Pioneer Anomaly

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Astrodelugeologist</i>
<br />Both of NASA's old Pioneer spacecraft are decelerating in a manner inconsistent with mainstream theories on gravity.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">No, they aren't. That is a claim by John Anderson. But the cause of the anomaly cannot be gravitational because it does not affect planets, moons, asteroids, comets, or spacecraft without RTG generators. Instead, it affects only the three spacecraft with RTG generators: 2 Pioneers and Ulysses (which never gets much beyond Jupiter).

The waste heat from these generators is enough to produce a force 30 time larger than the "Pioneer anomaly". But it goes out in all directions. The asymmetry propeling the spacecraft toward the Sun is estimated to account for about half the anomaly seen. But that sets only a lower limit.

See metaresearch.org/home/viewpoint/meta-in-news.asp for more details.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">can the C-gravitons of the Meta Model account for this anomalous deceleration?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Fortunately, it does not. In my opinion, the money spent on a new mission to test for this effect will be wasted because no off-spacecraft effect has yet been demonstrated to exist, but an on-spacecraft effect is known to exist. -|Tom|-

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">But the cause of the anomaly cannot be gravitational because it does not affect planets, moons, asteroids, comets, or spacecraft without RTG generators<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
The effect would be unmeasurable in an orbiting body which would necessarily be at equilibrium with gravitation and the "mysterious force" (if there were one). So we would interpret the sun to have less mass than it actually had since it would be holding bodies in tighter orbits partly by the mysterious force rather than entirely by its mass.

More telling would be the absence of such an effect in other craft exiting the solar system in similar non-equilibrium fashion. If this is the case then the effect must be some anomalous craft-born decelerator. If non-gravitational, my guess would be something having to do with heating on the sunward side and cooling on the shadow side of the craft but this seems to produce symmetric accelerations (

Hmmmmm ...

How about this? There is a plugged hole leaking. In the sun the plug in the hole expands and closes the leak. In the shade, the plug cools and shrinks and lets the leak decelerate the craft ... something like that.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by EBTX</i>
<br />The effect would be unmeasurable in an orbiting body which would necessarily be at equilibrium with gravitation and the "mysterious force" (if there were one). So we would interpret the sun to have less mass than it actually had since it would be holding bodies in tighter orbits partly by the mysterious force rather than entirely by its mass.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">If that were true, the same would apply to the two Pioneers and to Ulysses. All are "orbiting" under the Sun's influence to the same degree. It is just that the orbits of the Pioneers are slightly hyperbolic in shape instead of elliptical, just as many comet orbits are as they depart the solar system. And the Ulysses spacecraft simply orbits the Sun in the inner solar system the same way planets and asteroids do.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">More telling would be the absence of such an effect in other craft exiting the solar system in similar non-equilibrium fashion.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">The Voyager spacecraft are examples. They do not show this effect.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">my guess would be something having to do with heating on the sunward side and cooling on the shadow side of the craft but this seems to produce symmetric accelerations<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">The heat generated by the nuclear power source on these spacecraft is much more powerful than heat from sunlight. And it is emitted asymmetrically because the spacecraft itself blocks heat trying to leave in the sunward direction. Hence, the acceleration toward the Sun. -|Tom|-

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by tvanflandern</i>
The Voyager spacecraft are examples. They do not show this effect.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">As far as I am aware, the the communication system for the Pioneer spacecraft is different from the Voyager missions, allowing a more accurate determination of the effect. For the Voyager probes, the effect would simply not be measurable.


<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">The heat generated by the nuclear power source on these spacecraft is much more powerful than heat from sunlight. And it is emitted asymmetrically because the spacecraft itself blocks heat trying to leave in the sunward direction. Hence, the acceleration toward the Sun<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">I thought possibilites like this had been ruled out by NASA already years ago (I quote from spaceprojects.arc.nasa.gov/Space_Projects/pioneer/PNStat.html : 'A variety of possible causes were considered including: perturbations from the gravitational attraction of planets and smaller bodies in the solar system; radiation pressure, the tiny transfer of momentum when photons impact the spacecraft; general relativity; interactions between the solar wind and the spacecraft; possible corruption to the radio Doppler data; wobbles and other changes in Earth's rotation; outgassing or thermal radiation from the spacecraft; and the possible influence of non-ordinary or dark matter. After exhausting the list of explanations deemed most plausible, the researchers examined possible modification to the force of gravity as explained by Newton's law with the sun being the dominant gravitational force. "Clearly, more analysis, observation, and theoretical work are called for," the researchers concluded. The scientists expect the explanation when found will involve conventional physics'.)

As already mentioned by me in one or two other threads, the observed mismatch (the spacecraft appears to lag behind the anticipated position by about 400 000 km) can well be explained by the fact that the usual concept of the 'speed' of light is incorrect: as argued on my page www.physicsmyths.org.uk/lightspeed.htm , the travel time of the communication signal does not depend on the velocity of the probe but only on the distance at the time of emission; this means the distance is underestimated by the amount the probe travels during the time it takes the signal to reach it; this amounts to about the quoted mismatch for the corresponding distance (50 AU) and speed (10 km/sec) if you consider a two-way communication signal.

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www.physicsmyths.org.uk
www.plasmaphysics.org.uk

i'm wondering if the slow down effect could be the combination of plasma and electromagetism in certain regions of space since apparently,plasma is everywhere even if we can't see it.as well it seems as though electromagnetism is far stronger a force than gravity over distance,therefore perhaps overwhelms gravity and takes over,if flowing toward the Sun perhaps this flow(plasma directed by electromagnetics) although perhaps weak, could over time have an effect.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Thomas</i>
<br /><b>outgassing or thermal radiation from the spacecraft</b><hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Only JPL's John Anderson still claims that. But the JPL expert in these areas is Standish, and he thinks Anderson is dead wrong. Others have now proved that the RTG heat dumps produce 30 times the needed thrust, so only a 3% asymmetry would explain the whole effect. By studies of similar model spacecraft still on Earth, the actual Pioneer aysmmetry has been estimated to be about 1.5%. (The smallest asymmetry estimate by any investigator was 1%.) So this RTG heat dumping <i>must</i> be the explanation for at least part of the anomaly, and probably explains it all.

Why do your arguments consistently ignore Ulysses, which shows the same anomaly but orbits the Sun and never gets much farther out than Jupiter; and long-period comets, which have similar near-linear orbits and show either no anomaly or one with the opposite sign? -|Tom|-