Voyager 1 Has Outdistanced the Solar Wind | Hacker News Reader

Voyager 1 Has Outdistanced the Solar Wind

universetoday.com

80 points_b8r029 comments

Since it's such a large number and difficult to comprehend Voyager 1 is about 116 AU away. 1 AU is the distance from earth to the sun (150,000,000 km). Earths circumference is 40,000 km. Space is big.

Also, a neat summary of the computers on Voyager can be found here: http://voyager.jpl.nasa.gov/faq.html

I'm still trying to track down the article on the comm used.

Great websites to browse around.

I can only heavily recommend the "did you know" [ http://voyager.jpl.nasa.gov/mission/didyouknow.html ] and "fast facts" [ http://voyager.jpl.nasa.gov/mission/fastfacts.html ] pages.

It makes one truly appreciate and wonder about the amazing accomplishments of this machine (and it's sister, Voyager 2) and the men and women who made this 'grand tour' mission possible.

Sometimes I've wished I was born a few decades earlier so I could have been a part of the team that really pushed mankind's space boundaries and knowledge.

Initial reaction: Now that's reliable hardware! Somebody forgot about the warranty expiring ...

More serious thoughts: This is really amazing, I would never have imagined it would even be possible to keep contact with a probe for this long.

Makes you wonder, way back then we could launch a probe that runs for several decades and reaches the absolute edge of the solar system ... nowadays we can ... make missions into space on several decades old hardware ...

Something isn't right here guys, I thought rocket science was supposed to be bleeding edge?

Well, there is New Horizons on its way to Pluto and the Kuiper belt, Juno will launch in 2011 to Jupiter. Cassini will have explored Saturn for 13 years at the end of its mission in 2017. (Cassini is in many ways more impressive than the Voyager spacecrafts.)

Then there are of course Spirit and Opportunity on Mars and their successor, Curiosity, is scheduled to land in 2012.

It sucks a bit that not much else is planned at the moment, though. (Probably no Mars Sample Return before 2020, no missions to Europa, …)

It's kind of surprising there is no mission to Europa in any form of advanced planning, the idea certainly seems to have been around for a long time.

You would imagine to that there would be much to learn from Cassini like missions to Uranus and Neptune.

There have been a couple of Europa missions which got cancelled in the planning stages, which is why we don't have one in the works right now. Europa missions have a habit of getting extremely elaborate and expensive and then getting cancelled.

We'll get there eventually. In the meantime, the big (and very expensive) mission in the works which the grandparent didn't mention is the Titan Saturn System Mission:

http://en.wikipedia.org/wiki/Titan_Saturn_System_Mission

which is currently planned to have a Titan orbiter, a Titan lake lander, and a Titan hot air balloon. If this one launches in its planned form it's going to be impressive. Mind you, it's not due to launch 'til 2020 and it's got a nine-year flight to Saturn, so don't hold your breath either way.

Cassini is doing some awesome work. I've been watching the website ever since orbital insertion in 2004, and it keeps returning gorgeous images of the moons and really interesting science. Apparently it still has lots of propellant left, since it's been approved to continue to about 2017. The web site doesn't have a photo gallery of the best pictures, but the daily pictures, which have some interesting write-ups are archived at http://saturn.jpl.nasa.gov/photos/.

I thought rocket science was supposed to be bleeding edge?

It is not. The main problem in space are the high energy particles. They penetrate everything (and I mean everything, also metal, processors, they cause bit flips and can do a lot of harm). So a first priority objective is reliable (=tested) hardware. There is little tested hardware for obvious reasons.

I work in ESAs Herschel project. Herschel runs on 16 MHz processors (Mega - not Giga!) - like your good old Atari St. You don't wan't to risk a 1 Billion Euro Spacecraft, because of one failing chip.

The detectors of the instruments, of course, are another story. These are indeed bleeding edge. Their readout electronics on the other hand, good old stuff again. So the whole thing is a funny mixture of old but fool proof hardware combined with new developments.

Couldn't you just shield against high energy particles with a strong magnetic field like Earth does?

Or would that be too heavy to lug around and/or too difficult to supply with enough energy?

How should we do that? You would need superconducting coils on board and an extra 1000 liters of helium to cool the coils. Then run 200 Amperes through them.

You see yourself...

Earths magnetic field stretches far into space. So the particles have to be diverted from their original course only a little bit. Impossible to do that for a spacecraft. Magnetic field strength decreases with 1/(r to the power of 3).

In fact, for a small spacecraft, there are only a few hits into the electronics per day.

I know a funny story from an astronaut, who was on the ISS for a while. He told us, even with eyes closed at "night", he could see light flashes, when a particle was absorbed within his eyeball. Nice place out there...

Another "simple" solution would be to surround the probe with a 5m thick shell of water, the protons in there will absorb most of the high enerqy particles. It might just make it a bit difficult to accelerate the whole contraption to escape velocity...

Well... A heavily shielded spacecraft could be built and launched from the Moon... Use regolith for shielding and a magnetic rail to launch. This way most of the mass will never have to be lifted from Earth and, still, you get a lot of shielding, as much as your rail can launch.

But that is decades (a good couple of them, more like a dozen) away. And the rail itself would be so easy to weaponize the diplomatic nightmare required to build it would dwarf the technical difficulties.

Eh, it wouldn't be great to weaponize. You'd have way too much warning. The prompt global strike using a submarine launched ICBM mounted with a convential warhead accomplishes everything you would want from space based weapons without your targets being able to track things as easily, yet the US doesn't do it becuase of fear it would spark diplomatic problems.

There are plenty of weapon systems better than a mag rail on the moon that we don't use today already, we don't need more.

This is the "Moon is a Harsh Mistress" scenario. The people weaponizing it may not be the Earth-bound nation state, it may be the lunar residents themselves. By the time you can run a rail system like this you've got at least a small village up there, minimum.

There's something to be said for just throwing rocks at your opponent, when your rocks have the equivalent of a small nuke in yield. They're hard to divert, there's no clever electronics tricks you can play to fool them into not detonating, it's like trying to divert a multi-ton bullet. Everything in space is a weapon, and anything capable of launching "interesting" spacecraft opens the bidding at "capable of destroying cities" and moves up from there.

Reminds me of this clip from Mass Effect 2: http://www.youtube.com/watch?v=7GqqDCe4Yrs

> it may be the lunar residents themselves

Not only that - by the time Earthlings notice, they can put a whole lot of mass flying towards Earth. By tuning the mass of the individual parts, teyh can even make all of them arrive at once.

Also, the trip between Earth and Moon takes a couple days because we have limited energy. A magnetic rail, provided enough power, could launch cargo as fast as the designed limits allow. When using it as a weapon, you really don't care whether your projectile will be able to enter LEO.

Compounding that, nuclear weapons are useless on the Moon. There is no atmospheric blast, only direct radiation. Earthlings would have a hard time retaliating.

I think you forget about how awesome the mars rover is. It was only supposed to do a mission that 90 days and lasted more than 1800 [1] and that Martian environment is really tough. Though I still think it's amazing that the voyager is still kicking ass, I just wanted to point out that their is still some awesome work being done.

[1]http://en.wikipedia.org/wiki/Spirit_rover#Mission_overview

And most importantly it was built cheap. Voyager was best of the best, but the rovers were built to break and still outlived their expected life cycles.

This is especially cool for me, in that I remember the day in grade school I told the other kids about how Voyager 1 was passing Saturn and was the farthest-away man made object; now, some 30 years later, it is still making news and performing a useful scientific function.

It's awesome that they have a second probe to repeat and confirm the data from the first one.

The Voyagers just leave me astonished - something that far and we are still communicating with it. I hope we are able to collect them one day.

Yes, if the Klingons don't destroy them... ;o). Just kidding. I still remember the launch. A remarkable instrument indeed. Like Pioneer. Two of the most impressive space missions.

Just wondering about two things:

[1] If speed of the space-craft(craft) and solar-wind (wind) become equal that doesn't mean winds have stopped? That means they are same or slower than the craft. Right?

[2] The time that signal from craft takes to reach us, is that accounted for in their estimation of 'how much time in...' equation?

Dummy questions but just very curious.

[1] True. But the default speed of the charged particles are a lot faster than a spacecraft, so effectively they've stopped.

[2] The light travel time is on the order of hours, not significant on these scales.

But has it forgotten who its creator is yet?

Almost about to jump into hyperspace!

Graphic of locations of Voyager and Pioneer spacecraft:

http://upload.wikimedia.org/wikipedia/en/7/75/Outersolarsyst...

From 2007. Would love to see something updated!

Add four pixels to each line. ;)

Also Heliographic Latitudes for the spacecraft:

http://cohoweb.gsfc.nasa.gov/helios/book2/b2_12.html

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