By Coares, Dr. Andrew; Jones, Bryn; Bentley, Dr. Bob
New Statesman (1996) , Vol. 131, No. 4588
In May 2000, an EU directive was implemented in UK law, requiring protection for commercial aircrew from exposure to cosmic radiation. Cosmic radiation is present at aircraft altitudes and primarily originates from beyond our solar system. But our sun can also cause variations to exposure in ways we are still not able to predict. A good example occurred just two months later.
Magnetic fields on the sun's surface erupted on 14 July 2000 with the power of a billion tonnes of high explosive. Solar flare activity, accompanied by intense flashes of X-rays and gamma rays, is nothing new, but this particular event unleashed a massive radiation storm into the solar system. Such storms can last several days and are mainly energetic protons, which arrive at Earth half an hour later.
Energetic protons from solar flares can severely disrupt the memory patterns of on-board instruments on orbiting spacecraft and can distort or fog satellite camera images. But there is a more direct effect on humans.
Astronauts on the International Space Station (ISS), orbiting high above Earth's protective atmosphere, are continuously subjected to cosmic rays. During violent solar out bursts, they are bombarded by additional protons from the sun and can receive significant doses of radiation. Aircraft flying within the protective atmosphere of Earth are not directly affected by primary protons, but they are bombarded by secondary cosmic rays, caused when the energetic primary particles hit the top of Earth's atmosphere. These secondary rays expose passengers and crew to increased levels of solar radiation. At altitudes of 30,000 feet or more, the dose is a factor over 100 higher than that at ground level.
A unique "dream team" has been initiated by academia and the private sector to study the phenomena in detail. The Mullard Space Science Laboratory (MSSL-University College London)supplies expertise in solar and plasma physics, Virgin Atlantic Airways supplies the aircraft, and the National Physical Laboratory (NPL) provides expertise with detectors and their calibration. …