FSW09 Garcia

Slide 1: 

Flight-like Flight Software Testing Methods Celina A Garcia Jet Propulsion Laboratory California Institute of Technology ©2009 California Institute of Technology. Government sponsorship acknowledged.

Introduction : 

Introduction Flight Software (FSW) testing methods used by Mars Science Laboratory (MSL) Not a new concept, many contributors What is “flight-like” testing? Same means & methods used in Mission Operations Use flight scenarios similar to those defined by Systems to test FSW Celina A Garcia, Nov 2009, Flight-like FSW Testing Methods 11/5/2009 2

Previous FSW Test Methods : 

Previous FSW Test Methods Past experience with FSW test methods FSW Developer: white box testing FSW Build & Integration: minimal gray box testing Systems Engineering: black box testing Normal S/W development, the schedule can absorb any changes due to design flaws Tight S/W schedules can’t afford to catch design flaws during Systems Eng. & ATLO (Assembly Test & Launch Ops) testing. Celina A Garcia, Nov 2009, Flight-like FSW Testing Methods 11/5/2009 3

Issue : 

Issue FSW schedule is impacted Very tight schedule Unscheduled point releases due to problems found during systems tests Causes: FSW team testing did not necessarily include sending commands and verifying telemetry Dynamic design and/or poor interpretation of requirements & functionality Celina A Garcia, Nov 2009, Flight-like FSW Testing Methods 11/5/2009 4

Solution : 

Solution Formation of MSL FSW internal test (FIT) team Objective: Use gray box testing approach to discover FSW problems before Systems Eng. testing does Employ same interfaces to S/C as Systems Eng. Use FSW knowledge to test & stress FSW in ways Systems Eng. may not FSW Event Reporting throttling Stressing uplink & downlink Results in fewer point builds & ensures a more stable FSW product Celina A Garcia, Nov 2009, Flight-like FSW Testing Methods 11/5/2009 5

FIT Approach : 

FIT Approach Gray box testing “Test as you fly and fly as you test” Mix of black & white box testing Going beyond traditional unit testing Testing against FSW requirements & functionality described in Functional Description Documents Ensure that FSW works how Systems Eng. expects it to work Make use of Ground S/W tools scripting interface 11/5/2009 6 Celina A Garcia, Nov 2009, Flight-like FSW Testing Methods

FIT Approach (cont.) : 

FIT Approach (cont.) Test using same venues as Systems Eng. Workstation Testset (WSTS) simulated avionics with closed loop simulation for Attitude Control Sys. & Entry, Descent, & Landing Testbed combination of simulated and real avionics with closed loop simulation as well 11/5/2009 7 Celina A Garcia, Nov 2009, Flight-like FSW Testing Methods

Flight-like FSW Testing Process : 

Flight-like FSW Testing Process FIT testers create functional tests by: Reviewing Functional Description Documents (FDDs) and FSW design docs Consulting FSW developer and Systems Engineer Test script design & test results are reviewed & approved Testing done using Workstation Simulation Testset and/or Testbed Celina A Garcia, Nov 2009, Flight-like FSW Testing Methods 11/5/2009 8

Initial Results : 

Initial Results In progress Short term benefits: FSW integration is an easier task near code freeze and release FSW has access to the FIT test suite FIT can act as a liaison between Systems, Ground S/W and FSW developer Provide early feedback to Ground & Simulation S/W Functional tests become means for regression testing Celina A Garcia, Nov 2009, Flight-like FSW Testing Methods 11/5/2009 9

Contact Info : 

Contact Info E-mail: Celina.A.Garcia@jpl.nasa.gov MSL FSW Build & Integration Lead & FIT team member Celina A Garcia, Nov 2009, Flight-like FSW Testing Methods 11/5/2009 10