Source Code

This is an attempt to recreate Luminary 99 Rev 2, otherwise known as LUM99R2, from Luminary 99 Rev 1 and ephemeris data from Luminary 116. The differences are confined to the last 10-12 lines of the CONTROLLED CONSTANTS. Luminary 99 Rev 1 source-code was transcribed from a printout in the MIT Museum, while Luminary 116 source code was transcribed from a printout belonging to Don Eyles. AGC developer James Kernan, the "rope mother" for the Apollo 11 Lunar Module's AGC, explains as follows: "At the last minute, Dan Lickly, our chief engineer, appeared with ephemerides updates and it took two tries to get it right. The result was that we created Lum99 Revision 1 and Lum99 Revision 2." It is suspected that the former is what's in the MIT Museum, and the latter is what we are trying to recreate here. As for which revision actually flew in Apollo 11, all of the other available surviving evidence points to Rev 1 rather than to Rev 2, so we're just not sure!

053266,000002:                                                                                                  ## Copyright:   Public domain.
053267,000003:                                                                                                  ## Filename:    TIME_OF_FREE_FALL.agc
053268,000004:                                                                                                  ## Purpose:     Part of the source code for Luminary 1A build 099.
053269,000005:                                                                                                  ##              It is part of the source code for the Lunar Module's (LM)
053270,000006:                                                                                                  ##              Apollo Guidance Computer (AGC), for Apollo 11.
053271,000007:                                                                                                  ## Assembler:   yaYUL
053272,000008:                                                                                                  ## Contact:     Ron Burkey <info@sandroid.org>.
053273,000009:                                                                                                  ## Website:     www.ibiblio.org/apollo.
053274,000010:                                                                                                  ## Pages:       1268-1283
053275,000011:                                                                                                  ## Mod history: 2009-05-26 RSB  Adapted from the corresponding 
053276,000012:                                                                                                  ##                              Luminary131 file, using page 
053277,000013:                                                                                                  ##                              images from Luminary 1A.
053278,000014:                                                                                                  ##              2011-01-06 JL   Fixed pseudo-label indentation.
053279,000015:                                                                                                  ##              2016-12-17 RSB  Proofed text comments with octopus/ProoferComments
053280,000016:                                                                                                  ##                              and corrected the errors found.
053281,000017:                                                                                                  ##              2017-03-03 RSB  Snapshot of Luminary 99 Rev 1. 
053282,000018:                                                                                                  ##              2017-03-14 RSB  Comment-text fixes noted in proofing Luminary 116.
053283,000019:                                                                                                  ##              2017-03-16 RSB  Comment-text fixes identified in 5-way
053284,000020:                                                                                                  ##                              side-by-side diff of Luminary 69/99/116/131/210.
053285,000021: 

Page 1268

053287,000023:                                                                                                  #  THE TFF SUBROUTINES MAY BE USED IN EITHER EARTH OR MOON CENTERED COORDINATES.  THE TFF ROUTINES NEVER
053288,000024:                                                                                                  #  KNOW WHICH ORIGIN APPLIES.  IT IS THE USER WHO KNOWS, AND WHO SUPPLIES RONE, VONE AND 1/SQRT(MU) AT THE
053289,000025:                                                                                                  #  APPROPRIATE SCALE LEVEL FOR THE PROPER PRIMARY BODY.
053290,000026: 
053291,000027:                                                                                                  #        EARTH ORIGIN    POSITION        -29     METERS
053292,000028:                                                                                                  #                        VELOCITY        -7      METERS/CENTISECOND
053293,000029:                                                                                                  #                        1/SQRT(MU)      +17     SQRT(CS SQ/METERS CUBED)
053294,000030: 
053295,000031:                                                                                                  #        MOON ORIGIN     POSITION        -27     METERS
053296,000032:                                                                                                  #                        VELOCITY        -5      METERS/CENTISECONDS
053297,000033:                                                                                                  #                        1/SQRT(MU)      +14     SQRT(CS SQ/METERS CUBED)
053298,000034: 
053299,000035:                                                                                                  #  ALL DATA PROVIDED TO AND RECEIVED FROM ANY TFF SUBROUTINE WILL BE AT ONE OF THE LEVELS ABOVE.  IN ALL CASES,
053300,000036:                                                                                                  #  THE FREE FALL TIME IS RETURNED IN CENTISECONDS AT (-28).  PROGRAM TFF/CONIC WILL GENERATE VONE/RTMU AND
053301,000037:                                                                                                  #  LEAVE IT IN VONE' AT (+10) IF EARTH ORIGIN AND (+9) IF MOON ORIGIN.
053302,000038: 
053303,000039:                                                                                                  #  THE USER MUST STORE THE STATE VECTOR IN RONE, VONE  AND MU IN THE FORM 1/SQRT(MU) IN TFF/RTMU
053304,000040:                                                                                                  #  AT THE PROPER SCALE BEFORE CALLING TFF/CONIC.  SINCE RONE, VONE ARE IN THE EXTENDED VERB STORAGE AREA,
053305,000041:                                                                                                  #  THE USER MUST ALSO LOCK OUT THE EXTENDED VERBS, AND RELEASE THEM WHEN FINISHED.
053306,000042: 
053307,000043:                                                                                                  #  PROGRAMS CALC/TFF AND CALC/TPER ASSUME THAT THE TERMINAL RADIUS IS LESS THAN THE PRESENT
053308,000044:                                                                                                  #  RADIUS.  THIS RESTRICTION CAN BE REMOVED BY A 15 W CODING CHANGE, BUT AT PRESENT IT IS NOT DEEMED NECESSARY.
053309,000045: 
053310,000046:                                                                                                  #  THE FOLLOWING ERASABLE QUANTITIES ARE USED BY THE TFF ROUTINES, AND ARE LOCATED IN THE PUSH LIST.
053311,000047: 
053312,000048:                                                                                                  #                                        BELOW   E:  IS USED FOR EARTH ORIGIN SCALE
053313,000049:                                                                                                  #                                                M:  IS USED FOR MOON  ORIGIN SCALE
053314,000050: 
053315,000051:                                                                                                  # TFFSW          =       119D    BIT1    0 = CALCTFF             1 = CALCTPER
053316,000052: 10,2213                        TFFDELQ            =        10D                                   #        Q2-Q1                   E: (-16)  M: (-15)
053317,000053: 10,2213                        RMAG1              =        12D                                   #        ABVAL(RN)  M            E: (-29)  M: (-27)
053318,000054:                                                                                                  # RPER           =       14D             PERIGEE RADIUS  M       E: (-29)  M: (-27)
053319,000055: 10,2213                        TFFQ1              =        14D                                   #        R.V / SQRT(MUE)         E: (-16)  M: (-15)
053320,000056:                                                                                                  # SDELF/2                                SIN(THETA) /2
053321,000057: 10,2213                        CDELF/2            =        14D                                   #        COS(THETA) /2
053322,000058:                                                                                                  # RAPO           =       16D             APOGEE RADIUS  M        E: (-29)  M: (-27)
053323,000059: 10,2213                        NRTERM             =        16D                                   #        TERMINAL RADIUS  M      E: (-29+NR)
053324,000060:                                                                                                  #                                          M: (-27+NR)
053325,000061: 10,2213                        RTERM              =        18D                                   #        TERMINAL RADIUS  M      E: (-29)  M: (-27)
053326,000062: 10,2213                        TFFVSQ             =        20D                                   #        -(V SQUARED/MU)  1/M    E: (20)   M: (18)
053327,000063: 10,2213                        TFF1/ALF           =        22D                                   #        SEMI MAJ AXIS  M        E: (-22-2 NA)
053328,000064:                                                                                                  #                                          M: (-20-2 NA)
053329,000065: 10,2213                        TFFRTALF           =        24D                                   #        SQRT(ALFA)              E:(10+NA) M: (9+NA)
053330,000066: 10,2213                        TFFALFA            =        26D                                   #        ALFA  1/M               E:(26-NR) M: (24-NR)
053331,000067: 10,2213                        TFFNP              =        28D                                   #        SEMI LATUS RECTUM  M    E: (-38+2 NR)
053332,000068:                                                                                                  #                                          M: (-36+2 NR)
053333,000069: 10,2213                        TFF/RTMU           =        30D                                   #        1/SQRT(MU)              E: (17)   M: (14)
053334,000070: 10,2213                        NRMAG              =        32D                                   #        PRESENT RADIUS  M       E: (-29+NR)
053335,000071:                                                                                                  #                                          M: (-27+NR)
053336,000072: 10,2213                        TFFX               =        34D                                   
053337,000073: 10,2213                        TFFTEM             =        36D                                   #        TEMPORARY

Page 1269

053339,000075:                                                                                                  #                REGISTERS S1, S2 ARE UNTOUCHED BY ANY TFF SUBROUTINE
053340,000076:                                                                                                  #                INDEX REGISTERS X1, X2 ARE USED BY ALL TFF SUBROUTINES.  THEY ARE ESTAB-
053341,000077:                                                                                                  #                LISHED IN TFF/CONIC AND MUST BE PRESERVED BETWEEN CALLS TO SUBSEQUENT
053342,000078:                                                                                                  #                SUBROUTINES.
053343,000079:                                                                                                  #                -NR                             C(X1) = NORM COUNT OF RMAG
053344,000080:                                                                                                  #                -NA                             C(X2) = NORM COUNT OF SQRT(ABS(ALFA))
053345,000081: 

Page 1270

053347,000083:                                                                                                  #  SUBROUTINE NAME:  TFFCONIC                                            DATE:  01.29.67
053348,000084:                                                                                                  #  MOD NO:  0                                                            LOG SECTION:  TIME OF FREE FALL
053349,000085:                                                                                                  #  MOD BY:  RR BAIRNSFATHER
053350,000086:                                                                                                  #  MOD NO:  1    MOD BY:  RR BAIRNSFATHER        DATE: 11 APR 67
053351,000087:                                                                                                  #  MOD NO:  2    MOD BY:  RR BAIRNSFATHER        DATE: 21 NOV 67         ADD MOON MU.
053352,000088:                                                                                                  #  MOD NO:  3    MOD BY:  RR BAIRNSFATHER        DATE: 21 MAR 68         ACCEPT DIFFERENT EARTH/MOON SCALES
053353,000089: 
053354,000090:                                                                                                  #  FUNCTIONAL DESCRIPTION:  THIS SUBROUTINE IS CALLED TO COMPUTE THOSE CONIC PARAMETERS REQUIRED BY THE TFF
053355,000091:                                                                                                  #        SUBROUTINES AND TO ESTABLISH THEM IN THE PUSH LIST AREA.  THE PARAMETERS ARE LISTED UNDER OUTPUT.
053356,000092:                                                                                                  #        THE EQUATIONS ARE
053357,000093:                                                                                                  #                _   __ __
053358,000094:                                                                                                  #                H = RN*VN                       ANGULAR MOMENTUM
053359,000095:                                                                                                  #                      _ _
053360,000096:                                                                                                  #                LCP = H.H / MU                  SEMI LATUS RECTUM
053361,000097:                                                                                                  #                              __ __
053362,000098:                                                                                                  #                ALFA = 2/RN - VN.VN / MU        RECIPROCAL SEMI MAJ AXIS, SIGNED
053363,000099: 
053364,000100:                                                                                                  #        AND ALFA IS POS FOR ELLIPTIC ORBITS
053365,000101:                                                                                                  #                      0 FOR PARABOLIC ORBITS
053366,000102:                                                                                                  #                    NEG FOR HYPERBOLIC ORBITS.
053367,000103:                                                                                                  #        SUBROUTINE ALSO COMPUTES AND SAVES RMAG.
053368,000104: 
053369,000105:                                                                                                  #  CALLING SEQUENCE:
053370,000106:                                                                                                  #        TFFCONIC EXPECTS CALLER TO ENTER WITH CORRECT GRAVITATIONAL CONSTANT IN MPAC, IN THE FORM
053371,000107:                                                                                                  #        1/SQRT(MU).  PROGRAM WILL SAVE IN TFF/RTMU.  THE SCALE IS DETERMINED BY WHETHER EARTH OR MOON
053372,000108:                                                                                                  #        ORIGIN IS USED.  THE CALLER MUST LOCK OUT THE EXTENDED VERBS BEFORE PROVIDING STATE VECTOR IN RONE,
053373,000109:                                                                                                  #        VONE AT PROPER SCALE.  THE EXTENDED VERBS MUST BE RESTORED WHEN THE CALLER IS FINISHED USING THE
053374,000110:                                                                                                  #        TFF ROUTINES.
053375,000111: 
053376,000112:                                                                                                  #        ENTRY POINT TFFCONMU EXPECTS THAT TFF/RTMU IS ALREADY LOADED.
053377,000113: 
053378,000114:                                                                                                  #        TO SPECIFY MU:  DLOAD   CALL                            IF MU ALREADY STORED:   CALL
053379,000115:                                                                                                  #                                YOURMU  1/RTMU E:(17) M:(14)                                    TFFCONMU
053380,000116:                                                                                                  #                                TFFCONIC
053381,000117:                                                                                                  #        PUSHLOC = PDL+0, ARBITRARY IF LEQ 18D
053382,000118: 
053383,000119:                                                                                                  #  SUBROUTINES CALLED:  NONE
053384,000120: 
053385,000121:                                                                                                  #  NORMAL EXIT MODES:  RVQ
053386,000122: 
053387,000123:                                                                                                  #  ALARMS:  NONE
053388,000124: 
053389,000125:                                                                                                  #  OUTPUT:       THE FOLLOWING ARE STORED IN THE PUSH LIST AREA.
053390,000126:                                                                                                  #                RMAG1           E:(-29) M:(-27) M  RN, PRESENT RADIUS LENGTH.
053391,000127:                                                                                                  #                NRMAG           E:(-29+NR)      M  RMAG, NORMALIZED
053392,000128:                                                                                                  #                                M:(-27+NR)
053393,000129:                                                                                                  #                X1                              -NR, NORM COUNT
053394,000130:                                                                                                  #                TFFNP           E:(-38+2NR)     M  LCP, SEMI LATUS RECTUM, WEIGHTED BY NR.      FOR VGAMCALC
053395,000131:                                                                                                  #                                M:(-36+2NR)
053396,000132:                                                                                                  #                TFF/RTMU        E:(17) M:(14)   1/SQRT(MU)
053397,000133:                                                                                                  #                TFFVSQ          E:(20) M:(18)   1/M  -(V SQ/MU):  PRESENT VELOCITY,NORMLIZED.   FOR VGAMCALC
053398,000134:                                                                                                  #                TFFALFA         E:(26-NR)       1/M  ALFA, WEIGHTED BY NR
053399,000135:                                                                                                  #                                M:(24-NR)
053400,000136:                                                                                                  #                TFFRTALF        E:(10+NA)       SQRT(ALFA), NORMALIZED
053401,000137:                                                                                                  #                                M:(9+NA)

Page 1271

053403,000139:                                                                                                  #                X2                              -NA, NORMCOUNT
053404,000140:                                                                                                  #                TFF1/ALF        E:(-22-2NA)     SIGNED SEMI MAJ AXIS, WEIGHTED BY NA
053405,000141:                                                                                                  #                                M:(-20-2NA)
053406,000142:                                                                                                  #                PUSHLOC AT PDL+0
053407,000143: 
053408,000144:                                                                                                  #        THE FOLLOWING IS STORED IN GENERAL ERASABLE
053409,000145:                                                                                                  #                VONE'           E:(10) M:(9)    V/RT(MU), NORMALIZED VELOCITY
053410,000146: 
053411,000147:                                                                                                  #  ERASABLE INITIALIZATION REQUIRED:
053412,000148:                                                                                                  #                RONE            E:(-29) M:(-27) M  STATE VECTOR         LEFT BY CALLER
053413,000149:                                                                                                  #                VONE            E:(-7) M:(-5)   M/CS  STATE VECTOR      LEFT BY CALLER
053414,000150:                                                                                                  #                TFF/RTMU        E:(17) M:(14)   1/RT(CS SQ/M CUBE)      IF ENTER VIA TFFCONMU.
053415,000151: 
053416,000152:                                                                                                  #  DEBRIS:       QPRET,          PDL+0 ... PDL+3
053417,000153: 
053418,000154: 33,3777                                           BANK     33                                    
053419,000155: 27,2000                                           SETLOC   TOF-FF                                
053420,000156: 27,2000                                           BANK                                           
053421,000157: 
053422,000158: 27,3360                                           COUNT*   $$/TFF                                
053423,000159: 
053424,000160: 27,3360           00037        TFFCONIC           STORE    TFF/RTMU                              #  1/SQRT(MU)    E:(17) M:(14)
053425,000161: 
053426,000162: 27,3361           53575        TFFCONMU           VLOAD    UNIT                                  #  COME HERE WITH TFFRTMU LOADED.
053427,000163: 27,3362           02207                                    RONE                                  #  SAVED RN.  M  E:(-29) M:(-27)
053428,000164: 27,3363           77725                           PDDL                                           #  UR/2 TO PDL+0, +5
053429,000165: 27,3364           00045                                    36D                                   #  MAGNITUDE
053430,000166: 27,3365           00015                           STORE    RMAG1                                 #  M  E:(-29) M:(-27)
053431,000167: 
053432,000168: 27,3366           77701                           NORM                                           
053433,000169: 27,3367           00047                                    X1                                    #  -NR
053434,000170: 27,3370           24041                           STOVL    NRMAG                                 #  RMAG  M  E:(-29+NR) M:(-27+NR)
053435,000171: 27,3371           02215                                    VONE                                  #  SAVED VN.  M/CS  E:(-7) M:(-5)
053436,000172: 27,3372           77761                           VXSC                                           
053437,000173: 27,3373           00037                                    TFF/RTMU                              #  E:(17) M:(14)
053438,000174: 27,3374           02170                           STORE    VONE'                                 #  VN/SQRT(MU)  E:(10) M:(9)
053439,000175: 
053440,000176: 27,3375           47361                           VXSC     VXV                                   
053441,000177: 27,3376           00041                                    NRMAG                                 #  E:(-29+NR) M:(-27+NR)
053442,000178:                                                                                                  #  UR/2 FROM PDL
053443,000179: 27,3377           47572                           VSL1     VSQ                                   #  BEFORE:  E:(-19+NR) M:(-18+NR)
053444,000180: 27,3400           14035                           STODL    TFFNP                                 #  LC P  M  E:(-38+2NR) M:(-36+2NR)
053445,000181:                                                                                                  #  SAVE ALSO FOR VGAMCALC
053446,000182: 27,3401           06512                                    TFF1/4                                
053447,000183: 27,3402           63271                           DDV      PDVL                                  #  (2/RMAG)  1/M  E:(26-NR) M:(24-NR)
053448,000184: 27,3403           00041                                    NRMAG                                 #  RMAG  M  E:(-29+NR) M:(-27+NR)
053449,000185: 27,3404           02170                                    VONE'                                 #  SAVED VN.  E:(10) M:(9)
053450,000186: 27,3405           57436                           VSQ      DCOMP                                 #  KEEP MPAC+2 HONEST FOR SQRT.
053451,000187: 27,3406           00025                           STORE    TFFVSQ                                #  -(V SQ/MU)  E:(20) M:(18)
053452,000188:                                                                                                  #  SAVE FOR VGAMCALC
053453,000189: 27,3407           43257                           SR*      DAD                                   

Page 1272

053455,000191: 27,3410           20573                                    0          -6,1                       #  GET -VSQ/MU  E:(26-NR) M:(24-NR)
053456,000192: 27,3411           77626                           STADR                                          
053457,000193:                                                                                                  #  2/RMAG  FROM PDL+2
053458,000194: 27,3412           77744                           STORE    TFFALFA                               #  ALFA  1/M  E:(26-NR) M:(24-NR)
053459,000195: 27,3413           41457                           SL*      PUSH                                  #  TEMP SAVE ALFA  E:(20) M:(18)
053460,000196: 27,3414           20173                                    0          -6,1                       
053461,000197: 27,3415           75446                           ABS      SQRT                                  #  E:(10) M:(9)
053462,000198: 27,3416           77701                           NORM                                           
053463,000199: 27,3417           00050                                    X2                                    #  X2 = -NA
053464,000200: 27,3420           00031                           STORE    TFFRTALF                              #  SQRT( ABS(ALFA) )  E:(10+NA) M:(9+NA)
053465,000201: 27,3421           75316                           DSQ      SIGN                                  #  NOT SO ACCURATE, BUT OK
053466,000202:                                                                                                  #  ALFA FROM PDL+2  E:(20) M:(18)
053467,000203: 27,3422           55254                           BZE      BDDV                                  #  SET 1/ALFA =0, TO SHOW SMALL ALFA
053468,000204: 27,3423           57425                                    +2                                    
053469,000205: 27,3424           06512                                    TFF1/4                                
053470,000206: 27,3425           00027                 +2        STORE    TFF1/ALF                              #  1/ALFA  E:(-22-2NA) M:(-20-2NA)
053471,000207: 27,3426           77616        DUMPCNIC           RVQ                                            
053472,000208: 
053473,000209:                                                                                                  #                                                              39 W

Page 1273

053475,000211:                                                                                                  #  SUBROUTINE NAME:  TFFRP/RA                                            DATE: 01.17.67
053476,000212:                                                                                                  #  MOD NO:  0                                                            LOG SECTION:  TIME OF FREE FALL
053477,000213:                                                                                                  #  MOD BY:  RR BAIRNSFATHER
053478,000214:                                                                                                  #  MOD NO:  1    MOD BY:  RR BAIRNSFATHER        DATE: 11 APR 67
053479,000215:                                                                                                  #  MOD NO:  2    MOD BY:  RR BAIRNSFATHER        DATE: 21 MAR 68         ACCEPT DIFFERENT EARTH/MOON SCALES
053480,000216:                                                                                                  #                                                                        ALSO IMPROVE ACCURACY OF RAPO.
053481,000217: 
053482,000218:                                                                                                  #  FUNCTIONAL DESCRIPTION:  USED BY CALCTPER AND TFF DISPLAYS TO CALCULATE PERIGEE RADIUS AND ALSO
053483,000219:                                                                                                  #        APOGEE RADIUS FOR A GENERAL CONIC.
053484,000220:                                                                                                  #        PROGRAM GIVES PERIGEE RADIUS AS         APOGEE RADIUS IS GIVEN BY
053485,000221:                                                                                                  #                RP = P/(1+E)                            RA = (1+E) / ALFA
053486,000222:                                                                                                  #        WHERE    2
053487,000223:                                                                                                  #                E  = 1 - P ALFA
053488,000224:                                                                                                  #        IF RA IS NEGATIVE OR SHOWS DIVIDE OVERFLOW, THEN RA = POSMAX BECAUSE
053489,000225:                                                                                                  #                1. APOGEE RADIUS IS NOT MEANINGFUL FOR HYPERBOLA
053490,000226:                                                                                                  #                2. APOGEE RADIUS IS NOT DEFINED FOR PARABOLA
053491,000227:                                                                                                  #                3. APOGEE RADIUS EXCEEDS THE SCALING FOR ELLIPSE.
053492,000228: 
053493,000229:                                                                                                  #        THIS SUBROUTINE REQUIRES THE SIGNED RECIPROCAL SEMI MAJ AXIS, ALFA, AND SEMI LATUS RECTUM AS DATA.
053494,000230: 
053495,000231:                                                                                                  #  CALLING SEQUENCE:     CALL
053496,000232:                                                                                                  #                                TFFRP/RA
053497,000233:                                                                                                  #        PUSHLOC = PDL+0, ARBITRARY IF LEQ 10D
053498,000234:                                                                                                  #        C(MPAC) UNSPECIFIED
053499,000235: 
053500,000236:                                                                                                  #  SUBROUTINES CALLED:   NONE
053501,000237: 
053502,000238:                                                                                                  #  NORMAL EXIT MODE:     RVQ
053503,000239:                                                                                                  #        IF ELLIPSE, WITHIN NORMAL SCALING, RAPO IS CORRECT.
053504,000240:                                                                                                  #        OTHERWISE, RAPO = POSMAX.
053505,000241: 
053506,000242:                                                                                                  #  ALARMS:       NONE
053507,000243: 
053508,000244:                                                                                                  #  OUTPUT:       STORED IN PUSH LIST AREA.  SCALE OF OUTPUT AGREES WITH DATA SUPPLIED TO TFF/CONIC.
053509,000245:                                                                                                  #        RPER    E:(-29) M:(-27)         M       PERIGEE RADIUS          DESTROYED BY CALCTFF/CALCTPER, TFFTRIG.
053510,000246:                                                                                                  #        RAPO    E:(-29) M:(-27)         M       APOGEE RADIUS           WILL BE DESTROYED BY CALCTFF/CALCTPER
053511,000247:                                                                                                  #        PUSHLOC AT PDL+0
053512,000248: 
053513,000249:                                                                                                  #  ERASABLE INITIALIZATION REQUIRED:
053514,000250:                                                                                                  #        TFFALFA E:(26-NR)               M       1/SEMI MAJ AXIS         LEFT BY TFFCONIC
053515,000251:                                                                                                  #                M:(24-NR)
053516,000252:                                                                                                  #        TFFNP   E:(-38+2NR)             M       LC P, SEMI LATUS RECTUM LEFT BY TFFCONIC
053517,000253:                                                                                                  #                M:(-36+2NR)
053518,000254:                                                                                                  #        X1                              -NR, NORM COUNT OF RMAG         LEFT BY TFFCONIC
053519,000255:                                                                                                  #        X2                              -NA, NORM COUNT OF ALFA         LEFT BY TFFCONIC
053520,000256: 
053521,000257:                                                                                                  #  DEBRIS:       QPRET, PDL+0 ... PDL+1
053522,000258: 

Page 1274

053524,000260: 27,3427                        RAPO               =        16D                                   #  APOGEE RADIUS  M  E:(-29) M:(-27)
053525,000261: 27,3427                        RPER               =        14D                                   #  PERIGEE RADIUS  M  E:(-29) M:(-27)
053526,000262: 
053527,000263: 27,3427           41345        TFFRP/RA           DLOAD    DMP                                   
053528,000264: 27,3430           00033                                    TFFALFA                               #  ALFA  1/M  E:(26-NR) M:(24-NR)
053529,000265: 27,3431           00035                                    TFFNP                                 #  LC P  M E:(-38+2NR) M:(-36+2NR)
053530,000266: 27,3432           57457                           SR*      DCOMP                                 #  ALFA P (-12+NR)
053531,000267: 27,3433           20571                                    0          -8D,1                      #  ALFA P (-4)
053532,000268: 27,3434           51415                           DAD      ABS                                   #  (DCOMP GIVES VALID TP RESULT FOR SQRT)
053533,000269:                                                                                                  #  (ABS PROTECTS SQRT IF E IS VERY NEAR 0)
053534,000270: 27,3435           17765                                    DP2(-4)                               
053535,000271: 27,3436           43366                           SQRT     DAD                                   #  E SQ = (1- P ALFA) (-4)
053536,000272: 27,3437           06512                                    TFF1/4                                
053537,000273: 27,3440           55206                           PUSH     BDDV                                  #  (1+E)  (-2)  TO PDL+0
053538,000274: 27,3441           00035                                    TFFNP                                 #  LCP  M  E:(-38+2NR) M:(-36+2NR)
053539,000275: 27,3442           53657                           SR*      SR*                                   #  (DOES SR THEN SL TO AVOID OVFL)
053540,000276: 27,3443           20601                                    0,1                                   #  X1=-NR
053541,000277: 27,3444           20572                                    0          -7,1                       #  (EFFECTIVE SL)
053542,000278: 27,3445           14017                           STODL    RPER                                  #  PERIGEE RADIUS  M  E:(-29) M:(-27)
053543,000279:                                                                                                  #  (1+E)  (-2)  FROM PDL+0
053544,000280: 27,3446           41005                           DMP      BOVB                                  
053545,000281: 27,3447           00027                                    TFF1/ALF                              #  E:(-22-2NA) M:(-20-2NA)
053546,000282: 27,3450           57753                                    TCDANZIG                              #  CLEAR OVFIND, IF ON.
053547,000283: 27,3451           53654                           BZE      SL*                                   
053548,000284: 27,3452           57461                                    MAXRA                                 #  SET POSMAX, IF ALFA=0
053549,000285: 27,3453           57603                                    0          -5,2                       #  -5+NA
053550,000286: 27,3454           40057                           SL*      BOV                                   
053551,000287: 27,3455           57576                                    0,2                                   
053552,000288: 27,3456           57461                                    MAXRA                                 #  SET POSMAX IF OVFL.
053553,000289: 27,3457           77644                           BPL                                            #  CONTINUE WITH VALID RAPO.
053554,000290: 27,3460           57463                                    +3                                    
053555,000291: 27,3461           77745        MAXRA              DLOAD                                          #  RAPO CALC IS NOT VALID.  SET RAPO =
053556,000292: 27,3462           17771                                    NEARONE                               #  POSMAX AS A TAG.
053557,000293: 27,3463           00021                 +3        STORE    RAPO                                  #  APOGEE RADIUS  M  E:(-29) M:(-27)
053558,000294: 27,3464           77616        DUMPRPRA           RVQ                                            
053559,000295: 
053560,000296:                                                                                                  #                                                                30 W

Page 1275

053562,000298:                                                                                                  #  SUBROUTINE NAME:  CALCTPER / CALCTFF                                  DATE:  01.29.67
053563,000299:                                                                                                  #  MOD NO:  0                                                            LOG SECTION:  TIME OF FREE FALL
053564,000300:                                                                                                  #  MOD BY:  RR BAIRNSFATHER
053565,000301:                                                                                                  #  MOD NO:  1    MOD BY:  RR BAIRNSFATHER        DATE: 21 MAR 67
053566,000302:                                                                                                  #  MOD NO:  2    MOD BY:  RR BAIRNSFATHER        DATE: 14 APR 67
053567,000303:                                                                                                  #  MOD NO:  3    MOD BY:  RR BAIRNSFATHER        DATE: 8 JUL 67          NEAR EARTH MUE AND NEG TFF (GONEPAST)
053568,000304:                                                                                                  #  MOD NO:  4    MOD BY:  RR BAIRNSFATHER        DATE: 21 NOV 67         ADD VARIABLE MU.
053569,000305:                                                                                                  #  MOD NO:  5    MOD BY:  RR BAIRNSFATHER        DATE: 21 MAR 68         ACCEPT DIFFERENT EARTH/MOON SCALES
053570,000306: 
053571,000307:                                                                                                  #  FUNCTIONAL DESCRIPTION:  PROGRAM CALCULATES THE FREE-FALL TIME OF FLIGHT FROM PRESENT POSITION RN AND
053572,000308:                                                                                                  #        VELOCITY VN TO A RADIUS LENGTH SPECIFIED BY RTERM, SUPPLIED BY THE USER.  THE POSITION VECTOR
053573,000309:                                                                                                  #        RN MAY BE ON EITHER SIDE OF THE CONIC, BUT RTERM IS CONSIDERED ON THE INBOUND SIDE.
053574,000310:                                                                                                  #        THE EQUATIONS ARE
053575,000311: 
053576,000312:                                                                                                  #                Q2 = -SQRT(RTERM (2-RTERM ALFA) - LCP)  (INBOUND SIDE)) LEQ +- LCE/SQRT(ALFA)
053577,000313:                                                                                                  #                     __ __
053578,000314:                                                                                                  #                Q1 = RN.VN / SQRT(MU)                                   LEQ +- LCE/SQRT(ALFA)
053579,000315: 
053580,000316:                                                                                                  #                Z = NUM / DEN                                           LEQ +- 1/SQRT(ALFA)
053581,000317: 
053582,000318:                                                                                                  #        WHERE, IF INBOUND
053583,000319:                                                                                                  #                NUM = RTERM -RN                                         LEQ +- 2 LCE/ALFA
053584,000320:                                                                                                  #                DEN = Q2+Q1                                             LEQ +- 2 LCE/SQRT(ALFA)
053585,000321: 
053586,000322:                                                                                                  #        AND, IF OUTBOUND
053587,000323:                                                                                                  #                NUM = Q2-Q1                                             LEQ +- 2 LCE/SQRT(ALFA)
053588,000324:                                                                                                  #                DEN = 2 - ALFA (RTERM + RN).                            LEQ +- 2 LCE
053589,000325: 
053590,000326:                                                                                                  #        IF      ALFA ZZ < 1.0           (FOR ALL CONICS EXCEPT ELLIPSES HAVING ABS(DEL ECC ANOM) G 90 DEG)
053591,000327:                                                                                                  #        THEN    X = ALFA Z Z
053592,000328:                                                                                                  #        AND     TFF = (RTERM +RN -2 ZZ T(X) ) Z/SQRT(MU)
053593,000329:                                                                                                  #                EXCEPT  IF ALFA PNZ, AND IF TFF NEG,
053594,000330:                                                                                                  #                THEN    TFF = 2 PI /(ALFA SQRT(ALFA)) + TFF
053595,000331:                                                                                                  #        OR      IF ALFA ZZ GEQ 1.0      (FOR ELLIPSES HAVING ABS(DEL ECC ANOM) GEQ 90 DEG)
053596,000332:                                                                                                  #        THEN    X = 1/ALFA Z Z
053597,000333:                                                                                                  #        AND     TFF = (PI/SQRT(ALFA) -Q2 +Q1 +2(X T(X) -1) /ALFA Z) /ALFA SQRT(MU)
053598,000334:                                                                                                  #        WHERE   T(X) IS A POLYNOMIAL APPROXIMATION TO THE SERIES
053599,000335:                                                                                                  #                             2      3             2
053600,000336:                                                                                                  #                1/3 - X/5 + X /7 - X /9 ...     (X  < 1.0)
053601,000337: 
053602,000338:                                                                                                  #  CALLING SEQUENCE:     TIME TO RTERM                   TIME TO PERIGEE
053603,000339:                                                                                                  #                        CALL                            CALL
053604,000340:                                                                                                  #                                CALCTFF                         CALCTPER
053605,000341:                                                                                                  #                        C(MPAC) = TERMNL RAD M          C(MPAC) = PERIGEE RAD M
053606,000342:                                                                                                  #        FOR EITHER, E:(-29) M:(-27)
053607,000343:                                                                                                  #        FOR EITHER, PUSHLOC = PDL+0, ARBITRARY IF LEQ 8D.

Page 1276

053609,000345: 
053610,000346:                                                                                                  #  SUBROUTINES CALLED:   T(X), VIA RTB
053611,000347: 
053612,000348:                                                                                                  #  NORMAL EXIT MODE:     RVQ
053613,000349:                                                                                                  #        HOWEVER, PROGRAM EXITS WITH ONE OF THE FOLLOWING VALUES FOR TFF (-28) CS IN MPAC.  USER MUST STORE.
053614,000350:                                                                                                  #                A. TFF = FLIGHT TIME.  NORMAL CASE FOR POSITIVE FLIGHT TIME LESS THAN ONE ORBITAL PERIOD.
053615,000351:                                                                                                  #                B. (THIS OPTION IS NO LONGER USED.)
053616,000352:                                                                                                  #                C. TFF = POSMAX.  THIS INDICATES THAT THE CONIC FROM THE PRESENT POSITION WILL NOT RETURN TO
053617,000353:                                                                                                  #                   THE SPECIFIED ALTITUDE.  ALSO INDICATES OUTBOUND PARABOLA OR HYPERBOLA.
053618,000354: 
053619,000355:                                                                                                  #  OUTPUT:       C(MPAC)         (-28) CS        TIME OF FLIGHT, OR TIME TO PERIGEE
053620,000356:                                                                                                  #                TFFX            (0)             X,                                      LEFT FOR ENTRY DISPLAY TFF ROUTINES
053621,000357:                                                                                                  #                NRTERM          E:(-29+NR) M    RTERM, WEIGHTED BY NR                   LEFT FOR ENTRY DISPLAY TFF ROUTINES
053622,000358:                                                                                                  #                                M:(-27+NR)
053623,000359:                                                                                                  #                TFFTEM          E:(-59+2NR)     LCP Z Z SGN(SDELF)                      LEFT FOR ENTRY DISPLAY TFF ROUTINES
053624,000360:                                                                                                  #                                M:(-55+2NR)     LCP /ALFA SGN(SDELF)                    LEFT FOR ENTRY DISPLAY TFF ROUTINES
053625,000361:                                                                                                  #                NOTE:   TFFTEM = PDL 36D AND WILL BE DESTROYED BY .:UNIT:.
053626,000362:                                                                                                  #                RMAG1           E:(-29) M:(-27) PDL 12 NOT TOUCHED.
053627,000363:                                                                                                  #                TFFQ1           E:(-16) M:(-15) PDL 14D
053628,000364:                                                                                                  #                TFFDELQ         E:(-16) M:(-15) PDL 10D
053629,000365:                                                                                                  #                PUSHLOC AT PDL+0
053630,000366: 
053631,000367:                                                                                                  #  ERASABLE INITIALIZATION REQUIRED:
053632,000368:                                                                                                  #                RONE            E:(-29) M:(-27) M  STATE VECTOR                         LEFT BY USER
053633,000369:                                                                                                  #                VONE'           E:(+10) M:(+9)  VN/SQRT(MU)                             LEFT BY TFF/CONIC
053634,000370:                                                                                                  #                RMAG1           E:(-29) M:(-27) PRESENT RADIUS, M                       LEFT BY TFFCONIC
053635,000371:                                                                                                  #                C(MPAC)         E:(-29) M:(-27) RTERM, TERMINAL RADIUS LENGTH, M        LEFT BY USER
053636,000372: 
053637,000373:                                                                                                  #                THE FOLLOWING ARE STORED IN THE PUSH LIST AREA.
053638,000374:                                                                                                  #                TFF/RTMU        E:(17) M:(14)   1/SQRT(MU)                              LEFT BY TFFCONIC.
053639,000375:                                                                                                  #                NRMAG           E:(-29+NR)      M  RMAG, NORMALIZED                     LEFT BY TFFCONIC
053640,000376:                                                                                                  #                                M:(-27+NR)
053641,000377:                                                                                                  #                X1                              -NR, NORM COUNT                         LEFT BY TFFCONIC
053642,000378:                                                                                                  #                TFFNP           E:(-38+2NR)     M  LCP, SEMI LATUS RECTUM, WEIGHT NR    LEFT BY TFFCONIC
053643,000379:                                                                                                  #                                M:(-36+2NR)
053644,000380:                                                                                                  #                TFFALFA         E:(26-NR)       1/M  ALFA, WEIGHT NR                    LEFT BY TFFCONIC
053645,000381:                                                                                                  #                                M:(24-NR)
053646,000382:                                                                                                  #                TFFRTALF        E:(10+NA)       SQRT(ALFA), NORMALIZED                  LEFT BY TFFCONIC
053647,000383:                                                                                                  #                                M:(9+NA)
053648,000384:                                                                                                  #                X2                              -NA, NORMCOUNT                          LEFT BY TFFCONIC
053649,000385:                                                                                                  #                TFF1/ALF        E:(-22-2NA)     SIGNED SEMIMAJ AXIS, WEIGHTED BY NA     LEFT BY TFFCONIC
053650,000386:                                                                                                  #                                M:(-20-2NA)
053651,000387: 
053652,000388:                                                                                                  #  DEBRIS:       QPRET, PDL+0 ... PDL+3
053653,000389:                                                                                                  #                RTERM           E:(-29) M:(-27) RTERM, TERMINAL RADIUS LENGTH
053654,000390:                                                                                                  #                RAPO            E:(-29) M:(-27) PDL 16D (=NRTERM)
053655,000391:                                                                                                  #                RPER            E:(-29) M:(-27) PDL 14D (=TFFQ1)
053656,000392: 

Page 1277

053658,000394: 27,3465           77614        CALCTPER           SETGO                                          #  ENTER WITH RPER IN MPAC
053659,000395: 27,3466           03436                                    TFFSW                                 
053660,000396: 27,3467           57472                                    +3                                    
053661,000397: 27,3470           77614        CALCTFF            CLEAR                                          #  ENTER WITH RTERM IN MPAC
053662,000398: 27,3471           03676                                    TFFSW                                 
053663,000399: 27,3472           00023                 +3        STORE    RTERM                                 #  E:(-29) M:(-27)
053664,000400: 27,3473           77657                           SL*                                            
053665,000401: 27,3474           20201                                    0,1                                   #  X1=-NR
053666,000402: 27,3475           00021                           STORE    NRTERM                                #  RTERM  E:(-29+NR) M:(-27+NR)
053667,000403: 27,3476           44205                           DMP      BDSU                                  
053668,000404: 27,3477           00033                                    TFFALFA                               #  ALFA  E:(26-NR) M:(24-NR)
053669,000405: 27,3500           06512                                    TFF1/4                                
053670,000406: 27,3501           41206                           PUSH     DMP                                   #  (2-ALFA RTERM)  (-3)  TO PDL+0
053671,000407: 27,3502           00021                                    NRTERM                                #  E:(-29+NR) M:(-27+NR)
053672,000408: 27,3503           53725                           PDDL     SR*                                   #  RTERM(2-ALFA RTERM) TO PDL+2
053673,000409:                                                                                                  #  E:(-32+NR) M:(-30+NR)
053674,000410: 27,3504           00035                                    TFFNP                                 #  LC P  E:(-38+2NR) M:(-36+2NR)
053675,000411: 27,3505           20573                                    0          -6,1                       #  X1 = -NR
053676,000412: 27,3506           43276                           DCOMP    DAD                                   #  DUE TO SHIFTS, KEEP PRECISION FOR SQRT
053677,000413:                                                                                                  #  RTERM(2-ALFA RTERM) FROM PDL +2
053678,000414:                                                                                                  #  E:(-32+NR) M:(-30+NR)
053679,000415: 27,3507           77657                           SR*                                            #  LEAVE  E:(-32) M:(-30)
053680,000416: 27,3510           20601                                    0,1                                   #  X1 = -NR
053681,000417: 27,3511           71214                           BOFF     DLOAD                                 #  CHECK TFF /TPER SWITCH
053682,000418: 27,3512           03756                                    TFFSW                                 
053683,000419: 27,3513           57515                                    +2                                    #  IF TFF, CONTINUE
053684,000420: 27,3514           06522                                    TFFZEROS                              #  IF TPER, SET Q2 = 0
053685,000421: 27,3515           75440                 +2        BMN      SQRT                                  #  E:(-16) M:(-15)
053686,000422: 
053687,000423: 27,3516           57650                                    MAXTFF1                               #  NO FREE FALL CONIC TO RTERM FROM HERE
053688,000424:                                                                                                  #  RESET PDL, SET TFF=POSMAX, AND EXIT.
053689,000425: 
053690,000426: 27,3517           41076                           DCOMP    BOVB                                  #  RT IS ON INBOUND SIDE.  ASSURE OVFIND=0
053691,000427: 27,3520           57753                                    TCDANZIG                              #  ANY PORT IN A STORM.
053692,000428: 27,3521           24045                           STOVL    TFFTEM                                #  Q2  E:(-16) M:(-15)
053693,000429: 27,3522           02170                                    VONE'                                 #  VN/SQRT(MU)  E:(10) M:(9)
053694,000430: 27,3523           52441                           DOT      SL3                                   
053695,000431: 27,3524           02207                                    RONE                                  #  SAVED RN.  E:(-29) M:(-27)
053696,000432: 27,3525           00017                           STORE    TFFQ1                                 #  Q1, SAVE FOR GONEPAST TEST.
053697,000433:                                                                                                  #  E:(-16) M:(-15)
053698,000434: 27,3526           44240                           BMN      BDSU                                  
053699,000435: 27,3527           57550                                    INBOUND                               #  USE ALTERNATE Z
053700,000436: 27,3530           00045                                    TFFTEM                                #  Q2  E:(-16) M:(-15)
053701,000437: 
053702,000438:                                                                                                  #  OUTBOUND Z CALC CONTINUES HERE
053703,000439: 
053704,000440: 27,3531           14043                           STODL    TFFX                                  #  NUM=Q2-Q1  E:(-16) M:(-15)
053705,000441: 27,3532           00033                                    TFFALFA                               #  ALFA  E:(26-NR) M:(24-NR)
053706,000442: 27,3533           44205                           DMP      BDSU                                  

Page 1278

053708,000444: 27,3534           00041                                    NRMAG                                 #  RMAG  E:(-29+NR) M:(-27+NR)
053709,000445:                                                                                                  #  (2-RTERM ALFA)  (-3) FROM PDL+0
053710,000446: 27,3535           51406        SAVEDEN            PUSH     ABS                                   #  DEN TO PDL+0  E:(-3) OR (-16)
053711,000447:                                                                                                  #                M:(-3) OR (-15)
053712,000448: 27,3536           40015                           DAD      BOV                                   #  INDETERMINANCY TEST
053713,000449: 27,3537           17757                                    LIM(-22)                              #  =1.0-B(-22)
053714,000450: 27,3540           57561                                    TFFXTEST                              #  GO IF DEN >/= B(-22)
053715,000451: 27,3541           65345                           DLOAD    PDDL                                  #  SET DEN=0 OTHERWISE
053716,000452: 27,3542           06522                                    TFFZEROS                              
053717,000453:                                                                                                  #  XCH ZERO WITH PDL+0
053718,000454: 27,3543           57545                           DLOAD    DCOMP                                 
053719,000455: 27,3544           00033                                    TFFALFA                               #  ALFA  E:(26-NR) M:(24-NR)
053720,000456: 27,3545           71240                           BMN      DLOAD                                 #  FOR TPER:  Z INDET AT DELE/2=0 AND 90.
053721,000457: 27,3546           57655                                    TFFEL1                                #  ASSUME 90, AND LEAVE 0 IN PDL: 1/Z=D/N
053722,000458: 
053723,000459:                                                                                                  #  Z INDET. AT PERIGEE FOR PARAB OR HYPERB.
053724,000460: 27,3547           77616        DUMPTFF1           RVQ                                            #  RETURN TFF =0
053725,000461: 
053726,000462:                                                                                                  #  INBOUND Z CALC CONTINUES HERE
053727,000463: 
053728,000464: 27,3550           77745        INBOUND            DLOAD                                          #  RESET PDL+0
053729,000465: 27,3551           45345                           DLOAD    DSU                                   #  ALTERNATE Z CALC
053730,000466: 27,3552           00023                                    RTERM                                 #  E:(-29) M:(-27)
053731,000467: 27,3553           00015                                    RMAG1                                 #  E:(-29) M:(-27)
053732,000468: 27,3554           14043                           STODL    TFFX                                  #  NUM=RTERM-RN  E:(-29) M:(-27)
053733,000469: 27,3555           00045                                    TFFTEM                                #  Q2  E:(-16) M:(-15)
053734,000470: 27,3556           52015                           DAD      GOTO                                  
053735,000471: 27,3557           00017                                    TFFQ1                                 #  Q1  E:(-16) M:(-15)
053736,000472: 27,3560           57535                                    SAVEDEN                               #  DEN = Q2+Q1  E:(-16) M:(-15)
053737,000473: 
053738,000474: 27,3561           65215        TFFXTEST           DAD      PDDL                                  #  (ABS(DEN) TO PDL+2))  E:(-3) OR (-16)
053739,000475:                                                                                                  #                        M:(-3) OR (-15)
053740,000476: 27,3562           17761                                    DP(-22)                               #  RESTORE ABS(DEN) TO MPAC
053741,000477: 27,3563           00043                                    TFFX                                  #  NUM  E:(-16) OR (-29)  M:(-15) OR (-27)
053742,000478: 27,3564           53605                           DMP      SR*                                   
053743,000479: 27,3565           00031                                    TFFRTALF                              #  SQRT(ALFA)  E:(10+NA) M:(9+NA)
053744,000480: 27,3566           57201                                    0          -3,2                       #  X2=-NA
053745,000481: 27,3567           77671                           DDV                                            #  C(MPAC) =NUM SQRT(ALFA)       E:(-3) OR (-16)
053746,000482:                                                                                                  #                                M:(-3) OR (-15)
053747,000483:                                                                                                  #  ABS(DEN) FROM PDL+2   E:(-3) OR (-16)
053748,000484:                                                                                                  #                        M:(-3) OR (-15)
053749,000485: 27,3570           40145                           DLOAD    BOV                                   #  (THE DLOAD IS SHARED WITH TFFELL)
053750,000486: 27,3571           00043                                    TFFX                                  #  NUM  E:(-16) OR (-29)  M:(-15) OR (-27)
053751,000487: 27,3572           57653                                    TFFELL                                #  USE EQN FOR DELE GEQ 90, LEQ -90
053752,000488: 
053753,000489:                                                                                                  #  OTHERWISE, CONTINUE FOR GENERAL CONIC FOR TFF EQN
053754,000490: 
053755,000491: 27,3573           45471                           DDV      STADR                                 
053756,000492:                                                                                                  #  DEN FROM PDL+0        E:(-3) OR (-16)
053757,000493:                                                                                                  #                        M:(-3) OR (-15)
053758,000494: 27,3574           77732                           STORE    TFFTEM                                #  Z SAVE FOR SIGN OF SDELF.

Page 1279

053760,000496:                                                                                                  #  E:(-13) M:(-12)
053761,000497: 27,3575           63406                           PUSH     DSQ                                   #  Z TO PDL+0
053762,000498: 27,3576           41206                           PUSH     DMP                                   #  Z SQ TO PDL+2  E:(-26) M:(-24)
053763,000499: 27,3577           00035                                    TFFNP                                 #  LC P  E:(-38+2NR) M:(-36+2NR)
053764,000500: 27,3600           75261                           SL       SIGN                                  
053765,000501: 27,3601           20206                                    5                                     
053766,000502: 27,3602           00045                                    TFFTEM                                #  AFFIX SIGN FOR SDELF (ENTRY DISPLAY)
053767,000503: 27,3603           14045                           STODL    TFFTEM                                #  P ZSQ  E:(-59+2NR) M:(-55+2NR)
053768,000504:                                                                                                  #  (ARG IS USED IN TFF/TRIG)
053769,000505:                                                                                                  #  ZSQ FROM PDL+2  E:(-26) M:(-24)
053770,000506: 27,3604           41206                           PUSH     DMP                                   #  RESTORE PUSH LOC
053771,000507: 27,3605           00033                                    TFFALFA                               #  ALFA  E:(26-NR) M:(24-NR)
053772,000508: 27,3606           77657                           SL*                                            
053773,000509: 27,3607           20201                                    0,1                                   #  X1=-NR
053774,000510: 27,3610           00043                           STORE    TFFX                                  #  X
053775,000511: 27,3611           41234                           RTB      DMP                                   
053776,000512: 27,3612           57735                                    T(X)                                  #  POLY
053777,000513:                                                                                                  #  ZSQ FROM PDL+2  E:(-26) M:(-24)
053778,000514: 27,3613           44302                           SR2      BDSU                                  #  2 ZSQ T(X)  E:(-29) M:(-27)
053779,000515: 27,3614           00023                                    RTERM                                 #  RTERM  E:(-29) M:(-27)
053780,000516: 27,3615           41215                           DAD      DMP                                   
053781,000517: 27,3616           00015                                    RMAG1                                 #  E:(-29) M:(-27)
053782,000518:                                                                                                  #  Z FROM PDL+0  E:(-13) M:(-12)
053783,000519: 27,3617           51042                           SR3      BPL                                   #  TFF SQRT(MU)  E:(-45) M:(-42)
053784,000520: 27,3620           57641                                    ENDTFF                                #  (NO PUSH UP)
053785,000521: 27,3621           75206                           PUSH     SIGN                                  #  TFF SQRT(MU) TO PDL+0
053786,000522: 27,3622           00017                                    TFFQ1                                 #  Q1 FOR GONEPAST TEST
053787,000523: 27,3623           71244                           BPL      DLOAD                                 #  GONE PAST ?
053788,000524: 27,3624           57645                                    NEGTFF                                #  YES. TFF < 0.
053789,000525: 27,3625           00027                                    TFF1/ALF                              #  1/ALFA  E:(-22-2NA) M:(-20-2NA)
053790,000526: 27,3626           51076                           DCOMP    BPL                                   #  ALFA > 0 ?
053791,000527: 27,3627           57645                                    NEGTFF                                #  NO. TFF IS NEGATIVE.
053792,000528: 
053793,000529:                                                                                                  #  CORRECT FOR ORBITAL PERIOD.
053794,000530: 
053795,000531: 27,3630           77676                           DCOMP                                          #  YES.  CORRECT FOR ORB PERIOD.
053796,000532: 27,3631           56205                           DMP      DDV                                   
053797,000533: 27,3632           17755                                    PI/16                                 #  2 PI (-5)
053798,000534: 27,3633           00031                                    TFFRTALF                              #  SQRT(ALFA)  E:(10+NA) M:(9+NA)
053799,000535: 27,3634           53657                           SL*      SL*                                   
053800,000536: 27,3635           57602                                    0          -4,2                       #  X2=-NA
053801,000537: 27,3636           57602                                    0          -4,2                       
053802,000538: 27,3637           43257                           SL*      DAD                                   
053803,000539: 27,3640           57576                                    0,2                                   
053804,000540:                                                                                                  #  TFF SQRT(MU) FROM PDL+0       E:(-45) M:(-42)
053805,000541: 27,3641           40005        ENDTFF             DMP      BOV                                   #  TFF SQRT(MU) IN MPAC          E:(-45) M:(-42)
053806,000542: 27,3642           00037                                    TFF/RTMU                              #  E:(17) M:(14)
053807,000543: 27,3643           57651                                    MAXTFF                                #  SET POSMAX IF OVFL.
053808,000544: 
053809,000545: 27,3644           77616        DUMPTFF2           RVQ                                            #  RETURN TFF (-28) CS IN MPAC.
053810,000546: 

Page 1280

053812,000548: 27,3645           77745        NEGTFF             DLOAD                                          
053813,000549:                                                                                                  #  TFF SQRT(MU) FROM PDL+0, NEGATIVE.
053814,000550: 27,3646           77650                           GOTO                                           
053815,000551: 27,3647           57641                                    ENDTFF                                
053816,000552: 
053817,000553: 27,3650           77745        MAXTFF1            DLOAD                                          #  RESET PDL
053818,000554: 27,3651           43545        MAXTFF             DLOAD    RVQ                                   
053819,000555: 27,3652           17771                                    NEARONE                               
053820,000556: 
053821,000557:                                                                                                  #  TIME OF FLIGHT ELLIPSE WHEN DEL (ECCENTRIC ANOM) GEQ 90 AND LEQ -90.
053822,000558: 
053823,000559:                                                                                                  #  NUM FROM TFFX.        E:(-16) OR (-29)
053824,000560:                                                                                                  #                        M:(-15) OR (-27)
053825,000561: 27,3653           77712        TFFELL             SL2                                            #  NUM  E:(-14) OR (-27)  M:(-13) OR (-25)
053826,000562: 27,3654           41465                           BDDV     PUSH                                  #  TEMP SAVE D/N IN PDL+0
053827,000563:                                                                                                  #  DEN FROM PDL+0  E:(-3)/( 16) M:(-3)/(-15)
053828,000564:                                                                                                  #  N/D TO PDL+0  E:(11) M:(10)
053829,000565: 27,3655           45345        TFFEL1             DLOAD    DSU                                   #  (ENTER WITH D/N=0 IN PDL+0)
053830,000566: 27,3656           00045                                    TFFTEM                                #  Q2  E:(-16) M:(-15)
053831,000567: 27,3657           00017                                    TFFQ1                                 #  Q1  E:(-16) M:(-15)
053832,000568: 27,3660           14013                           STODL    TFFDELQ                               #  Q2-Q1  E:(-16) M:(-15)
053833,000569:                                                                                                  #  D/N FROM PDL+0
053834,000570: 27,3661           77626                           STADR                                          
053835,000571: 27,3662           77732                           STORE    TFFTEM                                #  D/N  E:(11) M:(10)
053836,000572: 27,3663           53605                           DMP      SL*                                   
053837,000573: 27,3664           00027                                    TFF1/ALF                              #  1/ALFA  E:(-22-2NA) M:(-20-2NA)
053838,000574: 27,3665           57576                                    0,2                                   #  1/ALFA Z  E:(-11-NA) M:(-10-NA)
053839,000575: 27,3666           41206                           PUSH     DMP                                   #  TO PDL+0
053840,000576: 27,3667           00045                                    TFFTEM                                #  1/Z  E:(11) M:(10)
053841,000577: 27,3670           41057                           SL*      BOVB                                  
053842,000578: 27,3671           57576                                    0,2                                   #  X2= -NA
053843,000579: 27,3672           21712                                    SIGNMPAC                              #  IN CASE X= 1.0, CONTINUE
053844,000580: 27,3673           00043                           STORE    TFFX                                  #  X=1/ALFA ZSQ
053845,000581: 27,3674           41234                           RTB      DMP                                   
053846,000582: 27,3675           57735                                    T(X)                                  #  POLY
053847,000583: 27,3676           00043                                    TFFX                                  
053848,000584: 27,3677           45242                           SR3      DSU                                   
053849,000585: 27,3700           17763                                    DP2(-3)                               
053850,000586: 27,3701           41405                           DMP      PUSH                                  #  2(X T(X)-1) /Z ALFA   E:(-15-NA)
053851,000587:                                                                                                  #                        M:(-14-NA)
053852,000588:                                                                                                  #  1/ALFA Z FROM PDL+0   E:(-11-NA)
053853,000589:                                                                                                  #                        M:(-10-NA)
053854,000590: 27,3702           41345                           DLOAD    DMP                                   #  GET SIGN FOR SDELF
053855,000591: 27,3703           00045                                    TFFTEM                                #  1/Z  E:(11) M:(10)
053856,000592: 27,3704           00015                                    RMAG1                                 #  E:(-29) M:(-27)
053857,000593: 27,3705           43312                           SL2      DAD                                   
053858,000594: 27,3706           00017                                    TFFQ1                                 #  Q1  E:(-16) M:(-15)
053859,000595: 27,3707           14045                           STODL    TFFTEM                                #  (Q1+R 1/Z) =SGN OF SDELF  E:(-16) M:(-15
053860,000596: 27,3710           00035                                    TFFNP                                 #  LC P  E:(-38+2NR) M:(-36+2NR)
053861,000597: 27,3711           53605                           DMP      SL*                                   #  CALC FOR ARG FOR TFF/TRIG.

Page 1281

053863,000599: 27,3712           00027                                    TFF1/ALF                              #  1/ALFA  E:(-22-2NA) M:(-20-2NA)
053864,000600: 27,3713           57575                                    1,2                                   #  X2=-NA
053865,000601: 27,3714           53765                           SIGN     SL*                                   
053866,000602: 27,3715           00045                                    TFFTEM                                #  AFFIX SIGN FOR SDELF
053867,000603: 27,3716           57576                                    0,2                                   
053868,000604: 27,3717           14045                           STODL    TFFTEM                                #  P/ALFA  E:(-59+2NR) M:(-55+2NR)
053869,000605:                                                                                                  #  (ARG FOR USE IN TFF/TRIG)
053870,000606: 27,3720           00027                                    TFF1/ALF                              #  1/ALFA  E:(-22-2NA) M:(-20-2NA)
053871,000607: 27,3721           41366                           SQRT     DMP                                   
053872,000608: 27,3722           17755                                    PI/16                                 #  PI (-4)
053873,000609: 27,3723           77615                           DAD                                            
053874,000610:                                                                                                  #  2(XT(X)-1)/Z ALFA FROM PDL    E:(-15-NA)
053875,000611:                                                                                                  #                                M:(-14-NA)
053876,000612: 27,3724           45257                           SL*      DSU                                   
053877,000613: 27,3725           57577                                    0          -1,2                       
053878,000614: 27,3726           00013                                    TFFDELQ                               #  Q2-Q1  E:(-16) M:(-15)
053879,000615: 27,3727           53605                           DMP      SL*                                   
053880,000616: 27,3730           00027                                    TFF1/ALF                              #  1/ALFA  E:(-22-2NA) M:(-20-2NA)
053881,000617: 27,3731           57601                                    0          -3,2                       
053882,000618: 27,3732           52057                           SL*      GOTO                                  
053883,000619: 27,3733           57602                                    0          -4,2                       
053884,000620: 27,3734           57641                                    ENDTFF                                #  TFF SQRT(MU) IN MPAC E:(-45) M:(-42)
053885,000621: 

Page 1282

053887,000623:                                                                                                  #  PROGRAM NAME:  T(X)                           DATE:  01.17.67
053888,000624:                                                                                                  #  MOD NO:  0                                    LOG SECTION:  TIME OF FREE FALL
053889,000625:                                                                                                  #  MOD BY:  RR BAIRNSFATHER
053890,000626: 
053891,000627:                                                                                                  #  FUNCTIONAL DESCRIPTION:  THE POLYNOMIAL T(X) IS USED BY TIME OF FLIGHT SUBROUTINES CALCTFF AND
053892,000628:                                                                                                  #        CALCTPER TO APPROXIMATE THE SERIES
053893,000629:                                                                                                  #                           2     3
053894,000630:                                                                                                  #                1/3 -X/5 +X /7 -X /9 ...
053895,000631: 
053896,000632:                                                                                                  #        WHERE   X = ALFA Z Z            IF ALFA Z Z LEQ 1
053897,000633:                                                                                                  #                X = 1/(ALFA Z Z)        IF ALFA Z Z G 1
053898,000634: 
053899,000635:                                                                                                  #        ALSO    X IS NEG FOR HYPERBOLIC ORBITS
053900,000636:                                                                                                  #                X = 0 FOR PARABOLIC ORBITS
053901,000637:                                                                                                  #                X IS POSITIVE FOR ELLIPTIC ORBITS
053902,000638: 
053903,000639:                                                                                                  #        FOR FLIGHT 278, THE POLYNOMIAL T(X) IS FITTED OVER THE RANGE (0,+1) AND HAS A MAXIMUM
053904,000640:                                                                                                  #        DEVIATION FROM THE SERIES OF 2 E-5   (T(X) IS A CHEBYCHEV TYPE FIT AND WAS OBTAINED USING
053905,000641:                                                                                                  #        MAC PROGRAM AUTCURFIT294RRB AND IS VALID TO THE SAME TOLERANCE OVER THE RANGE (-.08,+1).)
053906,000642: 
053907,000643:                                                                                                  #  CALLING SEQUENCE:     RTB
053908,000644:                                                                                                  #                                T(X)
053909,000645:                                                                                                  #        C(MPAC) = X
053910,000646: 
053911,000647:                                                                                                  #  SUBROUTINES CALLED:  NONE
053912,000648: 
053913,000649:                                                                                                  #  NORMAL EXIT MODE:  TC   DANZIG
053914,000650: 
053915,000651:                                                                                                  #  ALARMS:  NONE
053916,000652: 
053917,000653:                                                                                                  #  OUTPUT:  C(MPAC) = T(X)
053918,000654: 
053919,000655:                                                                                                  #  ERASABLE INITIALIZATION REQUIRED:
053920,000656:                                                                                                  #        C(MPAC) = X
053921,000657: 
053922,000658:                                                                                                  #  DEBRIS:  NONE
053923,000659: 
053924,000660: 27,3735           07222        T(X)               TC       POLY                                  
053925,000661: 27,3736           00004                           DEC      4          B-14                       #  N-1
053926,000662: 27,3737           12525 12525                     2DEC     3.333333333 E-1                        
053927,000663: 
053928,000664: 27,3741           71463 57703                     2DEC*    -1.999819135 E-1*                       
053929,000665: 
053930,000666: 27,3743           04423 17645                     2DEC*    1.418148467 E-1*                       
053931,000667: 
053932,000668: 27,3745           74604 43667                     2DEC*    -1.01310997 E-1*                       
053933,000669: 
053934,000670: 27,3747           01626 37256                     2DEC*    5.609004986 E-2*                       
053935,000671: 
053936,000672: 27,3751           77404 52071                     2DEC*    -1.536156925 E-2*                       
053937,000673: 
053938,000674: 27,3753           06061        ENDT(X)            TC       DANZIG                                
053939,000675: 
053940,000676: 27,3754  27,3753               TCDANZIG           =        ENDT(X)                               
053941,000677: 

Page 1283

053943,000679:                                                                                                  #  TFF CONSTANTS
053944,000680: 
053945,000681: 32,3773                                           BANK     32                                    
053946,000682: 
053947,000683: 27,2000                                           SETLOC   TOF-FF1                               
053948,000684: 27,2000                                           BANK                                           
053949,000685: 
053950,000686:                                                                                                  #                                                NOTE _  NOTE _  ADJUSTED MUE FOR NEAR EARTH TRAJ.
053951,000687:                                                                                                  # MUE            =       3.990815471 E10         M CUBE/CS SQ
053952,000688:                                                                                                  # RTMUE          =       1.997702549 E5 B-18*    MODIFIED EARTH MU
053953,000689: 
053954,000690:                                                                                                  #                                                NOTE _  NOTE _  ADJUSTED MUE FOR NEAR EARTH TRAJ.
053955,000691:                                                                                                  # MUM            =       4.902778 E8             M CUBE/CS SQ
053956,000692:                                                                                                  # RTMUM          2DEC*   2.21422176 E4 B-18*
053957,000693: 
053958,000694: 27,3754           06220 37553  PI/16              2DEC     3.141592653 B-4                        
053959,000695: 
053960,000696: 27,3756           37777 37700  LIM(-22)           2OCT     3777737700                            #  1.0 -B(-22)
053961,000697: 
053962,000698: 27,3760           00000 00100  DP(-22)            2OCT     0000000100                            #  B(-22)
053963,000699: 
053964,000700: 27,3762           04000 00000  DP2(-3)            2DEC     1          B-3                        
053965,000701: 
053966,000702: 27,3764           02000 00000  DP2(-4)            2DEC     1          B-4                        #  1/16
053967,000703: 
053968,000704:                                                                                                  #  RPAD1         2DEC    6373338 B-29            M (-29) = 20909901.57 FT
053969,000705: 
053970,000706: 27,3766  23,2314               RPAD1              =        RPAD                                  
053971,000707: 
053972,000708: 27,3766           00305 11205  R300K              2DEC     6464778    B-29                       #  (-29) M
053973,000709: 
053974,000710: 27,3770           37777 37777  NEARONE            2DEC     .999999999                            
053975,000711: 
053976,000712: 27,3772  23,2521               TFFZEROS           EQUALS   HI6ZEROS                              
053977,000713: 27,3772  23,2511               TFF1/4             EQUALS   HIDP1/4                               
053978,000714: 

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