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| There are many high altitude [[ http://www2.dem.inpe.br/val/atmod/default.html | atmospheric models]], evolving from Jacchia64. Here is an [[ http://omniweb.gsfc.nasa.gov/vitmo/msis_vitmo.html | online model]] from NASA, based on MSIS-E-90 and valid to 1000 km altitude. The most useful model for our purposes (above 120 km) is the [[ http://www2.dem.inpe.br/val/atmod/msisc.zip | MSIS-86 model ]]. For estimation, we will use MSIS-86 with static density and F10.7 daily solar fluxes of 70 (minimum), 120 (average), and 200 (maximum) x10^-22^W/m^2^Hz. In the past, F10.7, has cycled from low to high and back with an 11.5 year period. The geomagnetic index [[ http://en.wikipedia.org/wiki/K-index | Kp ]] is a "kinda logarithmic" number ranging from 0 to 9, near zero at quiet times. Assume low/middle/high of 0.4, 2, 5.5 (5%, 50%, 95% percentile). | There are many high altitude [[ http://www2.dem.inpe.br/val/atmod/default.html | atmospheric models]], evolving from Jacchia64. Here is an [[ http://omniweb.gsfc.nasa.gov/vitmo/msis_vitmo.html | online model]] from NASA, based on MSIS-E-90 and valid to 1000 km altitude. The most useful model for our purposes (above 120 km) is the [[ http://www2.dem.inpe.br/val/atmod/msisc.zip | MSIS-86 model ]]. For estimation, we will use MSIS-86 with static density and F10.7 daily solar fluxes of 70 (minimum), 120 (average), and 200 (maximum) x10^-22^W/m^2^Hz. In the past, F10.7, has cycled from low to high and back with an 11.5 year period. The geomagnetic index [[ http://en.wikipedia.org/wiki/K-index | Kp ]] is a "kinda logarithmic" number ranging from 0 to 9, near zero at quiet times, probably above 10 for a 500 year [[ http://en.wikipedia.org/wiki/Solar_storm_of_1859 | Carrington Event]]. Assume low/middle/high of 0.4, 2, 5.5 (5%, 50%, 95% percentile). |
Exosphere Models
Exosphere
Production server sky orbits will be at 6411 kilometer altitude, or above, far into the exosphere. Such high orbits offer little detectable drag to big iron satellites, so their densities are characterized indirectly and perhaps imprecisely above 1000 km altitudes. Thinsats have much higher "sail" ratios and are more sensitive to density.
There are many high altitude atmospheric models, evolving from Jacchia64. Here is an online model from NASA, based on MSIS-E-90 and valid to 1000 km altitude. The most useful model for our purposes (above 120 km) is the MSIS-86 model. For estimation, we will use MSIS-86 with static density and F10.7 daily solar fluxes of 70 (minimum), 120 (average), and 200 (maximum) x10-22W/m2Hz. In the past, F10.7, has cycled from low to high and back with an 11.5 year period. The geomagnetic index Kp is a "kinda logarithmic" number ranging from 0 to 9, near zero at quiet times, probably above 10 for a 500 year Carrington Event. Assume low/middle/high of 0.4, 2, 5.5 (5%, 50%, 95% percentile).
The MSIS static density model uses these double precision variables:
inputs |
|
alt |
local geocentric altitude, 90000 to 2000000 meters |
sf[1] |
daily solar flux F10.7, Jensen |
sf[2] |
averaged daily flux, Jensen |
sf[3] |
3 hourly planetary geomagnetic index Kp |
outputs |
|
tp[1] |
exospheric temperature, Kelvin |
tp[2] |
local temperature, Kelvin |
ad[1-6] |
log10 number densities, He, O2, N2, Ar, O, H |
wmol |
mean molecular weight |
dens |
thermospheric density, kg/m3 |