Voyager Set To Enter Interstellar Space 362
Phoghat writes "More than 30 years after they were launched, NASA's two Voyager probes have traveled to the edge of the solar system and are on the doorstep of interstellar space. Today, April 28, 2011, NASA held a live briefing to reflect on what the Voyager mission has accomplished — and to preview what lies ahead as the probes prepare to enter the realm of the Milky Way itself."
Re:What exists beyond? (Score:5, Informative)
Radio Lab has a great episode [radiolab.org] interviewing Ann Druyan, Carl Sagan's widow, regarding her part in developing the sound recordings for the voyager mission. She beautifully captures the art and love inherent in such an awesome act of science and exploration. If you have a free few minutes, you won't be sorry you listened.
Re:Let me say (Score:4, Informative)
More then likely written in pure Assembler or Machine Code. Hand Debugged, Hand Optimized back when software engineers were programmers in the very real sense of the word.
Although unconfirmed AFAIK the whole thing is run on a RCA CDP1802, also known as the COSMAC (Complementary Symmetry Monolithic Array Computer) [wikipedia.org] and at this moment the entire spacecraft runs on +/- 275 watts of power at 30 Volts DC which is pretty damn amazing.
Put that in your god damn JVM/Python/PHP/Erlang/Lang De Jur pipe and smoke it ya damn weenies!
Re:Let me say (Score:5, Informative)
How many times did they have to reboot Voyager?
In case you didn't know, it wasn't a reboot, but there was a problem where they actually did have to live patch the voyager 2 computer [nasa.gov] last year for a bit-flip problem...
Of course this was discussed previously [slashdot.org]
Although that's impressive, in general, the SW architecture of voyager is quite complicated and fragile, and during the operation, several mistakes have been made one of which caused the primary receiver on Voyager 2 to be accidently shut down, never to work again (so it's relying on a backup which has a faultly frequency tuning circuit which they compensate in software).
It's really only heroics which keep these probes up and running. The original engineering, while impressive, is really not the thing that's keeping things working now...
Re:not yet (Score:5, Informative)
You're probably thinking of the Oort Cloud.
From the wikipedia [wikipedia.org]
In August 2009, Voyager 1 was over 16.5 terameters (16.5×1012 meters, or 16.5×109 km, 110.7 AU, or 10.2 billion miles) from the Sun, and thus had entered the heliosheath region between solar wind's termination shock and the heliopause (the limit of the solar wind). Beyond heliopause is the bow shock of the interstellar medium, beyond which is interstellar space, a vast area where the Sun's influence gives way to that of the Milky Way galaxy in general. At this distance, light from the Sun takes over 16 hours to reach the probe.
The Kuiper belt [wikipedia.org] extends from 30 AU to 55 AU.
Re:Let me say (Score:5, Informative)
How Long ? (Score:5, Informative)
It's not aimed at any other solar system, and the times involved are such that we can't predict what's going to happen very well.
In places like Wikipedia [wikipedia.org] you will read things like
"in about 40,000 years [Voyager 1] will pass within 1.6 light years of the star AC+79 3888 in the constellation Camelopardalis."
but this is highly misleading. 1.6 light years is almost 1000 times further away from that star than either Voyager is from the Sun right now, so it won't in any sense be "in" that stellar system.
Worse, stars travel (relative to each other) at ~ 0.001 c, so even in 40,000 years all the nearby stars will move around by 10's of light years. We can estimate stellar velocities reasonably well, but their accelerations are very poorly measured, and so, after a few million years at most, we really don't know which star will go where.
The bottom line is, it will be millions of years before any of these spacecraft get as close to another star as they are now, and we have no idea which star that will be... ... unless, of course, our descendants pick them up and put them in a museum somewhere, which is what I would predict.
Re:Let me say (Score:3, Informative)
In case you didn't know voyager 2 already does have a twitter account [twitter.com] which is updated regularly.