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Thank you for this post. I was wondering if a thin lead sheet would be beneficial for the cockpit ceiling and maybe aisles of jetliners to protect the crew fro

Thank you for this post. I was wondering if a thin lead sheet would be beneficial for the cockpit ceiling and maybe aisles of jetliners to protect the crew from the prolonged exposure to increased radiation. Do you think this is a bad idea for the same reasons as the spacecraft? (Of course there are other materials besides lead, that was what first came to mind because I incorrectly thought it was a panacea for all radiation types).

chasil 2y ago
I had read elsewhere that water is a useful shield. A quick search found this document, that mentions the danger of secondary particles. https://www.nasa.gov/wp-content/uploads/2009/07/284275main_radiation_hs_mod3.pdf?emrc=f9d9bd https://www.nasa.gov/wp-content/uploads/2009/07/284275main_r...
perihelions 2y ago
Air pressure at airliner altitudes is still about 20-30% of the sea level value. That means 20-30% of the atmosphere is above that—a column of mass equal to 2-3 meters of liquid water. A thin lead sheet would be a rounding error next to that. This is an oversimplification that's rather wrong, but: a decrease in altitude of just 300 meters, at airliner levels, puts an additional atmospheric mass equal to ~1 cm of lead (Pb) above your head.
- gosub100 2y ago
  Have you seen the explanations of radiation where they say flying (as a passenger) is about equal to the dosage of a dental X-ray (or something similar)? Someone who spends their career getting exposed at that rate might be worth making them a shield.
  - Dylan16807 2y ago
    It's not worth it. Like, you could mandate planes fly 100 meters lower, but a lead coating would be so heavy. Let's say a 737 with a max weight of 70 tons. Covering the top half with lead would mean a 200 square meter sheet, and at 1cm thick it would weigh more than 20 tons.
  - perihelions 2y ago
    It's *not possible* to make a shield. The cosmic radiation that reaches that altitude is highly energetic and highly penetrating—enough so to go through 3 meters of water—and would be completely unaffected by lead sheets. Any easily-shielded types of cosmic radiation have already been blocked by the atmosphere.

chasil 2y ago

I had read elsewhere that water is a useful shield. A quick search found this document, that mentions the danger of secondary particles. https://www.nasa.gov/wp-content/uploads/2009/07/284275main_radiation_hs_mod3.pdf?emrc=f9d9bd https://www.nasa.gov/wp-content/uploads/2009/07/284275main_r...

perihelions 2y ago

Air pressure at airliner altitudes is still about 20-30% of the sea level value. That means 20-30% of the atmosphere is above that—a column of mass equal to 2-3 meters of liquid water. A thin lead sheet would be a rounding error next to that. This is an oversimplification that's rather wrong, but: a decrease in altitude of just 300 meters, at airliner levels, puts an additional atmospheric mass equal to ~1 cm of lead (Pb) above your head.

gosub100 2y ago
Have you seen the explanations of radiation where they say flying (as a passenger) is about equal to the dosage of a dental X-ray (or something similar)? Someone who spends their career getting exposed at that rate might be worth making them a shield.
- Dylan16807 2y ago
  It's not worth it. Like, you could mandate planes fly 100 meters lower, but a lead coating would be so heavy. Let's say a 737 with a max weight of 70 tons. Covering the top half with lead would mean a 200 square meter sheet, and at 1cm thick it would weigh more than 20 tons.
- perihelions 2y ago
  It's *not possible* to make a shield. The cosmic radiation that reaches that altitude is highly energetic and highly penetrating—enough so to go through 3 meters of water—and would be completely unaffected by lead sheets. Any easily-shielded types of cosmic radiation have already been blocked by the atmosphere.