Whisper Heard From Pioneer 10

Irishman writes "NASA has heard from the Pioneer 10 spacecraft for the first time since March. Unfortunately, it is too faint to get scientific data from the craft. CNN has the story here. Considering that the craft is twice the distance from the Sun as Pluto is and that it has spent 30 years subjected to space, this is amazing! Now if only computer manufacturers could make equipment even remotely this sturdy."

Comments

use repeaters ... ?

[mystik]

Why didn't NASA send out repeaters behind it ? I'd imagine that a series of repeaters behind it would be able to get information back to us on earth...

Re:use repeaters ... ?

[CynicTheHedgehog]

It would be nice to know when it hits heliopause, or the point in space where the sun's magnetic field ends. That way it would no longer be in the solar system, but truly an interstellar craft. Not only would that give us useful scientific data with which we can revise our solar model and dynamo theory, but it would also be a historical achievement for man.

Re:use repeaters ... ?

[Mysticalfruit]

Since Deep Space 1 is going alot faster than either Pioneer 10 or 11, I wonder how long before it becomes the farthest object away?

Signal strenght?

[jonr]

Apart from all the moronic comments about sturdy computers (Nice going Irishman, trolling in the story), Isn't this a clue about the silence in space? You know, the Drake equation? How strong must a signal be, to be heard? Pioneer is only 2x orbit of Pluto away from the Sun, and already impossible to listen to. Nearest star is 4.2 light years away, and nearest galaxy is "just" 75,000 light years away. How strong signal would be needed to communicate these distances. I know the Pioneer signal is only a few milli (micro?) watts, but still...
J.

Rad hardened really neccesary...?

[EnglishTim]

I don't believe that's actually always the case. I have a friend who works for the Surrey Space Centre on very small satellites - I was chatting to him down the pub about it one day and I was quite surprised to find out that it ran on an ordinary StrongArm Chip running at something like 133Mhz (Sorry - I don't recall the exact speed).

However, I suppose it's possible that the nanosatellite they built was sufficiently close to the earth to be sheilded from the radiation you speak of...

Re:Rad hardened really neccesary...?

[JGski]

Rad Hardening is required for deep space or in LEO or MEO under certain circumstances.

Yes, the satellites you refer to are LEO and are thus still within and protected from solar radiation by the Earth's magnetic fields. Also the expected lifetime for LEO satellites is short because there is enough atmospheric drag at LEO to assure reentry in just a few years (the central cost flaw with Teledesic, BTW). NASA's push to use off-the-shelf parts is based on the assumption that most satellite projects can and will exist at LEO and will be cheap enough to be disposable with shorter lifespans. Remove these assumptions and you will have trouble using commerical parts.

Anything in a higher orbit, with longer life or unusual mission will be exposed to direct solar or other radiation. Over time through the sun spot cycle (12 years), solar flares will raise total dose levels typically 1-2 orders of magnitude over sunspot minimums.

Most commercial ICs are laughably soft. When I was in the business of testing such we tried commercial Intel uP's in our radiation chambers; they'd die in a matter of minutes while the space-grade equivalents lasted much longer (I could tell you how long but I'd have to kill you :-) ). Pioneer's lifespan using space-grade parts gives a clue though.

JGSki

Reliability

[jd]

They can, but the reasons they don't are not those others have given.

The transputer, for example, was mathematically proven correct, and cost $15 a chip. Given that a T400 was as powerful as an 80486, several years before Intel made any, it's pretty obvious cost isn't the reason.

(The transputer was a marvel, for its time - it was linearly scalable, regardless of number. 1000 of them would give you the same performance as a Cray 1, for 1% of the cost.)

The reason is complexity. Mathematical proofs aren't trivial, so few chip companies bother. It's simpler to ship defective goods, and hope nobody notices. Notice I'm saying "simpler", not "cheaper". Mathematicians aren't much more expensive than good VLSI engineers.

Why is simple important? Because of PR. If you can get a product out fast, or a new press release out fast, then that's Good Business. Taking your time to get it right doesn't fill newspaper columns. Nobody ever wrote an editorial on how so-and-so proved the ALU free of bugs. They =WILL= write plenty on Intel/whoever releasing the latest nth generation processor, even if their last release was the month before.

The cost of replacement is about the same as the cost of getting it right, but the PR life-cycle is much faster, and so gets more attention & higher stock value.

For those of you who have chosen "popular" over "quality" in any part of your life, you know the lure, even though you know the real price you'll pay in the end.

Re:Couldn't lock on ?

[spaceyhackerlady]

I skimmed the article. It says that they were unable to lock on the signal using one of the largest radio antennae on the planet.

Any ideas if this was due to atmospheric distrubance (as well as distance, obviously...).

Unlikely. NASA deep space stuff is up around 8 GHz, where atmospheric effects are minimal. No, the thing is just too far away, and its signal just isn't strong enough.

So, when are we going to see plans for building a relay on the moon? Surely NASA's got to be looking into this. I'm not an engineer, but surely they could build a permanent relay on the moon using solar panels for power...

What for?

In the present situation, it wouldn't make any difference. Goldstone et al are out in the middle of nowhere, and have no significant radio interference problems. The atmosphere isn't an issue at these frequencies.

If I wanted to build the Proverbial Really Big Radio Telescope I'd park it at a Lagrange point. No gravity at all to worry about, I could make it as big as I wanted, and in a vacuum I could have all sorts of fun making it out of improbable materials.

The main seelling point for a radio telescope on the Moon would be interferometry, providing a much longer baseline than any telescopes on Earth could muster. Until we set up shop on Mars...

...laura

Re:What it said:

[Tablizer]

"Khaaaaaaaan!"

Because of the signal distance, it was actually received as:

Kh&.aa.a#aaa.*n!

Then again, that is close to how Kirk used to talk anyhow :-)

Here is an interesting snippet:

"On the rare occasions when astronomers have coaxed even sparse data from Pioneer 10 in recent years, they have used the readings to investigate everything from cosmic rays to chaos theory to gravitational mechanics."

Pioneer 10 is getting near the expected border of the "heliosphere" (sp?) which is often considered the border of our solar system and interstellar space. It is the "spot" where the radiation pressure from interstellar space becomes stronger than the Sun's (due to the distance from the Sun).

Pioneer has also been used to inspect a very odd gravity anomally, also found in other probes. Nobody has found a way to account for it using known physics. It is a small force, but consitent. The anomally may relate to the mysterious "dark matter" which seems to be pulling on stars, but nobody knows what it is. Voyagers cannot also measure it for some reason which I never figured out. Something to do with its navigation adjustments/propellant being too complicated to factor out motion adjustments I think.

It was originally thought that the gravity anomally was due to the nuclear heat or radiation from Pioneer's power system "pushing" the probe. However, it drops over time, but the gravity difference does not fit that drop-off curve.

Too bad the signal is not strong enough to get good data for the next decade or so. They probably could if they put many *more* antenna's on the listening job (a beowulf cluster of antenna's? :-), but NASA is already backlogged on communication with probes, so Mars and Voyager would probably get priority.

Too bad they spend so much on ISS and get so little science when working probes at the edge of our system have to be ignored. Sigh.

Re:They can

[quasarc]

They can, they have, and they will. The power source is available (provided you can pass the background check). It's called a radioisotope thermoelectric generator or RTG. Links follow, beware of wrap.

http://nuclear.gov/space/space-desc.html

http://science.slashdot.org/science/02/10/28/172 32 59.shtml?tid=126

http://spacelink.nasa.gov/NASA.Projects/Human.Ex pl oration.and.Development.of.Space/Human.Space.Fligh t/Shuttle/Shuttle.Missions/Flight.031.STS-34/Galil eos.Power.Supply/RTG.Fact.Sheet

http://www.snakeriveralliance.org/PhotoGallery/S pa ce%20Batteries.htm

Re:What it said:

[RedDevilCG]

My bad I accidently replied to this somewhere else, so this is a duplicate post by me.... Anyways:

"Pioneer has also been used to inspect a very odd gravity anomally, also found in other probes. Nobody has found a way to account for it using known physics. It is a small force, but consitent."

If anyone else wanted to know a little bit more what Tablizer was talking about here is some info on BBC.

http://news.bbc.co.uk/1/hi/sci/tech/1332368.stm

They also had some environmental bonuses

[msobkow]

1. No users. None. Nada. Zip. Not one filthy human peanut-butter smudged hand to touch the damned thing after it was turned on. Friends with families have equipment fail within a year or two, while my identical equipment runs for years after.
2. Vacuum environment. See prior point. No dust to eventually cause heating problems by clogging fans or fins, just nice cozy isolation to radiate heat into.
3. Simplicity. Pioneer 10 was less complex than a modern pocket organizer, and less powerful.
4. Industrial design. Home buyers don't want something as rugged as Pioneer 10 -- they want something shiny with lots of blinking lights and switches. (Also related to (1).)
5. No "Made in China/Korea/Vietnam/..." parts. If there were, they'd have been individually tested (as were the components actually used), rather than testing n/1000 and using the results to decide if the lot is "good enough" to ship.
6. Pride. People working on NASA projects had pride, something sorely lacking in modern manufacturing. Profit margin has replaced pride in product quality. Can you imagine a space probe designed and built by HPaq? or by a whitebox "manufacturer"?

Yarkovsky Effect -- normal physics only.

[Dr. Zowie]

The force could be caused by the Yarkovsky Effect, a weak lateral force on spinning bodies in the solar system. It's being studied by planetary scientists as a way that asteroids can move around the solar system. The idea is that the sunlit side of the asteroid (or, in this case, spacecraft) gets warm and its properties change; then it rotates to the sunset side, yielding an asymmetry to the thermal profile of the body. (for example, here on Earth it's almost always coldest just before dawn).

If the asteroid (or spacecraft) isn't too old, it outgasses, and the outgassing rate depends strongly on temperature, forming a weak natural rocket engine. Even for refractory materials (or old asteroids that have outgassed all that they are going to) the photon pressure from the warm side can have a significant effect over millions of years.

I haven't done the calculation myself, but I've discussed it over cocktails with Bill Bottke, a leading asteroid scientist, and he seemed to think it was a plausible explanation for the Pioneer 10 orbital drift. P10 is a spinner.