
NASA resets computer,  repairs data corruption on Voyager 2 interstellar probe - terra_t
http://www.jpl.nasa.gov/news/news.cfm?release=2010-151
======
eob
Whenever I read stories like this, I always look in awe at the white-beards in
my building who were around back in the days when computers were machines
instead of abstractions.

The Story of Mel -- A Real Programmer comes to mind:

<http://www.pbm.com/~lindahl/mel.html>

~~~
jgrahamc
Go program a microcontroller and you'll grow a grey beard all your own.

[http://blog.jgc.org/2009/08/just-give-me-simple-cpu-and-
few-...](http://blog.jgc.org/2009/08/just-give-me-simple-cpu-and-few-io.html)

The Voyager computers are of similar scale to microcontroller.

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Aaronontheweb
This is really amazing given the age of the Voyager craft and the massive
distances they have to beam instructions across. I'd imagine that all of the
engineering staff would be on pins and needles for hours while they waited for
what has to be the galaxy's largest (in terms of distance crossed) SYN-ACK :p

~~~
jakevoytko
As someone who works with autonomous robots, restarting a system 30 feet away
in demo conditions can cause pins and needles. I can't fathom how the NASA
engineers felt. They probably didn't get any good work done waiting for the
ACK

It's incredible that NASA, 30 years ago, built such a durable and reliable
system. The hardware has withstood one of the harshest environments in the
universe for decades, and the software hasn't been irreversibly scrambled by
passing cosmic rays. My cable modem doesn't even last an afternoon without
rebooting itself.

~~~
Qz
The Egyptians built the pyramids 5000 years ago. What I find incredible is how
we can't seem to build things that last anymore.

~~~
ugh
Yeah, but they built them for religious reasons, not because they actually
wanted to do something useful with them (for some definition of useful).

Sure, we could build pyramids – better pyramids even than the original ones –
but they wouldn’t be terribly useful.

(Oh, and sometimes we do build things that last. The six Apollo descent stages
are still on the moon and probably will be for Millennia. That, to me, is a
lot more impressive than any pyramid.)

~~~
Qz
> Sure, we could build pyramids - better pyramids even than the original ones
> - but they wouldn’t be terribly useful.

There are innumerable Discovery Channel-esque documentaries explaining that we
can barely build a small scale reproduction of the Pyramids, at least using
the knowledge they had available then.

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sliverstorm
I wonder, is it still possible to get involved with the Voyager craft, i.e.
secure employment at JPL and get into that team? Voyager 1 & 2 are hands-down
the most incredible machines/computers we have ever made, IMHO.

~~~
prawn
I hear you. I actually managed to wrangle Voyager 1 into a brief nerd-out
component of my wedding speech:

"Like me, the space probe Voyager 1 launched in 1977. Unlike me, it is one of
the pinnacles of human achievement. It is currently the farthest man-made
object from the Earth but it could not have achieved its speed and distance to
date without gravity assists from Saturn and Jupiter. When space probes are
launched, their path is often planned to get a gravitational slingshot from
the most significant entities in our planetary family, to take them further
than their launch alone might do. That boost is something invaluable, natural
and efficient."

"I don't want to call my parents, (mother) and (father), giant balls of gas,
but the boost, the impact they have had on my life, on my sister's life, my
brother's life and now the lives of our partners, is huge." And then, later
on: "Everybody, wish me luck that in our future together, there are only few
occasions where (bride) wishes I was the farthest made-made object from
Earth."

~~~
dimitar
You are awesome. I hope your comment gets into Hacker Monthly.

And I thought making a presentation about culture shock with Dr. Spock was
good.

~~~
prawn
Hey, thanks. I also managed to incorporate a bit about companion planting and
its similarities to relationships in there without it being too bland or dry.

It was all well received and only trumped by my father who wrote something
very original that had people in stitches. I should put both online just in
case other grooms are looking for inspiration - almost all of what's out there
is pretty basic and there is little worse than a cookie-cutter wedding speech.

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aheilbut
Sometimes it's worth springing for the ECC memory.

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dctoedt
Launched in 1977 - wow.

(See <http://en.wikipedia.org/wiki/Voyager_2>)

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johnohara
Distance: 8,600,000,000 miles

Radio wave: 186,282 miles per second

Push instructions: 12 hours, 49 minutes, 12 seconds

Flip bit: ?? milliseconds [+]

Wait for sample data: 12 hours, 49 minutes, ?? seconds

Process sample data: ?? milliseconds [+]

Analyze and confirm sample data: ~4 hours

[+] does anyone know this value?

It's a continuous signal so it had to have been exciting to view the stream at
the appointed time and see the correct format. Kind of like setting the baud
rate and parity on an old VT100 and getting the username prompt.

Congratulations to everyone involved.

~~~
asmithmd1
It is kind of depressing to think this spacecraft that we launched over 30
years ago is only 1/2 light day away and the next nearest star is over 4 light
years away.

More good info here: <http://voyager.jpl.nasa.gov/science/index.html>

Batteries should be good until 2025, data is sent back at 160 bits/second

~~~
InclinedPlane
500 years ago the only way a human could go faster than, say, 20mph was by
jumping off a tall structure. Even 200 years ago nobody knew much about the
nature of the Universe outside our own Solar System, nobody knew how atoms
worked, nobody knew about fission or fusion, nobody knew how the Sun worked,
automobiles, computers, heavier than air flying machines, and spacecraft were
as fantastical and unbelievable as any Greek myth, perhaps more so.

Since then humanity has grown by leaps and bounds. Conquered diseases.
Conquered limitations of distance. Learned many of the answers to the
Universe's deepest questions. We know how stars work to a degree that would
astound an astronomer from 1800. We know the age of the Universe to an
incredible precision. We've spied on the microwave echo of the big bang. We've
sent humans into space repeatedly and landed on a neighboring planetary body.
The Universe is a big place, we've only barely started to explore it and
understand it, but we shouldn't ignore how far we've come.

~~~
celoyd
Horses and some sailing ships go faster than 20 mph, but yeah.

Also, Voyager wasn’t designed for maximal speed out of the solar system. Even
then, if we had wanted to get to Alpha Centauri as fast as possible, we could
have done better. Not that the numbers aren’t humbling.

------
vmmenon
Reminds me of Ron Garret's article on Lisp at JPL ...

"Having a read-eval-print loop running on the spacecraft proved invaluable in
finding and fixing the problem."

<http://www.flownet.com/gat/jpl-lisp.html>

~~~
jurjenh
Following the chain of articles to <http://www.flownet.com/gat/jpl-lisp.html>
\- Lisping at JPL and seeing that essentially lisp was abandoned because of an
unreliable inter-process communications app written in C makes me wonder what
SpaceX, Boeing etc are using.

------
thunk
It's so easy to anthropomorphize spacecraft like Voyager 2. I get choked up
thinking about her bravely leaving the solar system, transmitting data until
~2025, alone in empty space.

~~~
trafficlight
XKCD nailed this perfectly when the Spirit rover got stuck and NASA had to
call it quits.

<http://xkcd.com/695/>

------
sandee
33 years and going .. Congrats to all

Images from voyager :
[http://ffden-2.phys.uaf.edu/212_fall2003.web.dir/Brian_Herol...](http://ffden-2.phys.uaf.edu/212_fall2003.web.dir/Brian_Herold/gallery.html)

From Wikipedia : "It is possible that one or both craft may have enough RTG
energy to last until 2025, but there is only a small probability of this"

<http://en.wikipedia.org/wiki/Voyager_program>

------
jberryman
everyone needs to read about voyager 2. among other amazing things, its
engineers designed it so that it would stay functional in various ways as its
battery depleted over the decades. if it does not receive a transmission from
earth after a given time interval it will go into some kind of autopilot,
faithfully beaming data back to earth. third thing i recall: the signal from
the probe is about as faint as a cell phone on the other side of the world

~~~
waterlesscloud
In various papers I had to write in college, I'd tend to base them on space
probes whenever possible. A great excuse to read journal articles about the
Lunar Prospector mission and so on.

------
doron
I know its off topic, but when you see this dedication to quality, and the
aspirations that led the Voyager mission, you cannot but feel saddened and
stupefied by the clusterfuck we are witnessing these past 2 months in the gulf
of mexico.

{edited}

~~~
earnubs
I think this this raises an interesting point, why do we look at space with
such awe in comparison arguably more complex and certainly more dangerous
engineering tasks closer to home?

~~~
mturmon
I agree that the point is interesting.

Part of it is the _differentness_ of the environment (high radiation, low
temperature, microgravity, great distance). This necessitates a rethinking of
design constraints at a fundamental physical level -- i.e. deriving system
constraints from first principles.

Another part of it is the unique nature of a lot of the stuff we send out
there -- rovers to Mars, planetary orbiters with exotic cameras, Earth-
orbiting satellites with hyperspectral imagers or advanced radars, powerful
telescopes with cryogenic optical/infrared cameras.

Here's an example (.mov):

[http://marsrover.nasa.gov/gallery/video/movies/mer_ch_edl_Te...](http://marsrover.nasa.gov/gallery/video/movies/mer_ch_edl_TerrorComb.mov)

from

<http://marsrover.nasa.gov/gallery/video/challenges.html>

~~~
prawn
A building on water doesn't seem that different to the regular world for most
of us. When most of what you see is on the surface (aerial shots of oil rig,
smoke plumes, oil slick, etc), 95% of the population probably wouldn't realise
that the rough stuff is happening over a kilometre under water.

------
savrajsingh
In case you were wondering where the spacecraft gets energy, it's powered by
nuclear decay:

[http://www.nytimes.com/1989/08/26/us/voyager-s-heartbeat-
is-...](http://www.nytimes.com/1989/08/26/us/voyager-s-heartbeat-is-nuclear-
battery.html)

------
ScotterC
Is amazing at the wealth of knowledge these older guys have.

Funny, I had heard some article trying to say that voyager was sending 'alien
messages'. Of course it's just one bit swung the wrong way.

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fletchowns
What caused the bit to be flipped? Cosmic rays?

~~~
pepijndevos
Exactly my thought! Remember this one?
<http://blog.ksplice.com/2010/06/attack-of-the-cosmic-rays/>

------
budgi3
do they just telnet into it? anyone know the login?

seriously though, how do they go about accessing the system?

~~~
mturmon
First, you need a 70m antenna.

<http://deepspace.jpl.nasa.gov/dsn/>

[http://deepspace.jpl.nasa.gov/dsn/images/realtime/latestS.jp...](http://deepspace.jpl.nasa.gov/dsn/images/realtime/latestS.jpg)

And, it seems simple, but is not: you need very precise pointing, and very
precise ephemeris (<http://ssd.jpl.nasa.gov/?horizons>) to get the relative
velocity to the s/c. You need velocity so you know what the Doppler-shifted
frequency of the transmission will be.

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donohoe
Furthermost SSH ever?

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gubatron
that always works

