Post by Shaggietrip on Oct 10, 2017 19:55:36 GMT
Ok bear with me on this.Read through the first link and only a portion of the second. Looking into this Parker Probe. The following mostly deals with antenna. But does go into other items dependent on. Could only handle so much. In hopes that others with better understanding will read and post some thoughts of their own. I will try to look at more areas of this probe but for now 1.5 hrs on the antenna is all i could handle for today.
From reading this it is not going to be a walk in the park even with the data and testing done. Reminds me of the Lunar lander tested once ,fails and yet they still launched and succeeded. Posting a couple snippets and leave links for those with greater knowledge to look at the ONE portion I have looked into so far.
Please read the links. what posted does no justice read links.
Source: solarprobe.gsfc.nasa.gov/SP_Antenna_Thermal.pdflink
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Fig3
[^ The electric potential surrounding a simple model of the SPP spacecraft near perihelion [see Ergun et al. 2010 for details on the simulation]. The X-direction is toward the sun. The Y-direction is the orbital track of the spacecraft. Color represents potential in volts. The thick black lines depict the electric field antennas. The plasma density is 7000 cm−3, the electron temperature is 85 eV and the ion temperature is 85 eV. The solar wind speed is 200 km/s and the spacecraft orbital speed is 180 km/s. The plot is in the frame of the spacecraft]
Source: link.springer.com/article/10.1007/s11214-016-0244-5
That is a fragment. You will find restrictions on antenna location to the craft and position key for it to work. Also do not believe any CME or events applied to the calculation presented. So keeping the antenna in a wake created by the craft is well, absurd really. Will do my best to get more on this when possible.
From reading this it is not going to be a walk in the park even with the data and testing done. Reminds me of the Lunar lander tested once ,fails and yet they still launched and succeeded. Posting a couple snippets and leave links for those with greater knowledge to look at the ONE portion I have looked into so far.
Please read the links. what posted does no justice read links.
It is almost impossible,to satisfy any of the above criteria without extending the antennas out of the shield’s shadow.
The Debye lengths and spacecraft radius are both on the order of ~1m,so the antennas should be ideally ~5m,and least
~ 3 m from the spacecraft. For short antennas,it is best to extend the active part of the receiving element away from
the spacecraft (rather than use the entire boom for the antenna) to improve the effective baseline and reduce the influence of the spacecraft potential on the antenna’s signal.
The Debye lengths and spacecraft radius are both on the order of ~1m,so the antennas should be ideally ~5m,and least
~ 3 m from the spacecraft. For short antennas,it is best to extend the active part of the receiving element away from
the spacecraft (rather than use the entire boom for the antenna) to improve the effective baseline and reduce the influence of the spacecraft potential on the antenna’s signal.
______________
Fig3
[^ The electric potential surrounding a simple model of the SPP spacecraft near perihelion [see Ergun et al. 2010 for details on the simulation]. The X-direction is toward the sun. The Y-direction is the orbital track of the spacecraft. Color represents potential in volts. The thick black lines depict the electric field antennas. The plasma density is 7000 cm−3, the electron temperature is 85 eV and the ion temperature is 85 eV. The solar wind speed is 200 km/s and the spacecraft orbital speed is 180 km/s. The plot is in the frame of the spacecraft]
Fig 3 also shows the electrostatic barrier formation on the shield (thin blue region on the +X side of the spacecraft). This barrier blocks a surprisingly large fraction (nearly 90 %) of the photoelectron fluxes from escaping the sunward side of the spacecraft, which is the primary cause of the spacecraft charging negatively (−25 V). This barrier has a beneficial influence on the electric field measurement as it creates a symmetric potential structure about the spacecraft near the electric field antennas. However, it may have a detrimental effect on measurements of the electron distributions. Since the electrostatic barrier results from a nonlinear and non-monotonic potential structure, the depth and influence of the barrier are difficult to quantify even with simulation.
Source: link.springer.com/article/10.1007/s11214-016-0244-5
That is a fragment. You will find restrictions on antenna location to the craft and position key for it to work. Also do not believe any CME or events applied to the calculation presented. So keeping the antenna in a wake created by the craft is well, absurd really. Will do my best to get more on this when possible.