Sat, Oct 05, 2013 - Page 11 News List

Astronauts face radiation threat on long Mars trip

US astronaut Michael Hopkins, left, and Russian cosmonauts Oleg Kotov, center, and Sergey Ryazanskiy attend a training session at the Star City space center outside Moscow on Aug. 23.

Photo: Reuters

Astronauts traveling to and from Mars would be bombarded with as much radiation as they would get from a full-body CT scan about once a week for a year, researchers reported.

That dose would, in some cases, exceed NASA’s standards and is enough to raise an astronaut’s cancer risk by three percent.

As plans for deep space exploration ramp up, radiation is a big concern — from high-energy galactic cosmic rays spewed by distant supernova explosions to sporadic bursts of charged particles hurled by the sun. Earth’s magnetic field helps to deflect much of that harmful radiation.

NASA aims to send a crew to orbit the red planet by the mid-2030s. Private outfits like Inspiration Mars are seeking volunteers for a Mars flight.

There have been previous efforts to gauge the radiation risk for future Mars travelers, but the best estimate is coming from NASA’s Curiosity mission. Tucked inside the rover when it launched in 2011 was a radiation sensor that took readings during the eight-and-a-half-month cruise to Mars.

From those figures, scientists calculated a spacefarer’s radiation exposure for a quicker six-month voyage in a similarly shielded spacecraft — round-trip approximately 662 millisieverts.

The estimate is just for zipping there and back. It does not include time spent on the Martian surface, which would add to an astronaut’s exposure.








1. outfit n.

公司;機構 (gong1 si1; ji1 gou4)

例: Some big outfits are working on developing similar products.


2. round-trip n.

來回之行 (lai2 hui2 zhi1 xing2)

例: It will cost you US$1,500 round-trip.


3. zip v.


(xun4 su4 xing2 dong4; yi3 jian1 xiao1 sheng1 xing2 jin4)

例: We zipped through the homework and then went to a movie.




(美聯社/翻譯: 魏國金)

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