Pioneer Anomaly
June 13, 2005 12:00 PM   Subscribe

The Pioneer Anomaly. Something's up in deep space: the Pioneer spacecraft, now out of contact, have shown an unexplained Doppler drift, indicating sunward acceleration, effectively decelerating the probes cumulatively. The effect may be be nongravitational, and could be explained by any number of factors: an undiscovered twist in Newtonian physics, localized cosmological contraction issues, or just venting gas. Other deep space probes may have experienced the anomaly as well, and a new mission could explore the puzzle; but for now, all we have is past Pioneer data, and that's stored on old 9 track tape which can only be read by antique readers. What's to be done? (Also see Pioneer Odyssey for a nostalgic romp through those early days of deep space exploration. And NASA, bring back the original Pioneer home page plz, kthx.)
posted by brownpau (21 comments total)
The Pioneer anomaly could be a breakthrough in the way we think about gravity, or it could be a mundane helium leak. IMHO, the vastly different possibilities is part of what makes the question so compelling.
posted by Plutor at 12:09 PM on June 13, 2005

In 500 years, a race that worships P'neer will head to Earth in an attempt to touch the face of god, Robert Bloch will be killed in the process of stopping them. You have been warned.
posted by dial-tone at 12:35 PM on June 13, 2005

localized cosmological contraction issues, or just venting gas.

i didn't fart, i'm just having localized cosmological contraction issues.
posted by quonsar at 12:37 PM on June 13, 2005

"It's nothing. Outgassing, don't worry about it. Say, you seen that new BT-16?"
posted by keswick at 12:39 PM on June 13, 2005

We'll see them orbiting the Earth in 35 years with sheepish expressions. "I was nearly at the Oort cloud, man, and I realized I forgot the...".
posted by CynicalKnight at 12:45 PM on June 13, 2005

One more link I missed.
posted by brownpau at 12:52 PM on June 13, 2005

Thanks for the great link brownpau! I'd forgotten about the Planetary Society and their great work. Truly a good cause to support. Funny that it deals with the problems of retrieving old digital info, as I'd just finished reading that askme thread about archiving and retrieving music.
posted by jasper411 at 1:19 PM on June 13, 2005

Excellent post. Thanks.
posted by AlexReynolds at 2:43 PM on June 13, 2005

Killer stuff brownpau - I've never seen the Planetary site and that site alone has tons to look at. Thanks.
posted by Slack-a-gogo at 2:46 PM on June 13, 2005

I think it would be practical to read old tapes, films etc by making a device to scan the surface of the tape for magnetic fluctuations, physical alterations (like punches), and a visual scan. From this data an image of the tape can be created, and then the researchers can write a program to interpret the image. The principle would work for any tape-like method of data storage. With modern data storage capacity, the image of the tape could easily be far more detailed than was ever required by the original reading/projecting methods.

No need to resurrect the old hardware (although the old manuals would be very useful), and if it were done carefully, it could be completely non-destructive.
posted by aeschenkarnos at 3:52 PM on June 13, 2005

the original pioneer homepage?
posted by reflection at 4:19 PM on June 13, 2005

8 + laugh track?
posted by dreamsign at 4:45 PM on June 13, 2005

Dreamsign: Heh.

No, either 8 tracks, one bit per track, with the 9th track writing either odd (IBM) or even (Everyone Else) parity, in the early days, or various 8-on-9 interleaves as tapes became faster and hit higher densities (and thus, less reliable as data storage -- a problem that's just as true today as it was then. Google up PMRL to get a sense of the issue.)

The problem is, of course, that we've gone through several generations of data storage since the days of nine track 800/1600bpi tapes (or the earlier 5 and 7 track tapes.)

It was huge, expensive, and slow -- the fastest drives used large loops of tape to allow fast seeking, but to do this, you had to reduce air drag. So, the big drives would, after load, pull a rather hard vacuum onto the tape. The IBM 3420 Model 8 could read 6250bpi 9 track tape at almost a megabyte a second, and there was a great deal of tape flying while it did so -- 16 feet of tape went by the head every second.

The power requirements were pretty stiff, and lord help you if the vacuum failed when the tape was at speed. What happened wasn't pretty, or for that matter, quiet.
posted by eriko at 5:51 PM on June 13, 2005

Lost asteroid clue to Pioneer puzzle

Gary Page of George Mason University in Fairfax, Virginia, and his colleagues have identified 15 asteroids that might also be subjected to the mysterious force.
posted by furvyn at 5:51 PM on June 13, 2005

intergalactic planetary
planetary intergalactic
another dimension
another dimension
posted by kcds at 7:15 PM on June 13, 2005

outgassing? couldn't they figure out how much "gas" is potentially accountable, and perhaps eliminate that as a possibility? Or have they done the calculation already, and it's actually plausible that the theoretically possible amount of outgassing could indeed produce the observed trajectory? I assume this outgassing would have to be somewhat constant (and continuing)...? So Pioneer should run out of gas (no pun intended) soon, right?
posted by mhh5 at 12:09 AM on June 14, 2005

mhh.... keswick was making a joke. it's a star wars thing.

which made me snarf my water. good one keswick!

"Yeah, a couple of the fellows were talking about it, they say it's quite a sight to see."
posted by zoogleplex at 9:57 AM on June 14, 2005


Sidenote. The Michael Jackson thread get 200+ comments and this not even 50.

Will the asteroid please hit us already.
posted by tkchrist at 11:23 AM on June 14, 2005

Wow - I totally missed this yesterday. Great set of links. Fascinating stuff.
posted by Joey Michaels at 4:40 PM on June 14, 2005

Too bad it wasn't stored on an 8 track, then we could just plug it into an old 76 firebird and listen to the rockin' sounds of Pioneer.
posted by joelf at 8:02 PM on June 14, 2005

The Classic Computer mailing list (a list for people who collect and restore old computers (and routinely recover data from old tapes)) hashed this out this month (thread at here & here)

Consensus seems to be that getting the data off the tapes is relatively easy (much easier than is being claimed) & interpreting it is more difficult, neither require the original machines that wrote it, and might have already been done by NASA. This has lead some on the list to consider the Planetary Society to be engaged in a fund raising exercise, not a data recovery exercise.
posted by kjs3 at 12:56 PM on June 15, 2005

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