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THE MSX PERFORMANCE ASSURANCE PROGRAM

The MSX Performance Assurance Program

M. Edwin Goss

T

INTRODUCTION

he structure and organization of the Performance Assurance Program developed

for the Midcourse Space Experiment (MSX) spacecraft are discussed. Included is an

overview of the engineering disciplines of the program: reliability, quality assurance,

and system safety. The performance assurance role in each of the four MSX

development phases is explained, followed by a review of MSX integration and test

history as it relates to performance assurance. A discussion of lessons learned

summarizes the results of the Performance Assurance Program.

It is generally agreed that the performance assurance

role involves two basic activities: engineering and

product assurance. Engineering functions include reli-

ability, quality assurance, and system safety. Product

assurance consists of elements needed to establish

confidence that the product is being designed and

manufactured as intended to meet the reliability goal.

In addition to these engineering and product assurance

fundamentals, the Midcourse Space Experiment

(MSX) Performance Assurance Program emphasized

design integrity by specifying conformance to the APL

Space Department’s Engineering Notebook, which in-

cludes guidelines for part usage and test, software qual-

ity assurance, and design reviews. Figure 1 presents the

organization of the MSX Performance Assurance

Program, and shows that the performance assurance

engineer reports directly to APL’s Space Department

management.

MSX PERFORMANCE ASSURANCE

PROGRAM STRUCTURE

Management

The Performance Assurance Program established for

MSX was governed by the APL Product Assurance Plan,

a detailed document tailored for MSX from a generic

master plan. Other important documents that helped

shape the MSX Performance Assurance Program in-

cluded the MSX Integrated Safety Program Plan, the MSX

Accident Risk Assessment Report, interface control draw-

ings, individual equipment specifications for subcon-

tracted hardware, and detail drawings. The MSX per-

formance assurance engineer, who is part of the APL

Space Department’s Satellite Reliability Group (SOR),

managed the program and documented its status with

monthly reports. This engineer was also responsible

for reviewing as-built documentation and other test

and inspection records to ensure conformance to the

JOHNS HOPKINS APL TECHNICAL DIGEST, VOLUME 17,NUMBER 2 (1996)

189

Space

Department

(SDO)

Chief

engineer

MSX

program

manager

Space Department

Reliability Group

MSX performance

assurance engineer

Reliability

and quality

disciplines

System

safety

Quality

assurance

Reliability

and

component

engineering

Material

control

Test and

inspection

Radiation

effects

Figure MSX Performance Assurance organization.

program. Complete hardware documentation, as well as

integration and test records such as problem/failure

reports (P/FRs), were presented to the sponsor at MSX

pre-ship and flight readiness reviews.

Reliability Engineering

The MSX spacecraft hardware was designed, fabricat-

ed, and tested to achieve a 4-year (5-year-goal), on-orbit

operational life while operating under environmental

guidelines specified for each subsystem. Reliability en-

gineers in design reviews verified proper part selection

and stress derating, using the Goddard Space Flight

Center (GSFC) Preferred Parts List as a guideline. In

addition, critical functions and single-point failures were

examined and selectively analyzed for redundancy and

cross-strapping needs.

Parts lists submitted by all APL designers and sub-

contractors were reviewed by the SOR Reliability

Engineering Section for correct grade level, nonstand-

ard part approval request (NSPAR) requirements, and

part usage concerns. Nonstandard parts required a

destructive physical analysis to be performed and were

upgrade screened (screened to standard part level re-

quirements) before use.

although critical precap (inspection of the integrated

circuit die before package lidding) and other source

inspections were performed by APL personnel. Other

quality assurance functions included verification of

equipment calibration, setup of an electrostatic dis-

charge monitoring and control system, parts and assem-

bly problem investigation, failed parts analysis, quality

and configuration

audits, and personnel training for

electrostatic discharge

and clean room certification.

Software quality assurance was performed on an

audit basis, where conformance to the Software Quality

Assurance Plan was verified by the performance assur-

ance engineer. The plan was written by the MSX soft-

ware system engineer, and covered such topics as man-

agement of the Software Quality Assurance Program,

documentation and record collection, standards and

practices, reviews and audits, configuration manage-

ment, problem reporting and corrective action, and

software testing.

Parts Test and Material Control

Electrical, electronic, or electromechanical parts

were selected, to the extent possible, from the APL

Space Department Preferred Parts List, which includes

approved parts from the GSFC Preferred Parts List and

MIL-STD-975. APL-fabricated hardware used in

construction of the MSX spacecraft required 140,000

electrical, electronic, or electromechanical parts, con-

sisting of approximately 1600 different line items. Over

4000 parts constituting 1140 line items underwent

Quality Assurance Engineering

The

SOR Quality Assurance Section inspected

both in-house hardware and subcontracted items. The

section also coordinated the use of contract inspectors,

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JOHNS HOPKINS APL TECHNICAL DIGEST, VOLUME 17,NUMBER 2 (1996)