager probes two days ago in my blog - The two Voyager spacecraft are the greatest love letters humanity has ever sent into the void. Voyager 2 actually launched first, on August 20, 1977, followed by Voyager 1 on September 5, 1977. Because Voyager 1 was on a faster, shorter trajectory (it used a rare alignment to slingshot past both Jupiter and Saturn quicker), it overtook its twin and became the f…

Voyager 2 was the real beneficiary of the rare outer planet alignment, as it went on the famous Grand Tour, visiting all four of the giants. It did gravity assists at Jupiter, Saturn, and Uranus. [1] shows the rough velocity of V2 over time. Voyager 1 was directed to perform a flyby of Titan, at the cost of being thrown out of the ecliptic and being unable to visit the ice giants like its sister. But this was deemed…

There isn’t much value in gravity assists from Uranus or Neptune since they move much more slowly than Jupiter and Saturn.

Re: Voyager 1 is about to reach one light-day from Earth

#173

Post by pfdietz »

Musk is now talking about near term putting servers in space, because that's where power will be cheapest.

Should this happen, we'll see many gigawatts of power in space. A spinoff of this would be large solar-electric spacecraft, or even large lasers for beam powered spacecraft. Either case should allow considerably higher delta-V than chemical rockets.

Re: Voyager 1 is about to reach one light-day from Earth

#174

Post by moron4hire »

dheera wrote: post #169
danishSuri1994 wrote: post #159

It’s wild how Voyager forces two truths to sit together: Technically, what we’ve done is almost boringly modest. ~17 km/s ~1 light-day in ~50 years No realistic way to steer it anywhere meaningful now On cosmic scales it’s… basically still on our doorstep. Psychologically, it’s still one of the most ambitious things we’ve ever done. We built something meant to work for decades, knowing the people who launched it woul…

> It’s proof that humans will build absurdly long-horizon projects anyway They used to. But these days the people who control the economy and funding for things like this are either politicians interested in 4 year cycles or VCs interested in 5-10 year cycles. Nobody gives a damn about long horizon stuff anymore. We landed humans on the moon half a century ago, and we still haven't reached Mars. Instead we're buildin…

To be fair to our generation, people didn't build so much stupid shit in the 60s not because they weren't interested in stupid shit but because the whole world was too poor to be able to afford it. Our generation created the economic conditions in which people could have the spare cash to spend on stupid shit.

I would put good money on a bet that there are more people today who deeply care about the long-term horizon than did in the 60s. I don't think we spent money on long-shots in the 60s because people cared more. I think we did it because it was relatively low-hanging fruit in a gigantic culture war between US-centric Western powers and USSR-centric Eastern powers. We don't have that kind of "most people agree it's an existential threat" level of cultural difference anymore. China? They sell us most of our stuff. We don't hate China, not really. But we hated the Soviets.

Re: Voyager 1 is about to reach one light-day from Earth

#175

Post by vee-kay »

dtgriscom wrote: post #154
vee-kay wrote: post #80

Earlier quoted context omitted.

This old video is a beautiful and astounding demonstration of just how vastly, hugely, mind-bogglingly big the Universe is, and where in all this endless space our dear favourite little Pale Blue Dot (Earth) resides: https://m.youtube.com/watch?v=X-3Oq_82XNA We all Earthlings are extremely lucky to be alive and thriving (or trying to) in such a beautiful bountiful rarest-of-rare ecosystem that somehow survived and th…

The classic, from 1977: https://www.youtube.com/watch?v=0fKBhvDjuy0

Awesome, thanks. I think the video I had linked was Google's tribute to this Power Of Ten video that you have linked, a classic video that demonstrates the scale of the Universe from the micro to the macro perspectives in a scaling increase by a factor of ten for each scene.

Another relevant video (thanks to user christev for sharing the link): A Brief History of Geologic Time: https://youtu.be/rWp5ZpJAIAE

Absolutely humbling to realise how infinitesimally small and irrelevant our existence is, in the grand scheme of theme. Nature and science are amazing.

Re: Voyager 1 is about to reach one light-day from Earth

#176

Post by FireBeyond »

BobbyTables2 wrote: post #48
Aperocky wrote: post #33

Earlier quoted context omitted.

Not useful, because the signal are too weak to be picked up probe to probe. On earth, the tiny signal from Voyager at this distance is picked up by dish the size of a football field; same with sending of the signal.

Football field might even be too small… Wasn’t Arecibo used for Voyager?

No. Or not any more, DSS-43 at the Canberra Deep Dish Communication Complex is the only antenna that can communicate with the Voyagers.

Re: Voyager 1 is about to reach one light-day from Earth

#177

Post by vee-kay »

vee-kay wrote: post #82
Tepix wrote: post #66

Earlier quoted context omitted.

Yes, the distances are mind-boggling. There are a few somewhat realistic solutions for making such a trip in the forseeable future. If you send something of significant mass, it is certain to take a long time. So we're either talking generation ships(§), embryo space colonization (growing into adults en route or at destination) or hibernation. That or a breakthrough in fundamental physics. -- (§) Something like O'Nei…

This old video is a beautiful and astounding demonstration of just how vastly, hugely, mind-bogglingly big the Universe is, and where in all this endless space our dear favourite little Pale Blue Dot (Earth) resides: https://m.youtube.com/watch?v=X-3Oq_82XNA We all Earthlings are extremely lucky to be alive and thriving (or trying to) in such a beautiful bountiful rarest-of-rare ecosystem that somehow survived and th…

I think the video I have linked above is Google's tribute to this Power Of Ten video (linked below, thanks to user dtgriscom for sharing the link in another comment), a classic video that demonstrates the scale of the Universe from the micro to the macro perspectives in a scaling increase by a factor of ten for each scene.

Power of 10: https://www.youtube.com/watch?v=0fKBhvDjuy0

Another relevant video (thanks to user christev for sharing the link): A Brief History of Geologic Time: https://youtu.be/rWp5ZpJAIAE

Absolutely humbling to realise how infinitesimally small and irrelevant our existence is, in the grand scheme of theme. Nature and science are amazing.

Re: Voyager 1 is about to reach one light-day from Earth

#178

Post by flanderizedNed »

pfdietz wrote: post #173

Musk is now talking about near term putting servers in space, because that's where power will be cheapest. Should this happen, we'll see many gigawatts of power in space. A spinoff of this would be large solar-electric spacecraft, or even large lasers for beam powered spacecraft. Either case should allow considerably higher delta-V than chemical rockets.

[dead]

Re: Voyager 1 is about to reach one light-day from Earth

#179

Post by Sanzig »

TheOtherHobbes wrote: post #167
Sanzig wrote: post #106

Earlier quoted context omitted.

Provided we don't wipe ourselves out, there's no technical reason why we can't go interstellar. It's just way harder and more energy intensive than most people imagine, so I doubt it's happening any time in the next few hundred years. But we already understand the physics and feasibility of "slow" (single-digit fractions of c ) interstellar propulsion systems. Nuclear pulse propulsion and fission fragment rockets req…

Nuclear pulse and fission fragment designs require no new physics in the same way that a Saturn 5 didn't require new physics when compared to a Goddard toy rocket. It's easy until you try to actually build the damn thing. Then you discover it's not easy at all, and there's actually quite a bit of new physics required. It's not New Physics™ in the warp drive and wormhole sense, but any practical interstellar design is…

I thought I was pretty clear that I don't see this happening for hundreds of years at least.

The engineering problem is insurmountable today. But there doesn't seem to be any reason it couldn't be done eventually, given our technological trajectory, unless we believe we are truly on the precipice of severe diminishing returns in most science and engineering fields, and I just don't see that right now.

George Cayley figured out how to build an airplane in 1799, but it wasn't for another century until materials science and high power-to-weight ratio engines made the Wright Flyer possible.

There are plenty of depths to plumb in space systems engineering that we haven't even really had a proper look at yet. A Mars mission with chemical propulsion is hard, but could be made substantially easier with nuclear thermal propulsion - something we know should work, given the successful test fires on the NERVA program back in the 60s. First stage reusability was fantasy 15 years ago, today it's routine.

Obviously, I'm extrapolating a long way out, and maybe at some point we'll run against an unexpected wall. But we'll never know until we get there.

Re: Voyager 1 is about to reach one light-day from Earth

#180

Post by jjk166 »

danishSuri1994 wrote: post #159

It’s wild how Voyager forces two truths to sit together: Technically, what we’ve done is almost boringly modest. ~17 km/s ~1 light-day in ~50 years No realistic way to steer it anywhere meaningful now On cosmic scales it’s… basically still on our doorstep. Psychologically, it’s still one of the most ambitious things we’ve ever done. We built something meant to work for decades, knowing the people who launched it woul…

This is not an example of nor even an attempt at long horizon thinking. Voyager wasn't built with the intention that it would last for decades. It was a rush job to take advantage of a very rare planetary alignment and it's primary mission was completed 12 years after it started.

It is a testament to the ingenuity of the engineers who have worked and are still working on the project that they've managed to keep it to some degree functioning for so much longer than it was intended to last.

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