Eliminating radiation protection

Up to 9 0 % of a spacecraft’s weight is in radiation shielding. In our quest to create the lightest, smallest, simplest space settlement, we have searched for ways of reducing this unneeded weight by as much as possible, to the point of completely eliminating it.

The unit used for measuring small ionizing radiation doses and their impact in the International System of Units is the Sievert. It has been shown that 1 Sievert is enough to raise the probability of eventually developing cancer by 5 .5 %.

[14][15]

Dose examples in Sieverts[16][17]:

0.098 μSv 0.2 μSv

radiation from a typical banana a single airport screening in the U.S.

5 to 10μSv

one set of dental radiographs 10 to 30 mSv full-body CT scan 80 mSv 6 months stay on the International Space Station 250 mSv 6 months trip to Mars 1 Sv: maximum allowed exposure for NASA astronauts over their career

Even more important in the context of space travel are the radiation dose rates. Below are several examples[18]:

2.4 mSv/a human exposure to natural background radiation, global average 24 mSv/a natural background radiation at airline cruise altitude 9Sv/a NRC definition of a high radiation area in a nuclear power plant

In his 2015 paper – Orbital Space Settlement Radiation Shielding [19] – Al Globus has shown that human adults can withstand radiation levels of up to 2 0 m S v / y e ar, while pregnant women have a threshold of 5 m G y / p r e g n an c y. According to the same research paper, placing a settlement in the equatorial Lower Earth Orbit (ELEO) where the radiation levels are at their lowest point, one can virtually eliminate the need for any radiation protection. This is hugely important for the Honeycomb Space Settlement, as it fits the minimalistic philosophy of our entire project. Removing radiation shielding will lower both weight and costs, as well as the construction time.