Pioneer and a 6mph drag

[Chief Engineer Scott]

A friend of mine at a party asked "whats this about Pioneer 10 slowing at 6mph per century ?" It seems a source he came across states that Pioneer (and other craft now left or leaving the solar system) are decelerating at the rate of 6mph per century, the source also stated that this was inexplicable at the moment when all gravitational effects were accounted for.
I seem to remember something about this before, but as I have a memory like a sieve I can't recall what explanation was given.
Can anyone help

[GrapesOfWrath]

There are a couple threads in the Against The Mainstream forum: Anomalous Acceleration of Pioneer 10 and 11 and Pioneer 10 off course: an electric universe?

<font size=-1>[Added thread titles]</font>

<font size=-1>[ This Message was edited by: GrapesOfWrath on 2002-02-12 08:33 ]</font>

[Thargoid]

Could they have hit the heliopause? Just a WAG.

[informant]

LOL! [img]/phpBB/images/smiles/icon_biggrin.gif[/img]

[brianok]

The article I read states:

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"The effect shows no sign of getting weaker as the spacecraft travels deeper into space, and scientists are considering the possibility that the probe has revealed a new force of nature."
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Maybe for some reason we don't yet understand, it's impossible for us to leave our solar system!

[hoozi]

There are a couple threads in the Against The Mainstream forum: Anomalous Acceleration of Pioneer 10 and 11 and Pioneer 10 off course: an electric universe?

<font size=-1>[Added thread titles]</font>

<font size=-1>[ This Message was edited by: GrapesOfWrath on 2002-02-12 08:33 ]</font>

When I click on the links, all I get is a site where some guy is whining about creationism.

[ravens_cry]

Woah, dude!
That's some heavy, heavy thread necromancy, bub!
Let the dead lie in peace!

[Swift]

When I click on the links, all I get is a site where some guy is whining about creationism.

This is an 11 year old thread; not many things on the Internet will have the same links after 11 years. If you are interested in the topic, search out more recent threads on the Pioneer Anomaly. But the answer is it has been solved:

By 2012 several papers by different groups, all reanalyzing the thermal radiation pressure forces inherent in the spacecraft, showed that a careful accounting of this could account for the entire anomaly, and thus the cause was mundane and did not point to any new phenomena or need for a different physical paradigm.[

[Selfsim]

What I find interesting, is that the effect was not immediately recognised for what it eventually turned out to be ie: thermal recoil. It kept quite a few guessing for a number of years, and all the data gathered, still continues to be analysed.

According to Wiki, it was originally noticed as early as 1980, but was not seriously investigated until 1994 (last contact being 2003).

One wonders what other factors don't we know about, (or somewhat more accurately, we do know about, but have been overlooked as being of seemingly of 'lesser significance'), when it comes to the navigation of deep space long distance voyages?

There are many things we typically, (and reasonably), de-emphasise, because they are of lesser significance over shorter distances and shorter durations. But, perhaps the lesson here, is to remind ourselves that longer distances, and longer voyages, require a different paradigm of thinking, when it comes to the design aspects and mission goals(??)

Seemingly trivial details like this, if not taken into consideration beforehand, could quite easily result in significant course deviations, (fuel budget issues, more navigational corrections, loss of comms, etc). The distances and the durations, seemingly call for different strategies and precision levels than what we might be used to(??)