 +_____________________________________________________________________
 ] AUTHOR:            ]                             ] DR:              ]
 ] J. MAGLEY          ]    PASS PROGRAM NOTE        ]     50112        ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE:  10/23/87  ]
 ] IBM/282-8939       ]      RELEASE NOTE( )        ] REV B: 06/12/91  ]
 ]____________________]_____________________________]__________________]
 ] OI/FLIGHT EFFECTIVITY:        ]  USER AFFECTED:                     ]
 ]   OI20 AND SUBS               ]  CREW (X)  GROUND ( )  DUMP ONLY ( )]
 ]_______________________________]_____________________________________]
 ]        MAJOR SOFTWARE AREA:       ] OPS MODES AFFECTED:             ]
 ]SSW ( )  GNC (X)  VU ( )  SM/PL ( )] G2, G8                          ]
 ]_____________________________________________________________________]
 ] SOFTWARE SUB-AREA: ORBIT, GUID, DAP                                 ]
 ]_____________________________________________________________________]
 ] PRINCIPAL FUNCTIONS: 4.213, 4.35                                    ]
 ]_____________________________________________________________________]
 ] TITLE: UNIVERSAL POINTING ROTATION OPTION LIMITATION                ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ] A.  IF A UNIVERSAL POINTING ROTATION OR TRACK OPTION IS INITIATED   ]
 ]     WITH THE ORBIT DAP IN ANY MANUAL MODE (INERTIAL, FREE DRIFT,    ]
 ]     OR LVLH), UNIVERSAL POINTING DOES NOT COMPUTE COMMANDED BODY    ]
 ]     ATTITUDE (Q_B_M50_CMD) AND TRACK RATE.  ONCE THE DAP IS MODED   ]
 ]     TO AUTO, THE ORBIT DAP IMMEDIATELY USES THE LAST COMPUTED       ]
 ]     QUATERNION AND TRACK RATE VALUE.  A MANEUVER IN THE WRONG       ]
 ]     DIRECTION COULD OCCUR.  UNIVERSAL POINTING WILL COMPUTE         ]
 ]     QUATERNION AND TRACK RATE WHEN IT SEES AUTO MODE ON.  CURRENT   ]
 ]     PHASING WOULD TAKE APPROXIMATELY 2 TO 3 SECONDS TO RESPOND AND  ]
 ]     MANEUVER IN THE CORRECT DIRECTION.                              ]
 ] B.  IF UNIVERSAL POINTING ROTATION OR TRACK OPTION IS INTERRUPTED   ]
 ]     BY ANY MANUAL (INERTIAL, FREE DRIFT, OR LVLH) MODE AND LATER A  ]
 ]     TRANSITION TO G2/G8 OCCURS, THEN BECAUSE OF THE PHASING         ]
 ]     SEQUENCE, ORBIT DAP USES MANUAL MODE DATA FOR APPROXIMATELY ONE ]
 ]     SECOND BEFORE UNIVERSAL POINTING SENDS ROTATION OR TRACK OPTION ]
 ]     DATA TO DAP.  THIS DELAY COULD POTENTIALLY CAUSE A SLIGHT       ]
 ]     MANEUVER PRIOR TO PICKING UP ROTATION OR TRACK OPTION DATA.     ]
 ]_____________________________________________________________________]
 ]USER RESPONSE:                                                       ]
 ] FOR CASE A ABOVE:                                                   ]
 ]                                                                     ]
 ] INITIATE ANY UNIVERSAL POINTING ROTATION OR TRACK MANEUVERS (ITEMS  ]
 ] 19 OR 20 ON THE UNIVERSAL POINT DISPLAY) ONLY IN THE AUTO DAP MODE. ]
 ] IF THE MANEUVER IS INITIATED OR INTERRUPTED BY SELECTING ANY MANUAL ]
 ] DAP MODE, EXPECT A DELAY IN THE RESUMPTION OF THE MANEUVER AFTER    ]
 ] THE AUTO MODE IS ENTERED.                                           ]
 ]                                                                     ]
 ]                 - CONTINUED ON SUPPLEMENT PAGE -                    ]
 ]_____________________________________________________________________]
 ]CONCURRENCE:                           ]APPROVAL:                    ]
 ]IBM: PATTI A. THORNTON    DATE 07/09/91]                             ]
 ]    --------------------      ---------]                             ]
 ]FDSD: W. R. PRUETT        DATE 07/09/91]                             ]
 ]     -------------------      ---------] DARRELL E. STAMPER 07/11/91 ]
 ]PF MGR:  K. L. LINDSAY    DATE 07/10/91]------------------- -------- ]
 ]         M. N. MONTEZ          07/11/91] CHAIRMAN, SASCB      DATE   ]
 ]_______________________________________]_____________________________]
 @

 +_____________________________________________________________________
 ]                                                                     ]
 ]                       SUPPLEMENTAL SHEET                            ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] AUTHOR:            ]                             ] DR:              ]
 ] J. MAGLEY          ]    PASS PROGRAM NOTE        ]     50112        ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE:  10/23/87  ]
 ] IBM/282-8939       ]      RELEASE NOTE( )        ] REV B: 06/12/91  ]
 ]____________________]_____________________________]__________________]
 ] TITLE: UNIVERSAL POINTING ROTATION OPTION LIMITATION                ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]USER RESPONSE:                                                       ]
 ]                                                                     ]
 ] FOR CASE B ABOVE:                                                   ]
 ]                                                                     ]
 ] SELECT AUTO DAP MODE (ROTATION OR TRACK OPTION WILL BE REINITIATED) ]
 ] PRIOR TO OPS TRANSITION.                                            ]
 ]                                                                     ]
 ] NOTE:  TO MINIMIZE THE MANEUVER, SELECT VERNIER JETS BEFORE MODING  ]
 ]        TO AUTO.                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 @
