1. The Proton Flux in the SAA ranges from 20 Protons/cm^2-sec to 400 protons/cm^2-sec depending on flight path.
2. The Proton Flux in the VAB ranges from 1*10^4 to 2*10^8 or 25 to 500,000 times as high as the highest region of the SAA.
3. More than half of the ISS exposure is from the SAA.
4. The ISSís Labs 1 & 2 have a nominal radiation shield thickness of 40 gms/cm^2.
5. The Apollo Lunar Craft had a nominal radiation shield thickness of 7 gms/cm^2 but letís assume it was as high as 10 gms/cm^2.
6. The exposure rate on the ISS in the SAA is 120 to 160 μGy/day (5 to 6.67 μGy/hr).
7. The daily overall exposure rate from Ionizing radiation dose measurements, made within the habitable volume of the ISS with thermoluminescent dosimeters and crew personal dosimeters, range from 5 to 12 μ Gy (0.5 to 1.2 milli rads) per hour, depending on location in the habitable volume, corresponding to an annual dose range of 44 to 105 milli Gy (4.4 to 10.5 rads).
8. The International Space Station travels in orbit around Earth at a speed of roughly 17,150 miles per hour (that's about 5 miles per second!). This means that the Space Station orbits Earth (and sees a sunrise) once every 92 minutes!
9. 12:22 p.m.- Another firing of the third-stage engine, still attached to the command service module, boosts Apollo 11 out of orbit midway in its second trip around the Earth and onto its lunar trajectory at an initial speed of 24,200 miles an hour.
10. 2:54 p.m. - The spacecraft is reported 22,000 nautical miles from Earth and traveling at 12,914 feet per second. Crew members keep busy with housekeeping duties.
11. 10:59 p.m. - Because of the pull of Earth's gravity, the spacecraft has slowed to 7,279 feet per second at a distance of 63,880 nautical miles from Earth.
12. 2:54 minus 12:22 equals 2:32 or 2.533 hrs. 22,000 miles/2.533 hrs = 8684.32 mph. That is to say the transit through the VAB was at a speed of 8684.32 mph
13. Assuming the duration of the VAB Proton Belt is 6 earth radii then Earth Radii = 3949 miles. 3949 miles * 6 = 23754 miles. So there was roughly a 2.75 hour transit across the VAB.
14. Using the ISS exposure rate for peak SAA exposure of 400 protons/Cm^2 behind a 40 gms/cm^2 radiation shield and ratio it out to the lowest VAB path of radiation of 10^4 (Which is generous to a fault). We get: 6.67 μGy/hr /400 protons/Cm^2 = x/10^4 protons/Cm^2 = 6670 μGy/hr.
15. 6670 μGy/hr * 2 trips *2.75 hr transit time = a mission dose of 36685 μGy or 36.69 mGy.
16. So letís recap If the ISS were to travel through the VAB with is greater shielding of 4 times the Apollo and it followed a path through the VAB that limited its proton flux rate to 1 * 10^4 protons/cm^2-sec then the mission dose would have been 36.69 mGy/actual reported Apollo mission dose of 2.40 mGy = 15.29 times higher and this is without the GCR or lunar surface radiation components. Now because the Apollo had ľ of the shielding of the ISS it is reasonable to assume it would get 4 times the exposure.