"res17uuf" wrote in message
. ..
I'm doing a research project for school on the apollo missions
and I have been having trouble finding information on what was
used to shield the apollo vehicles when they passed through the
van allen belts. I've found some radiation statistics I'm
curious how they solved this problem. also it is kinda needed
for my project.

In "The Space Environment" by N. H. Langton (1969) they say the
Apollo plan was to avoid most of the van Allen belt radiation
by going near the edge. Cape Canaveral is 28.5 degrees North,
which is about right for going toward the Moon. The radiation
belts are inclined about 11 degrees (as is the Earth's magnetic
field) and are about +- 40 degrees wide. If you time your
departure for the Moon so you are at the Northern part of your
orbit while over the place where the radiation belts are South,
you can miss most of the radiation. From pages 134-136 I quote:

The problem of making a suitable exit through the trapped radiation
is not in fact particularly difficult. The lunar missions at
present proposed will leave from a parking orbit below the van Allen
region and the most opportune instant to leave this orbit will of
course be chosen. The radiation intensity is quite low at and above
magnetic latitude 40 degrees North or 40 degrees South and the
geomagnetic dipole is at an angle of 11 degrees to the Earth's
rotational axis. The rotational axis is at an angle of 66.5 degrees
to the plane of the ecliptic at the equinoxes and the plane of the
lunar orbit is inclined at 5 degrees to that of the ecliptic,
around which it rotates with a period of just over 18 years.
Accordingly, once every 18 years, at the equinox, there is an
instant each day when a straight line from Earth to the Moon is the
normal at magnetic latitude 39.5 degrees. The situation is shown
in Fig. 4.10. While this ideal path may not be followed (it imposes
considerable restrictions on dates and times of lunar missions, and
takes no account of solar flare incidence) the general principles
involved are clear, and a lunar mission is unlikely to incur
a high dose burden from the van Allen belts on its way from and
to the Earth.

-- Vince