oren-speiser/radiation-load-radar

This project is a data analysis study about cosmic ray radiation and how it changes over time, aimed at anyone thinking about long crewed trips to Mars. The core idea is simple: the shielding built into a spacecraft is fixed once it is built, but the amount of radiation the crew actually absorbs depends heavily on when the ship launches, since the Sun's activity naturally pushes cosmic rays away or lets them back in over an eleven year cycle. The author first tried to use dips in cosmic ray readings to predict incoming geomagnetic storms a few hours in advance, and reports plainly that this did not work: it produced far too many false alarms to be useful as a warning system. That negative result is stated upfront rather than hidden. What the analysis does find, using eleven years of hourly measurements from a real neutron monitoring station in Oulu, Finland, is that the background cosmic ray level swings by about 23 percent between the calmest and most active points of the solar cycle. Applying that swing to real past Mars departure dates shows that a crew flying the exact same spacecraft could have absorbed about 18 percent more radiation on one launch date compared to another, purely because of timing, with no change to the ship itself. Using the shape of the solar cycle, the project also makes a forward looking projection, clearly labeled as unverified rather than measured, that the worst radiation window of the next decade for a Mars mission falls around February 2031. The author is careful to separate what is measured from what is projected, and notes clear limitations: a ground station is a stand in for a real radiation dose meter, sudden solar particle events are a separate problem not covered here, and the projection depends on the solar cycle's timing repeating as it has for centuries. The code needed to reproduce the analysis is included and written in Python, and the code is under the MIT license while the findings are under a Creative Commons license.