Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Cosmic rays threaten future deep-space astronaut missions


Crewed missions to Mars remain an essential goal for NASA, but scientists are only now beginning to understand and characterize the radiation hazards that could make such ventures risky, concludes a new paper by University of New Hampshire scientists.

In a paper published online in the journal Space Weather, associate professor Nathan Schwadron of the UNH Institute for the Study of Earth, Oceans, and Space (EOS) and the department of physics says 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 provide critical information on the radiation hazards that will be faced by astronauts on extended missions to deep space such as those to Mars. The papers can be viewed here:

"These data are a fundamental reference for the radiation hazards in near Earth 'geospace' out to Mars and other regions of our sun's vast heliosphere," says Schwadron.

At the heart of CRaTER is material called "tissue equivalent plastic"—a stand-in for human muscle capable of gauging radiation dosage. Ionizing radiation from galactic cosmic rays and solar energetic particles remains a significant challenge to long-duration crewed missions to deep space. Human beings face a variety of consequences ranging from acute effects (radiation sickness) to long-term effects including cancer induction and damage to organs including the heart and brain.

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.

UNH coauthors on the capstone paper titled "Does the worsening radiation environment preclude future manned deep-space exploration?" include Colin Joyce, Marty Quinn, Charles Smith, Sonya Smith, Harlan Spence, and Jody Wilson.


The CRaTER investigation is a collaboration with team members at UNH, the University of Tennessee at Knoxville, Southwest Research Institute, Harvard-Smithsonian Center for Astrophysics, The Aerospace Corporation, the University of Michigan, and NASA Goddard Spaceflight Center. For more information on the CRaTER instrument and the LRO mission, visit

Support for this research comes from NASA's LRO/CRaTER mission, and NASA'S Earth-Moon-Mars Radiation Environment Module and Corona-Solar Wind Energetic Particle Acceleration projects. Additional support is provided by the National Science Foundation's Frontiers in Earth-System Dynamics program, which funds the UNH-led "Sun-to-Ice" project that uses theory and modeling results to inform the analysis of current space-based NASA measurements of the radiation environment.

The NASA Goddard Space Flight Center in Greenbelt, Md. developed and manages the LRO mission. LRO's current science mission is implemented for NASA's Science Mission Directorate. NASA's Exploration Systems Mission Directorate sponsored LRO's initial one-year exploration mission that concluded in September 2010.

The University of New Hampshire, founded in 1866, is a world-class public research university with the feel of a New England liberal arts college. A land, sea, and space-grant university, UNH is the state's flagship public institution, enrolling 12,300 undergraduate and 2,200 graduate students.

Images to download:

Caption: Solar flare observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager and associated coronal mass ejection observed by the Solar and Heliospheric Observatory spacecraft. Solar energetic particles from these events can easily penetrate typical shielding and damage spacecraft electronics and biological cells. Image courtesy of Nathan Schwadron, UNH-EOS.

Caption: Artist's rendition of the Lunar Reconnaissance Orbiter at the moon. The CRaTER telescope is seen pointing out at the bottom right center of the LRO spacecraft. Illustration by Chris Meaney/NASA.

David Sims | Eurek Alert!

More articles from Physics and Astronomy:

nachricht Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1
21.03.2018 | Fraunhofer-Institut für Hochfrequenzphysik und Radartechnik FHR

nachricht Taming chaos: Calculating probability in complex systems
21.03.2018 | American Institute of Physics

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

TRAPPIST-1 planets provide clues to the nature of habitable worlds

21.03.2018 | Physics and Astronomy

The search for dark matter widens

21.03.2018 | Materials Sciences

Natural enemies reduce pesticide use

21.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>