Section 450.151 - Work shift and rest requirements(a)General. For any launch or reentry, an operator must document and implement rest requirements that ensure safety-critical personnel are physically and mentally capable of performing all assigned tasks.(b)Work shifts and deviation approval process. An operator's rest requirements must address the following:(1) Duration of each work shift and the process for extending this shift, including the maximum allowable length of any extension;(2) Number of consecutive work shift days allowed before rest is required;(3) Minimum rest period required- (i) Between each work shift, including the period of rest required immediately before the flight countdown work shift; and(ii) After the maximum number of work shift days allowed; and(4) Approval process for any deviation from the rest requirements.(c)Application requirement. An applicant must submit rest rules that demonstrate compliance with the requirements of this section.