Over at YouTube there is a Jarrah fanboy by the name of FakeMoonRocks who keeps posting stuff like the following:
You pro-Apollo nutters are hilarious. Bob Braeunig has a webpage titled, "Apollo 11's Translunar Trajectory and how they avoided the radiation belts." But then he does an entire article underneath that title, referring to NASA information, that shows the Apollo missions did not "avoid", "steer clear" or go "around" the belts...however you want to word it...Apollo missions didn't do any of that. The NASA information shows they went through them. End of story.
He keeps harping on about the subtitle of the page where I said Apollo "avoided" the belts. Of course I didn't mean to imply they avoided them entirely, just that the avoided the most intense and dangerous parts of the belts. This meaning is apparent by the article. It's true the trajectories still went through the belts, but they went through the far weaker parts near the edges.
FakeMoonRocks also continually downplays the significance of the Apollo trajectories in terms of mitigating the radiation hazard. This got me thinking, just what would have been the exposure had Apollo flown through the heart of the belts rather than skirting around the perimeter.
During
my analysis of Apollo 11, I computed the dose that a totally exposed and unprotected astronaut would receive had he passed through the radiation belts following the trajectories of Apollo 11. The total dose came to 180 rem; however there was a significant difference between the outbound and inbound trajectories. The outbound trajectory had an inclination of 31.383
o (about 42
o to the geomagnetic equator), while the inbound trajectory had an inclination of 39.925
o (about 51
o to the geomagnetic equator). Since the inbound trajectory was farther out toward the edges of the radiation belts, we would expect a smaller dose. The unshielded dose along the outbound trajectory is 149 rem and that along the inbound trajectory is 31 rem.
Let's now assume a worst case scenario, that is, we pass right through the heart of the belts. In this scenario the plane of the orbit is the same as the plane of the geomagnetic equator, which results in dramatically higher doses. The unshielded doses for the outbound and inbound trajectories are about 3250 rem and 3200 rem respectively. This means that the Apollo 11 trajectories resulted in reductions of 95% and 99% from the potential worst case radiation exposure.
These computations are, or course, those for an exposed and unprotected astronaut. Inside the shielded spacecraft, the actual doses are far less. I estimate that the actual Apollo 11 dose was only about 32 mrem, all coming from protons >100 MeV. For the worst case trajectory through the geomagnetic plane, I estimate that the dose inside the spacecraft could possibly be as high as 5 rem total for both trips.
