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Bjarne
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Several space probes was by gravity assist manoeuvre gaining between 4 and 13 mm velocity per second. Are this values average based on acceleration through time, or are these pure deceleration per second?
Bjarne said:Several space probes was by gravity assist manoeuvre gaining between 4 and 13 mm velocity per second. Are this values average based on acceleration through time, or are these pure deceleration per second?
Bjarne said:Several space probes was by gravity assist manoeuvre gaining between 4 and 13 mm velocity per second. Are this values average based on acceleration through time, or are these pure deceleration per second?
I think you're referring to this anomaly, rather than the pioneer anomaly (related? maybe.) ttp://en.wikipedia.org/wiki/Flyby_anomaly
Bjarne said:Yes that's right, flyby anomaly...
For instance Near experienced an anomalous velocity increase of 13.46 mm/s after its Earth encounter.
It's a pretty strong acceleration, million times stronger than the force decelerating Piooner 10 and 11.
I was just wondering why the big difference.
Widdekind said:which — if the diffuse density is exclusively gas — is equivalent to about [tex]n \approx 2 \times 10^{11} \; m^{-3}[/tex], or [tex]n \approx 2 \times 10^{5} \; cm^{-3}[/tex]. Are such densities completely implausible ?
Could this have something to do w/ the "Termination Shock" of the Heliosphere ? Compare:
ideasrule said:According to Wikipedia' "Interplanetary medium" article, the interplanetary medium's density is 5 particles per cm^3 near Earth's orbit and decreases with increasing distance from the Sun. So yes, 2*10^5 per cm^3 is implausible.
The Pioneer Anomaly is the observed phenomenon where the Pioneer 10 and 11 spacecrafts deviated from their predicted trajectories while traveling through the outer solar system. This deviation was initially noticed as a slight deceleration of the spacecrafts, but further analysis showed that it was a constant acceleration towards the Sun.
The cause of the Pioneer Anomaly is still unknown and remains a subject of scientific debate. Some proposed explanations include the effects of gas leaks, radiation pressure, or an unknown gravitational pull from a large object in the outer solar system. However, none of these explanations have been able to fully account for the observed anomaly.
The Pioneer Anomaly was first noticed in the late 1980s when scientists were analyzing the data sent back from the Pioneer 10 and 11 spacecrafts. The spacecrafts were found to be deviating from their predicted trajectories, and a systematic study of the anomaly was later conducted in 1998.
The Pioneer Anomaly is important because it challenges our understanding of gravity and the laws of physics. It also has implications for future space missions, as understanding and potentially correcting for this anomaly could improve the accuracy of spacecraft trajectories and reduce fuel usage.
Several studies have been conducted to investigate the Pioneer Anomaly, including analyzing data from other spacecrafts and conducting computer simulations. In 2018, NASA launched the Pioneer Anomaly Follow-up Engineering Test (PAFET) to conduct a physical test of the proposed explanations for the anomaly. However, the results of these efforts have been inconclusive, and the Pioneer Anomaly remains a mystery.