From: NASA Exploration Systems Mission Directorate
Posted: Wednesday, December 29, 2010
The Commercial Crew Transportation System (CCTS) Certification Requirements Document is a consolidated set of technical requirements, standards, and processes built upon the National Aeronautics and Space Administration's (NASA's) vast human spaceflight knowledge and experience. The intent of this document is to define the requirements, standards, and certification package contents that will be used to certify a CCTS to carry NASA crewmembers on Low Earth Orbit (LEO) Missions.
NASA plans to purchase commercial crew space transportation services to LEO and the International Space Station (ISS) as part of NASA's exploration plans and policies. Certification of a commercial space transportation system during development/demonstration and procurement of services, rather than the space system itself, represents a significant departure from the way NASA has approached human spaceflight in the past. Agency policy does not currently mandate human rating for anything but NASA developments. However, as outlined in NASA Procedural Requirement (NPR) 8715.3C, NASA General Safety Program Requirements, paragraph 1.14, Agency policy does require NASA to analyze the risk and decide on necessary steps for safety when putting NASA personnel in harm's way using designs or operations that NASA does not control. Per this policy, NASA's approach for commercial crew transport is to base CCTS certification on NPR 8705.2, Human Rating Requirements for Space Systems. This certification will apply to NASA missions only (i.e. those carrying NASA or NASA sponsored crew members). The term 'human rating' is intentionally not used when referring to the certification of commercial systems because it implies a broader context of certification to fly any humans. NASA will not be involved in the certification of commercial systems when they are used for other purposes.
Protecting the health and safety of humans is of paramount importance for those involved in or exposed to space activities. For NASA, safety is a core value, and NASA recognizes that there can be no successful missions without first ensuring the safety of all personnel including the public, crew, passengers, and ground personnel. A crew transport capability that meets the safety requirements in this document will be approximately an order of magnitude safer than the Space Shuttle for ascent plus entry. The overall mission risk requirement will depend on the specific Design Reference Mission (DRM).
This document defines the requirements, standards and certification package contents that will be used to certify a CCTS for LEO Missions. It will be the responsibility of the NASA Program Manager and Technical Authorities to determine the applicability of individual requirements and standards based on the DRM being certified and apply the Agency risk posture (for the DRM) to arrive at the final set of requirements and standards for certification. The Program Manager will then request Certification from NASA HQ per Agency policy.
1.3 Verb Application
Statements containing "shall" are used for binding requirements that must be verified and have an accompanying method of verification; "will" is used as a statement of fact, declaration of purpose, or expected occurrence; and "should" denotes a statement of best practice.
2.0 Reference Documents
NPR 8705.2 NASA Human-Rating Requirements for Space Systems
3.1 Certification Philosophy
Certification of a spaceflight system to transport NASA or NASA sponsored personnel to/from the ISS or to other low earth orbit destinations consists of four separate functions: 1) validation of the technical and performance requirements/standards; 2) verification of compliance with those requirements/standards; 3) consideration of relevant operational experience; and 4) acceptance of residual technical risk due to hazards, waivers, non-compliances, etc. The NASA Program Manager is responsible for ensuring that the operational and design certification requirements and standards are met through the appropriate instrument (agreement milestone, statement of work, contract requirements, engineering and operations plans etc). The NASA Program Manager is also responsible for ensuring that a CCTS Certification Package (based on the Human Rating Certification Package in NPR 8705.2) is compiled. At each of the major program milestones, the Certification package contents are endorsed by the Program Manager and Technical Authorities (TAs) and the JSC Center Director (for crew risk acceptance). The Program Manager is also responsible for coordination with the Mission Directorate AAs at each milestone, in accordance with the NASA governance model. Thus, the Program Manager will be able to ensure satisfactory progress toward certification. Prior the first crewed flight for the reference mission, the Certification Package is submitted for approval to the NASA Associate Administrator as chair of the Agency PMC.
In the event that existing commercial systems (or elements of a system) are proposed for transport of NASA crewmembers, NASA will take into account the flight history along with existing design, flight data, and test results to determine compliance and/or equivalence in meeting the intent of applicable CCTS Certification Requirements. At the discretion of NASA, modifications to existing space systems may be required along with the appropriate milestone reviews. The CCTS Certification process will still be followed, but may be accelerated and milestones may be combined based on flight history and heritage.
As with earlier requirements and design reviews during the development, NASA will participate in the CCTS Flight Readiness Review for NASA missions. NASA will collectively evaluate CCTS design changes, manufacturing (or refurbishment) process changes, and testing changes to verify the mission falls within the bounds of the CCTS certification and that anomalies from previous missions have been addressed. NASA will decide, based on the flight readiness certification and residual risk posture, whether to authorize the NASA mission. During the operations/services phase, NASA will monitor the safety performance by evaluating the risk based on the significance of observed anomalies, and by updating its independent assessments of safety performance. This will ensure that safety requirements continue to be met and there is an established process for continuous improvement towards achievement of the safety goal.
3.2 Certification Applicability
Based on the mission phases, the required systems for the LEO mission are:
* Spacecraft (includes any Launch Abort or Launch Escape system)
* Launch Vehicle
* Ground Systems
* Mission Systems
Certification will apply to the integrated spacecraft, launch vehicle, ground systems, and mission systems in combinations specific to the NASA DRM.
3.3 Configuration Management
ESMD will maintain configuration management and control of the CCTS Certification Requirements for NASA LEO Missions. The NASA Program Manager for the CCTS development/services will maintain configuration management and control of their specific certification requirements documents for each DRM.
3.4 Certification Change Authority
After the NASA Associate Administrator has granted CCTS design Certification, all changes that affect the Certification will be evaluated and approved by the NASA Program Manager and cognizant TAs as part of the flight readiness review process. Any changes that affect the risk to the crew also require endorsement from the JSC Center Director. If determined that a recertification is required, the Program Manager will submit a revised certification package to the NASA Associate Administrator as Chair of the Agency PMC, per the process defined in NPR 8705.2.
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