Shappell, 1997

1. Crew Rest and Duty Restrictions for Commercial Space Flight: Recommendations Based Upon the Scientific Literature Scott Shappell, PhD Michael Sawyer, MS Jessica Patterson, MS Work sponsored by: FAA Volpe Center Aerospace Corporation Shappell, 1997

2. CURRENT DUTY TIME & REST REGULATION • No personnel will be scheduled for more than a 12-hour shift during the mission or preceding a reentry mission. • A minimum of an 8 hour rest period is required after 12-hours of work. • During the 7 day period prior to the start of the mission, a maximum of 60 hours can be worked. • No person will work more than 14 consecutive days and after 5 consecutive days of 12 hour shifts, a 48-hour rest period must be given. Code of Federal Regulations (sub part 431.43) Reusable launch vehicle mission operational requirements and restrictions

3. Performance Effects of Fatigue • Increased reaction time • Timing errors in response sequences • Less smooth control • Reduced attention • Preoccupation with single tasks • Reduced audiovisual scan • Diminished memory • Forget peripheral tasks • Revert to “old” habit patterns • Withdrawn mood • Less likely to converse • Less likely to perform low-demand tasks • Increased risk taking

4. The worst person to ask if he is fatigued or sleepy is the person that you are worried about! Subjective vs. Physiological Fatigue

5. ALERT OPTIMAL PEAK Circadian Trough PERFORMANCE SLEEPINESS NADIR WORST SLEEPY Time of Day (24 hour) Circadian Rhythms

6. Sleep • Our sleep/wake cycle is closely tied to our circadian body temperature a) Cave studies

7. ALERT OPTIMAL PEAK Circadian Trough PERFORMANCE SLEEPINESS NADIR WORST SLEEPY Time of Day (24 hour) Circadian Rhythms

8. Stages of Sleep

9. ALERT OPTIMAL PEAK Circadian Trough PERFORMANCE SLEEPINESS NADIR WORST SLEEPY Time of Day (24 hour) Circadian Rhythms

10. Sleep • Our sleep/wake cycle is closely tied to our circadian body temperature a) Cave studies • It is the timing of sleep, not necessarily the amount of sleep, that is important.

11. How Much Sleep Do You Really Need? • Sleep requirements vary among individuals. • A minimum of 5 hours of uninterrupted “core” sleep during the circadian trough is necessary to maintain 80% performance in the lab. • In space, where environmental factors, and physical and mental workload can exceed normal limits, the minimum amount of sleep needed to sustain performance is more. Source: Walter Reed Army Institute of Research

12. While all sleep is beneficial, SWS is more recuperative. • The best time to sleep is during the circadian trough (between 2200-0800). • Interruptions of nighttime core sleep reduce sleep quality and effectiveness. • Individuals need roughly 8 hours of sleep to be properly refreshed. • Sleep loss is cumulative and may take multiple nights of sleep to fully recover. What We Know About Sleep

13. Commercial Aviation Crew Rest Requirements

14. Unique Crew Rest Considerations • Lodging Considerations in Space • Long Duration Flight • Limited Trained Relief Pilots • Restrictive Work Environment • Workload • Stress • Others …

15. CURRENT DUTY TIME & REST REGULATION • No personnel will be scheduled for more than a 12-hour shift during the mission or preceding a reentry mission. • A minimum of an 8 hour rest period is required after 12-hours of work. • During the 7 day period prior to the start of the mission, a maximum of 60 hours can be worked. • No person will work more than 14 consecutive days and after 5 consecutive days of 12 hour shifts, a 48-hour rest period must be given. Code of Federal Regulations (sub part 431.43) Reusable launch vehicle mission operational requirements and restrictions

16. Recommended Modifications/Additions • 8 hours of uninterrupted sleep (not rest as currently defined). • - Sleep should not be pharmacologically induced. • Sleep should occur during the circadian trough. • Attention should be paid to the quality of sleep • - Domicile vs. temporary lodging (e.g., hotels) • Define “off-duty” to include sleep plus personal time (hygiene, meals, etc.) and transit time to and from workplace. • - Transit time will depend on location of sleep, time of day (rush hour), etc. CURRENT DUTY TIME & REST REGULATION A maximum 12-hour work shift with at least 8 hours of rest after 12 hours of work, preceding initiation of an RLV reentry mission or during the conduct of a mission.

17. The regulation should address flight time and duty time for flightcrew and duty time for ground personnel. • Given the unknown stress of space flight, all regulations should reflect a conservative approach. • Flightcrew • - 30 hrs flight time • 60 hrs of duty • * Short-haul vs. Long-haul flights • Ground personnel • 60 hrs of duty • * Overtime issues (Air Traffic Model) CURRENT DUTY TIME & REST REGULATION A maximum of 60 hours worked in the 7 days, preceding initiation of an RLV mission.

18. Flightcrew • The nature of space flight may require 14 consecutive work days; however, consideration should be given to the type of work scheduled with more stressful tasks spaced apart. • 14 consecutive work days also assumes that flightcrew are fully adapted to space flight, circadian dysrhythmia, and a full 8 hours of sleep during circadian trough. • Groundcrew • While this area has yet to be fully reviewed, 14 consecutive days seems excessive given the lack of constraints on personnel augmentation. CURRENT DUTY TIME & REST REGULATION A maximum of 14 consecutive work days.

19. CURRENT DUTY TIME & REST REGULATION A minimum 48-hour rest period after 5 consecutive days of 12-hour shifts. • Flightcrew & Groundcrew • This seems like a reasonable recommendation since actual flight time is capped at 30 hours. • Although we are still researching this particular topic area, a 48-hour recovery should be sufficient to restore most performance deficits incurred by 5 consecutive days of 12-hour shifts.

20. RECOMMENDED DUTY TIME & REST REGULATION

21. QUESTIONS

22. Countermeasures to Fatigue and Insomnia Break glass in case of emergency