Did you know that pilots and flight attendants have the largest average annual effective dose and more chances of having skin cancer than the general population? It’s because the higher you go, the higher the dose of radiation especially for frequent flyers. The higher the dose, the greater the chance of getting cancer.
Like aircrews, astronauts are placed at risk whenever they go on space missions. Since the International Space Station is still in low Earth orbit, they’re still within the protective magnet. Beyond this, outside of the Earth’s atmosphere and magnetic shield, cosmic radiation is much stronger. How do space agencies protect them from health risks?
Solar Radiation and Galactic Cosmic Rays
There’s a variety of radiation sources in space, including solar radiation and galactic cosmic rays (GCR).
Solar radiation comes from the Sun, the biggest radiation source. It emits all wavelengths in the electromagnetic spectrum, most of which are visible, infrared and ultraviolet radiation.
From smallest to the most dangerous, solar flares can also happen. These are explosions and bursts of electromagnetic radiation from the sun’s surface.
In August 1972, historically powerful solar storms caused disturbances in the electric and communication grid. The Apollo 16 crew would have died from this disaster if they didn’t land on Earth in April of that year.
The other source are galactic cosmic rays, high-energy particles outside of our Solar System. Some of the generated GCRs are from the remnants of massive star explosions or supernovae.
When these pass through atoms, they can cause them to ionise, damage cells and genetic material.
Space Radiation on the Human Body
According to NASA, the highest skin dose received was 1.14 rad during the Apollo 14 mission in 1971. In all of the Apollo missions, the astronauts’ average radiation skin dose was 0.38 rad and each of these missions went on for no longer than 12 days. Compare it to the standard dose here on Earth, which is just about 0.36 rad/year.
Without protection, astronauts can acquire acute and chronic health problems from prolonged radiation exposure. Females have a much higher risk of cancer from radiation, studies have found. That’s why they have lower career exposure limits for NASA.
For female astronauts aged below 35, the limit is 1.00 Sv or 100 rad while male astronauts’ limit is 1.50 Sv.
Younger astronauts have lower limits too since exposure to larger amounts early in their careers could present greater health risks during old age.
For example, male astronauts aged 55 have a 4.00 Sv limit while 25-year-old males have a 1.50 Sv limit.
Radiation Shielding
How do astronauts shield themselves from radiation?
Space Suits – Astronauts wear garments typically constructed from spandex, nylon and other synthetic polymers. EVA Space Suits are extra-vehicular, working like a mini spacecraft for the astronaut to provide everything they need. It may consist of 16 layers with different purposes, including reducing radiation exposure, shielding against space dust and reflecting heat from the sun.
Spacecraft Design – Multiple layers of protective materials make up spacecrafts, as they are the first line of defence. Aluminium and polyethylene are some of the materials. Astronauts can also position their sleeping quarters in the centre of the spacecraft where they are surrounded by supplies and equipment, creating a natural barrier.
Radiation monitoring – Astronauts’ exposure are continuously monitored through personal dosimeters.
Real Time Radiation Monitoring for Space Explorations
Early in 2023, SensaWeb presented in the Boeing’s Sustainability in Space Pitch Competition as a finalist. Our real time radiation monitoring can provide information on the incidence and impact of radiation exposure in space, helping space agencies make informed decisions for their safety.
Getting radiation data would help us understand the effects of different radiation levels on different organisms. Understanding the effects would help in developing drugs or treatments that can treat or reduce adverse effects.
Connect with us here or at our email address: info@sensaweb.com.au. You can also call us at +61 415 409 467.