Voyager 1 Beyond Solar Wind

healeyb noted that Voyager 1 has now reached a distance from the sun where it is no longer able to detect solar wind. Launched in 1977 to get up close and personal with our solar system's gas giants, scientists estimate that in another 4 years it will cross the heliosphere.

Comments

I feel a kinship with voyager

[arcite]

Since it is almost the same age as me, I feel a kinship with the little guy. It's amazing that it's still sending back readings after all theses years and millions of miles travelled in the deep dark infinite space. Onward to interstellar space! Godspeed!

Re:Data transfers

[john83]

From here,

The total cost of the Voyager mission from May 1972 through the Neptune encounter (including launch vehicles, radioactive power source (RTGs), and DSN tracking support) is 865 million dollars.

and

A total of five trillion bits of scientific data had been returned to Earth by both Voyager spacecraft at the completion of the Neptune encounter.

That's $0.001384 per bit. There are 1120 bits in an SMS message. That's about $1.55 per SMS. Not exactly cheap, but then Vodafone don't have coverage beyond Pluto.

Re:17.5 billion kilometers

[crunchygranola]

True, Voyager 1 has only travelled a short way between stars within our galaxy -- but here is a cool fact (I think).The Milky Way Galaxy is moving relative to the rest of the Universe (as defined by the Cosmic Microwave Background frame of reference) at 279 ± 68 km/sec, just under 0.1% the speed of light. This is the speed with which we are moving through the Universe. Thus if you live to be 80 years old (a typical lifespan today) you will die in a region of the Universe 0.074 light years from where you were born, and the first pyramids were built in Egypt in a region of the Universe more distant than Alpha Centauri.

CPU - lowly RCA 1802

[Sooner Boomer]

Wow, just wow! Not even a 6502. The Voyagers used a trio of 1802s clocked at 6.4MHz. Just goes to show what you can do with a specific bit of hardware and tight code.

Re:An amazing achievement

[Chris Burke]

If we had the collective courage [read - no enviro-wackos] to use RTGs [wikipedia.org] on our Mars probes, we wouldn't have lost Spirit to freezing temperatures brought on by low power from the solar cells.

LOL, that's why you think Spirit and Opportunity didn't use them? Enviro-wackos?

The real reason is simply optimizing for the mission profile. The MERs were relatively small devices with very tight mass budgets, and an RTG of sufficient power would have been too heavy compared to the solar panel/battery combo they went with instead. It was an engineering trade-off. They did, by the way, use RHUs to heat components but this was not sufficient to stave off freezing by itself.

The Mars Science Laboratory is going to use an RTG. It is a much larger rover, with power demands beyond what solar panels could provide, and with a more generous amount of mass to dedicate to the power system.

We used 'em on quite a few spacecraft [wikipedia.org] - why they aren't used more often for solar power-limited missions escapes me.

Yeah, which I would think would have suggested that maybe enviro-wacko objection to the concept of RTGs had nothing to do with it. This is a lobby with surprisingly less power than you might think. :)