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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

#121
post #58

Not that we would literally do this with Voyager, but it makes me wonder at the potential utility of a string of probes, one sent every couple of [insert correct time interval, decades, centuries?], to effectively create a communication relay stretching out into deep space somewhere. My understanding with the Voyagers 1 and 2 is (a) they will run out of power before they would ever get far enough to benefit from a re…

What you are describing has been proposed before, for example within context of projects like Breakthrough Starshot. In that the case the idea is to launch thousands of probes, each weighing only a few grams or less, and accelerating them to an appreciable fraction of the speed of light using solar sails and (powerful) earth-based lasers. The probes could reach alpha centauri within 20-30 years. There seems to be som…

If I don't recall wrongly, Breakthrough Starshot was not a means for commnunicaiton relay as he describes.

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

#122
post #107

Earlier quoted context omitted.

Well voyager depended on a solar system alignment that only happens every 175 years(?) so it'd be a while before we get that same advantage again. The longer it takes the further of a head start voyager gets?

The headstart doesn't really matter, anything faster than Voyager will catch up eventually

Voyager 1 is traveling at 16.9 km/s.

New Horizons (which has the distinguishing feature of being the fastest human-made object ever launched from earth https://www.scientificamerican.com/blog/life-unbounded/the-f... ) is traveling at 12.6 km/s.

The key part there is that it got multiple gravity assists as part of the Grand Tour https://en.wikipedia.org/wiki/Grand_Tour_program . You can see the heliocentric velocity https://space.stackexchange.com/questions/10346/why-did-voya... https://www.americanscientist.org/article/the-voyagers-odyss...

The conjunction for the Grand Tour is once every 175 years. While you might be able to get a Jupiter and Saturn assist sooner, it is something that would take the right alignment and a mission to study the outer planets (rather than getting captured by Jupiter or Saturn for study of those planets and their moons).

While I would love to see a FOCAL mission https://en.wikipedia.org/wiki/FOCAL_(spacecraft) which would have reason for such a path, I doubt any such telescope would launched... this century.

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

#123

If Voyager could stay operational and keep its speed of ~61,000 km/hr, it would reach the nearest star (Proxima Centauri) in about 72,000 years. My mind understands the numbers, but can't grasp them.

For reference, the oldest cave drawings we know of were made by neanderthals around ~70,000 years ago [0].

[0] https://www.southampton.ac.uk/news/2018/02/neanderthals-art....

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

#124
post #117

We are flying "faster" on earth. You often hear about the fatality rate per 100 million or 1 billion passenger miles in transportation statistics, but over the last 15 years, U.S. airlines have averaged less than 1 fatality per passenger light-year traveled https://x.com/RyanRadia/status/1764868263903723874

Technically when tweeted for the given selective timespan, but no longer true since the crash this year in DC. Still, mind blowing. When fact checking this I learned we went over 2 passenger light years worth of airline travel with no fatalities during that time frame. Incredible safety record. Real shame this year has been so terrible for our reputation.

Yes, when I saw the tweet, I thought the next crash might be near, and then happened DC soon after.

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

#125
post #42

Earlier quoted context omitted.

Laser communication could potentially address some of those issues.

Maybe, but if your probe is heading directly towards another solar system then it will be backlit by its destination.

https://space.stackexchange.com/questions/33338/why-is-the-o... is a neat question that addresses this issue.

And yes, the transmitters will need to be powerful enough be a distinct signal over the background of the star that is in the line of sight of the receiver / beyond the transmitter.

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

#126
post #40

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.

What if the probes carry smaller probes left behind at specific intervals that act as repeaters? These baby probes could unfold a larger spiderweb antenna the size of a tennis court.

You can't leave anything behind. That would need to be accelerated to 50,000 km/h or have even bigger rockets than launched Voyager in the first place.

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

#127
post #31

Wow, this gives a reflection about our future. The nearest potentially habitable planet known is Proxima Centauri b, which orbits the red dwarf star Proxima Centauri about 4 light‑years from Earth (at least it is in a habitable zone of its star) [1]. So we don't have a choice actually except protecting and make sure our planet survives. That's regardless if it really would be able to support life as we know or not (p…

Space is cool, and I support the scientific work some of its pioneers discover. But the category of people who believe space travel is somehow the solution to problems on Earth give me headaches.

Even if we find another habitable planet, figure out how to get there, start a colony, what in the world makes us think we won't fuck up that planet like we've fucked up this one?

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

#128

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?

It might have from time to time... but it had limited ability to track.

As I type this, DNS Now is currently receiving data from Voyager 1. https://eyes.nasa.gov/apps/dsn-now/dsn.html

https://imgur.com/a/kXbhRsj for a screen shot of the relevant data.

The antenna data is https://www.mdscc.nasa.gov/index.php/en/dss-63-2/

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

#129
post #106

Earlier quoted context omitted.

No one likes to think this but it’s very possible voyager is the farthest humanity will go. In fact realistically speaking it is the far more likeliest possibility.

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…

Yes, it's incredibly easy to do these things once you've done all these other, incredibly difficult things first.

The furthest a human has been is 250k miles (far side of the moon). The fastest a human has traveled is only 0.0037% the speed of light.

The ISS is about 260 miles from the Earth. At that height, the gravity is actually roughly the same as on the surface, it's only because it is in constant freefall that you experience weightlessness on it.

Mars is 140 million miles away. And not exactly hospitable.

I like how you treat "the fusion problem" with a throwaway, "Yeah, we'd have to solve that" as if we just haven't sufficiently applied ourselves yet.

All of those incredibly difficult things we have not even begun to do are the technical reasons we have not gone interstellar and may be the reason we will never do so.

And even if we solve the issue of accelerating a human being to acceptable speeds to reach another star, the next closest star is 4 light years away. That means light takes 4 years to reach. Even if you could average half the speed of light, that's 8 years, one way. Anything you send is gone.

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

#130
post #38

Earlier quoted context omitted.

Less than that is you are constantly accelerating.

If you can figure out a way to apply thrust that doesn't require you to lug mass with you and throw it out the back of your spacecraft you will open up the stars to exploration. If not the rocket equation will wreck your plans every time.

Why?

75k years in geological timescales is nothing.

If there are creatures who could live longer than that, perhaps by hibernating or just having really long lifetimes, space exploration is feasible with slow craft.

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