 +_____________________________________________________________________
 ] AUTHOR:            ]                             ] DR:              ]
 ] J. MAGLEY          ]    PASS PROGRAM NOTE        ]     35151        ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE: AUG. 1987  ]
 ] ENG/282-8939       ]      RELEASE NOTE( )        ]                  ]
 ]____________________]_____________________________]__________________]
 ] OI/FLIGHT EFFECTIVITY:        ]  USER AFFECTED:                     ]
 ] REL 19 AND SUBS               ]  CREW (X)  GROUND (X)  DUMP ONLY ( )]
 ]_______________________________]_____________________________________]
 ]        MAJOR SOFTWARE AREA:       ] OPS MODES AFFECTED:             ]
 ]SSW ( )  GNC (X)  VU ( )  SM/PL ( )] G2, G3                          ]
 ]_____________________________________________________________________]
 ] SOFTWARE SUB-AREA: SPEC                                             ]
 ]_____________________________________________________________________]
 ] PRINCIPAL FUNCTIONS: 4.66                                           ]
 ]_____________________________________________________________________]
 ] TITLE:                                                              ]
 ] IMPROPER COAS OPERATION                                             ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ]                                                                     ]
 ] IMPROPER CREWMAN OPTICAL ALIGNMENT SIGHT (COAS) OPERATION MAY       ]
 ] RESULT FROM THE FOLLOWING CONDITIONS:                               ]
 ]                                                                     ]
 ] A. COAS SIGHT MODE                                                  ]
 ]                                                                     ]
 ]    ACCEPT COMMAND WITHOUT A MARK.                                   ]
 ]                                                                     ]
 ]    IN THE COAS SIGHT MODE, A MARK IS MADE PRIOR TO AN ACCEPT        ]
 ]    COMMAND FOR A STAR SIGHTING. THIS IS THE PROCEDURE NORMALLY      ]
 ]    TAKEN FOR STAR SIGHTINGS. HOWEVER, IT IS POSSIBLE TO ENTER AN    ]
 ]    ACCEPT COMMAND WITHOUT A MARK. THE FLIGHT SOFTWARE IS NOT        ]
 ]    REQUIRED TO PROTECT AGAINST SUCH AN OCCURRENCE.                  ]
 ]                                                                     ]
 ]    IF NO MARK IS MADE PRIOR TO AN ACCEPT COMMAND, THE SOFTWARE WILL ]
 ]    NEITHER INDICATE IT NOR REJECT THE ACCEPT COMMAND. HOWEVER, IT   ]
 ]    IS LIKELY TO SHOW UP AS BAD DATA ON THE DISPLAY. THIS WILL       ]
 ]    OCCUR AFTER THE ACCEPT COMMAND FOR THE SECOND STAR SIGHTING.     ]
 ]    THE SEPARATION ANGLE BETWEEN THE MEASURED LINE-OF-SIGHT VECTORS  ]
 ]    IN THE STAR SIGHTING TABLE AND THE SEPARATION ANGLE BETWEEN THE  ]
 ]    CORRESPONDING LINE-OF-SIGHT VECTORS IN THE STAR CATALOG ARE      ]
 ]    COMPUTED AND DISPLAYED. THE DIFFERENCE BETWEEN THE SEPARATION    ]
 ]    ANGLES IS ALSO COMPUTED AND DISPLAYED AS AN ANGULAR ERROR. AN    ]
 ]    ACCEPT COMMAND WITHOUT A MARK WOULD PROBABLY RESULT IN A LARGE   ]
 ]    ANGULAR ERROR WHICH INDICATES BAD STAR SIGHTINGS TO THE CREW.    ]
 ]                                                                     ]
 ] B. COAS OPERATION FROM THE AFT STATION IN OPS 3. IN OPS 3 SWITCH    ]
 ]    PROCESSING DOES NOT OCCUR FOR THE AFT STATION, SO THAT MARKS     ]
 ]    FROM THE AFT STATION ARE NOT DETECTED BY THE FLIGHT SOFTWARE.    ]
 ]    CONSEQUENTLY, COAS SIGHT MODE PROCESSING BEHAVES LIKE AN ACCEPT  ]
 ]    COMMAND WITHOUT A MARK AS DESCRIBED ABOVE IN (A); AND COAS CAL   ]
 ]    MODE IS ESSENTIALLY INACTIVE WITH NO DELTA BIAS VALUES COMPUTED. ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 @



 DR35151
 +_____________________________________________________________________
 ]                       SUPPLEMENTAL SHEET                            ]
 ]_____________________________________________________________________]
 ] AUTHOR:            ]                             ] DR:              ]
 ] J. MAGLEY          ]    PASS PROGRAM NOTE        ]     35151        ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE: AUG. 1987  ]
 ] ENG/282-8939       ]      RELEASE NOTE ( )       ]                  ]
 ]____________________]_____________________________]__________________]
 ] TITLE:                                                              ]
 ] IMPROPER COAS OPERATION                                             ]
 ]_____________________________________________________________________]
 ]USER RESPONSE:                                                       ]
 ]                                                                     ]
 ] A. FOR AN ACCEPT COMMAND WITHOUT A MARK, COMPLETE THE CURRENT       ]
 ]    SIGHT MODE PROCESSING BY ENTERING THE SECOND ACCEPT COMMAND,     ]
 ]    REINITIALIZE BY ENTERING A STAR TABLE CLEAR (ITEM 20), AND       ]
 ]    THEN PERFORM THE NORMAL SIGHT MODE PROCEDURE.                    ]
 ]                                                                     ]
 ] B. IN OPS 3, PERFORM COAS OPERATIONS FROM THE FORWARD STATION.      ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]CONCURRENCE:                           ]APPROVAL:                    ]
 ]IBM: WYATT COOPER         DATE 7/28/88 ]                             ]
 ]    --------------------      ---------]                             ]
 ]SSD: SAM ANKNEY           DATE 7/28/88 ]                             ]
 ]    --------------------      ---------] RW MOOREHEAD        7/30/88 ]
 ]PF MGR: JOE THIBODEAU     DATE 7/29/88 ]------------------- -------- ]
 ]       -----------------      ---------] CHAIRMAN, SASCB      DATE   ]
 ]_______________________________________]_____________________________]
 @



