Hypomagnetic field, an ignorable environmental factor in space?

All living organisms on the earth have been exposed to the geomagnetic field (GMF, ~50 mT), a nature component of the habitability environment, throughout the evolutionary history. However, the environmental magnetic field (MF) in space decreases geometrically with the distance from the ground. The MF magnitude (|B|) at the International Space Station (ISS; near-earth orbit) is similar to the GMF (~80% GMF with limited variation), except that the radial component (Br) exhibits significant variations both in direction and magnitude. The environmental MF in outer space is extremely lower than the GMF, called a hypomagnetic field (HMF), e.g., Martian MF is l5 mT, Lunar MF is l300 nT and interplanetary MF is just a few nanotesla. Thus, besides micro-gravity (m-gravity) and cosmic radiation, astronauts have to be exposed and adapt to the HMF condition when onboard in the long-term and long-distance space missions. Even though biological effects of the HMF were valued in early studies (1960s), exploration of the space HMF has not rapidly progressed in the following decades...