35 Years Later, Voyager 1 Is Heading For the Stars

DevotedSkeptic writes with news that today is the 35th anniversary of Voyager 1's launch. (Voyager 2 reached the same anniversary on August 20.) Voyager 1 is roughly 18 billion kilometers from the sun, slowly but steadily pushing through the heliosheath and toward interstellar space. From the article: "Perhaps no one on Earth will relish the moment more than 76-year-old Ed Stone, who has toiled on the project from the start. 'We're anxious to get outside and find what's out there,' he said. When NASA's Voyager 1 and Voyager 2 first rocketed out of Earth's grip in 1977, no one knew how long they would live. Now, they are the longest-operating spacecraft in history and the most distant, at billions of miles from Earth but in different directions. ... Voyager 1 is in uncharted celestial territory. One thing is clear: The boundary that separates the solar system and interstellar space is near, but it could take days, months or years to cross that milestone. ... These days, a handful of engineers diligently listen for the Voyagers from a satellite campus not far from the NASA Jet Propulsion Laboratory, which built the spacecraft. The control room, with its cubicles and carpeting, could be mistaken for an insurance office if not for a blue sign overhead that reads 'Mission Controller' and a warning on a computer: 'Voyager mission critical hardware. Please do not touch!' There are no full-time scientists left on the mission, but 20 part-timers analyze the data streamed back. Since the spacecraft are so far out, it takes 17 hours for a radio signal from Voyager 1 to travel to Earth. For Voyager 2, it takes about 13 hours."

Comments

You have to give it to the engineers

[PCK]

Granted it's built to more demanding specifications, but something lasting 35 years in deep space is quite an achievement.

Re:You have to give it to the engineers

[khallow]

The problem is hard and easy. It's hard in that the primary problems of deep space spacecraft are very difficult, such as maintaining electronics for decades in an environment with hard radiation. But it's easy in that the environment doesn't change.

You engineer for a fixed problem. Once you have something that works for a time in deep space, then you can tweak that solution to greatly extend the lifespan.

Re:You have to give it to the engineers

[DevotedSkeptic]

You are definitely correct. It is amazing to think that technology from 35 years ago is still operating and sending back data. We generally don't keep cars around for 35 years let alone computers, phones, or even kitchen appliances. Now there is a world of difference between these things i mentioned and the tight tolerances that went into Voyager, but it still absolutely amazing what we as humans have accomplished. Carl Sagan would have been excited with the current Mars Rover, along with all of the other projects that we have successfully launched, but I think he would be a bit saddened by the state of the manned programs.

Re:You have to give it to the engineers

[SJHillman]

Not to understate the achievement, but comparing it to consumer hardware like cars is a bit of apples and oranges. It'd be more akin to military grade hardware like ships and planes. Of course, even for some of those, 35 years is a stretch... and NASA has never had the budget that the military does.

Re:You have to give it to the engineers

[petteyg359]

That's why NASA gets stuff that works, and the military gets stuff that lets the contractors line their Olympic-sized pools with money.

Re:You have to give it to the engineers

[Dr. Spork]

Let's not forget that ships and planes have regular maintenance. This is a huge portion of the DoD budget. But nobody has taken a wrench or a soldering iron to the Voyagers in 35 years. At best there have been firmware updates.

Re:You have to give it to the engineers

[Anonymous Coward]

Actually, he's saying that his job was easier than what the current generation is doing with robotic devices. Look at Mars. Rocky terrain, sandy terrain, dusty terrain, soft terrain. Sometimes it's light, sometimes, it's dark. These are variations in the environment. With Voyager, they had exactly one environment to plan for. That environment had some very difficult problems to overcome but once they'd made their solution work for one environment, they were done. They didn't have to make their solution work for another environment.

In other words, congratulations on being an angry bitch who sees the worst in everyone.

V'GER!

[TaoPhoenix]

You will disclose the First Post. V'GER requires the information.

Has it made it ?

[mbone]

If you look at this picture, it sure does look like Voyager 1 may have left the solar system (in a plasma sense) in late August. (In other words, it is no longer seeing protons from the solar wind, which means it may be outside of the Sun's bubble of plasma, and into the interstellar medium.

If so, it has impeccable timing.

Re:Has it made it ?

[Immerman]

As they state, it is currently within the heliosheath - the turbulent boundary layer between Sol's plasma bubble and the interstellar medium, so it's outside the region thoroughly dominated by the sun's influence, but not yet within the interstellar medium. Quite an interesting region in it's own right, but not terribly informative of either bounding environment.

Always the frontrunner?

[Coisiche]

It would be nice to think that one day we'll reach a technological level that allows us to overtake Voyager 1. I'm not that hopeful though. I think that the head start Voyager 1 has means that it always will be more remote from Earth than anything else constructed here. Excluding Pioneer 10, that is.

Re:Always the frontrunner?

[vlm]

It would be nice to think that one day we'll reach a technological level that allows us to overtake Voyager 1. I'm not that hopeful though. I think that the head start Voyager 1 has means that it always will be more remote from Earth than anything else constructed here. Excluding Pioneer 10, that is.

There's some planetary alignment issues such that it would be really hard to catch Voyager. The New Horizons probe, despite being something like the fastest probe ever launched, is moving considerably slower because it had unfavorable gravitational assists, something like 10% slower than voyager. The planets have to line up, unless you do something ridiculous like launch a tennis ball a Saturn-V

Both are practically slow crawling compared to the Helios probes from the late 70s/early 80s which were moving something like 6 times the speed, although toward the sun not away. The Helios probes are still the fastest controllable "things" produced by mankind. The "controllable" is necessary because there's a famous nuke bomb test film where analysis of adjacent frames shows a manhole cover moving about about 0.1c... at least for a little while.

Re:Always the frontrunner?

[Sponge Bath]

CEOs and the politicians all need new Ferraris!

Average people all need new mobile phones and x-boxes, when they could have pooled that money for space exploration. CEOs and politicians make easy targets.

Re:Always the frontrunner?

[K. S. Kyosuke]

It would be nice to think that one day we'll reach a technological level that allows us to overtake Voyager 1.

Keep in mind that with the small velocities that our probes are leaving the Earth with at the moment, a small change of initial velocity makes for a big change in asymptotic velocity as the craft flies through the shallow parts of the gravity well (i.e., when it is far away). That means that we can already do that today.

You don't even need to integrate any trajectory to find this out, that's simple physics the kind of which I was doing in high school. Just calculate the kinetic + potential energy balance of the Sun-Earth-spacecraft system. Just escaping the Sun means balancing the (negative) potential energy of the probe within Sun's gravity well. The balance is v_terminal^2*m*(1/2) = E_p + v_initial^2*m*(1/2), where E_p is negative, of course, and v_initial is the speed relative to the Sun after leaving the Earth ("leaving the Earth" meaning here "getting far away enough so that the remaining potential energy caused by the presence of Earth won't skew the results too much"). If v_initial is 42.1 kps, you'll end up with v_terminal = 0. You'll get that if you leave Earth with initial speed of 16.6 kps which you can calculate in a similar manner. Now as to the the deltas to initial velocity of 16.6 kps near Earth and respective final velocities relative to the Sun in the infinity:

extra 1 kps => 10.6

extra 2 kps => 15

extra 3 kps => 18.4

extra 4 kps => 21.2

There are diminishing returns, but you can overtake Voyager 1 by having extra 3 kps when leaving the Earth *at any time*. The reason Voyager 1 is so fast despite having left Earth at a very modest velocity are the four grav assists. Today, all you need is the same ion engine that Dawn has and you're well on the way much faster than any probe before.

Re:Always the frontrunner?

[JoshuaZ]

The manhole in question went 45 miles a second. That's around 70 kilometers a second whereas the speed of light is around 3*10^5 km/s. So it was going around .002 the speed of light, which is still very damn impressive but is a lot less than .1c. See http://professionalparanoid.wordpress.com/the-fastest-man-made-object-ever-a-nuclear-powered-manhole-cover-true/ for more about the manhole cover and the circumstances of its launch.

Re:Always the frontrunner?

[mbone]

Sorry, but wrong. Voyager I overtook Pioneer 10 in 1998 :

Until 17 February 1998, the heliocentric radial distance of Pioneer 10 has been greater than that of any other manmade object. But late on that date Voyager 1's heliocentric radial distance, in the approximate apex direction, equaled that of Pioneer 10 at 69.419 AU. Thereafter, Voyager 1's distance will exceed that of Pioneer 10 at the approximate rate of 1.016 AU per year.

iPod

[SJHillman]

"Each only has 68 kilobytes of computer memory. To put that in perspective, the smallest iPod — an 8-gigabyte iPod Nano — is 100,000 times more powerful."

So what you're saying is that if I upgrade my computer from a 500GB hard disk to a 2TB hard disk, it makes the entire computer 4 times more powerful?

Some kind of dupe

[Anonymous Coward]

Voyager seems to be "heading for the stars" once every six months:
- http://science.slashdot.org/story/12/06/15/0115226/new-signs-voyager-is-nearing-interstellar-space
- http://science.slashdot.org/story/12/04/14/012219/voyager-and-the-coming-great-hiatus-in-deep-space
- http://science.slashdot.org/story/11/12/07/2127247/voyager-1-exits-our-solar-system
- http://science.slashdot.org/story/11/04/28/2314203/voyager-set-to-enter-interstellar-space
- http://science.slashdot.org/story/10/12/14/1451216/voyager-1-beyond-solar-wind

Re:Voyager 2 launched first?

[Jason Levine]

George Lucas is to blame. He edited the order in Voyager: Special Edition.

Re:Voyager 2 launched first?

[Anonymous Coward]

So Voyager 2 was launched weeks before Voyager 1? Was the launch schedule changed at the last minute?

No. Per this:

http://space.about.com/od/spaceexplorationhistory/p/voyager1.htm

"Voyager 1 was launched after Voyager 2, but because of a faster route, it exited the asteroid belt earlier than its twin. It began its Jovian imaging mission in April 1978 at a range of 265 million kilometers from the planet; images sent back by January the following year indicated that Jupiter's atmosphere was more turbulent than during the Pioneer flybys in 1973 and 1974."

Re:They just don't build 'em like they used to.

[fuzzyfuzzyfungus]

Depends on what compromises you are willing to accept, really...

One big killer in consumer electronics is that(if the state of the shelves is to be taken as indicative of what customers actually want) people apparently care more about devices being thin than about batteries being standardized, or replaceable at all... Barring a minor miracle on the Li-ion side, that provides a nice, hard, cap on the viable lifespan of most portables. It wouldn't be rocket surgery to standardize batteries(even if the AA is a bit old school, a standardized Li-ion rectangle could probably be CADed up in about 20 minutes and then entirely ignored by the industry at large); but there seems to be minimal interest in doing so.

Most of the rest would come down to either accepting component choices that are bad for BOM costs(ie. electrolytic capacitors are delightfully cheap for the performance they give; but they are born to die, doubly so in toasty environments, all solid caps is better, but costs rather more) or would constrain you to performance that is somewhat behind the curve(people run 130watt processors, with their demand for moving parts in the cooling system and tendency to cook their own smoothing caps, because they want something faster than a 1-10 watt processor can survive...)

Especially since it doesn't need to be rad-hard, you could probably build many contemporary consumer devices for a 35 year life span for not more than 2-3x the cost and a rather bulkier case; but good luck selling that...

Re:2020?

[fuzzyfuzzyfungus]

Communications, I believe. It is just going where its inertia takes it at this point, and heading out of the solar system. It is obviously still under the gravitational influence of bodies in the solar system(and all the other ones, as best we can tell); but it isn't on a path that would be described as an 'orbit' in anything like the usual use of the term.

Re:2020?

[mbone]

The two Voyagers are gyroscope stabilized, so they don't need fuel for attitude control.

They are powered by Plutonium 238 RTG's, and that power is steadily declining as the Plutonium decays and the thermocouples age. I think that is what the article is referring to. I wouldn't call them fuel.

Re:2020?

[camperdave]

The fuel they speak of is hydrazine, and it is used for maneuvering; specifically for maintaining the orientation of the craft so that the antenna is pointed Earthward, and also to spin the craft about its axis periodically to recalibrate some of the sensors. The electronics are powered by three nuclear batteries, which are also expected to "run out" at about the same time. From Wikipedia:

Both spacecraft also have adequate electrical power and attitude control propellant to continue operating until around 2025, after which there may not be available electrical power to support science instrument operation. At that time, science data return and spacecraft operations will cease.

Not really...

[xded]

Radiation damage builds up with time, see Total Ionizing Dose (TID) effects. Not so easy to "tweak" silicon devices to counteract lattice displacement effects (the only real solution being not relying on the silicon lattice, i.e., working with vacuum tubes).

My grandfather would be proud...

[vjl]

I wish my grandfather was still alive to see Voyager 1 still in operation. He worked on the batteries and electrical system on the Voyager probes, spending most of his adult life working at JPL. He would be thrilled to know that they were both still operating, exploring, and sending data back to earth. Impressive!