Attachment_C_-_Human_Rating_and_Habitability_Criteria_for_FF.docx

NextSTEP-2 BAA, Appendix K: Commercial Destination Development in Low Earth Orbit (LEO) Free Flyer – Attachment C

Space Administration

Johnson Space Center Houston, Texas

Next Space Technologies for Exploration Partnerships-2 (NextSTEP-2)

Broad Agency Announcement NNH16ZCQ001K-CDFF Appendix K: Commercial Destination Development in Low Earth Orbit (LEO) Free Flyer

Attachment C Human Rating and Habitability Criteria

Human Rating and Habitability Criteria The technical checklists contained in this document encompass the applicable Human Rating criteria pertaining to a crewed space system. The Human Rating and Habitability criteria checklists prescribe that a human-rated system accommodates human needs, effectively utilizes human capabilities, controls hazards with sufficient certainty to be considered safe for human operations, and provides, to the maximum extent practical, the capability for the crew and vehicle to safely recover from hazardous situations.

Human Rating and Habitability Plan The FF Contractor will develop a Human Rating and Habitability Plan (DRD 019) that includes products listed in the tables below. The plan is not intended to duplicate or repackage existing FF contractor documentation but rather to provide a summarization of information, with pointers to applicable sections of referenced documents, links, or data sources. The plan collectively illustrates, with supporting evidence and rationale, that the system is safe to carry NASA crewmembers.

Table 1: Human Rating Criteria Checklist

Develop a plan detailing how the vehicle systems will maintain the human rating with respect to the following parameters:

Process and Standards

Designing the System

a. A list of the significant risk contributors to loss of crew

b. The appropriate hazard controls and mitigations to reduce the risk to the crew, including the level and implementation of failure tolerance to catastrophic events for the FF

c. Specific rationale for dynamic flight phases where dissimilar redundancy, backup systems, are not available to limit the likelihood of a catastrophic event

d. The effectiveness of crew survival capabilities under conditions and time constraints to be encountered during high-risk accident conditions and their impact on the risk to the crew

Verifying and Validating the System Capabilities and Performance

a. Any updates to the safety analyses based on the results of validation and verification testing,

b. Validation and verification of the design in circumstances where testing was not accomplished.

Table 2: Crew Health Maintenance Criteria Checklist

Develop a plan detailing how the vehicle systems will maintain the crew health with respect to the following parameters:

Table 3: Habitable Environment Criteria Checklist

Develop a plan detailing how the FF systems will maintain the crew environment with respect to the following parameters:

(3.3 psia) The ranges/limits provided are nominal physiological values for indefinite human exposure without measurable impairments to health or performance and is within the range that ISS operates. For reference, the nominal ppO2 pressure for the ISS is between 20.3 kPa (2.95 psi) and 23.7 kPa (3.45 psi) for a cabin pressure of 101.35 kPa (14.7 psi).

(7.75 psi/min) Repress: 800 Pa/sec (6.96 psi/min) These rates are derived from ISS cargo limits and are well within the physiological limits of the crew, however, it is expected that pressure changes will be effected more slowly than this where possible. The intent is to limit exposure of the crew and cargo to the specified rate of change in order to prevent injury to the crew's ears and lungs and to avoid damage to cargo during depressurization and re-pressurization.

(65 °F)

26.7 °C (80 °F) These temperature limits protect for human comfort (and thus performance of routine activities) without the use of thermal protective garments resulting in this narrow temperature range. Thermal comfort is affected by the work rate, clothing, and state of acclimatization.

(66% of bulk time-average velocity/ minimum velocity)

4.6 m/min (15 ft/min) [bulk]

2.1 m/min (7 ft/min) [Min]

36.6 m/min (120 ft/min) [bulk]

60.9 m/min (200 ft/min)[Max] Crew and equipment give off heat, moisture, and CO2 that will lead to parameters outside the bounds of environmental requirements if adequate ventilation is not provided. Maintaining proper ventilation within the internal atmosphere is necessary to ensure that stagnant pockets do not form, and the temperature, humidity, and atmospheric constituents are maintained within their appropriate ranges. For example, see ref: JSC 65993, Commercial Human-Systems Integration Requirements, CH6008 for rationale pertaining to values.

Note: The measurements exclude any area that is 15.2 cm (6 in) or less from the walls of the crew habitable cabin. It also excludes any area that is 7.6 cm (3 in) or less from avionics/secondary structure permanently in the crew habitable cabin.

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