The Challenge of Living on Mars: Sleep

Every Martian day is exactly 24 hours, 39 minutes, 35 seconds in length.

Scientists and engineers in the Space community refer to a Mar’s day as a “sol”. Living on Earth and working in “sols” creates problems.

Arthur C. Clark’s 2001: A Space Odyssey offered a prescient deep space flight hibernation by means of low temperature electronic device that created a coma-type stasis for some of the  astronauts on the long flight to Jupiter. NASA , 2014, is evaluating a high-tech deep space sleep option using a RhinoChill torpor system that lowers the astronaut’s body temperatures to between 89-92 degrees F and reduce the body metabolic process.

Many of the NASA Apollo astronauts from every lunar mission reported light flashes. Charlie Duke said in an interview, “it was like light flashing in my eyeballs” and explained how it was a spectacular effect similar  fireworks. The astronauts reported the phenomena were seen when eyes were open or shut; NASA engineers believed these were caused by cosmic rays of high energy charged particles from the sun. They developed experimental boxes or helmets that were placed over the astronauts heads named Apollo Light Flash Moving Emulsion Detectors (ALFMED) designed with interiors lined with silver bromide film  to detect cosmic rays. These were deep space moon landing missions. Now we aim for Mars.

One of the major hurdles that humans face adjusting to the Mars “sol” is as Atlantic Magazine (Feb. 26, 2015) summarized, “The extra 40 minutes in a Martian day adds up quickly. Its like heading west by two time zones every three days. Call it  ‘rocket lag’”. Atlantic goes on to explain what problems this phenomena caused with NASA Spirit and Opportunity twin rovers engineering teams as 90 “sols” had passed and the Earth had passed 2.5 days ahead of them.

Human adults natural circadian rhythm (Earth clock) times average 24 hours 6 minutes for women and 24 hours 12 minutes for men—with individual adjustments, but none moving far from the 24 hour post.

One research project Lim et al. (Nov. 6, 2014) reported, “Circadian rhythms modulate the biology of many human tissues, including brain tissues, and are driven by a near 24-hour transcriptional feedback loops.” The study “analyzed DNA methylation levels in post-mortem brain samples from 738 subjects. We assessed for 24-hour rhythmicity of 420,132 DNA  methylation sites throughout the genome…determined global statistical significance.”

Dr. Charles Czisler, a professor of sleep medicine at Harvard, advised NASA on the problems of humans adjusting circadian rhythms and directed the agency in ways of using bright light or blue light therapy in evenings to reset the body clock.

There challenges of deep space flight, including the energy particles that bombard the astronauts and light beams that are seen even while sleeping, along with the physiological requirements of circadian rhythms and proper sleep, must be overcome to avoid safety issues, mistakes, accidents exhibited by sleep deprivation and assuring dangerous physical degradation is not the by-product of deep space flight.

Any dramatization or science-fiction work that suggests a deep space flight to explore and colonize Mars would be inaccurate, at least based on our present knowledge of human sleep physiology, if it did not address and demonstrate astronauts using light therapy. (And that treatment has not been proven 100% effective in a real deep space mission yet.)


Here are more links about sleep from NASA:

Deep Space, Deep Sleep Torpor (PDF)

The Right Ratio of Rest (PDF)

Biological Clock Misalignment (website)


Some other links of interest:

Jet Lag is Worse On Mars (The Atlantic)

Project Exodus: What’s Behind the Dream of Colonizing Mars? (The New Yorker)


And some videos: