Chris Benton, M.B.Ch.B.: "The hazards of the space flight to Mars"
March 31 - 8:30 am
My notes from this science lecture are a mess, but I figure I might as well make them public in case anyone wants to look. Maybe I'll clean them up to be readable some day, but given that I haven't done that for all of my 2012 science lectures, I may never get around to it.
ISS Human Sciences Research Lab
Lots of blood tests. Lots of heart tests. MRI before and after space. Echocardiograms in space. Doppler blood flow in carotid and jugular. Clot risk.
Negative pressure lower body suit, Russian design attached to the wall for 20 minutes, frustrating. NASA has a mobile negative pressure body suit not yet in service.
Bones and muscles weaken. Normal tight lattice. Less loading, more osteoclast, less osteoblast. Less calcium in diet. 1.5% per month on ISS, like sedentary elderly per year. Slow recovery, 6 months to recover 60%, two years full recovery.
Countermeasures.
Treadmills, ISS ARED. Medication bisphospholates, Fosamax and others. Vitamin D and calcium. Without, 2.1% bone loss in 4 to 12 months. Combine all, no significant loss.
Parathyroid hormone, genetically modified lettuce can make it.
Muscles can lose 20% mass, 30% strength. Studied by biopsies, MRI, etc. Tests have Earth spinoffs. “Penguin suit” has springs and pulleys for resistance. Electrical stimulation.
Ionizing radiation.
Atmosphere and magnetosphere on Earth.
Solar and rest of galaxy.
Ultraviolet and solar wind, low energy, easy to protect against.
Solar flares, coronal mass ejection = Solar particle events, mostly protons
Galactic cosmic rays
Protons 83% He 13% e- 2% heavier 2%
Secondary radiation
Dose, rate, long-term accumulation
Acute radiation syndrome
Chronic, cancer, immunodeficiency, coronary heart disease, infertility, cataracts
Measured in millisieverts. 1 mSv = 3 chest xray.
Women more sensitive, breast, ovary, lungs
Children more time to develop cancer
NASA limit 3% added risk of fatal cancer (180 mSv for 30 year old woman, 700 for 60 year old man. Lifetime cap is 600.)
Three year Mars mission 1000 mSv, 9 month travel
Future, woman waive risk to 600? Avoid solar particle events.
NASA cap of 600 more conservative
Shield, 20 to 30 g/cm² limit for secondary radiation, hydrogen best, water, polyethylene, Kevlar. High charge to mass radiation, no fragmentation risk. Current polyethylene and Kevlar 55% reduction.
AstroRad vest, protects sensitive torso organs.
On Mars, boron nitride hydrogenated nanotubes
5 to 10 meters of soil, local magnetic fields, ice structures
Timing of launch 6 months after solar maximum, solar particles reduce galactic cosmic rays
Faster propulsion
Replace chemical with
Nuclear, but hydrogen working fluid leaks out of storage tanks faster than any other fuel
Ion, easy storage, but uses lots of electricity (X3 xenon system)
Hybrid, nuclear, ion, and chemical thrusters
Radiation monitoring
[On a ship's PA announcement, Cruise Director Erin pitches entertainment. Lecturer: "That sounds exciting. I can't wait for the 11 o'clock bingo." Pretty much everyone in the lecture hall laughed.]
Monitoring bioeffects per individual
Nutrition, pharmacology
The future, the CIPHER Project
Q&A:
Psychology - day off, movie nights, rotate command, psychology observations of fellow crew
Blood volume: 5 liter blood 40+ liter fluid, 20% blood fluid loss
My notes from this science lecture are a mess, but I figure I might as well make them public in case anyone wants to look. Maybe I'll clean them up to be readable some day, but given that I haven't done that for all of my 2012 science lectures, I may never get around to it.
ISS Human Sciences Research Lab
Lots of blood tests. Lots of heart tests. MRI before and after space. Echocardiograms in space. Doppler blood flow in carotid and jugular. Clot risk.
Negative pressure lower body suit, Russian design attached to the wall for 20 minutes, frustrating. NASA has a mobile negative pressure body suit not yet in service.
Bones and muscles weaken. Normal tight lattice. Less loading, more osteoclast, less osteoblast. Less calcium in diet. 1.5% per month on ISS, like sedentary elderly per year. Slow recovery, 6 months to recover 60%, two years full recovery.
Countermeasures.
Treadmills, ISS ARED. Medication bisphospholates, Fosamax and others. Vitamin D and calcium. Without, 2.1% bone loss in 4 to 12 months. Combine all, no significant loss.
Parathyroid hormone, genetically modified lettuce can make it.
Muscles can lose 20% mass, 30% strength. Studied by biopsies, MRI, etc. Tests have Earth spinoffs. “Penguin suit” has springs and pulleys for resistance. Electrical stimulation.
Ionizing radiation.
Atmosphere and magnetosphere on Earth.
Solar and rest of galaxy.
Ultraviolet and solar wind, low energy, easy to protect against.
Solar flares, coronal mass ejection = Solar particle events, mostly protons
Galactic cosmic rays
Protons 83% He 13% e- 2% heavier 2%
Secondary radiation
Dose, rate, long-term accumulation
Acute radiation syndrome
Chronic, cancer, immunodeficiency, coronary heart disease, infertility, cataracts
Measured in millisieverts. 1 mSv = 3 chest xray.
Women more sensitive, breast, ovary, lungs
Children more time to develop cancer
NASA limit 3% added risk of fatal cancer (180 mSv for 30 year old woman, 700 for 60 year old man. Lifetime cap is 600.)
Three year Mars mission 1000 mSv, 9 month travel
Future, woman waive risk to 600? Avoid solar particle events.
NASA cap of 600 more conservative
Shield, 20 to 30 g/cm² limit for secondary radiation, hydrogen best, water, polyethylene, Kevlar. High charge to mass radiation, no fragmentation risk. Current polyethylene and Kevlar 55% reduction.
AstroRad vest, protects sensitive torso organs.
On Mars, boron nitride hydrogenated nanotubes
5 to 10 meters of soil, local magnetic fields, ice structures
Timing of launch 6 months after solar maximum, solar particles reduce galactic cosmic rays
Faster propulsion
Replace chemical with
Nuclear, but hydrogen working fluid leaks out of storage tanks faster than any other fuel
Ion, easy storage, but uses lots of electricity (X3 xenon system)
Hybrid, nuclear, ion, and chemical thrusters
Radiation monitoring
[On a ship's PA announcement, Cruise Director Erin pitches entertainment. Lecturer: "That sounds exciting. I can't wait for the 11 o'clock bingo." Pretty much everyone in the lecture hall laughed.]
Monitoring bioeffects per individual
Nutrition, pharmacology
The future, the CIPHER Project
Q&A:
Psychology - day off, movie nights, rotate command, psychology observations of fellow crew
Blood volume: 5 liter blood 40+ liter fluid, 20% blood fluid loss