Mechanical Systems Working Group



The Mechanical Systems Working Group (MSWG) reviews the functionality, design, testing, and analyses of all safety-critical mechanical systems to ensure that they meet the following applicable requirements:

NSTS 1700.7B, Safety Policy and Requirements for payloads aboard the STS and ISS
Mechanical Systems Safety letter of interpretation MA2-00-057 (found in NSTS 18798)

The MSWG provides this technical support to:

The Payload Safety Review Panel (PSRP)
The International Space Station (ISS) Safety Review Panel (SRP)
Payload developers: civil, commercial, international

Specific MSWG tasks include:

Reviewing and approving ALL safety-critical mechanisms*
Reviewing Mechanical Systems Verification Plans (MSVP's)
Reviewing Mechanical Systems Verification Reports (MSVR's)
Interpreting and verifying compliance with Design for Minimum Risk (DFMR) requirements
Interpreting mechanisms under consideration for "simple mechanism" desigination**

* Note that the MSWG must review and approve ALL safety-critical mechanisms, not just DFMR mechanisms.

Also note that MSWG approval must be explicitly sought for the following:

A DFMR designation
A “simple mechanism” designation (don’t count on this—there are very, very few mechanisms that will be so designated. See the MSWG’s policy on the “simple mechanism.”)
The system MSVP
Any approach other than acceptance testing for torque/force margins
Any approach other than acceptance testing for holding torque/force margins
Adjustment to proto-flight qualification, acceptance, and/or design life verification test parameters to avoid excessive endurance or fatigue limit erosion


Curator: Brandan Robertson
Responsible NASA Official: Joseph L. Prather
Last Update: 10/28/2011