Source Code

These source-code files are part of a reconstructed copy of Luminary 178, the final release of the Apollo 14 Lunar Module (LM) Apollo Guidance Computer (AGC) software.

The reconstruction began with source code of Zerlina 56, Luminary 210, and Luminary 131, previously transcribed from digitized copies of those programs. The code was created by combining the three, using Zerlina 56 as a base, since it was based off of Luminary 183. The differences between the three were carefully merged using the Luminary memos as a guide, with all changes made after Luminary 178 being backed out. The reconstruction was verified by matching memory-bank checksums to those listed in drawing 2021152N. Note that page numbers in the reconstructed code match those for the baseline log section mentioned in each file's changelog; the page numbers for a real Luminary 178 listing would be different.

Comments from the original source code are prefixed with a single '#' symbol, whereas comments added later are prefixed by "##" or "###". Report any errors noted by creating an issue report at the Virtual AGC project's GitHub repository.

053723,000002:                                                                                                  ## Copyright:   Public domain.
053724,000003:                                                                                                  ## Filename:    TIME_OF_FREE_FALL.agc
053725,000004:                                                                                                  ## Purpose:     A section of Luminary revision 178.
053726,000005:                                                                                                  ##              It is part of the reconstructed source code for the final
053727,000006:                                                                                                  ##              release of the flight software for the Lunar Module's
053728,000007:                                                                                                  ##              (LM) Apollo Guidance Computer (AGC) for Apollo 14. The
053729,000008:                                                                                                  ##              code has been recreated from copies of Zerlina 56, Luminary
053730,000009:                                                                                                  ##              210, and Luminary 131, as well as many Luminary memos.
053731,000010:                                                                                                  ##              It has been adapted such that the resulting bugger words
053732,000011:                                                                                                  ##              exactly match those specified for Luminary 178 in NASA
053733,000012:                                                                                                  ##              drawing 2021152N, which gives relatively high confidence
053734,000013:                                                                                                  ##              that the reconstruction is correct.
053735,000014:                                                                                                  ## Reference:   pp. 1257-1272
053736,000015:                                                                                                  ## Assembler:   yaYUL
053737,000016:                                                                                                  ## Contact:     Ron Burkey <info@sandroid.org>.
053738,000017:                                                                                                  ## Website:     www.ibiblio.org/apollo/index.html
053739,000018:                                                                                                  ## Mod history: 2019-08-14 MAS  Created from Zerlina 56.
053740,000019: 

Page 1257

053742,000021:                                                                                                  #           THE TFF SUBROUTINES MAY BE USED IN EITHER EARTH OR MOON CENTERED COORDINATES. THE TFF ROUTINES NEVER
053743,000022:                                                                                                  #  KNOW WHICH ORIGIN APPLIES. IT IS THE USER WHO KNOWS, AND WHO SUPPLIES  RONE, VONE AND 1/SQRT(MU)  AT THE
053744,000023:                                                                                                  #  APPROPRIATE SCALE LEVEL FOR THE PROPER PRIMARY BODY.
053745,000024: 
053746,000025:                                                                                                  #           EARTH ORIGIN           POSITION      -29       METERS
053747,000026:                                                                                                  #                                  VELOCITY      -7        METERS/CENTISECOND
053748,000027:                                                                                                  #                                  1/SQRT(MU)    +17       SQRT(CS SQ/METERS CUBED)
053749,000028: 
053750,000029:                                                                                                  #           MOON ORIGIN            POSITION      -27       METERS
053751,000030:                                                                                                  #                                  VELOCITY      -5        METERS/CENTISECONDS
053752,000031:                                                                                                  #                                  1/SQRT(MU)    +14       SQRT(CS SQ/METERS CUBED)
053753,000032: 
053754,000033:                                                                                                  #  ALL DATA PROVIDED TO AND RECEIVED FROM ANY TFF SUBROUTINE WILL BE AT ONE OF THE LEVELS ABOVE. IN ALL CASES,
053755,000034:                                                                                                  #  THE FREE FALL TIME IS RETURNED IN CENTISECONDS AT (-28). PROGRAM  TFF/CONIC  WILL GENERATE VONE/RTMU  AND
053756,000035:                                                                                                  #  LEAVE IT IN  VONE' AT (+10) IF EARTH ORIGIN AND (+9) IF MOON ORIGIN.
053757,000036:                                                                                                  #           THE USER MUST STORE THE STATE VECTOR IN  RONE, VONE  AND MU IN  THE FORM 1/SQRT(MU) IN  TFF/RTMU
053758,000037:                                                                                                  #  AT THE PROPER SCALE BEFORE CALLING  TFF/CONIC. SINCE  RONE, VONE  ARE IN THE EXTENDED VERB STORAGE AREA,
053759,000038:                                                                                                  #  THE USER MUST ALSO LOCK OUT THE EXTENDED VERBS, AND RELEASE THEM WHEN FINISHED.
053760,000039:                                                                                                  #           PROGRAMS     CALC/TFF  AND  CALC/TPER  ASSUME THAT THE TERMINAL RADIUS IS LESS THAN THE PRESENT
053761,000040:                                                                                                  #  RADIUS. THIS RESTRICTION CAN BE REMOVED BY A  15 W CODING CHANGE, BUT AT PRESENT IT IS NOT DEEMED NECESSARY.
053762,000041: 
053763,000042:                                                                                                  #           THE FOLLOWING ERASABLE QUANTITIES ARE USED BY THE TFF ROUTINES, AND ARE LOCATED IN THE PUSH LIST.
053764,000043: 
053765,000044:                                                                                                  #  BELOW      E:   IS USED FOR EARTH ORIGIN SCALE
053766,000045:                                                                                                  #             M:   IS USED FOR MOON  ORIGIN SCALE
053767,000046: 
053768,000047:                                                                                                  # TFFSW          =       119D       BIT1      0 = CALCTFF        1 = CALCTPER
053769,000048: 10,2213                        TFFDELQ            =        10D                                   #             Q2-Q1              E: (-16)  M: (-15)
053770,000049: 10,2213                        RMAG1              =        12D                                   #             ABVAL(RN)  M       E: (-29)  M: (-27)
053771,000050:                                                                                                  # RPER           =       14D                  PERIGEE RADIUS M   E: (-29)  M: (-27)
053772,000051: 10,2213                        TFFQ1              =        14D                                   #             R.V / SQRT(MUE)    E: (-16)  M: (-15)
053773,000052:                                                                                                  # SDELF/2                                     SIN(THETA) /2
053774,000053: 10,2213                        CDELF/2            =        14D                                   #             COS(THETA) /2
053775,000054:                                                                                                  # RAPO           =       16D                  APOGEE RADIUS  M   E: (-29)  M: (-27)
053776,000055: 10,2213                        NRTERM             =        16D                                   #             TERMINAL RADIUS M  E: (-29+NR)
053777,000056:                                                                                                  #                                M: (-27+NR)
053778,000057: 10,2213                        RTERM              =        18D                                   #             TERMINAL RADIUS M  E: (-29)  M: (-27)
053779,000058: 10,2213                        TFFVSQ             =        20D                                   #             -(V SQUARED/MU)  1/M  E: (20)  M: (18)
053780,000059: 10,2213                        TFF1/ALF           =        22D                                   #             SEMI MAJ AXIS  M  E: (-22-2 NA)
053781,000060:                                                                                                  #                               M: (-20-2 NA)
053782,000061: 10,2213                        TFFRTALF           =        24D                                   #             SQRT(ALFA)  E: (10+NA)  M: (9+NA)
053783,000062: 10,2213                        TFFALFA            =        26D                                   #             ALFA  1/M   E: (26-NR)  M: (24-NR)
053784,000063: 10,2213                        TFFNP              =        28D                                   #             SEMI LATUS RECTUM  M  E: (-38+2 NR)
053785,000064:                                                                                                  #                                   M: (-36+2 NR)
053786,000065: 10,2213                        TFF/RTMU           =        30D                                   #             1/SQRT(MU)         E: (17)   M: (14)
053787,000066: 10,2213                        NRMAG              =        32D                                   #             PRESENT RADIUS  M  E: (-29+NR)
053788,000067:                                                                                                  #                                M: (-27+NR)
053789,000068: 10,2213                        TFFX               =        34D                                   
053790,000069: 10,2213                        TFFTEM             =        36D                                   #             TEMPORARY
053791,000070: 

Page 1258

053793,000072:                                                                                                  #                                           REGISTERS S1, S2 ARE UNTOUCHED BY ANY TFF SUBROUTINE
053794,000073:                                                                                                  #                                           INDEX REGISTERS X1, X2 ARE USED BY ALL TFF SUBROUTINES. THEY ARE ESTAB-
053795,000074:                                                                                                  #                                           LISHED IN TFF/CONIC AND MUST BE PRESERVED BETWEEN CALLS TO SUBSEQUENT
053796,000075:                                                                                                  #                                           SUBROUTINES.
053797,000076:                                                                                                  #                                           -NR                             C(X1) = NORM COUNT OF RMAG
053798,000077:                                                                                                  #                                           -NA                             C(X2)= NORM COUNT OF SQRT(ABS(ALFA))
053799,000078: 

Page 1259

053801,000080: 
053802,000081: 
053803,000082:                                                                                                  #  SUBROUTINE NAME:     TFFCONIC                                           DATE:    01.29.67
053804,000083:                                                                                                  #  MOD NO:  0                                                              LOG SECTION:    TIME OF FREE FALL
053805,000084:                                                                                                  #  MOD BY:  RR BAIRNSFATHER
053806,000085:                                                                                                  #  MOD NO:  1           MOD BY:  RR BAIRNSFATHER      DATE:  11 APR 67
053807,000086:                                                                                                  #  MOD NO:  2           MOD BY:  RR BAIRNSFATHER      DATE:  21 NOV 67     ADD MOON MU.
053808,000087:                                                                                                  #  MOD NO:  3           MOD BY:  RR BAIRNSFATHER      DATE:  21 MAR 68     ACCEPT DIFFERENT EARTH/MOON SCALES
053809,000088:                                                                                                  #  FUNCTIONAL DESCRIPTION:      THIS SUBROUTINE IS CALLED TO COMPUTE THOSE CONIC PARAMETERS REQUIRED BY THE TFF
053810,000089:                                                                                                  #           SUBROUTINES AND TO ESTABLISH THEM IN THE PUSH LIST AREA. THE PARAMETERS ARE LISTED UNDER OUTPUT.
053811,000090:                                                                                                  #           THE EQUATIONS ARE
053812,000091:                                                                                                  #                  -   -  -
053813,000092:                                                                                                  #                  H = RN*VN                                               ANGULAR MOMENTUM
053814,000093:                                                                                                  #                        - -
053815,000094:                                                                                                  #                  LCP = H.H / MU                                          SEMI LATUS RECTUM
053816,000095:                                                                                                  #                                -  -
053817,000096:                                                                                                  #                  ALFA = 2/RN - VN.VN / MU                                RECIPROCAL SEMI MAJ AXIS, SIGNED
053818,000097: 
053819,000098:                                                                                                  #           AND ALFA IS POS FOR ELLIPTIC  ORBITS
053820,000099:                                                                                                  #                        0  FOR PARABOLIC ORBITS
053821,000100:                                                                                                  #                       NEG FOR HYPERBOLIC ORBITS.
053822,000101:                                                                                                  #           SUBROUTINE ALSO COMPUTES AND SAVES  RMAG.
053823,000102:                                                                                                  #  CALLING SEQUENCE:
053824,000103:                                                                                                  #           TFFCONIC  EXPECTS CALLER TO ENTER WITH CORRECT GRAVITATIONAL CONSTANT IN MPAC, IN THE FORM
053825,000104:                                                                                                  #           1/SQRT(MU). PROGRAM WILL SAVE IN  TFF/RTMU  . THE SCALE IS DETERMINED BY WHETHER EARTH OR MOON
053826,000105:                                                                                                  #           ORIGIN IS USED.  THE CALLER MUST LOCK OUT THE EXTENDED VERBS BEFORE PROVIDING STATE VECTOR IN RONE,
053827,000106:                                                                                                  #           VONE  AT PROPER SCALE. THE EXTENDED VERBS MUST BE RESTORED WHEN THE CALLER IS FINISHED USING THE
053828,000107:                                                                                                  #           TFF ROUTINES.
053829,000108:                                                                                                  #           ENTRY POINT  TFFCONMU  EXPECTS THAT  TFF/RTMU  IS ALREADY LOADED.
053830,000109:                                                                                                  #           TO SPECIFY MU:      DLOAD  CALL                IF MU ALREADY STORED:    CALL
053831,000110:                                                                                                  #                                      YOURMU       1/RTMU   E: (17)  M: (14)              TFFCONMU
053832,000111:                                                                                                  #                                      TFFCONIC
053833,000112:                                                                                                  #           PUSHLOC = PDL+0, ARBITRARY IF LEQ 18D
053834,000113: 
053835,000114:                                                                                                  #  SUBROUTINES CALLED:  NONE
053836,000115:                                                                                                  #  NORMAL EXIT MODES:   RVQ
053837,000116:                                                                                                  #  ALARMS:  NONE
053838,000117:                                                                                                  #  OUTPUT:  THE FOLLOWING ARE STORED IN THE PUSH LIST AREA.
053839,000118:                                                                                                  #           RMAG1  E:(-29) M:(-27) M  RN, PRESENT RADIUS LENGTH.
053840,000119:                                                                                                  #           NRMAG  E: (-29+NR)     M  RMAG, NORMALIZED
053841,000120:                                                                                                  #                  M: (-27+NR)
053842,000121:                                                                                                  #           X1                     -NR, NORM COUNT
053843,000122:                                                                                                  #           TFFNP  E: (-38+2NR)    M  LCP, SEMI LATUS RECTUM, WEIGHTED BY NR.       FOR VGAMCALC
053844,000123:                                                                                                  #                  M: (-36+2NR)
053845,000124:                                                                                                  #           TFF/RTMU  E:(17)  M:(14)       1/SQRT(MU)
053846,000125:                                                                                                  #           TFFVSQ E:(20)  M:(18)  1/M   -(V SQ/MU): PRESENT VELOCITY,NORMLIZED.    FOR VGAMCALC
053847,000126:                                                                                                  #           TFFALFA  E: (26-NR)    1/M   ALFA, WEIGHTED BY NR
053848,000127:                                                                                                  #                    M: (24-NR)
053849,000128:                                                                                                  #           TFFRTALF  E: (10+NA)   SQRT(ALFA), NORMALIZED
053850,000129:                                                                                                  #                     M: (9+NA)

Page 1260

053852,000131:                                                                                                  #           X2                     -NA, NORM COUNT
053853,000132:                                                                                                  #           TFF1/ALF  E: (-22-2NA) SIGNED SEMI MAJ AXIS, WEIGHTED BY NA
053854,000133:                                                                                                  #                     M: (-20-2NA)
053855,000134:                                                                                                  #           PUSHLOC AT PDL+0
053856,000135:                                                                                                  #           THE FOLLOWING  IS STORED IN GENERAL ERASABLE
053857,000136:                                                                                                  #           VONE'  E:(10)  M:(9)   V/RT(MU), NORMALIZED VELOCITY
053858,000137:                                                                                                  #  ERASABLE INITIALIZATION REQUIRED:
053859,000138:                                                                                                  #           RONE   E:(-29)  M:(-27)  M      STATE VECTOR                   LEFT BY CALLER
053860,000139:                                                                                                  #           VONE   E:(-7)   M:(-5)   M/CS   STATE VECTOR                   LEFT BY CALLER
053861,000140:                                                                                                  #           TFF/RTMU  E:(17)  M:(14)      1/RT(CS SQ/M CUBE)               IF ENTER VIA  TFFCONMU.
053862,000141:                                                                                                  #  DEBRIS:  QPRET,    PDL+0 ... PDL+3
053863,000142: 
053864,000143: 
053865,000144: 33,3560                                           BANK     33                                    
053866,000145: 27,2000                                           SETLOC   TOF-FF                                
053867,000146: 27,2000                                           BANK                                           
053868,000147: 
053869,000148: 27,3361                                           COUNT*   $$/TFF                                
053870,000149: 
053871,000150: 27,3361           00037        TFFCONIC           STORE    TFF/RTMU                              #  1/SQRT(MU)       E: (17)   M: (14)
053872,000151: 
053873,000152: 27,3362           53575        TFFCONMU           VLOAD    UNIT                                  #  COME HERE WITH TFFRTMU LOADED.
053874,000153: 27,3363           02207                                    RONE                                  #  SAVED RN.  M     E: (-29)  M: (-27)
053875,000154: 27,3364           77725                           PDDL                                           #  UR/2 TO PDL+0, +5
053876,000155: 27,3365           00045                                    36D                                   #  MAGNITUDE
053877,000156: 27,3366           00015                           STORE    RMAG1                                 #  M    E: (-29)   M: (-27)
053878,000157: 
053879,000158: 27,3367           77701                           NORM                                           
053880,000159: 27,3370           00047                                    X1                                    #  -NR
053881,000160: 27,3371           24041                           STOVL    NRMAG                                 #  RMAG  M   E: (-29+NR)  M: (-27+NR)
053882,000161: 27,3372           02215                                    VONE                                  #  SAVED VN.  M/CS   E: (-7)   M: (-5)
053883,000162: 27,3373           77761                           VXSC                                           
053884,000163: 27,3374           00037                                    TFF/RTMU                              #  E: (17)   M: (14)
053885,000164: 27,3375           02170                           STORE    VONE'                                 #  VN/SQRT(MU)   E: (10)   M: (9)
053886,000165: 
053887,000166: 27,3376           47361                           VXSC     VXV                                   
053888,000167: 27,3377           00041                                    NRMAG                                 #  E: (-29+NR)  M: (-27+NR)
053889,000168:                                                                                                  #  UR/2 FROM PDL
053890,000169: 27,3400           47572                           VSL1     VSQ                                   #  BEFORE:  E:(-19+NR)  M:(-18+NR)
053891,000170: 27,3401           14035                           STODL    TFFNP                                 #  LC P  M   E:(-38+2NR)  M:(-36+2NR)
053892,000171:                                                                                                  #  SAVE ALSO FOR VGAMCALC
053893,000172: 27,3402           06460                                    TFF1/4                                
053894,000173: 27,3403           63271                           DDV      PDVL                                  #  (2/RMAG)  1/M   E:(26-NR)   M:(24-NR)
053895,000174: 27,3404           00041                                    NRMAG                                 #  RMAG  M   E:(-29+NR)  M:(-27+NR)
053896,000175: 27,3405           02170                                    VONE'                                 #  SAVED VN.   E: (10)   M: (9)
053897,000176: 27,3406           57436                           VSQ      DCOMP                                 #  KEEP MPAC+2 HONEST FOR SQRT.
053898,000177: 27,3407           00025                           STORE    TFFVSQ                                #  -(V SQ/MU)   E:(20)   M:(18)
053899,000178:                                                                                                  #  SAVE FOR VGAMCALC
053900,000179: 27,3410           43257                           SR*      DAD                                   

Page 1261

053902,000181: 27,3411           20573                                    0          -6,1                       #  GET -VSQ/MU   E:(26-NR)   M:(24-NR)
053903,000182: 27,3412           77626                           STADR                                          
053904,000183:                                                                                                  #  2/RMAG   FROM PDL+2
053905,000184: 27,3413           77744                           STORE    TFFALFA                               #  ALFA  1/M   E:(26-NR)   M:(24-NR)
053906,000185: 27,3414           41457                           SL*      PUSH                                  #  TEMP SAVE ALFA    E:(20)   M:(18)
053907,000186: 27,3415           20173                                    0          -6,1                       
053908,000187: 27,3416           75446                           ABS      SQRT                                  #  E:(10)   M:(9)
053909,000188: 27,3417           77701                           NORM                                           
053910,000189: 27,3420           00050                                    X2                                    #  X2 = -NA
053911,000190: 27,3421           00031                           STORE    TFFRTALF                              #  SQRT( ABS(ALFA) )  E:(10+NA)   M:(9+NA)
053912,000191: 27,3422           75316                           DSQ      SIGN                                  #  NOT SO ACCURATE, BUT OK
053913,000192:                                                                                                  #  ALFA FROM PDL+2   E:(20)   M:(18)
053914,000193: 27,3423           55254                           BZE      BDDV                                  #  SET 1/ALFA =0, TO SHOW SMALL ALFA
053915,000194: 27,3424           57426                                    +2                                    
053916,000195: 27,3425           06460                                    TFF1/4                                
053917,000196: 27,3426           00027                 +2        STORE    TFF1/ALF                              #  1/ALFA   E:(-22-2 NA)   M:(-20-2 NA)
053918,000197: 27,3427           77616        DUMPCNIC           RVQ                                            
053919,000198: 
053920,000199:                                                                                                  #                          39 W
053921,000200: 

Page 1262

053923,000202:                                                                                                  #  SUBROUTINE NAME:     TFFRP/RA                                           DATE:  01.17.67
053924,000203:                                                                                                  #  MOD NO:  0                                                              LOG SECTION:    TIME OF FREE FALL
053925,000204:                                                                                                  #  MOD BY:  RR BAIRNSFATHER
053926,000205:                                                                                                  #  MOD NO:  1           MOD BY:  RR BAIRNSFATHER      DATE:  11 APR 67
053927,000206:                                                                                                  #  MOD NO:  2           MOD BY:  RR BAIRNSFATHER      DATE:  21 MAR 68     ACCEPT DIFFERENT EARTH/MOON SCALES
053928,000207:                                                                                                  #                                                                          ALSO IMPROVE ACCURACY OF RAPO.
053929,000208:                                                                                                  #  FUNCTIONAL DESCRIPTION:         USED BY CALCTPER AND TFF DISPLAYS TO CALCULATE PERIGEE RADIUS AND ALSO
053930,000209:                                                                                                  #           APOGEE RADIUS FOR A GENERAL CONIC.
053931,000210:                                                                                                  #           PROGRAM GIVES PERIGEE RADIUS AS               APOGEE RADIUS IS GIVEN BY
053932,000211:                                                                                                  #                  RP = P /(1+E)                                 RA = (1+E) / ALFA
053933,000212:                                                                                                  #           WHERE   2
053934,000213:                                                                                                  #                  E  = 1 - P ALFA
053935,000214:                                                                                                  #           IF RA IS NEGATIVE OR SHOWS DIVIDE OVERFLOW, THEN RA = POSMAX BECAUSE
053936,000215:                                                                                                  #                  1. APOGEE RADIUS IS NOT MEANINGFUL FOR HYPERBOLA
053937,000216:                                                                                                  #                  2. APOGEE RADIUS IS NOT DEFINED FOR PARABOLA
053938,000217:                                                                                                  #                  3. APOGEE RADIUS EXCEEDS THE SCALING FOR ELLIPSE.
053939,000218:                                                                                                  #           THIS SUBROUTINE REQUIRES THE SIGNED  RECIPROCAL SEMI MAJ AXIS,  ALFA,  AND SEMI LATUS RECTUM AS DATA.
053940,000219:                                                                                                  #  CALLING SEQUENCE:  CALL
053941,000220:                                                                                                  #                            TFFRP/RA
053942,000221:                                                                                                  #           PUSHLOC = PDL+0, ARBITRARY IF LEQ 10D
053943,000222:                                                                                                  #           C(MPAC) UNSPECIFIED
053944,000223: 
053945,000224:                                                                                                  #  SUBROUTINES CALLED:  NONE
053946,000225:                                                                                                  #  NORMAL EXIT MODE:    RVQ
053947,000226:                                                                                                  #           IF ELLIPSE, WITHIN NORMAL SCALING, RAPO IS CORRECT.
053948,000227:                                                                                                  #           OTHERWISE, RAPO = POSMAX.
053949,000228:                                                                                                  #  ALARMS:  NONE
053950,000229:                                                                                                  #  OUTPUT:  STORED IN PUSH LIST AREA. SCALE OF OUTPUT AGREES WITH DATA SUPPLIED TO  TFF/CONIC.
053951,000230:                                                                                                  #           RPER   E:(-29)  M:(-27)  M     PERIGEE RADIUS                  DESTROYED BY CALCTFF/CALCTPER, TFFTRIG.
053952,000231:                                                                                                  #           RAPO   E:(-29)  M:(-27)  M     APOGEE  RADIUS                  WILL BE DESTROYED BY CALCTFF/CALCTPER
053953,000232:                                                                                                  #           PUSHLOC AT PDL+0
053954,000233:                                                                                                  #  ERASABLE INITIALIZATION REQUIRED:
053955,000234:                                                                                                  #           TFFALFA E:(26-NR)      M   1/SEMI MAJ AXIS                     LEFT BY TFFCONIC
053956,000235:                                                                                                  #                   M:(24-NR)
053957,000236:                                                                                                  #           TFFNP  E: (-38+2NR)    M  LC P, SEMI LATUS RECTUM              LEFT BY TFFCONIC
053958,000237:                                                                                                  #                  M: (-36+2NR)
053959,000238:                                                                                                  #           X1                     -NR, NORM COUNT OF RMAG                 LEFT BY TFFCONIC
053960,000239:                                                                                                  #           X2                     -NA, NORM COUNT OF ALFA                 LEFT BY TFFCONIC
053961,000240:                                                                                                  #  DEBRIS:  QPRET,    PDL+0 ... PDL+1
053962,000241: 

Page 1263

053964,000243: 27,3430                        RAPO               =        16D                                   #  APOGEE RADIUS  M  E:(-29)  M:(-27)
053965,000244: 27,3430                        RPER               =        14D                                   #  PERIGEE RADIUS  M  E:(-29)  M:(-27)
053966,000245: 
053967,000246: 27,3430           41345        TFFRP/RA           DLOAD    DMP                                   
053968,000247: 27,3431           00033                                    TFFALFA                               #  ALFA  1/M  E:(26-NR)   M:(24-NR)
053969,000248: 27,3432           00035                                    TFFNP                                 #  LC P  M   E:(-38+2NR)   M:(-36+2NR)
053970,000249: 27,3433           57457                           SR*      DCOMP                                 #  ALFA P (-12+NR)
053971,000250: 27,3434           20571                                    0          -8D,1                      #  ALFA P  (-4)
053972,000251: 27,3435           51415                           DAD      ABS                                   #  (DCOMP GIVES VALID TP RESULT FOR SQRT)
053973,000252:                                                                                                  #  (ABS PROTECTS SQRT IF E IS VERY NEAR 0)
053974,000253: 27,3436           17766                                    DP2(-4)                               
053975,000254: 27,3437           43366                           SQRT     DAD                                   #  E SQ = (1- P ALFA)   (-4)
053976,000255: 27,3440           06460                                    TFF1/4                                
053977,000256: 27,3441           55206                           PUSH     BDDV                                  #  (1+E)  (-2)  TO PDL+0
053978,000257: 27,3442           00035                                    TFFNP                                 #  LCP  M E:(-38+2NR)   M:(-36+2NR)
053979,000258: 27,3443           53657                           SR*      SR*                                   #  (DOES SR THEN SL TO AVOID OVFL)
053980,000259: 27,3444           20601                                    0,1                                   #  X1=-NR
053981,000260: 27,3445           20572                                    0          -7,1                       #  (EFFECTIVE SL)
053982,000261: 27,3446           14017                           STODL    RPER                                  #  PERIGEE RADIUS  M   E:(-29)   M:(-27)
053983,000262:                                                                                                  #  (1+E)  (-2)   FROM PDL+0
053984,000263: 27,3447           41005                           DMP      BOVB                                  
053985,000264: 27,3450           00027                                    TFF1/ALF                              #  E:(-22-2NA)  M:(-20-2NA)
053986,000265: 27,3451           57754                                    TCDANZIG                              #  CLEAR OVFIND, IF ON.
053987,000266: 27,3452           53654                           BZE      SL*                                   
053988,000267: 27,3453           57462                                    MAXRA                                 #  SET POSMAX, IF ALFA=0
053989,000268: 27,3454           57603                                    0          -5,2                       #  -5+NA
053990,000269: 27,3455           40057                           SL*      BOV                                   
053991,000270: 27,3456           57576                                    0,2                                   
053992,000271: 27,3457           57462                                    MAXRA                                 #  SET POSMAX IF OVFL.
053993,000272: 27,3460           77644                           BPL                                            #  CONTINUE WITH VALID RAPO.
053994,000273: 27,3461           57464                                    +3                                    
053995,000274: 27,3462           77745        MAXRA              DLOAD                                          #  RAPO CALC IS NOT VALID. SET RAPO =
053996,000275: 27,3463           17772                                    NEARONE                               #  POSMAX AS A TAG.
053997,000276: 27,3464           00021                 +3        STORE    RAPO                                  #  APOGEE RADIUS  M   E:(-29)   M:(-27)
053998,000277: 27,3465           77616        DUMPRPRA           RVQ                                            
053999,000278: 
054000,000279:                                                                                                  #                          30 W
054001,000280: 

Page 1264

054003,000282:                                                                                                  #  SUBROUTINE NAME:     CALCTPER  /  CALCTFF                               DATE:    01.29.67
054004,000283:                                                                                                  #  MOD NO:  0                                                              LOG SECTION:    TIME OF FREE FALL
054005,000284:                                                                                                  #  MOD BY:  RR BAIRNSFATHER
054006,000285:                                                                                                  #  MOD NO:  1           MOD BY:  RR BAIRNSFATHER      DATE:  21 MAR 67
054007,000286:                                                                                                  #  MOD NO:  2           MOD BY:  RR BAIRNSFATHER      DATE:  14 APR 67
054008,000287:                                                                                                  #  MOD NO:  3           MOD BY:  RR BAIRNSFATHER      DATE:  8JUL 67       NEAR EARTH MUE AND NEG TFF (GONEPAST)
054009,000288:                                                                                                  #  MOD NO:  4           MOD BY:  RR BAIRNSFATHER      DATE:  21 NOV 67     ADD VARIABLE MU.
054010,000289:                                                                                                  #  MOD NO:  5           MOD BY:  RR BAIRNSFATHER      DATE:  21 MAR 68     ACCEPT DIFFERENT EARTH/MOON SCALES
054011,000290:                                                                                                  #  FUNCTIONAL DESCRIPTION:      PROGRAM CALCULATES THE FREE-FALL TIME OF FLIGHT FROM PRESENT POSITION  RN  AND
054012,000291:                                                                                                  #           VELOCITY  VN  TO A RADIUS LENGTH SPECIFIED BY  RTERM  , SUPPLIED BY THE USER. THE POSITION VECTOR
054013,000292:                                                                                                  #           RN  MAY BE ON EITHER SIDE OF THE CONIC, BUT  RTERM  IS CONSIDERED ON THE INBOUND SIDE.
054014,000293:                                                                                                  #           THE EQUATIONS ARE
054015,000294: 
054016,000295:                                                                                                  #                  Q2 = -SQRT(RTERM (2-RTERM ALFA) - LCP)    (INBOUND SIDE))        LEQ +- LCE/SQRT(ALFA)
054017,000296:                                                                                                  #                       -  -
054018,000297:                                                                                                  #                  Q1 = RN.VN / SQRT(MU)                                            LEQ +- LCE/SQRT(ALFA)
054019,000298: 
054020,000299:                                                                                                  #                  Z = NUM / DEN                                                    LEQ +- 1/SQRT(ALFA)
054021,000300: 
054022,000301:                                                                                                  #           WHERE, IF INBOUND
054023,000302:                                                                                                  #                  NUM = RTERM - RN                                                 LEQ +- 2 LCE/ALFA
054024,000303:                                                                                                  #                  DEN = Q2+Q1                                                      LEQ +- 2 LCE/SQRT(ALFA)
054025,000304: 
054026,000305:                                                                                                  #           AND, IF OUTBOUND
054027,000306:                                                                                                  #                  NUM = Q2-Q1                                                      LEQ +- 2 LCE/SQRT(ALFA)
054028,000307:                                                                                                  #                  DEN = 2 - ALFA (RTERM + RN) .                                    LEQ +- 2 LCE
054029,000308: 
054030,000309:                                                                                                  #           IF     ALFA ZZ  <  1.0               (FOR ALL CONICS EXCEPT ELLIPSES HAVING ABS(DEL ECC ANOM) G 90 DEG)
054031,000310: 
054032,000311:                                                                                                  #           THEN   X = ALFA Z Z
054033,000312:                                                                                                  #           AND    TFF = (RTERM +RN -2 ZZ T(X) ) Z/SQRT(MU)
054034,000313: 
054035,000314:                                                                                                  #                  EXCEPT IF ALFA PNZ, AND IF TFF NEG,
054036,000315:                                                                                                  #                  THEN   TFF = 2 PI /(ALFA SQRT(ALFA)) + TFF
054037,000316: 
054038,000317:                                                                                                  #           OR IF  ALFA ZZ  GEQ  1.0             (FOR ELLIPSES HAVING ABS(DEL ECC ANOM) GEQ 90 DEG)
054039,000318: 
054040,000319:                                                                                                  #           THEN   X = 1/ALFA Z Z
054041,000320:                                                                                                  #           AND    TFF = (PI/SQRT(ALFA) -Q2 +Q1 +2(X T(X) -1) /ALFA Z) /ALFA SQRT(MU)
054042,000321: 
054043,000322:                                                                                                  #           WHERE  T(X) IS A POLYNOMIAL APPROXIMATION TO THE SERIES
054044,000323:                                                                                                  #                             2     3                        2
054045,000324:                                                                                                  #                  1/3 -X/5 +X /7 -X /9 ...                (X   <  1.0)
054046,000325: 
054047,000326:                                                                                                  #  CALLING SEQUENCE:  TIME TO RTERM                           TIME TO PERIGEE
054048,000327:                                                                                                  #                     CALL                                    CALL
054049,000328:                                                                                                  #                            CALCTFF                                 CALCTPER
054050,000329:                                                                                                  #                     C(MPAC) = TERMNL RAD  M                 C(MPAC) = PERIGEE RAD  M
054051,000330:                                                                                                  #           FOR EITHER,   E: (-29)    M: (-27)
054052,000331:                                                                                                  #           FOR EITHER, PUSHLOC = PDL+0, ARBITRARY IF LEQ 8D.
054053,000332: 

Page 1265

054055,000334:                                                                                                  #  SUBROUTINES CALLED:  T(X),  VIA RTB
054056,000335:                                                                                                  #  NORMAL EXIT MODE:  RVQ
054057,000336:                                                                                                  #           HOWEVER, PROGRAM EXITS WITH ONE OF THE FOLLOWING VALUES FOR TFF (-28) CS  IN MPAC. USER MUST STORE.
054058,000337:                                                                                                  #                  A.  TFF= FLIGHT TIME. NORMAL CASE FOR POSITIVE FLIGHT TIME LESS THAN ONE ORBITAL PERIOD.
054059,000338:                                                                                                  #                  B.  (THIS OPTION IS NO LONGER USED.)
054060,000339:                                                                                                  #                  C.  TFF = POSMAX.  THIS INDICATES THAT THE CONIC FROM THE PRESENT POSITION WILL NOT RETURN TO
054061,000340:                                                                                                  #                      THE SPECIFIED ALTITUDE.  ALSO INDICATES OUTBOUND PARABOLA OR HYPERBOLA.
054062,000341:                                                                                                  #  OUTPUT:  C(MPAC)  (-28)  CS     TIME OF FLIGHT, OR TIME TO PERIGEE
054063,000342:                                                                                                  #           TFFX    (0)            X,                                      LEFT FOR ENTRY DISPLAY TFF ROUTINES
054064,000343:                                                                                                  #           NRTERM  E: (-29+NR)    M  RTERM, WEIGHTED BY NR                LEFT FOR ENTRY DISPLAY TFF ROUTINES
054065,000344:                                                                                                  #                   M: (-27+NR)
054066,000345:                                                                                                  #           TFFTEM  E: (-59+2NR)   LCP Z Z SGN(SDELF)                      LEFT FOR ENTRY DISPLAY TFF ROUTINES
054067,000346:                                                                                                  #                   M: (-55+2NR)   LCP /ALFA SGN(SDELF)                    LEFT FOR ENTRY DISPLAY TFF ROUTINES
054068,000347:                                                                                                  #           NOTE:  TFFTEM = PDL 36D AND WILL BE DESTROYED BY .:UNIT:.
054069,000348:                                                                                                  #           RMAG1  E:(-29)  M:(-27)  PDL 12 NOT TOUCHED.
054070,000349:                                                                                                  #           TFFQ1  E:(-16)  M:(-15)  PDL 14D
054071,000350:                                                                                                  #           TFFDELQ E:(-16) M:(-15)  PDL 10D
054072,000351:                                                                                                  #           PUSHLOC AT PDL+0
054073,000352:                                                                                                  #  ERASABLE INITIALIZATION REQUIRED:
054074,000353:                                                                                                  #           RONE   E:(-29)  M:(-27)  M   STATE VECTOR                      LEFT BY USER
054075,000354:                                                                                                  #           VONE'  E:(+10)  M:(+9)   VN/SQRT(MU)                           LEFT BY TFF/CONIC
054076,000355:                                                                                                  #           RMAG1  E:(-29)  M:(-27)  PRESENT RADIUS,  M                    LEFT BY TFFCONIC
054077,000356:                                                                                                  #           C(MPAC)E:(-29)  M:(-27)  RTERM, TERMINAL RADIUS LENGTH, M      LEFT BY USER
054078,000357: 
054079,000358:                                                                                                  #           THE FOLLOWING ARE STORED IN THE PUSH LIST AREA.
054080,000359:                                                                                                  #           TFF/RTMU  E:(17)  M:(14)  1/SQRT(MU)                           LEFT BY TFFCONIC.
054081,000360:                                                                                                  #           NRMAG  E: (-29+NR)  M  RMAG, NORMALIZED                        LEFT BY TFFCONIC
054082,000361:                                                                                                  #                  M: (-27+NR)
054083,000362:                                                                                                  #           X1                     -NR, NORM COUNT                         LEFT BY TFFCONIC
054084,000363:                                                                                                  #           TFFNP  E: (-38+2NR)  M   LCP, SEMI LATUS RECTUM, WEIGHT  NR    LEFT BY TFFCONIC
054085,000364:                                                                                                  #                  M: (-36+2NR)
054086,000365:                                                                                                  #           TFFALFA  E: (26-NR)    1/M  ALFA, WEIGHT  NR                   LEFT BY TFFCONIC
054087,000366:                                                                                                  #                    M: (24-NR)
054088,000367:                                                                                                  #           TFFRTALF  E:(10+NA)    SQRT(ALFA), NORMALIZED                  LEFT BY TFFCONIC
054089,000368:                                                                                                  #                     M:(9+NA)
054090,000369:                                                                                                  #           X2                     -NA, NORM COUNT                         LEFT BY TFFCONIC
054091,000370:                                                                                                  #           TFF1/ALF  E: (-22-2NA)  SIGNED SEMIMAJ AXIS, WEIGHTED BY NA    LEFT BY TFFCONIC
054092,000371:                                                                                                  #                     M: (-20-2NA)
054093,000372:                                                                                                  #  DEBRIS:  QPRET,   PDL+0 ... PDL+3
054094,000373:                                                                                                  #           RTERM  E:(-29)  M:(-27)  RTERM, TERMINAL RADIUS LENGTH
054095,000374:                                                                                                  #           RAPO   E:(-29)  M:(-27)  PDL 16D  (=NRTERM)
054096,000375:                                                                                                  #           RPER   E:(-29)  M:(-27)  PDL 14D   (=TFFQ1)
054097,000376: 

Page 1266

054099,000378: 27,3466           77614        CALCTPER           SETGO                                          #  ENTER WITH RPER  IN MPAC
054100,000379: 27,3467           03436                                    TFFSW                                 
054101,000380: 27,3470           57473                                    +3                                    
054102,000381: 27,3471           77614        CALCTFF            CLEAR                                          #  ENTER WITH RTERM IN MPAC
054103,000382: 27,3472           03676                                    TFFSW                                 
054104,000383: 27,3473           00023                 +3        STORE    RTERM                                 #  E: (-29)  M: (-27)
054105,000384: 27,3474           77657                           SL*                                            
054106,000385: 27,3475           20201                                    0,1                                   #  X1=-NR
054107,000386: 27,3476           00021                           STORE    NRTERM                                #  RTERM  E: (-29+NR)  M: (-27+NR)
054108,000387: 27,3477           44205                           DMP      BDSU                                  
054109,000388: 27,3500           00033                                    TFFALFA                               #  ALFA  E: (26-NR)  M: (24-NR)
054110,000389: 27,3501           06460                                    TFF1/4                                
054111,000390: 27,3502           41206                           PUSH     DMP                                   #  (2-ALFA RTERM)  (-3)  TO PDL+0
054112,000391: 27,3503           00021                                    NRTERM                                #  E: (-29+NR)  M: (-27+NR)
054113,000392: 27,3504           53725                           PDDL     SR*                                   #  RTERM(2-ALFA RTERM) TO PDL+2
054114,000393:                                                                                                  #  E: (-32+NR)   M: (-30+NR)
054115,000394: 27,3505           00035                                    TFFNP                                 #  LC P  E:(-38+2NR)  M:(-36+2NR)
054116,000395: 27,3506           20573                                    0          -6,1                       #  X1 = -NR
054117,000396: 27,3507           43276                           DCOMP    DAD                                   #  DUE TO SHIFTS, KEEP PRECISION FOR SQRT
054118,000397:                                                                                                  #  RTERM(2-ALFA RTERM) FROM PDL+2
054119,000398:                                                                                                  #  E: (-32+NR)  M: (-30+NR)
054120,000399: 27,3510           77657                           SR*                                            #  LEAVE  E: (-32)  M: (-30)
054121,000400: 27,3511           20601                                    0,1                                   #  X1 = -NR
054122,000401: 27,3512           71214                           BOFF     DLOAD                                 #  CHECK TFF / TPER SWITCH
054123,000402: 27,3513           03756                                    TFFSW                                 
054124,000403: 27,3514           57516                                    +2                                    #  IF TFF, CONTINUE
054125,000404: 27,3515           06470                                    TFFZEROS                              #  IF TPER, SET Q2 = 0
054126,000405: 27,3516           75440                 +2        BMN      SQRT                                  #  E: (-16)  M: (-15)
054127,000406: 
054128,000407: 27,3517           57651                                    MAXTFF1                               #  NO FREE FALL CONIC TO RTERM FROM HERE
054129,000408:                                                                                                  #  RESET PDL, SET TFF=POSMAX, AND EXIT.
054130,000409: 
054131,000410: 27,3520           41076                           DCOMP    BOVB                                  #  RT IS ON INBOUND SIDE.  ASSURE OVFIND=0
054132,000411: 27,3521           57754                                    TCDANZIG                              #  ANY PORT IN A STORM.
054133,000412: 27,3522           24045                           STOVL    TFFTEM                                #  Q2   E: (-16)  M: (-15)
054134,000413: 27,3523           02170                                    VONE'                                 #  VN/SQRT(MU) E: (10)  M: (9)
054135,000414: 27,3524           52441                           DOT      SL3                                   
054136,000415: 27,3525           02207                                    RONE                                  #  SAVED RN.  E: (-29)  M: (-27)
054137,000416: 27,3526           00017                           STORE    TFFQ1                                 #  Q1, SAVE FOR GONEPAST TEST.
054138,000417:                                                                                                  #  E: (-16)  M: (-15)
054139,000418: 27,3527           44240                           BMN      BDSU                                  
054140,000419: 27,3530           57551                                    INBOUND                               #  USE ALTERNATE Z
054141,000420: 27,3531           00045                                    TFFTEM                                #  Q2  E: (-16)  M: (-15)
054142,000421: 
054143,000422:                                                                                                  #                                          OUTBOUND Z CALC CONTINUES HERE
054144,000423: 
054145,000424: 27,3532           14043                           STODL    TFFX                                  #  NUM=Q2-Q1  E: (-16)  M: (-15)
054146,000425: 27,3533           00033                                    TFFALFA                               #  ALFA  E: (26-NR)  M: (24-NR)
054147,000426: 27,3534           44205                           DMP      BDSU                                  

Page 1267

054149,000428: 27,3535           00041                                    NRMAG                                 #  RMAG  E: (-29+NR)  M: (-27+NR)
054150,000429:                                                                                                  #  (2-RTERM ALFA)  (-3) FROM PDL+0
054151,000430: 27,3536           51406        SAVEDEN            PUSH     ABS                                   #  DEN TO PDL+0  E: (-3) OR (-16)
054152,000431:                                                                                                  #                M: (-3) OR (-15)
054153,000432: 27,3537           40015                           DAD      BOV                                   #  INDETERMINANCY TEST
054154,000433: 27,3540           17760                                    LIM(-22)                              #  =1.0-B(-22)
054155,000434: 27,3541           57562                                    TFFXTEST                              #  GO IF DEN >/= B(-22)
054156,000435: 27,3542           65345                           DLOAD    PDDL                                  #  SET DEN=0  OTHERWISE
054157,000436: 27,3543           06470                                    TFFZEROS                              
054158,000437:                                                                                                  #  XCH ZERO WITH PDL+0
054159,000438: 27,3544           57545                           DLOAD    DCOMP                                 
054160,000439: 27,3545           00033                                    TFFALFA                               #  ALFA  E: (26-NR)  M: (24-NR)
054161,000440: 27,3546           71240                           BMN      DLOAD                                 #  FOR TPER: Z INDET AT DELE/2=0 AND 90.
054162,000441: 27,3547           57656                                    TFFEL1                                #  ASSUME 90, AND LEAVE 0 IN PDL: 1/Z=D/N
054163,000442: 
054164,000443:                                                                                                  #  Z INDET. AT PERIGEE FOR PARAB OR HYPERB.
054165,000444: 27,3550           77616        DUMPTFF1           RVQ                                            #  RETURN  TFF =0
054166,000445: 
054167,000446:                                                                                                  #                                          INBOUND Z CALC CONTINUES HERE
054168,000447: 27,3551           77745        INBOUND            DLOAD                                          #  RESET PDL+0
054169,000448: 27,3552           45345                           DLOAD    DSU                                   #  ALTERNATE Z CALC
054170,000449: 27,3553           00023                                    RTERM                                 #  E: (-29)  M: (-27)
054171,000450: 27,3554           00015                                    RMAG1                                 #  E: (-29)  M: (-27)
054172,000451: 27,3555           14043                           STODL    TFFX                                  #  NUM=RTERM-RN  E: (-29)  M: (-27)
054173,000452: 27,3556           00045                                    TFFTEM                                #  Q2  E: (-16)  M: (-15)
054174,000453: 27,3557           52015                           DAD      GOTO                                  
054175,000454: 27,3560           00017                                    TFFQ1                                 #  Q1  E: (-16)  M: (-15)
054176,000455: 27,3561           57536                                    SAVEDEN                               #  DEN = Q2+Q1   E: (-16)  M: (-15)
054177,000456: 
054178,000457: 27,3562           65215        TFFXTEST           DAD      PDDL                                  #   (ABS(DEN) TO PDL+2))  E: (-3) OR (-16)
054179,000458:                                                                                                  #                         M: (-3) OR (-15)
054180,000459: 27,3563           17762                                    DP(-22)                               #  RESTORE ABS(DEN) TO MPAC
054181,000460: 27,3564           00043                                    TFFX                                  #  NUM E:(-16) OR (-29)  M:(-15) OR (-27)
054182,000461: 27,3565           53605                           DMP      SR*                                   
054183,000462: 27,3566           00031                                    TFFRTALF                              #  SQRT(ALFA)  E: (10+NA)  M: (9+NA)
054184,000463: 27,3567           57201                                    0          -3,2                       #  X2=-NA
054185,000464: 27,3570           77671                           DDV                                            #  C(MPAC) =NUM SQRT(ALFA)  E:(-3) OR (-16)
054186,000465:                                                                                                  #                           M:(-3) OR (-15)
054187,000466:                                                                                                  #  ABS(DEN) FROM PDL+2  E:(-3) OR (-16)
054188,000467:                                                                                                  #                       M:(-3) OR (-15)
054189,000468: 27,3571           40145                           DLOAD    BOV                                   #  (THE DLOAD IS SHARED WITH TFFELL)
054190,000469: 27,3572           00043                                    TFFX                                  #  NUM  E: (-16) OR (-29)  M:(-15) OR (-27)
054191,000470: 27,3573           57654                                    TFFELL                                #  USE EQN FOR DELE GEQ 90, LEQ -90
054192,000471: 
054193,000472:                                                                                                  #                                          OTHERWISE, CONTINUE FOR GENERAL CONIC FOR TFF EQN
054194,000473: 
054195,000474: 27,3574           45471                           DDV      STADR                                 
054196,000475:                                                                                                  #  DEN FROM PDL+0   E: (-3) OR (-16)
054197,000476:                                                                                                  #                   M: (-3) OR (-15)
054198,000477: 27,3575           77732                           STORE    TFFTEM                                #  Z  SAVE FOR SIGN OF SDELF.

Page 1268

054200,000479:                                                                                                  #  E: (-13)  M: (-12)
054201,000480: 27,3576           63406                           PUSH     DSQ                                   #  Z TO PDL+0
054202,000481: 27,3577           41206                           PUSH     DMP                                   #  Z SQ TO PDL+2  E: (-26)  M: (-24)
054203,000482: 27,3600           00035                                    TFFNP                                 #  LC P  E: (-38+2NR)  M: (-36+2NR)
054204,000483: 27,3601           75261                           SL       SIGN                                  
054205,000484: 27,3602           20206                                    5                                     
054206,000485: 27,3603           00045                                    TFFTEM                                #  AFFIX SIGN FOR SDELF (ENTRY DISPLAY)
054207,000486: 27,3604           14045                           STODL    TFFTEM                                #  P ZSQ  E: (-59+2NR)  M: (-55+2NR)
054208,000487:                                                                                                  #  (ARG IS USED IN TFF/TRIG)
054209,000488:                                                                                                  #  ZSQ FROM PDL+2   E: (-26)  M: (-24)
054210,000489: 27,3605           41206                           PUSH     DMP                                   #  RESTORE PUSH LOC
054211,000490: 27,3606           00033                                    TFFALFA                               #  ALFA  E: (26-NR)  M: (24-NR)
054212,000491: 27,3607           77657                           SL*                                            
054213,000492: 27,3610           20201                                    0,1                                   #  X1=-NR
054214,000493: 27,3611           00043                           STORE    TFFX                                  #  X
054215,000494: 27,3612           41234                           RTB      DMP                                   
054216,000495: 27,3613           57736                                    T(X)                                  #   POLY
054217,000496:                                                                                                  #  ZSQ FROM PDL+2  E: (-26)  M: (-24)
054218,000497: 27,3614           44302                           SR2      BDSU                                  #  2 ZSQ T(X)  E: (-29)  M: (-27)
054219,000498: 27,3615           00023                                    RTERM                                 #  RTERM  E: (-29)  M: (-27)
054220,000499: 27,3616           41215                           DAD      DMP                                   
054221,000500: 27,3617           00015                                    RMAG1                                 #  E: (-29)  M: (-27)
054222,000501:                                                                                                  #  Z FROM PDL+0  E: (-13)  M: (-12)
054223,000502: 27,3620           51042                           SR3      BPL                                   #  TFF SQRT(MU)   E: (-45)  M: (-42)
054224,000503: 27,3621           57642                                    ENDTFF                                #  (NO PUSH UP)
054225,000504: 27,3622           75206                           PUSH     SIGN                                  #  TFF SQRT(MU)  TO PDL+0
054226,000505: 27,3623           00017                                    TFFQ1                                 #  Q1 FOR GONEPAST TEST
054227,000506: 27,3624           71244                           BPL      DLOAD                                 #  GONE PAST ?
054228,000507: 27,3625           57646                                    NEGTFF                                #  YES. TFF < 0 .
054229,000508: 27,3626           00027                                    TFF1/ALF                              #  1/ALFA  E: (-22-2NA)  M: (-20-2NA)
054230,000509: 27,3627           51076                           DCOMP    BPL                                   #  ALFA > 0 ?
054231,000510: 27,3630           57646                                    NEGTFF                                #  NO. TFF IS NEGATIVE.
054232,000511: 
054233,000512:                                                                                                  #                                          CORRECT FOR ORBITAL PERIOD.
054234,000513: 
054235,000514: 27,3631           77676                           DCOMP                                          #  YES. CORRECT FOR ORB PERIOD.
054236,000515: 27,3632           56205                           DMP      DDV                                   
054237,000516: 27,3633           17756                                    PI/16                                 #  2 PI (-5)
054238,000517: 27,3634           00031                                    TFFRTALF                              #  SQRT(ALFA)  E: (10+NA)  M: (9+NA)
054239,000518: 27,3635           53657                           SL*      SL*                                   
054240,000519: 27,3636           57602                                    0          -4,2                       #  X2=-NA
054241,000520: 27,3637           57602                                    0          -4,2                       
054242,000521: 27,3640           43257                           SL*      DAD                                   
054243,000522: 27,3641           57576                                    0,2                                   
054244,000523:                                                                                                  #  TFF SQRT(MU) FROM PDL+0  E:(-45) M:(-42)
054245,000524: 27,3642           40005        ENDTFF             DMP      BOV                                   #  TFF SQRT(MU) IN MPAC     E:(-45) M:(-42)
054246,000525: 27,3643           00037                                    TFF/RTMU                              #  E: (17)  M: (14)
054247,000526: 27,3644           57652                                    MAXTFF                                #  SET POSMAX IF OVFL.
054248,000527: 
054249,000528: 27,3645           77616        DUMPTFF2           RVQ                                            #  RETURN  TFF   (-28) CS IN MPAC.
054250,000529: 

Page 1269

054252,000531: 27,3646           77745        NEGTFF             DLOAD                                          
054253,000532:                                                                                                  #  TFF SQRT(MU)  FROM PDL+0, NEGATIVE.
054254,000533: 27,3647           77650                           GOTO                                           
054255,000534: 27,3650           57642                                    ENDTFF                                
054256,000535: 
054257,000536: 27,3651           77745        MAXTFF1            DLOAD                                          #  RESET PDL
054258,000537: 27,3652           43545        MAXTFF             DLOAD    RVQ                                   
054259,000538: 27,3653           17772                                    NEARONE                               
054260,000539: 
054261,000540:                                                                                                  #  TIME OF FLIGHT ELLIPSE WHEN DEL (ECCENTRIC ANOM) GEQ 90 AND LEQ -90.
054262,000541: 
054263,000542:                                                                                                  #  NUM FROM TFFX.  E: (-16) OR (-29)
054264,000543:                                                                                                  #                  M: (-15) OR (-27)
054265,000544: 27,3654           77712        TFFELL             SL2                                            #  NUM  E:(-14) OR (-27)  M:(-13) OR (-25)
054266,000545: 27,3655           41465                           BDDV     PUSH                                  #  TEMP SAVE D/N IN PDL+0
054267,000546:                                                                                                  #  DEN FROM PDL+0 E:(-3)/( 16) M:(-3)/(-15)
054268,000547:                                                                                                  #  N/D TO PDL+0  E: (11)  M: (10)
054269,000548: 27,3656           45345        TFFEL1             DLOAD    DSU                                   #  (ENTER WITH D/N=0 IN PDL+0)
054270,000549: 27,3657           00045                                    TFFTEM                                #  Q2  E: (-16)  M: (-15)
054271,000550: 27,3660           00017                                    TFFQ1                                 #  Q1  E: (-16)  M: (-15)
054272,000551: 27,3661           14013                           STODL    TFFDELQ                               #  Q2-Q1  E: (-16)  M: (-15)
054273,000552:                                                                                                  #  D/N FROM PDL+0
054274,000553: 27,3662           77626                           STADR                                          
054275,000554: 27,3663           77732                           STORE    TFFTEM                                #  D/N  E: (11)  M: (10)
054276,000555: 27,3664           53605                           DMP      SL*                                   
054277,000556: 27,3665           00027                                    TFF1/ALF                              #  1/ALFA E: (-22-2NA)  M: (-20-2NA)
054278,000557: 27,3666           57576                                    0,2                                   #  1/ALFA Z  E: (-11-NA)  M: (-10-NA)
054279,000558: 27,3667           41206                           PUSH     DMP                                   #  TO PDL+0
054280,000559: 27,3670           00045                                    TFFTEM                                #  1/Z  E: (11)  M: (10)
054281,000560: 27,3671           41057                           SL*      BOVB                                  
054282,000561: 27,3672           57576                                    0,2                                   #  X2= -NA
054283,000562: 27,3673           21713                                    SIGNMPAC                              #  IN CASE X= 1.0, CONTINUE
054284,000563: 27,3674           00043                           STORE    TFFX                                  #  X=1/ALFA ZSQ
054285,000564: 27,3675           41234                           RTB      DMP                                   
054286,000565: 27,3676           57736                                    T(X)                                  #  POLY
054287,000566: 27,3677           00043                                    TFFX                                  
054288,000567: 27,3700           45242                           SR3      DSU                                   
054289,000568: 27,3701           17764                                    DP2(-3)                               
054290,000569: 27,3702           41405                           DMP      PUSH                                  #  2(X T(X)-1) /Z ALFA  E: (-15-NA)
054291,000570:                                                                                                  #                       M: (-14-NA)
054292,000571:                                                                                                  #  1/ALFA Z FROM PDL+0  E: (-11-NA)
054293,000572:                                                                                                  #                       M: (-10-NA)
054294,000573: 27,3703           41345                           DLOAD    DMP                                   #  GET SIGN FOR SDELF
054295,000574: 27,3704           00045                                    TFFTEM                                #  1/Z  E: (11)  M: (10)
054296,000575: 27,3705           00015                                    RMAG1                                 #  E: (-29)  M: (-27)
054297,000576: 27,3706           43312                           SL2      DAD                                   
054298,000577: 27,3707           00017                                    TFFQ1                                 #  Q1  E: (-16)  M: (-15)
054299,000578: 27,3710           14045                           STODL    TFFTEM                                #  (Q1+R 1/Z)  =SGN OF SDELF E:(-16) M:(-15
054300,000579: 27,3711           00035                                    TFFNP                                 #  LC P E: (-38+2NR) M: (-36+2NR)
054301,000580: 27,3712           53605                           DMP      SL*                                   #  CALC FOR ARG FOR TFF/TRIG.

Page 1270

054303,000582: 27,3713           00027                                    TFF1/ALF                              #  1/ALFA   E:(-22-2NA)  M:(-20-2NA)
054304,000583: 27,3714           57575                                    1,2                                   #  X2=-NA
054305,000584: 27,3715           53765                           SIGN     SL*                                   
054306,000585: 27,3716           00045                                    TFFTEM                                #  AFFIX SIGN FOR SDELF
054307,000586: 27,3717           57576                                    0,2                                   
054308,000587: 27,3720           14045                           STODL    TFFTEM                                #  P/ALFA  E:(-59+2NR)  M:(-55+2NR)
054309,000588:                                                                                                  #  (ARG FOR USE IN TFF/TRIG)
054310,000589: 27,3721           00027                                    TFF1/ALF                              #  1/ALFA E:(-22-2NA)  M:(-20-2NA)
054311,000590: 27,3722           41366                           SQRT     DMP                                   
054312,000591: 27,3723           17756                                    PI/16                                 #  PI (-4)
054313,000592: 27,3724           77615                           DAD                                            
054314,000593:                                                                                                  #  2(XT(X)-1)/Z ALFA FROM PDL E:(-15-NA)
054315,000594:                                                                                                  #                             M:(-14-NA)
054316,000595: 27,3725           45257                           SL*      DSU                                   
054317,000596: 27,3726           57577                                    0          -1,2                       
054318,000597: 27,3727           00013                                    TFFDELQ                               #  Q2-Q1  E: (-16)  M: (-15)
054319,000598: 27,3730           53605                           DMP      SL*                                   
054320,000599: 27,3731           00027                                    TFF1/ALF                              #  1/ALFA  E:(-22-2NA)  M:(-20-2NA)
054321,000600: 27,3732           57601                                    0          -3,2                       
054322,000601: 27,3733           52057                           SL*      GOTO                                  
054323,000602: 27,3734           57602                                    0          -4,2                       
054324,000603: 27,3735           57642                                    ENDTFF                                #  TFF SQRT(MU) IN MPAC E:(-45) M:(-42)
054325,000604: 

Page 1271

054327,000606:                                                                                                  #  PROGRAM NAME:      T(X)                                                 DATE:    01.17.67
054328,000607:                                                                                                  #  MOD NO:  0                                                              LOG SECTION:    TIME OF FREE FALL
054329,000608:                                                                                                  #  MOD BY:  RR BAIRNSFATHER
054330,000609:                                                                                                  #  FUNCTIONAL DESCRIPTION:      THE POLYNOMIAL T(X) IS USED BY TIME OF FLIGHT SUBROUTINES  CALCTFF AND
054331,000610:                                                                                                  #           CALCTPER TO APPROXIMATE THE SERIES
054332,000611:                                                                                                  #                             2     3
054333,000612:                                                                                                  #                  1/3 -X/5 +X /7 -X /9 ...
054334,000613: 
054335,000614:                                                                                                  #           WHERE  X = ALFA Z Z       IF ALFA Z Z  LEQ 1
054336,000615:                                                                                                  #                  X = 1/(ALFA Z Z )  IF ALFA Z Z   G  1
054337,000616: 
054338,000617:                                                                                                  #           ALSO   X IS NEG FOR HYPERBOLIC ORBITS
054339,000618:                                                                                                  #                  X = 0 FOR PARABOLIC ORBITS
054340,000619:                                                                                                  #                  X IS POSITIVE FOR ELLIPTIC ORBITS
054341,000620:                                                                                                  #           FOR FLIGHT 278, THE POLYNOMIAL  T(X) IS FITTED OVER THE RANGE  (0,+1)  AND HAS A MAXIMUM
054342,000621:                                                                                                  #           DEVIATION FROM THE SERIES OF  2 E-5       (T(X) IS A CHEBYCHEV  TYPE FIT AND WAS OBTAINED USING
054343,000622:                                                                                                  #           MAC PROGRAM AUTCURFIT294RRB  AND IS VALID TO THE SAME TOLERANCE OVER THE RANGE  (-.08,+1). )
054344,000623:                                                                                                  #  CALLING SEQUENCE:  RTB
054345,000624:                                                                                                  #                            T(X)
054346,000625:                                                                                                  #           C(MPAC) = X
054347,000626: 
054348,000627:                                                                                                  #  SUBROUTINES CALLED:  NONE
054349,000628:                                                                                                  #  NORMAL EXIT MODE:    TC   DANZIG
054350,000629:                                                                                                  #  ALARMS:  NONE
054351,000630:                                                                                                  #  OUTPUT:  C(MPAC) = T(X)
054352,000631:                                                                                                  #  ERASABLE INITIALIZATION REQUIRED:
054353,000632:                                                                                                  #           C(MPAC)  =  X
054354,000633:                                                                                                  #  DEBRIS:  NONE
054355,000634: 
054356,000635: 27,3736           07225        T(X)               TC       POLY                                  
054357,000636: 27,3737           00004                           DEC      4          B-14                       #  N-1
054358,000637: 27,3740           12525 12525                     2DEC     3.333333333 E-1                        
054359,000638: 
054360,000639: 27,3742           71463 57703                     2DEC*    -1.999819135 E-1*                       
054361,000640: 
054362,000641: 27,3744           04423 17645                     2DEC*    1.418148467 E-1*                       
054363,000642: 
054364,000643: 27,3746           74604 43667                     2DEC*    -1.01310997 E-1*                       
054365,000644: 
054366,000645: 27,3750           01626 37256                     2DEC*    5.609004986 E-2*                       
054367,000646: 
054368,000647: 27,3752           77404 52071                     2DEC*    -1.536156925 E-2*                       
054369,000648: 
054370,000649: 27,3754           06064        ENDT(X)            TC       DANZIG                                
054371,000650: 
054372,000651: 27,3755  27,3754               TCDANZIG           =        ENDT(X)                               
054373,000652: 

Page 1272

054375,000654:                                                                                                  #  TFF CONSTANTS
054376,000655: 
054377,000656: 32,3705                                           BANK     32                                    
054378,000657: 
054379,000658: 27,2000                                           SETLOC   TOF-FF1                               
054380,000659: 27,2000                                           BANK                                           
054381,000660: 
054382,000661:                                                                                                  #                             NOTE _  NOTE _ ADJUSTED MUE FOR NEAR EARTH TRAJ.
054383,000662: 
054384,000663:                                                                                                  # MUE            =       3.990 815 471 E10  M CUBE/CS SQ
054385,000664:                                                                                                  # RTMUE          =       1.997702549 E5 B-18*     MODIFIED EARTH MU
054386,000665: 
054387,000666:                                                                                                  #                             NOTE _  NOTE _ ADJUSTED MUE FOR NEAR EARTH TRAJ.
054388,000667: 
054389,000668:                                                                                                  # MUM            =       4.902 778  E8     M CUBE /CS SQ
054390,000669: 
054391,000670:                                                                                                  # RTMUM          2DEC*   2.21422176 E4 B-18*
054392,000671: 27,3755           06220 37553  PI/16              2DEC     3.141592653 B-4                        
054393,000672: 
054394,000673: 27,3757           37777 37700  LIM(-22)           2OCT     3777737700                            #  1.0 -B(-22)
054395,000674: 
054396,000675: 27,3761           00000 00100  DP(-22)            2OCT     0000000100                            #  B(-22)
054397,000676: 
054398,000677: 27,3763           04000 00000  DP2(-3)            2DEC     1          B-3                        
054399,000678: 
054400,000679: 27,3765           02000 00000  DP2(-4)            2DEC     1          B-4                        #  1/16
054401,000680: 
054402,000681:                                                                                                  # RPAD1          2DEC    6373338 B-29      M  (-29)   =20 909 901.57 FT
054403,000682: 
054404,000683: 27,3767  23,2333               RPAD1              =        RPAD                                  
054405,000684: 
054406,000685: 27,3767           00305 11205  R300K              2DEC     6464778    B-29                       #  (-29) M
054407,000686: 
054408,000687: 27,3771           37777 37777  NEARONE            2DEC     .999999999                            
054409,000688: 
054410,000689: 27,3773  23,2467               TFFZEROS           EQUALS   HI6ZEROS                              
054411,000690: 27,3773  23,2457               TFF1/4             EQUALS   HIDP1/4                               
054412,000691: 

End of include-file TIME_OF_FREE_FALL.agc.  Parent file is MAIN.agc