Learning to Live on a Mars Day: Fatigue Countermeasures during the Phoenix Mars Lander Mission

Barger, Laura K.; Sullivan, Jason P.; Vincent, Andrea S.; Fiedler, Edna R.; McKenna, Laurence M; Flynn‐Evans, Erin E.; Gilliland, Kirby; Sipes, Walter; Smith, Peter H.; Brainard, George C.; Lockley, Steven W.

doi:10.5665/sleep.2128

Cited by 32 publications

(39 citation statements)

References 91 publications

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“…There is a need for novel space exploration habitats and crew activity schedules that mimic the biological potency of Earth's geophysical cycle through both photic (22,45) and nonphotic (10,19,46) synchronizers to promote circadian entrainment and the temporal optimization of behavioral states during prolonged spaceflight. These needs extend to circadian adjustment for work in near-circadian environments, such as the Martian solar day (i.e., 24.67 h) (47). A balance must be struck during human exploration of space between the critical need for adequate time for sleep and rest and the need to maintain activity levels for physical and physiological fitness.…”

Section: Discussionmentioning

confidence: 99%

Mars 520-d mission simulation reveals protracted crew hypokinesis and alterations of sleep duration and timing

Basner

Dinges

Mollicone

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

154

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The success of interplanetary human spaceflight will depend on many factors, including the behavioral activity levels, sleep, and circadian timing of crews exposed to prolonged microgravity and confinement. To address the effects of the latter, we used a highfidelity ground simulation of a Mars mission to objectively track sleep-wake dynamics in a multinational crew of six during 520 d of confined isolation. Measurements included continuous recordings of wrist actigraphy and light exposure (4.396 million min) and weekly computer-based neurobehavioral assessments (n = 888) to identify changes in the crew's activity levels, sleep quantity and quality, sleep-wake periodicity, vigilance performance, and workload throughout the record-long 17 mo of mission confinement. Actigraphy revealed that crew sedentariness increased across the mission as evident in decreased waking movement (i.e., hypokinesis) and increased sleep and rest times. Light exposure decreased during the mission. The majority of crewmembers also experienced one or more disturbances of sleep quality, vigilance deficits, or altered sleep-wake periodicity and timing, suggesting inadequate circadian entrainment. The results point to the need to identify markers of differential vulnerability to hypokinesis and sleepwake changes during the prolonged isolation of exploration spaceflight and the need to ensure maintenance of circadian entrainment, sleep quantity and quality, and optimal activity levels during exploration missions. Therefore, successful adaptation to such missions will require crew to transit in spacecraft and live in surface habitats that instantiate aspects of Earth's geophysical signals (appropriately timed light exposure, food intake, exercise) required for temporal organization and maintenance of human behavior.sleep-wake regulation | astronaut T he success of human interplanetary spaceflight, which is anticipated to be in this century, will depend on the ability of spacefarers to remain confined and isolated from Earth much longer than previous missions or simulations, while maintaining the intensity and timing of behavioral activity necessary to accomplish the mission and mitigate the effects of microgravity. A total of four people have spent >1 y in space, with the record of 437 consecutive days on the Mir space station set by Valery Polyakov. The longest Earth-based spaceflight simulation involved four Russians confined in connected hyperbaric chambers for 240 consecutive days. Antarctic winter-over missions have extended up to 363 d. Prediction of how prolonged confinement affects activity levels and sleep-wake dynamics of space explorers is needed to inform spacecraft habitability requirements, crew selection, and behavioral countermeasures during interplanetary missions (1-3). To address this need, we obtained objective neurobehavioral data on the activity patterns of a multinational, culturally diverse crew of six males with backgrounds in engineering, medicine, physiology, and space training, who participated in a high-fidelity g...

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Section: Discussionmentioning

confidence: 99%

Mars 520-d mission simulation reveals protracted crew hypokinesis and alterations of sleep duration and timing

Basner

Dinges

Mollicone

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

154

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“…Prior work has, however, reported a strong relationship between circadian phase measured from urinary cortisol (less impacted by light exposure) and aMT6s ( n = 7; mean ± SD Pearson's r = 0.98 ± 0.01, P < 0.01) (Barger et al . ). Measuring circadian timing via urinary aMT6s is well established in the literature as a reliable assessment of phase in field settings, and has been used successfully in numerous prior studies of shift workers including nurses (Dumont et al .…”

Section: Discussionmentioning

confidence: 97%

Temporal dynamics of circadian phase shifting response to consecutive night shifts in healthcare workers: role of light–dark exposure

Stone

Sletten

Magee

et al. 2018

The Journal of Physiology

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Night shift workers show highly variable rates of circadian adaptation. This study examined the relationship between light exposure patterns and the magnitude of circadian phase resetting in response to night shift work. In 21 participants (nursing and medical staff in an intensive care unit) circadian phase was measured using 6-sulphatoxymelatonin at baseline (day/evening shifts or days off) and after 3-4 consecutive night shifts. Daily light exposure was examined relative to individual circadian phase to quantify light intensity in the phase delay and phase advance portions of the light phase response curve (PRC). There was substantial inter-individual variability in the direction and magnitude of phase shift after three or four consecutive night shifts (mean phase delay -1:08 ± 1:31 h; range -3:43 h delay to +3:07 h phase advance). The relative difference in the distribution of light relative to the PRC combined with diurnal preference accounted for 71% of the variability in phase shift. Regression analysis incorporating these factors estimated phase shift to within ±60 min in 85% of participants. No participants met criteria for partial adaptation to night work after three or four consecutive night shifts. Our findings provide evidence that the phase resetting that does occur is based on individual light exposure patterns relative to an individual's baseline circadian phase. Thus, a 'one size fits all' approach to promoting adaptation to shift work using light therapy, implemented without knowledge of circadian phase, may not be efficacious for all individuals.

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“…35,[55][56][57][58] To assess the potential impact of light on aMT6s, in a previous study we compared aMT6s with urinary cortisol (which is much less confounded by light) in a subset of sighted individuals (n = 7) and found a strong relationship between the phase estimates (average Pearson r ± SD, 0.98 ± 0.01, p < 0.05). 40 The study is limited by the short time lag between the estimation of phase and performance assessment in the laboratory (up to 24 hours).…”

Section: Discussionmentioning

confidence: 99%

Ocular Measures of Sleepiness Are Increased in Night Shift Workers Undergoing a Simulated Night Shift Near the Peak Time of the 6-Sulfatoxymelatonin Rhythm

Ftouni

Nicholas

Kennaway

et al. 2015

Journal of Clinical Sleep Medicine

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Study Objectives:The study examined the relationship between the circadian rhythm of 6-sulphatoxymelatonin (aMT6s) and ocular measures of sleepiness and neurobehavioral performance in shift workers undergoing a simulated night shift. Methods: Twenty-two shift workers (mean age 33.4, SD 11.8 years) were tested at approximately the beginning (20:00) and the end (05:55) of a simulated night shift in the laboratory. At the time point corresponding to the end of the simulated shift, 14 participants were classifi ed as being within range of 6-sulphatoxymelatonin (aMT6s) acrophasedefi ned as 3 hours before or after aMT6s peak-and 8 were classifi ed as outside aMT6s acrophase range. Participants completed the Karolinska Sleepiness Scale (KSS) and the auditory psychomotor vigilance task (aPVT). Waking electroencephalography (EEG) was recorded and infrared refl ectance oculography was used to collect ocular measures of sleepiness: positive and negative amplitude/velocity ratio (PosAVR, NegAVR), mean blink total duration (BTD), the percentage of eye closure (%TEC), and a composite score of sleepiness levels (Johns Drowsiness Scale; JDS).Results: Participants who were tested within aMT6s acrophase range displayed higher levels of sleepiness on ocular measures (%TEC, BTD, PosAVR, JDS), objective sleepiness (EEG delta power frequency band), subjective ratings of sleepiness, and neurobehavioral performance, compared to those who were outside aMT6s acrophase range. Conclusions:The study demonstrated that objective ocular measures of sleepiness are sensitive to circadian rhythm misalignment in shift workers. Keywords: oculometrics, circadian misalignment, shift work, performance, sleepiness Citation: Ftouni S, Sletten TL, Nicholas CL, Kennaway DJ, Lockley SW, Rajaratnam SM. Ocular measures of sleepiness are increased in night shift workers undergoing a simulated night shift near the peak time of the 6-sulfatoxymelatonin rhythm. J Clin Sleep Med 2015;11(10):1131 -1141 .pii: jc-00268-14 http://dx.doi.org/10.5664/jcsm.5086 S hift work has become a ubiquitous part of labor practices due to the increasing pressure for 24-hour provision of goods and services. This drive for round-the-clock productivity, however, has resulted in negative consequences to health, safety, and performance.1 Such consequences have been welldocumented in a number of occupational sectors in which peak functioning during the night shift is critical, for example, commercial transport, mining, emergency services, and health care. The impairment to alertness that occurs during night shift work is mainly attributed to misalignment of the imposed sleep-wake cycle from the internally generated circadian (~24-hour) rhythm of sleepiness, 3 often against a background of chronic sleep defi ciency and prolonged periods of wakefulness. Alertness and neurobehavioral performance peak when the circadian pacemaker promotes wakefulness during the daytime, and decline markedly during the night, particularly between 03:00 and 06:00, 4 as the circadian pacemaker strongly promotes...

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Learning to Live on a Mars Day: Fatigue Countermeasures during the Phoenix Mars Lander Mission

Abstract: The ability of the participants to adapt successfully to the Mars day suggests that future missions should utilize a similar circadian rhythm and fatigue management program to reduce the risk of sleepiness-related errors that jeopardize personnel safety and health during critical missions.

Cited by 32 publications

References 91 publications

Mars 520-d mission simulation reveals protracted crew hypokinesis and alterations of sleep duration and timing

Mars 520-d mission simulation reveals protracted crew hypokinesis and alterations of sleep duration and timing

Temporal dynamics of circadian phase shifting response to consecutive night shifts in healthcare workers: role of light–dark exposure

Ocular Measures of Sleepiness Are Increased in Night Shift Workers Undergoing a Simulated Night Shift Near the Peak Time of the 6-Sulfatoxymelatonin Rhythm

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