Why NASA’s women astronauts cannot fly as much as men - The Economist

LIKE EARTH, space has struggled with equality. When Wally Funk finally made the journey into space aboard Jeff Bezos’s New Shepard flight it was a milestone for female astronauts. As a young aviator she had excelled in her tests as part of the privately funded Women in Space programme. But, despite the competence of the programme’s participants, in 1961 the scheme was cancelled. Ms Funk’s voyage this year was the first time that any of the Mercury 13, as they have since been dubbed, have made it into space. In all 67 women have become astronauts. But they face some unique problems. Why can’t female NASA astronauts fly as much as their male counterparts?

The Economist Today

Hand-picked stories, in your inbox

A daily email with the best of our journalism

Earth’s atmosphere is constantly being bombarded with charged particles, mainly from the Sun and galactic cosmic rays (heavy, high-energy ions stripped of their electrons as they travel across solar systems at close to the speed of light). But Earth has a magnetic field that stretches to around 65,000km above its surface on the side facing the Sun, and much farther than that on the other side. This acts as a shield against the harmful rays. Beyond it astronauts are exposed to high levels of ionising radiation. This raises the risk of cancer, cardiovascular disease and cognitive impairment caused by damage to the nervous system.

Studying the effect of space radiation is hard. NASA has largely based its models on a study that has periodically tracked survivors of the atomic bombs dropped on Japan during the second world war. This research found women to be at a higher risk of developing cancer than men when exposed to radiation, partly because they live longer and are more likely to suffer certain cancers, such as those of the breast and thyroid. To limit these dangers NASA imposes a career limit for radiation exposure. This is supposed to keep the chance of developing radiation-induced fatal cancer to just 3% above that of non-astronauts. This means a 30-year-old female would be limited to exposure equivalent to 180 millisieverts (mSv), compared to a 55-year-old male whose limit would be 400 mSv. (The average American is exposed to around 3 mSv a year.) Astronauts taking a 180-day trip to the International Space Station would face exposure of between 50-120 mSv. Peggy Whitson, a former chief of NASA’s astronaut corps, has said that this ceiling means a female can fly only 45-50% of the number of missions that a male can.

NASA wants to replace this system with a standard career limit of 600 mSv for all of its astronauts, which would bring it in line with most of the other major space agencies. This would make gender less of a factor when deciding who gets picked for a mission. But some older male astronauts could find themselves able to take part in fewer missions. That will affect decisions about who can go to the Moon, which is almost 400,000km away from Earth. And the new rules will pose even more problems as humans set their sights on Mars, which even at its closest to Earth is around 55m km away. The researchers predict that a trip to the red planet would exceed the new radiation limit by 150%. They recommend individual risk assessments for each pilot based on their age and sex and waivers for trips which would exceed the limits. The risks should not have been an issue for Ms Funk. New Shepard traveled to a height of 106km, beyond the Kármán line, which for many people defines the boundary of space, but inside earth’s magnetic field.

Adblock test (Why?)

"much" - Google News
August 09, 2021 at 03:47PM
https://ift.tt/3xxW51d

Why NASA’s women astronauts cannot fly as much as men - The Economist
"much" - Google News
https://ift.tt/37eLLij
Shoes Man Tutorial
Pos News Update
Meme Update
Korean Entertainment News
Japan News Update

Bagikan Berita Ini