 +_____________________________________________________________________
 ] AUTHOR:            ]                             ] DR:              ]
 ] C. FLETCHER        ]    PASS PROGRAM NOTE        ]     41148        ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE: SEPT. 1987 ]
 ] IBM/282-7333       ]      RELEASE NOTE( )        ] REV B: 08/07/90  ]
 ]____________________]_____________________________]__________________]
 ] 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:  IPL                                             ]
 ]_____________________________________________________________________]
 ] PRINCIPAL FUNCTIONS: 4.126                                          ]
 ]_____________________________________________________________________]
 ] TITLE:                                                              ]
 ] WEIGHT INITIALIZATION REQUIRED FOR IN-FLIGHT IPL                    ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ] A. A PRO TO G2 RESULTING IN A MFB OVERLAY FROM MASS MEMORY WILL     ]
 ]    CAUSE THE VEHICLE MASS TO BE INITIALIZED INCORRECTLY OFF OF THE  ]
 ]    MASS MEMORY. THIS INCORRECT MASS (REPRESENTING ESTIMATED MASS OF ]
 ]    THE ORBITER AND ET AT LIFTOFF) WILL BE USED IN COMPUTING DRAG    ]
 ]    ACCELERATION AND VENTING ACCELERATION IN THIS CASE FOR USE BY    ]
 ]    NAVIGATION.                                                      ]
 ]                                                                     ]
 ] B. A PRO TO G3 WITH A MFB OVERLAY FROM MASS MEMORY THAT IS FOLLOWED ]
 ]    BY A PRO TO G2 PRIOR TO UPDATING VEHICLE WEIGHT WILL RESULT IN   ]
 ]    THE ESTIMATED VEHICLE MASS BEING SET TO ZERO.  IN THIS CASE      ]
 ]    INCORRECT (ZERO) DRAG OR VENTING ACCELERATIONS WILL BE COMPUTED. ]
 ]                                                                     ]
 ] IN BOTH A AND B ABOVE, IF A WEIGHT PARAMETER IS NOT INCLUDED IN     ]
 ] THE MANEUVER BURN TARGET SET, A DIVIDE BY ZERO WILL OCCUR WHEN THE  ]
 ] TARGET LOAD IS ATTEMPTED.                                           ]
 ]_____________________________________________________________________]
 ] USER RESPONSE:                                                      ]
 ] TO INSURE PROPER DRAG ACCELERATION COMPUTATIONS ON ORBIT (OPS 2)    ]
 ] FOLLOWING AN IPL FROM MASS MEMORY, AN ACCURATE ESTIMATE OF VEHICLE  ]
 ] WEIGHT SHOULD BE INCLUDED IN THE VEHICLE "PAST-DATA" RECOVERY PRO-  ]
 ] CEDURE. FOR TRUE NAV STATE UPDATING, THIS WEIGHT SHOULD BE SUPPLIED ]
 ] PRIOR TO THE NAV STATE RECOVERY.  THIS CAN BE DONE IN MM 202 VIA    ]
 ] UPLINK USING PEG 7 OR BY KEYBOARD ENTRY ON THE MNVR DISPLAY.        ]
 ] EXECUTION OF A TARGET LOAD ITEM ENTRY MUST BE PERFORMED FOLLOWING   ]
 ] THE UPDATE.                                                         ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]CONCURRENCE:                           ]APPROVAL:                    ]
 ]IBM: PATTI A. THORNTON    DATE 08/29/90]                             ]
 ]    --------------------      ---------]                             ]
 ]FDSD:    SAM ANKNEY       DATE 08/29/90]                             ]
 ]     -------------------      ---------]DARRELL E. STAMPER  09/10/90 ]
 ]PF MGR:MOISES N. MONTEZ   DATE 09/05/90]------------------- -------- ]
 ]       -----------------      ---------] CHAIRMAN, SASCB      DATE   ]
 ]_______________________________________]_____________________________]
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