 +_____________________________________________________________________
 ] AUTHOR:            ]                             ] DR:              ]
 ] CHUAN              ]    PASS PROGRAM NOTE        ]    53101         ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE: SEPT. 1987 ]
 ] VER/282-8937       ]      RELEASE NOTE( )        ]                  ]
 ]____________________]_____________________________]__________________]
 ] OI/FLIGHT EFFECTIVITY:        ]  USER AFFECTED:                     ]
 ] OI02 AND SUBS                 ]  CREW (X)  GROUND (X)  DUMP ONLY ( )]
 ]_______________________________]_____________________________________]
 ]        MAJOR SOFTWARE AREA:       ] OPS MODES AFFECTED:             ]
 ]SSW ( )  GNC (X)  VU ( )  SM/PL ( )] G2                              ]
 ]_____________________________________________________________________]
 ] SOFTWARE SUB-AREA:  TARGET, NAV                                     ]
 ]_____________________________________________________________________]
 ] PRINCIPAL FUNCTIONS: 4.213                                          ]
 ]_____________________________________________________________________]
 ] TITLE:                                                              ]
 ] TARGET TRACKING SELECTED WITHOUT RENDEZVOUS NAVIGATION              ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ]                                                                     ]
 ] EACH TIME GNC OPS 2 IS ENTERED, THE FSW VARIABLE REPRESENTING THE   ]
 ] DIFFERENCE BETWEEN THE ORBITER AND TARGET POSITIONS IS INITIALIZED  ]
 ] TO ZERO. THIS VECTOR IS UPDATED CYCLICALLY BY RENDEZVOUS NAVIGATION.]
 ] IF AN ORBITING VEHICLE TARGET TRACKING OPTION (ITEM 8 + 1 ON THE    ]
 ] UNIVERSAL POINTING DISPLAY) IS EXECUTED WITHOUT RENDEZVOUS NAVI-    ]
 ] GATION HAVING BEEN ENABLED SINCE THE LAST TIME GNC OPS 2 WAS        ]
 ] ENTERED, THE ZERO VALUE FOR THE DELTA POSITION VECTOR WILL CAUSE    ]
 ] DIVIDE BY ZERO (GROUP 3, CODE 12) GPC ERRORS.                       ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] USER RESPONSE:                                                      ]
 ]                                                                     ]
 ] NONE.                                                               ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]CONCURRENCE:                           ]APPROVAL:                    ]
 ]IBM: WYATT COOPER         DATE 07/28/88]                             ]
 ]    --------------------      ---------]                             ]
 ]SSD: SAM ANKNEY           DATE 08/02/88]                             ]
 ]    --------------------      ---------] JACK BOYKIN        08/17/88 ]
 ]PF MGR: DALLAS IVES       DATE 07/29/88]------------------- -------- ]
 ]       -----------------      ---------] CHAIRMAN, SASCB      DATE   ]
 ]_______________________________________]_____________________________]
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