Environment
Temperatures in space range from ridiculously low to extremely high. The temperature model consider solar radiation (the energy flux coming from the sun, if not occluded), albedo radiation (the energy flux reflected from a celestial body toward the vessel), body radiation (the radiative cooling flux from a near celestial body) and the cosmic background radiation. The temperature is then obtained according to the Stefan-Boltzmann law and assuming the vessel is a perfect black body. Inside an atmosphere, the stock atmospheric temperature model is used instead.
Celestial bodies interact in complex ways with radiation. Some have magnetopauses that shield radiation. Others have regions populated by extremely charged particles.
This is modelled with radiation fields: regions of space around a celestial body that have an associated radiation level. The overall radiation level for a vessel is then determined by evaluating all the fields overlapping at the vessel position.
These fields are rendered in map view or the tracking station. They can be toggled by pressing Keypad 0/1/2/3, or by using the Body Info window.
A RadiationModel define the signed distance functions parameters that determine the shapes of the inner belt, outer belt and magnetopause. The model can then be assigned to one or more celestial bodies using RadiationBody.
The inner belt is a torus. The 'a' radius define the distance from the section center to the origin. The 'b' radius define the radius of the section.
The outer belt is the boolean subtraction of a torus with another one. The second torus is equal to the first, except for the fact that the 'b' radius is reduced by a border factor. This in turn is not constant everywhere but fade from 'outer_border_start' at the origin to 'outer_border_end' at the domain boundary.
The magnetopause is simply a sphere, possibly deformed along the body->sun vector to define a magnetotail.
All values are in body radii.
| PROPERTY | DEFAULT | DESCRIPTION |
|---|---|---|
| name | Unique name for the radiation model | |
| has_inner | false | True if the model has an inner radiation belt |
| inner_dist | Inner belt torus 'a' radius | |
| inner_radius | Inner belt torus 'b' radius | |
| inner_compression | 1.0 | Deform space along the body->sun vector, in direction of the sun |
| inner_extension | 1.0 | Deform space along the body->sun vector, in opposite direction of the sun |
| inner_quality | 30.0 | Quality of border for rendering purposes, only influence precomputation time |
| inner_deform | 0.0 | Deform the surface using a sum of sine waves |
| has_outer | false | True if the model has an outer radiation belt |
| outer_dist | Outer belt torus 'a' radius | |
| outer_radius | Outer belt torus 'b' radius | |
| outer_compression | 1.0 | Deform space along the body->sun vector, in direction of the sun |
| outer_extension | 1.0 | Deform space along the body->sun vector, in opposite direction of the sun |
| outer_border_start | 0.1 | Outer belt border extension at the origin |
| outer_border_end | 1.0 | Outer belt border extension at the domain boundary |
| outer_deform | 0.0 | Deform the surface using a sum of sine waves |
| outer_quality | 40.0 | Quality of border for rendering purposes, only influence precomputation time |
| has_pause | false | True if the model has a magnetopause |
| pause_radius | Magnetopause radius | |
| pause_compression | 1.0 | Deform space along the body->sun vector, in direction of the sun |
| pause_extension | 1.0 | Deform space along the body->sun vector, in opposite direction of the sun |
| pause_height_scale | 1.0 | Deform space along the magnetic axis vector |
| pause_deform | 0.0 | Deform the surface using a sum of sine waves |
| pause_quality | 20.0 | Quality of border for rendering purposes, only influence precomputation time |
The RadiationBody associate a RadiationModel to a celestial body, and define the radiation contribution inside the zones delimited by the signed distance functions. Radiation values in a zone can be negative, that is usually the case for magnetopauses contribution.
| PROPERTY | DEFAULT | DESCRIPTION |
|---|---|---|
| name | Name of the celestial body | |
| model | Name of the RadiationModel | |
| radiation_inner | Radiation contribution inside the inner belt, in rad/h | |
| radiation_outer | Radiation contribution inside the outer belt, in rad/h | |
| radiation_pause | Radiation contribution inside the magnetopause, in rad/h | |
| reference | 0 | Index of the body used to determine radiation fields orientation |
Radiation is computed at a point by walking the 'body chain' and summing all contributions for that point, from all the fields overlapping with the point. When the top of the chain is reached the radiation value from Settings.ExternRadiation is added.
Coronal Mass Ejections events are generated in the sun corona, and move toward either a planetary system or a sun-orbiting vessel. A warning will be issued as soon as the CME is ejected toward a body of interest. When the CME hit a planetary system or a sun-orbiting vessel, all vessels outside a magnetopause and in direct line of sight with the Sun will receive extra radiation. Vessels inside a magnetopause will suffer a communications blackout instead. The effects last for some time, then the situation return to normality.