Maybe it’s good thing we do not have an active manned spaceflight mission at the moment. However with a planned mission to mars in the decade if this space weather does not calm down “Houston We Could Have a Problem”.
This week the online journal Space Weather reported that due to a highly abnormal and extended lack of solar activity, the solar wind is exhibiting extremely low densities and magnetic field strengths, which causes dangerous levels of hazardous radiation to pervade the space environment.
“The behavior of the sun has recently changed and is now in a state not observed for almost 100 years,” says Schwadron, lead author of the paper and principal investigator for the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on NASA’s Lunar Reconnaissance Orbiter (LRO). He notes that throughout most of the space age, the sun’s activity has shown a clockwork 11-year cycle, with approximately six- to eight-year lulls in activity (solar minimum) followed by two- to three-year periods when the sun is more active. “However, starting in about 2006, we observed the longest solar minimum and weakest solar activity observed in the space age.”
These conditions brought about the highest intensities of galactic cosmic rays seen since the beginning of the space age, which have created worsening radiation hazards that potentially threaten future deep-space astronaut missions.
“While these conditions are not necessarily a showstopper for long-duration missions to the moon, an asteroid, or even Mars, galactic cosmic ray radiation in particular remains a significant and worsening factor that limits mission durations,” says Schwadron.
The study is the capstone article in the Space Weather CRaTER Special Issue, which provides comprehensive findings on space-based radiation as measured by the UNH-led detector. The data provides critical information on the radiation hazards that will be faced by astronauts on extended missions to deep space such as those to Mars.
The high radiation levels seen during the sun’s last minimum cycle limits the allowable days for typical astronauts behind spacecraft shielding. Given the trend of reducing solar output, the allowable days in space for astronauts is dropping and estimated to be 20 percent lower in the coming solar minimum cycle as compared to the last minimum cycle.
How long will these high radiation conditions occur no one knows?