Source Code

These source-code files are part of a reconstructed copy of Luminary 97, the original release of the Apollo 11 Lunar Module (LM) Apollo Guidance Computer (AGC) software.

The reconstruction began with source code of Luminary 99 revision 1 previously transcribed from a digitized copy of that program. The code was then updated by undoing changes described in original Luminary memos 83 and 85, using asterisks indicating changed lines in the listing as a guide. The reconstruction was verified by matching memory-bank checksums to those listed in drawing 2021152D. Note that page numbers in the reconstructed code match those on the Luminary 099 revision 001 printout, although the added code would likely have changed page numbers for a real Luminary 97 listing.

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

053227,000002:                                                                                                  ## Copyright:   Public domain.
053228,000003:                                                                                                  ## Filename:    TIME_OF_FREE_FALL.agc
053229,000004:                                                                                                  ## Purpose:     A section of Luminary revision 97.
053230,000005:                                                                                                  ##              It is part of the reconstructed source code for the
053231,000006:                                                                                                  ##              original release of the flight software for the Lunar 
053232,000007:                                                                                                  ##              Module's (LM) Apollo Guidance Computer (AGC) for Apollo 11.
053233,000008:                                                                                                  ##              The code has been recreated from a copy of Luminary 99
053234,000009:                                                                                                  ##              revision 001, using asterisks indicating changed lines in
053235,000010:                                                                                                  ##              the listing and Luminary Memos #83 and #85, which list 
053236,000011:                                                                                                  ##              changes between Luminary 97 and 98, and 98 and 99. The
053237,000012:                                                                                                  ##              code has been adapted such that the resulting bugger words
053238,000013:                                                                                                  ##              exactly match those specified for Luminary 97 in NASA drawing
053239,000014:                                                                                                  ##              2021152D, which gives relatively high confidence that the
053240,000015:                                                                                                  ##              reconstruction is correct.
053241,000016:                                                                                                  ## Reference:   pp. 1268-1283
053242,000017:                                                                                                  ## Assembler:   yaYUL
053243,000018:                                                                                                  ## Contact:     Ron Burkey <info@sandroid.org>.
053244,000019:                                                                                                  ## Website:     www.ibiblio.org/apollo/index.html
053245,000020:                                                                                                  ## Mod history: 2019-07-28 MAS  Created from Luminary 99.
053246,000021: 

Page 1268

053248,000023:                                                                                                  #  THE TFF SUBROUTINES MAY BE USED IN EITHER EARTH OR MOON CENTERED COORDINATES.  THE TFF ROUTINES NEVER
053249,000024:                                                                                                  #  KNOW WHICH ORIGIN APPLIES.  IT IS THE USER WHO KNOWS, AND WHO SUPPLIES RONE, VONE AND 1/SQRT(MU) AT THE
053250,000025:                                                                                                  #  APPROPRIATE SCALE LEVEL FOR THE PROPER PRIMARY BODY.
053251,000026: 
053252,000027:                                                                                                  #        EARTH ORIGIN    POSITION        -29     METERS
053253,000028:                                                                                                  #                        VELOCITY        -7      METERS/CENTISECOND
053254,000029:                                                                                                  #                        1/SQRT(MU)      +17     SQRT(CS SQ/METERS CUBED)
053255,000030: 
053256,000031:                                                                                                  #        MOON ORIGIN     POSITION        -27     METERS
053257,000032:                                                                                                  #                        VELOCITY        -5      METERS/CENTISECONDS
053258,000033:                                                                                                  #                        1/SQRT(MU)      +14     SQRT(CS SQ/METERS CUBED)
053259,000034: 
053260,000035:                                                                                                  #  ALL DATA PROVIDED TO AND RECEIVED FROM ANY TFF SUBROUTINE WILL BE AT ONE OF THE LEVELS ABOVE.  IN ALL CASES,
053261,000036:                                                                                                  #  THE FREE FALL TIME IS RETURNED IN CENTISECONDS AT (-28).  PROGRAM TFF/CONIC WILL GENERATE VONE/RTMU AND
053262,000037:                                                                                                  #  LEAVE IT IN VONE' AT (+10) IF EARTH ORIGIN AND (+9) IF MOON ORIGIN.
053263,000038: 
053264,000039:                                                                                                  #  THE USER MUST STORE THE STATE VECTOR IN RONE, VONE  AND MU IN THE FORM 1/SQRT(MU) IN TFF/RTMU
053265,000040:                                                                                                  #  AT THE PROPER SCALE BEFORE CALLING TFF/CONIC.  SINCE RONE, VONE ARE IN THE EXTENDED VERB STORAGE AREA,
053266,000041:                                                                                                  #  THE USER MUST ALSO LOCK OUT THE EXTENDED VERBS, AND RELEASE THEM WHEN FINISHED.
053267,000042: 
053268,000043:                                                                                                  #  PROGRAMS CALC/TFF AND CALC/TPER ASSUME THAT THE TERMINAL RADIUS IS LESS THAN THE PRESENT
053269,000044:                                                                                                  #  RADIUS.  THIS RESTRICTION CAN BE REMOVED BY A 15 W CODING CHANGE, BUT AT PRESENT IT IS NOT DEEMED NECESSARY.
053270,000045: 
053271,000046:                                                                                                  #  THE FOLLOWING ERASABLE QUANTITIES ARE USED BY THE TFF ROUTINES, AND ARE LOCATED IN THE PUSH LIST.
053272,000047: 
053273,000048:                                                                                                  #                                        BELOW   E:  IS USED FOR EARTH ORIGIN SCALE
053274,000049:                                                                                                  #                                                M:  IS USED FOR MOON  ORIGIN SCALE
053275,000050: 
053276,000051:                                                                                                  # TFFSW          =       119D    BIT1    0 = CALCTFF             1 = CALCTPER
053277,000052: 10,2213                        TFFDELQ            =        10D                                   #        Q2-Q1                   E: (-16)  M: (-15)
053278,000053: 10,2213                        RMAG1              =        12D                                   #        ABVAL(RN)  M            E: (-29)  M: (-27)
053279,000054:                                                                                                  # RPER           =       14D             PERIGEE RADIUS  M       E: (-29)  M: (-27)
053280,000055: 10,2213                        TFFQ1              =        14D                                   #        R.V / SQRT(MUE)         E: (-16)  M: (-15)
053281,000056:                                                                                                  # SDELF/2                                SIN(THETA) /2
053282,000057: 10,2213                        CDELF/2            =        14D                                   #        COS(THETA) /2
053283,000058:                                                                                                  # RAPO           =       16D             APOGEE RADIUS  M        E: (-29)  M: (-27)
053284,000059: 10,2213                        NRTERM             =        16D                                   #        TERMINAL RADIUS  M      E: (-29+NR)
053285,000060:                                                                                                  #                                          M: (-27+NR)
053286,000061: 10,2213                        RTERM              =        18D                                   #        TERMINAL RADIUS  M      E: (-29)  M: (-27)
053287,000062: 10,2213                        TFFVSQ             =        20D                                   #        -(V SQUARED/MU)  1/M    E: (20)   M: (18)
053288,000063: 10,2213                        TFF1/ALF           =        22D                                   #        SEMI MAJ AXIS  M        E: (-22-2 NA)
053289,000064:                                                                                                  #                                          M: (-20-2 NA)
053290,000065: 10,2213                        TFFRTALF           =        24D                                   #        SQRT(ALFA)              E:(10+NA) M: (9+NA)
053291,000066: 10,2213                        TFFALFA            =        26D                                   #        ALFA  1/M               E:(26-NR) M: (24-NR)
053292,000067: 10,2213                        TFFNP              =        28D                                   #        SEMI LATUS RECTUM  M    E: (-38+2 NR)
053293,000068:                                                                                                  #                                          M: (-36+2 NR)
053294,000069: 10,2213                        TFF/RTMU           =        30D                                   #        1/SQRT(MU)              E: (17)   M: (14)
053295,000070: 10,2213                        NRMAG              =        32D                                   #        PRESENT RADIUS  M       E: (-29+NR)
053296,000071:                                                                                                  #                                          M: (-27+NR)
053297,000072: 10,2213                        TFFX               =        34D                                   
053298,000073: 10,2213                        TFFTEM             =        36D                                   #        TEMPORARY

Page 1269

053300,000075:                                                                                                  #                REGISTERS S1, S2 ARE UNTOUCHED BY ANY TFF SUBROUTINE
053301,000076:                                                                                                  #                INDEX REGISTERS X1, X2 ARE USED BY ALL TFF SUBROUTINES.  THEY ARE ESTAB-
053302,000077:                                                                                                  #                LISHED IN TFF/CONIC AND MUST BE PRESERVED BETWEEN CALLS TO SUBSEQUENT
053303,000078:                                                                                                  #                SUBROUTINES.
053304,000079:                                                                                                  #                -NR                             C(X1) = NORM COUNT OF RMAG
053305,000080:                                                                                                  #                -NA                             C(X2) = NORM COUNT OF SQRT(ABS(ALFA))
053306,000081: 

Page 1270

053308,000083:                                                                                                  #  SUBROUTINE NAME:  TFFCONIC                                            DATE:  01.29.67
053309,000084:                                                                                                  #  MOD NO:  0                                                            LOG SECTION:  TIME OF FREE FALL
053310,000085:                                                                                                  #  MOD BY:  RR BAIRNSFATHER
053311,000086:                                                                                                  #  MOD NO:  1    MOD BY:  RR BAIRNSFATHER        DATE: 11 APR 67
053312,000087:                                                                                                  #  MOD NO:  2    MOD BY:  RR BAIRNSFATHER        DATE: 21 NOV 67         ADD MOON MU.
053313,000088:                                                                                                  #  MOD NO:  3    MOD BY:  RR BAIRNSFATHER        DATE: 21 MAR 68         ACCEPT DIFFERENT EARTH/MOON SCALES
053314,000089: 
053315,000090:                                                                                                  #  FUNCTIONAL DESCRIPTION:  THIS SUBROUTINE IS CALLED TO COMPUTE THOSE CONIC PARAMETERS REQUIRED BY THE TFF
053316,000091:                                                                                                  #        SUBROUTINES AND TO ESTABLISH THEM IN THE PUSH LIST AREA.  THE PARAMETERS ARE LISTED UNDER OUTPUT.
053317,000092:                                                                                                  #        THE EQUATIONS ARE
053318,000093:                                                                                                  #                -   -  -
053319,000094:                                                                                                  #                H = RN*VN                       ANGULAR MOMENTUM
053320,000095:                                                                                                  #                      - -
053321,000096:                                                                                                  #                LCP = H.H / MU                  SEMI LATUS RECTUM
053322,000097:                                                                                                  #                              -  - 
053323,000098:                                                                                                  #                ALFA = 2/RN - VN.VN / MU        RECIPROCAL SEMI MAJ AXIS, SIGNED
053324,000099: 
053325,000100:                                                                                                  #        AND ALFA IS POS FOR ELLIPTIC ORBITS
053326,000101:                                                                                                  #                      0 FOR PARABOLIC ORBITS
053327,000102:                                                                                                  #                    NEG FOR HYPERBOLIC ORBITS.
053328,000103:                                                                                                  #        SUBROUTINE ALSO COMPUTES AND SAVES RMAG.
053329,000104: 
053330,000105:                                                                                                  #  CALLING SEQUENCE:
053331,000106:                                                                                                  #        TFFCONIC EXPECTS CALLER TO ENTER WITH CORRECT GRAVITATIONAL CONSTANT IN MPAC, IN THE FORM
053332,000107:                                                                                                  #        1/SQRT(MU).  PROGRAM WILL SAVE IN TFF/RTMU.  THE SCALE IS DETERMINED BY WHETHER EARTH OR MOON
053333,000108:                                                                                                  #        ORIGIN IS USED.  THE CALLER MUST LOCK OUT THE EXTENDED VERBS BEFORE PROVIDING STATE VECTOR IN RONE,
053334,000109:                                                                                                  #        VONE AT PROPER SCALE.  THE EXTENDED VERBS MUST BE RESTORED WHEN THE CALLER IS FINISHED USING THE
053335,000110:                                                                                                  #        TFF ROUTINES.
053336,000111: 
053337,000112:                                                                                                  #        ENTRY POINT TFFCONMU EXPECTS THAT TFF/RTMU IS ALREADY LOADED.
053338,000113: 
053339,000114:                                                                                                  #        TO SPECIFY MU:  DLOAD   CALL                            IF MU ALREADY STORED:   CALL
053340,000115:                                                                                                  #                                YOURMU  1/RTMU E:(17) M:(14)                                    TFFCONMU
053341,000116:                                                                                                  #                                TFFCONIC
053342,000117:                                                                                                  #        PUSHLOC = PDL+0, ARBITRARY IF LEQ 18D
053343,000118: 
053344,000119:                                                                                                  #  SUBROUTINES CALLED:  NONE
053345,000120: 
053346,000121:                                                                                                  #  NORMAL EXIT MODES:  RVQ
053347,000122: 
053348,000123:                                                                                                  #  ALARMS:  NONE
053349,000124: 
053350,000125:                                                                                                  #  OUTPUT:       THE FOLLOWING ARE STORED IN THE PUSH LIST AREA.
053351,000126:                                                                                                  #                RMAG1           E:(-29) M:(-27) M  RN, PRESENT RADIUS LENGTH.
053352,000127:                                                                                                  #                NRMAG           E:(-29+NR)      M  RMAG, NORMALIZED
053353,000128:                                                                                                  #                                M:(-27+NR)
053354,000129:                                                                                                  #                X1                              -NR, NORM COUNT
053355,000130:                                                                                                  #                TFFNP           E:(-38+2NR)     M  LCP, SEMI LATUS RECTUM, WEIGHTED BY NR.      FOR VGAMCALC
053356,000131:                                                                                                  #                                M:(-36+2NR)
053357,000132:                                                                                                  #                TFF/RTMU        E:(17) M:(14)   1/SQRT(MU)
053358,000133:                                                                                                  #                TFFVSQ          E:(20) M:(18)   1/M  -(V SQ/MU):  PRESENT VELOCITY,NORMLIZED.   FOR VGAMCALC
053359,000134:                                                                                                  #                TFFALFA         E:(26-NR)       1/M  ALFA, WEIGHTED BY NR
053360,000135:                                                                                                  #                                M:(24-NR)
053361,000136:                                                                                                  #                TFFRTALF        E:(10+NA)       SQRT(ALFA), NORMALIZED
053362,000137:                                                                                                  #                                M:(9+NA)

Page 1271

053364,000139:                                                                                                  #                X2                              -NA, NORMCOUNT
053365,000140:                                                                                                  #                TFF1/ALF        E:(-22-2NA)     SIGNED SEMI MAJ AXIS, WEIGHTED BY NA
053366,000141:                                                                                                  #                                M:(-20-2NA)
053367,000142:                                                                                                  #                PUSHLOC AT PDL+0
053368,000143: 
053369,000144:                                                                                                  #        THE FOLLOWING IS STORED IN GENERAL ERASABLE
053370,000145:                                                                                                  #                VONE'           E:(10) M:(9)    V/RT(MU), NORMALIZED VELOCITY
053371,000146: 
053372,000147:                                                                                                  #  ERASABLE INITIALIZATION REQUIRED:
053373,000148:                                                                                                  #                RONE            E:(-29) M:(-27) M  STATE VECTOR         LEFT BY CALLER
053374,000149:                                                                                                  #                VONE            E:(-7) M:(-5)   M/CS  STATE VECTOR      LEFT BY CALLER
053375,000150:                                                                                                  #                TFF/RTMU        E:(17) M:(14)   1/RT(CS SQ/M CUBE)      IF ENTER VIA TFFCONMU.
053376,000151: 
053377,000152:                                                                                                  #  DEBRIS:       QPRET,          PDL+0 ... PDL+3
053378,000153: 
053379,000154: 33,3757                                           BANK     33                                    
053380,000155: 27,2000                                           SETLOC   TOF-FF                                
053381,000156: 27,2000                                           BANK                                           
053382,000157: 
053383,000158: 27,3360                                           COUNT*   $$/TFF                                
053384,000159: 
053385,000160: 27,3360           00037        TFFCONIC           STORE    TFF/RTMU                              #  1/SQRT(MU)    E:(17) M:(14)
053386,000161: 
053387,000162: 27,3361           53575        TFFCONMU           VLOAD    UNIT                                  #  COME HERE WITH TFFRTMU LOADED.
053388,000163: 27,3362           02207                                    RONE                                  #  SAVED RN.  M  E:(-29) M:(-27)
053389,000164: 27,3363           77725                           PDDL                                           #  UR/2 TO PDL+0, +5
053390,000165: 27,3364           00045                                    36D                                   #  MAGNITUDE
053391,000166: 27,3365           00015                           STORE    RMAG1                                 #  M  E:(-29) M:(-27)
053392,000167: 
053393,000168: 27,3366           77701                           NORM                                           
053394,000169: 27,3367           00047                                    X1                                    #  -NR
053395,000170: 27,3370           24041                           STOVL    NRMAG                                 #  RMAG  M  E:(-29+NR) M:(-27+NR)
053396,000171: 27,3371           02215                                    VONE                                  #  SAVED VN.  M/CS  E:(-7) M:(-5)
053397,000172: 27,3372           77761                           VXSC                                           
053398,000173: 27,3373           00037                                    TFF/RTMU                              #  E:(17) M:(14)
053399,000174: 27,3374           02170                           STORE    VONE'                                 #  VN/SQRT(MU)  E:(10) M:(9)
053400,000175: 
053401,000176: 27,3375           47361                           VXSC     VXV                                   
053402,000177: 27,3376           00041                                    NRMAG                                 #  E:(-29+NR) M:(-27+NR)
053403,000178:                                                                                                  #  UR/2 FROM PDL
053404,000179: 27,3377           47572                           VSL1     VSQ                                   #  BEFORE:  E:(-19+NR) M:(-18+NR)
053405,000180: 27,3400           14035                           STODL    TFFNP                                 #  LC P  M  E:(-38+2NR) M:(-36+2NR)
053406,000181:                                                                                                  #  SAVE ALSO FOR VGAMCALC
053407,000182: 27,3401           06512                                    TFF1/4                                
053408,000183: 27,3402           63271                           DDV      PDVL                                  #  (2/RMAG)  1/M  E:(26-NR) M:(24-NR)
053409,000184: 27,3403           00041                                    NRMAG                                 #  RMAG  M  E:(-29+NR) M:(-27+NR)
053410,000185: 27,3404           02170                                    VONE'                                 #  SAVED VN.  E:(10) M:(9)
053411,000186: 27,3405           57436                           VSQ      DCOMP                                 #  KEEP MPAC+2 HONEST FOR SQRT.
053412,000187: 27,3406           00025                           STORE    TFFVSQ                                #  -(V SQ/MU)  E:(20) M:(18)
053413,000188:                                                                                                  #  SAVE FOR VGAMCALC
053414,000189: 27,3407           43257                           SR*      DAD                                   

Page 1272

053416,000191: 27,3410           20573                                    0          -6,1                       #  GET -VSQ/MU  E:(26-NR) M:(24-NR)
053417,000192: 27,3411           77626                           STADR                                          
053418,000193:                                                                                                  #  2/RMAG  FROM PDL+2
053419,000194: 27,3412           77744                           STORE    TFFALFA                               #  ALFA  1/M  E:(26-NR) M:(24-NR)
053420,000195: 27,3413           41457                           SL*      PUSH                                  #  TEMP SAVE ALFA  E:(20) M:(18)
053421,000196: 27,3414           20173                                    0          -6,1                       
053422,000197: 27,3415           75446                           ABS      SQRT                                  #  E:(10) M:(9)
053423,000198: 27,3416           77701                           NORM                                           
053424,000199: 27,3417           00050                                    X2                                    #  X2 = -NA
053425,000200: 27,3420           00031                           STORE    TFFRTALF                              #  SQRT( ABS(ALFA) )  E:(10+NA) M:(9+NA)
053426,000201: 27,3421           75316                           DSQ      SIGN                                  #  NOT SO ACCURATE, BUT OK
053427,000202:                                                                                                  #  ALFA FROM PDL+2  E:(20) M:(18)
053428,000203: 27,3422           55254                           BZE      BDDV                                  #  SET 1/ALFA =0, TO SHOW SMALL ALFA
053429,000204: 27,3423           57425                                    +2                                    
053430,000205: 27,3424           06512                                    TFF1/4                                
053431,000206: 27,3425           00027                 +2        STORE    TFF1/ALF                              #  1/ALFA  E:(-22-2NA) M:(-20-2NA)
053432,000207: 27,3426           77616        DUMPCNIC           RVQ                                            
053433,000208: 
053434,000209:                                                                                                  #                                                              39 W

Page 1273

053436,000211:                                                                                                  #  SUBROUTINE NAME:  TFFRP/RA                                            DATE: 01.17.67
053437,000212:                                                                                                  #  MOD NO:  0                                                            LOG SECTION:  TIME OF FREE FALL
053438,000213:                                                                                                  #  MOD BY:  RR BAIRNSFATHER
053439,000214:                                                                                                  #  MOD NO:  1    MOD BY:  RR BAIRNSFATHER        DATE: 11 APR 67
053440,000215:                                                                                                  #  MOD NO:  2    MOD BY:  RR BAIRNSFATHER        DATE: 21 MAR 68         ACCEPT DIFFERENT EARTH/MOON SCALES
053441,000216:                                                                                                  #                                                                        ALSO IMPROVE ACCURACY OF RAPO.
053442,000217: 
053443,000218:                                                                                                  #  FUNCTIONAL DESCRIPTION:  USED BY CALCTPER AND TFF DISPLAYS TO CALCULATE PERIGEE RADIUS AND ALSO
053444,000219:                                                                                                  #        APOGEE RADIUS FOR A GENERAL CONIC.
053445,000220:                                                                                                  #        PROGRAM GIVES PERIGEE RADIUS AS         APOGEE RADIUS IS GIVEN BY
053446,000221:                                                                                                  #                RP = P/(1+E)                            RA = (1+E) / ALFA
053447,000222:                                                                                                  #        WHERE    2
053448,000223:                                                                                                  #                E  = 1 - P ALFA
053449,000224:                                                                                                  #        IF RA IS NEGATIVE OR SHOWS DIVIDE OVERFLOW, THEN RA = POSMAX BECAUSE
053450,000225:                                                                                                  #                1. APOGEE RADIUS IS NOT MEANINGFUL FOR HYPERBOLA
053451,000226:                                                                                                  #                2. APOGEE RADIUS IS NOT DEFINED FOR PARABOLA
053452,000227:                                                                                                  #                3. APOGEE RADIUS EXCEEDS THE SCALING FOR ELLIPSE.
053453,000228: 
053454,000229:                                                                                                  #        THIS SUBROUTINE REQUIRES THE SIGNED RECIPROCAL SEMI MAJ AXIS, ALFA, AND SEMI LATUS RECTUM AS DATA.
053455,000230: 
053456,000231:                                                                                                  #  CALLING SEQUENCE:     CALL
053457,000232:                                                                                                  #                                TFFRP/RA
053458,000233:                                                                                                  #        PUSHLOC = PDL+0, ARBITRARY IF LEQ 10D
053459,000234:                                                                                                  #        C(MPAC) UNSPECIFIED
053460,000235: 
053461,000236:                                                                                                  #  SUBROUTINES CALLED:   NONE
053462,000237: 
053463,000238:                                                                                                  #  NORMAL EXIT MODE:     RVQ
053464,000239:                                                                                                  #        IF ELLIPSE, WITHIN NORMAL SCALING, RAPO IS CORRECT.
053465,000240:                                                                                                  #        OTHERWISE, RAPO = POSMAX.
053466,000241: 
053467,000242:                                                                                                  #  ALARMS:       NONE
053468,000243: 
053469,000244:                                                                                                  #  OUTPUT:       STORED IN PUSH LIST AREA.  SCALE OF OUTPUT AGREES WITH DATA SUPPLIED TO TFF/CONIC.
053470,000245:                                                                                                  #        RPER    E:(-29) M:(-27)         M       PERIGEE RADIUS          DESTROYED BY CALCTFF/CALCTPER, TFFTRIG.
053471,000246:                                                                                                  #        RAPO    E:(-29) M:(-27)         M       APOGEE RADIUS           WILL BE DESTROYED BY CALCTFF/CALCTPER
053472,000247:                                                                                                  #        PUSHLOC AT PDL+0
053473,000248: 
053474,000249:                                                                                                  #  ERASABLE INITIALIZATION REQUIRED:
053475,000250:                                                                                                  #        TFFALFA E:(26-NR)               M       1/SEMI MAJ AXIS         LEFT BY TFFCONIC
053476,000251:                                                                                                  #                M:(24-NR)
053477,000252:                                                                                                  #        TFFNP   E:(-38+2NR)             M       LC P, SEMI LATUS RECTUM LEFT BY TFFCONIC
053478,000253:                                                                                                  #                M:(-36+2NR)
053479,000254:                                                                                                  #        X1                              -NR, NORM COUNT OF RMAG         LEFT BY TFFCONIC
053480,000255:                                                                                                  #        X2                              -NA, NORM COUNT OF ALFA         LEFT BY TFFCONIC
053481,000256: 
053482,000257:                                                                                                  #  DEBRIS:       QPRET, PDL+0 ... PDL+1
053483,000258: 

Page 1274

053485,000260: 27,3427                        RAPO               =        16D                                   #  APOGEE RADIUS  M  E:(-29) M:(-27)
053486,000261: 27,3427                        RPER               =        14D                                   #  PERIGEE RADIUS  M  E:(-29) M:(-27)
053487,000262: 
053488,000263: 27,3427           41345        TFFRP/RA           DLOAD    DMP                                   
053489,000264: 27,3430           00033                                    TFFALFA                               #  ALFA  1/M  E:(26-NR) M:(24-NR)
053490,000265: 27,3431           00035                                    TFFNP                                 #  LC P  M E:(-38+2NR) M:(-36+2NR)
053491,000266: 27,3432           57457                           SR*      DCOMP                                 #  ALFA P (-12+NR)
053492,000267: 27,3433           20571                                    0          -8D,1                      #  ALFA P (-4)
053493,000268: 27,3434           51415                           DAD      ABS                                   #  (DCOMP GIVES VALID TP RESULT FOR SQRT)
053494,000269:                                                                                                  #  (ABS PROTECTS SQRT IF E IS VERY NEAR 0)
053495,000270: 27,3435           17765                                    DP2(-4)                               
053496,000271: 27,3436           43366                           SQRT     DAD                                   #  E SQ = (1- P ALFA) (-4)
053497,000272: 27,3437           06512                                    TFF1/4                                
053498,000273: 27,3440           55206                           PUSH     BDDV                                  #  (1+E)  (-2)  TO PDL+0
053499,000274: 27,3441           00035                                    TFFNP                                 #  LCP  M  E:(-38+2NR) M:(-36+2NR)
053500,000275: 27,3442           53657                           SR*      SR*                                   #  (DOES SR THEN SL TO AVOID OVFL)
053501,000276: 27,3443           20601                                    0,1                                   #  X1=-NR
053502,000277: 27,3444           20572                                    0          -7,1                       #  (EFFECTIVE SL)
053503,000278: 27,3445           14017                           STODL    RPER                                  #  PERIGEE RADIUS  M  E:(-29) M:(-27)
053504,000279:                                                                                                  #  (1+E)  (-2)  FROM PDL+0
053505,000280: 27,3446           41005                           DMP      BOVB                                  
053506,000281: 27,3447           00027                                    TFF1/ALF                              #  E:(-22-2NA) M:(-20-2NA)
053507,000282: 27,3450           57753                                    TCDANZIG                              #  CLEAR OVFIND, IF ON.
053508,000283: 27,3451           53654                           BZE      SL*                                   
053509,000284: 27,3452           57461                                    MAXRA                                 #  SET POSMAX, IF ALFA=0
053510,000285: 27,3453           57603                                    0          -5,2                       #  -5+NA
053511,000286: 27,3454           40057                           SL*      BOV                                   
053512,000287: 27,3455           57576                                    0,2                                   
053513,000288: 27,3456           57461                                    MAXRA                                 #  SET POSMAX IF OVFL.
053514,000289: 27,3457           77644                           BPL                                            #  CONTINUE WITH VALID RAPO.
053515,000290: 27,3460           57463                                    +3                                    
053516,000291: 27,3461           77745        MAXRA              DLOAD                                          #  RAPO CALC IS NOT VALID.  SET RAPO =
053517,000292: 27,3462           17771                                    NEARONE                               #  POSMAX AS A TAG.
053518,000293: 27,3463           00021                 +3        STORE    RAPO                                  #  APOGEE RADIUS  M  E:(-29) M:(-27)
053519,000294: 27,3464           77616        DUMPRPRA           RVQ                                            
053520,000295: 
053521,000296:                                                                                                  #                                                                30 W

Page 1275

053523,000298:                                                                                                  #  SUBROUTINE NAME:  CALCTPER / CALCTFF                                  DATE:  01.29.67
053524,000299:                                                                                                  #  MOD NO:  0                                                            LOG SECTION:  TIME OF FREE FALL
053525,000300:                                                                                                  #  MOD BY:  RR BAIRNSFATHER
053526,000301:                                                                                                  #  MOD NO:  1    MOD BY:  RR BAIRNSFATHER        DATE: 21 MAR 67
053527,000302:                                                                                                  #  MOD NO:  2    MOD BY:  RR BAIRNSFATHER        DATE: 14 APR 67
053528,000303:                                                                                                  #  MOD NO:  3    MOD BY:  RR BAIRNSFATHER        DATE: 8 JUL 67          NEAR EARTH MUE AND NEG TFF (GONEPAST)
053529,000304:                                                                                                  #  MOD NO:  4    MOD BY:  RR BAIRNSFATHER        DATE: 21 NOV 67         ADD VARIABLE MU.
053530,000305:                                                                                                  #  MOD NO:  5    MOD BY:  RR BAIRNSFATHER        DATE: 21 MAR 68         ACCEPT DIFFERENT EARTH/MOON SCALES
053531,000306: 
053532,000307:                                                                                                  #  FUNCTIONAL DESCRIPTION:  PROGRAM CALCULATES THE FREE-FALL TIME OF FLIGHT FROM PRESENT POSITION RN AND
053533,000308:                                                                                                  #        VELOCITY VN TO A RADIUS LENGTH SPECIFIED BY RTERM, SUPPLIED BY THE USER.  THE POSITION VECTOR
053534,000309:                                                                                                  #        RN MAY BE ON EITHER SIDE OF THE CONIC, BUT RTERM IS CONSIDERED ON THE INBOUND SIDE.
053535,000310:                                                                                                  #        THE EQUATIONS ARE
053536,000311: 
053537,000312:                                                                                                  #                Q2 = -SQRT(RTERM (2-RTERM ALFA) - LCP)  (INBOUND SIDE)) LEQ +- LCE/SQRT(ALFA)
053538,000313:                                                                                                  #                     -  -
053539,000314:                                                                                                  #                Q1 = RN.VN / SQRT(MU)                                   LEQ +- LCE/SQRT(ALFA)
053540,000315: 
053541,000316:                                                                                                  #                Z = NUM / DEN                                           LEQ +- 1/SQRT(ALFA)
053542,000317: 
053543,000318:                                                                                                  #        WHERE, IF INBOUND
053544,000319:                                                                                                  #                NUM = RTERM -RN                                         LEQ +- 2 LCE/ALFA
053545,000320:                                                                                                  #                DEN = Q2+Q1                                             LEQ +- 2 LCE/SQRT(ALFA)
053546,000321: 
053547,000322:                                                                                                  #        AND, IF OUTBOUND
053548,000323:                                                                                                  #                NUM = Q2-Q1                                             LEQ +- 2 LCE/SQRT(ALFA)
053549,000324:                                                                                                  #                DEN = 2 - ALFA (RTERM + RN).                            LEQ +- 2 LCE
053550,000325: 
053551,000326:                                                                                                  #        IF      ALFA ZZ < 1.0           (FOR ALL CONICS EXCEPT ELLIPSES HAVING ABS(DEL ECC ANOM) G 90 DEG)
053552,000327:                                                                                                  #        THEN    X = ALFA Z Z
053553,000328:                                                                                                  #        AND     TFF = (RTERM +RN -2 ZZ T(X) ) Z/SQRT(MU)
053554,000329:                                                                                                  #                EXCEPT  IF ALFA PNZ, AND IF TFF NEG,
053555,000330:                                                                                                  #                THEN    TFF = 2 PI /(ALFA SQRT(ALFA)) + TFF
053556,000331:                                                                                                  #        OR      IF ALFA ZZ GEQ 1.0      (FOR ELLIPSES HAVING ABS(DEL ECC ANOM) GEQ 90 DEG)
053557,000332:                                                                                                  #        THEN    X = 1/ALFA Z Z
053558,000333:                                                                                                  #        AND     TFF = (PI/SQRT(ALFA) -Q2 +Q1 +2(X T(X) -1) /ALFA Z) /ALFA SQRT(MU)
053559,000334:                                                                                                  #        WHERE   T(X) IS A POLYNOMIAL APPROXIMATION TO THE SERIES
053560,000335:                                                                                                  #                             2      3             2
053561,000336:                                                                                                  #                1/3 - X/5 + X /7 - X /9 ...     (X  < 1.0)
053562,000337: 
053563,000338:                                                                                                  #  CALLING SEQUENCE:     TIME TO RTERM                   TIME TO PERIGEE
053564,000339:                                                                                                  #                        CALL                            CALL
053565,000340:                                                                                                  #                                CALCTFF                         CALCTPER
053566,000341:                                                                                                  #                        C(MPAC) = TERMNL RAD M          C(MPAC) = PERIGEE RAD M
053567,000342:                                                                                                  #        FOR EITHER, E:(-29) M:(-27)
053568,000343:                                                                                                  #        FOR EITHER, PUSHLOC = PDL+0, ARBITRARY IF LEQ 8D.

Page 1276

053570,000345: 
053571,000346:                                                                                                  #  SUBROUTINES CALLED:   T(X), VIA RTB
053572,000347: 
053573,000348:                                                                                                  #  NORMAL EXIT MODE:     RVQ
053574,000349:                                                                                                  #        HOWEVER, PROGRAM EXITS WITH ONE OF THE FOLLOWING VALUES FOR TFF (-28) CS IN MPAC.  USER MUST STORE.
053575,000350:                                                                                                  #                A. TFF = FLIGHT TIME.  NORMAL CASE FOR POSITIVE FLIGHT TIME LESS THAN ONE ORBITAL PERIOD.
053576,000351:                                                                                                  #                B. (THIS OPTION IS NO LONGER USED.)
053577,000352:                                                                                                  #                C. TFF = POSMAX.  THIS INDICATES THAT THE CONIC FROM THE PRESENT POSITION WILL NOT RETURN TO
053578,000353:                                                                                                  #                   THE SPECIFIED ALTITUDE.  ALSO INDICATES OUTBOUND PARABOLA OR HYPERBOLA.
053579,000354: 
053580,000355:                                                                                                  #  OUTPUT:       C(MPAC)         (-28) CS        TIME OF FLIGHT, OR TIME TO PERIGEE
053581,000356:                                                                                                  #                TFFX            (0)             X,                                      LEFT FOR ENTRY DISPLAY TFF ROUTINES
053582,000357:                                                                                                  #                NRTERM          E:(-29+NR) M    RTERM, WEIGHTED BY NR                   LEFT FOR ENTRY DISPLAY TFF ROUTINES
053583,000358:                                                                                                  #                                M:(-27+NR)
053584,000359:                                                                                                  #                TFFTEM          E:(-59+2NR)     LCP Z Z SGN(SDELF)                      LEFT FOR ENTRY DISPLAY TFF ROUTINES
053585,000360:                                                                                                  #                                M:(-55+2NR)     LCP /ALFA SGN(SDELF)                    LEFT FOR ENTRY DISPLAY TFF ROUTINES
053586,000361:                                                                                                  #                NOTE:   TFFTEM = PDL 36D AND WILL BE DESTROYED BY .:UNIT:.
053587,000362:                                                                                                  #                RMAG1           E:(-29) M:(-27) PDL 12 NOT TOUCHED.
053588,000363:                                                                                                  #                TFFQ1           E:(-16) M:(-15) PDL 14D
053589,000364:                                                                                                  #                TFFDELQ         E:(-16) M:(-15) PDL 10D
053590,000365:                                                                                                  #                PUSHLOC AT PDL+0
053591,000366: 
053592,000367:                                                                                                  #  ERASABLE INITIALIZATION REQUIRED:
053593,000368:                                                                                                  #                RONE            E:(-29) M:(-27) M  STATE VECTOR                         LEFT BY USER
053594,000369:                                                                                                  #                VONE'           E:(+10) M:(+9)  VN/SQRT(MU)                             LEFT BY TFF/CONIC
053595,000370:                                                                                                  #                RMAG1           E:(-29) M:(-27) PRESENT RADIUS, M                       LEFT BY TFFCONIC
053596,000371:                                                                                                  #                C(MPAC)         E:(-29) M:(-27) RTERM, TERMINAL RADIUS LENGTH, M        LEFT BY USER
053597,000372: 
053598,000373:                                                                                                  #                THE FOLLOWING ARE STORED IN THE PUSH LIST AREA.
053599,000374:                                                                                                  #                TFF/RTMU        E:(17) M:(14)   1/SQRT(MU)                              LEFT BY TFFCONIC.
053600,000375:                                                                                                  #                NRMAG           E:(-29+NR)      M  RMAG, NORMALIZED                     LEFT BY TFFCONIC
053601,000376:                                                                                                  #                                M:(-27+NR)
053602,000377:                                                                                                  #                X1                              -NR, NORM COUNT                         LEFT BY TFFCONIC
053603,000378:                                                                                                  #                TFFNP           E:(-38+2NR)     M  LCP, SEMI LATUS RECTUM, WEIGHT NR    LEFT BY TFFCONIC
053604,000379:                                                                                                  #                                M:(-36+2NR)
053605,000380:                                                                                                  #                TFFALFA         E:(26-NR)       1/M  ALFA, WEIGHT NR                    LEFT BY TFFCONIC
053606,000381:                                                                                                  #                                M:(24-NR)
053607,000382:                                                                                                  #                TFFRTALF        E:(10+NA)       SQRT(ALFA), NORMALIZED                  LEFT BY TFFCONIC
053608,000383:                                                                                                  #                                M:(9+NA)
053609,000384:                                                                                                  #                X2                              -NA, NORMCOUNT                          LEFT BY TFFCONIC
053610,000385:                                                                                                  #                TFF1/ALF        E:(-22-2NA)     SIGNED SEMIMAJ AXIS, WEIGHTED BY NA     LEFT BY TFFCONIC
053611,000386:                                                                                                  #                                M:(-20-2NA)
053612,000387: 
053613,000388:                                                                                                  #  DEBRIS:       QPRET, PDL+0 ... PDL+3
053614,000389:                                                                                                  #                RTERM           E:(-29) M:(-27) RTERM, TERMINAL RADIUS LENGTH
053615,000390:                                                                                                  #                RAPO            E:(-29) M:(-27) PDL 16D (=NRTERM)
053616,000391:                                                                                                  #                RPER            E:(-29) M:(-27) PDL 14D (=TFFQ1)
053617,000392: 

Page 1277

053619,000394: 27,3465           77614        CALCTPER           SETGO                                          #  ENTER WITH RPER IN MPAC
053620,000395: 27,3466           03436                                    TFFSW                                 
053621,000396: 27,3467           57472                                    +3                                    
053622,000397: 27,3470           77614        CALCTFF            CLEAR                                          #  ENTER WITH RTERM IN MPAC
053623,000398: 27,3471           03676                                    TFFSW                                 
053624,000399: 27,3472           00023                 +3        STORE    RTERM                                 #  E:(-29) M:(-27)
053625,000400: 27,3473           77657                           SL*                                            
053626,000401: 27,3474           20201                                    0,1                                   #  X1=-NR
053627,000402: 27,3475           00021                           STORE    NRTERM                                #  RTERM  E:(-29+NR) M:(-27+NR)
053628,000403: 27,3476           44205                           DMP      BDSU                                  
053629,000404: 27,3477           00033                                    TFFALFA                               #  ALFA  E:(26-NR) M:(24-NR)
053630,000405: 27,3500           06512                                    TFF1/4                                
053631,000406: 27,3501           41206                           PUSH     DMP                                   #  (2-ALFA RTERM)  (-3)  TO PDL+0
053632,000407: 27,3502           00021                                    NRTERM                                #  E:(-29+NR) M:(-27+NR)
053633,000408: 27,3503           53725                           PDDL     SR*                                   #  RTERM(2-ALFA RTERM) TO PDL+2
053634,000409:                                                                                                  #  E:(-32+NR) M:(-30+NR)
053635,000410: 27,3504           00035                                    TFFNP                                 #  LC P  E:(-38+2NR) M:(-36+2NR)
053636,000411: 27,3505           20573                                    0          -6,1                       #  X1 = -NR
053637,000412: 27,3506           43276                           DCOMP    DAD                                   #  DUE TO SHIFTS, KEEP PRECISION FOR SQRT
053638,000413:                                                                                                  #  RTERM(2-ALFA RTERM) FROM PDL +2
053639,000414:                                                                                                  #  E:(-32+NR) M:(-30+NR)
053640,000415: 27,3507           77657                           SR*                                            #  LEAVE  E:(-32) M:(-30)
053641,000416: 27,3510           20601                                    0,1                                   #  X1 = -NR
053642,000417: 27,3511           71214                           BOFF     DLOAD                                 #  CHECK TFF /TPER SWITCH
053643,000418: 27,3512           03756                                    TFFSW                                 
053644,000419: 27,3513           57515                                    +2                                    #  IF TFF, CONTINUE
053645,000420: 27,3514           06522                                    TFFZEROS                              #  IF TPER, SET Q2 = 0
053646,000421: 27,3515           75440                 +2        BMN      SQRT                                  #  E:(-16) M:(-15)
053647,000422: 
053648,000423: 27,3516           57650                                    MAXTFF1                               #  NO FREE FALL CONIC TO RTERM FROM HERE
053649,000424:                                                                                                  #  RESET PDL, SET TFF=POSMAX, AND EXIT.
053650,000425: 
053651,000426: 27,3517           41076                           DCOMP    BOVB                                  #  RT IS ON INBOUND SIDE.  ASSURE OVFIND=0
053652,000427: 27,3520           57753                                    TCDANZIG                              #  ANY PORT IN A STORM.
053653,000428: 27,3521           24045                           STOVL    TFFTEM                                #  Q2  E:(-16) M:(-15)
053654,000429: 27,3522           02170                                    VONE'                                 #  VN/SQRT(MU)  E:(10) M:(9)
053655,000430: 27,3523           52441                           DOT      SL3                                   
053656,000431: 27,3524           02207                                    RONE                                  #  SAVED RN.  E:(-29) M:(-27)
053657,000432: 27,3525           00017                           STORE    TFFQ1                                 #  Q1, SAVE FOR GONEPAST TEST.
053658,000433:                                                                                                  #  E:(-16) M:(-15)
053659,000434: 27,3526           44240                           BMN      BDSU                                  
053660,000435: 27,3527           57550                                    INBOUND                               #  USE ALTERNATE Z
053661,000436: 27,3530           00045                                    TFFTEM                                #  Q2  E:(-16) M:(-15)
053662,000437: 
053663,000438:                                                                                                  #  OUTBOUND Z CALC CONTINUES HERE
053664,000439: 
053665,000440: 27,3531           14043                           STODL    TFFX                                  #  NUM=Q2-Q1  E:(-16) M:(-15)
053666,000441: 27,3532           00033                                    TFFALFA                               #  ALFA  E:(26-NR) M:(24-NR)
053667,000442: 27,3533           44205                           DMP      BDSU                                  

Page 1278

053669,000444: 27,3534           00041                                    NRMAG                                 #  RMAG  E:(-29+NR) M:(-27+NR)
053670,000445:                                                                                                  #  (2-RTERM ALFA)  (-3) FROM PDL+0
053671,000446: 27,3535           51406        SAVEDEN            PUSH     ABS                                   #  DEN TO PDL+0  E:(-3) OR (-16)
053672,000447:                                                                                                  #                M:(-3) OR (-15)
053673,000448: 27,3536           40015                           DAD      BOV                                   #  INDETERMINANCY TEST
053674,000449: 27,3537           17757                                    LIM(-22)                              #  =1.0-B(-22)
053675,000450: 27,3540           57561                                    TFFXTEST                              #  GO IF DEN >/= B(-22)
053676,000451: 27,3541           65345                           DLOAD    PDDL                                  #  SET DEN=0 OTHERWISE
053677,000452: 27,3542           06522                                    TFFZEROS                              
053678,000453:                                                                                                  #  XCH ZERO WITH PDL+0
053679,000454: 27,3543           57545                           DLOAD    DCOMP                                 
053680,000455: 27,3544           00033                                    TFFALFA                               #  ALFA  E:(26-NR) M:(24-NR)
053681,000456: 27,3545           71240                           BMN      DLOAD                                 #  FOR TPER:  Z INDET AT DELE/2=0 AND 90.
053682,000457: 27,3546           57655                                    TFFEL1                                #  ASSUME 90, AND LEAVE 0 IN PDL: 1/Z=D/N
053683,000458: 
053684,000459:                                                                                                  #  Z INDET. AT PERIGEE FOR PARAB OR HYPERB.
053685,000460: 27,3547           77616        DUMPTFF1           RVQ                                            #  RETURN TFF =0
053686,000461: 
053687,000462:                                                                                                  #  INBOUND Z CALC CONTINUES HERE
053688,000463: 
053689,000464: 27,3550           77745        INBOUND            DLOAD                                          #  RESET PDL+0
053690,000465: 27,3551           45345                           DLOAD    DSU                                   #  ALTERNATE Z CALC
053691,000466: 27,3552           00023                                    RTERM                                 #  E:(-29) M:(-27)
053692,000467: 27,3553           00015                                    RMAG1                                 #  E:(-29) M:(-27)
053693,000468: 27,3554           14043                           STODL    TFFX                                  #  NUM=RTERM-RN  E:(-29) M:(-27)
053694,000469: 27,3555           00045                                    TFFTEM                                #  Q2  E:(-16) M:(-15)
053695,000470: 27,3556           52015                           DAD      GOTO                                  
053696,000471: 27,3557           00017                                    TFFQ1                                 #  Q1  E:(-16) M:(-15)
053697,000472: 27,3560           57535                                    SAVEDEN                               #  DEN = Q2+Q1  E:(-16) M:(-15)
053698,000473: 
053699,000474: 27,3561           65215        TFFXTEST           DAD      PDDL                                  #  (ABS(DEN) TO PDL+2))  E:(-3) OR (-16)
053700,000475:                                                                                                  #                        M:(-3) OR (-15)
053701,000476: 27,3562           17761                                    DP(-22)                               #  RESTORE ABS(DEN) TO MPAC
053702,000477: 27,3563           00043                                    TFFX                                  #  NUM  E:(-16) OR (-29)  M:(-15) OR (-27)
053703,000478: 27,3564           53605                           DMP      SR*                                   
053704,000479: 27,3565           00031                                    TFFRTALF                              #  SQRT(ALFA)  E:(10+NA) M:(9+NA)
053705,000480: 27,3566           57201                                    0          -3,2                       #  X2=-NA
053706,000481: 27,3567           77671                           DDV                                            #  C(MPAC) =NUM SQRT(ALFA)       E:(-3) OR (-16)
053707,000482:                                                                                                  #                                M:(-3) OR (-15)
053708,000483:                                                                                                  #  ABS(DEN) FROM PDL+2   E:(-3) OR (-16)
053709,000484:                                                                                                  #                        M:(-3) OR (-15)
053710,000485: 27,3570           40145                           DLOAD    BOV                                   #  (THE DLOAD IS SHARED WITH TFFELL)
053711,000486: 27,3571           00043                                    TFFX                                  #  NUM  E:(-16) OR (-29)  M:(-15) OR (-27)
053712,000487: 27,3572           57653                                    TFFELL                                #  USE EQN FOR DELE GEQ 90, LEQ -90
053713,000488: 
053714,000489:                                                                                                  #  OTHERWISE, CONTINUE FOR GENERAL CONIC FOR TFF EQN
053715,000490: 
053716,000491: 27,3573           45471                           DDV      STADR                                 
053717,000492:                                                                                                  #  DEN FROM PDL+0        E:(-3) OR (-16)
053718,000493:                                                                                                  #                        M:(-3) OR (-15)
053719,000494: 27,3574           77732                           STORE    TFFTEM                                #  Z SAVE FOR SIGN OF SDELF.

Page 1279

053721,000496:                                                                                                  #  E:(-13) M:(-12)
053722,000497: 27,3575           63406                           PUSH     DSQ                                   #  Z TO PDL+0
053723,000498: 27,3576           41206                           PUSH     DMP                                   #  Z SQ TO PDL+2  E:(-26) M:(-24)
053724,000499: 27,3577           00035                                    TFFNP                                 #  LC P  E:(-38+2NR) M:(-36+2NR)
053725,000500: 27,3600           75261                           SL       SIGN                                  
053726,000501: 27,3601           20206                                    5                                     
053727,000502: 27,3602           00045                                    TFFTEM                                #  AFFIX SIGN FOR SDELF (ENTRY DISPLAY)
053728,000503: 27,3603           14045                           STODL    TFFTEM                                #  P ZSQ  E:(-59+2NR) M:(-55+2NR)
053729,000504:                                                                                                  #  (ARG IS USED IN TFF/TRIG)
053730,000505:                                                                                                  #  ZSQ FROM PDL+2  E:(-26) M:(-24)
053731,000506: 27,3604           41206                           PUSH     DMP                                   #  RESTORE PUSH LOC
053732,000507: 27,3605           00033                                    TFFALFA                               #  ALFA  E:(26-NR) M:(24-NR)
053733,000508: 27,3606           77657                           SL*                                            
053734,000509: 27,3607           20201                                    0,1                                   #  X1=-NR
053735,000510: 27,3610           00043                           STORE    TFFX                                  #  X
053736,000511: 27,3611           41234                           RTB      DMP                                   
053737,000512: 27,3612           57735                                    T(X)                                  #  POLY
053738,000513:                                                                                                  #  ZSQ FROM PDL+2  E:(-26) M:(-24)
053739,000514: 27,3613           44302                           SR2      BDSU                                  #  2 ZSQ T(X)  E:(-29) M:(-27)
053740,000515: 27,3614           00023                                    RTERM                                 #  RTERM  E:(-29) M:(-27)
053741,000516: 27,3615           41215                           DAD      DMP                                   
053742,000517: 27,3616           00015                                    RMAG1                                 #  E:(-29) M:(-27)
053743,000518:                                                                                                  #  Z FROM PDL+0  E:(-13) M:(-12)
053744,000519: 27,3617           51042                           SR3      BPL                                   #  TFF SQRT(MU)  E:(-45) M:(-42)
053745,000520: 27,3620           57641                                    ENDTFF                                #  (NO PUSH UP)
053746,000521: 27,3621           75206                           PUSH     SIGN                                  #  TFF SQRT(MU) TO PDL+0
053747,000522: 27,3622           00017                                    TFFQ1                                 #  Q1 FOR GONEPAST TEST
053748,000523: 27,3623           71244                           BPL      DLOAD                                 #  GONE PAST ?
053749,000524: 27,3624           57645                                    NEGTFF                                #  YES. TFF < 0.
053750,000525: 27,3625           00027                                    TFF1/ALF                              #  1/ALFA  E:(-22-2NA) M:(-20-2NA)
053751,000526: 27,3626           51076                           DCOMP    BPL                                   #  ALFA > 0 ?
053752,000527: 27,3627           57645                                    NEGTFF                                #  NO. TFF IS NEGATIVE.
053753,000528: 
053754,000529:                                                                                                  #  CORRECT FOR ORBITAL PERIOD.
053755,000530: 
053756,000531: 27,3630           77676                           DCOMP                                          #  YES.  CORRECT FOR ORB PERIOD.
053757,000532: 27,3631           56205                           DMP      DDV                                   
053758,000533: 27,3632           17755                                    PI/16                                 #  2 PI (-5)
053759,000534: 27,3633           00031                                    TFFRTALF                              #  SQRT(ALFA)  E:(10+NA) M:(9+NA)
053760,000535: 27,3634           53657                           SL*      SL*                                   
053761,000536: 27,3635           57602                                    0          -4,2                       #  X2=-NA
053762,000537: 27,3636           57602                                    0          -4,2                       
053763,000538: 27,3637           43257                           SL*      DAD                                   
053764,000539: 27,3640           57576                                    0,2                                   
053765,000540:                                                                                                  #  TFF SQRT(MU) FROM PDL+0       E:(-45) M:(-42)
053766,000541: 27,3641           40005        ENDTFF             DMP      BOV                                   #  TFF SQRT(MU) IN MPAC          E:(-45) M:(-42)
053767,000542: 27,3642           00037                                    TFF/RTMU                              #  E:(17) M:(14)
053768,000543: 27,3643           57651                                    MAXTFF                                #  SET POSMAX IF OVFL.
053769,000544: 
053770,000545: 27,3644           77616        DUMPTFF2           RVQ                                            #  RETURN TFF (-28) CS IN MPAC.
053771,000546: 

Page 1280

053773,000548: 27,3645           77745        NEGTFF             DLOAD                                          
053774,000549:                                                                                                  #  TFF SQRT(MU) FROM PDL+0, NEGATIVE.
053775,000550: 27,3646           77650                           GOTO                                           
053776,000551: 27,3647           57641                                    ENDTFF                                
053777,000552: 
053778,000553: 27,3650           77745        MAXTFF1            DLOAD                                          #  RESET PDL
053779,000554: 27,3651           43545        MAXTFF             DLOAD    RVQ                                   
053780,000555: 27,3652           17771                                    NEARONE                               
053781,000556: 
053782,000557:                                                                                                  #  TIME OF FLIGHT ELLIPSE WHEN DEL (ECCENTRIC ANOM) GEQ 90 AND LEQ -90.
053783,000558: 
053784,000559:                                                                                                  #  NUM FROM TFFX.        E:(-16) OR (-29)
053785,000560:                                                                                                  #                        M:(-15) OR (-27)
053786,000561: 27,3653           77712        TFFELL             SL2                                            #  NUM  E:(-14) OR (-27)  M:(-13) OR (-25)
053787,000562: 27,3654           41465                           BDDV     PUSH                                  #  TEMP SAVE D/N IN PDL+0
053788,000563:                                                                                                  #  DEN FROM PDL+0  E:(-3)/( 16) M:(-3)/(-15)
053789,000564:                                                                                                  #  N/D TO PDL+0  E:(11) M:(10)
053790,000565: 27,3655           45345        TFFEL1             DLOAD    DSU                                   #  (ENTER WITH D/N=0 IN PDL+0)
053791,000566: 27,3656           00045                                    TFFTEM                                #  Q2  E:(-16) M:(-15)
053792,000567: 27,3657           00017                                    TFFQ1                                 #  Q1  E:(-16) M:(-15)
053793,000568: 27,3660           14013                           STODL    TFFDELQ                               #  Q2-Q1  E:(-16) M:(-15)
053794,000569:                                                                                                  #  D/N FROM PDL+0
053795,000570: 27,3661           77626                           STADR                                          
053796,000571: 27,3662           77732                           STORE    TFFTEM                                #  D/N  E:(11) M:(10)
053797,000572: 27,3663           53605                           DMP      SL*                                   
053798,000573: 27,3664           00027                                    TFF1/ALF                              #  1/ALFA  E:(-22-2NA) M:(-20-2NA)
053799,000574: 27,3665           57576                                    0,2                                   #  1/ALFA Z  E:(-11-NA) M:(-10-NA)
053800,000575: 27,3666           41206                           PUSH     DMP                                   #  TO PDL+0
053801,000576: 27,3667           00045                                    TFFTEM                                #  1/Z  E:(11) M:(10)
053802,000577: 27,3670           41057                           SL*      BOVB                                  
053803,000578: 27,3671           57576                                    0,2                                   #  X2= -NA
053804,000579: 27,3672           21712                                    SIGNMPAC                              #  IN CASE X= 1.0, CONTINUE
053805,000580: 27,3673           00043                           STORE    TFFX                                  #  X=1/ALFA ZSQ
053806,000581: 27,3674           41234                           RTB      DMP                                   
053807,000582: 27,3675           57735                                    T(X)                                  #  POLY
053808,000583: 27,3676           00043                                    TFFX                                  
053809,000584: 27,3677           45242                           SR3      DSU                                   
053810,000585: 27,3700           17763                                    DP2(-3)                               
053811,000586: 27,3701           41405                           DMP      PUSH                                  #  2(X T(X)-1) /Z ALFA   E:(-15-NA)
053812,000587:                                                                                                  #                        M:(-14-NA)
053813,000588:                                                                                                  #  1/ALFA Z FROM PDL+0   E:(-11-NA)
053814,000589:                                                                                                  #                        M:(-10-NA)
053815,000590: 27,3702           41345                           DLOAD    DMP                                   #  GET SIGN FOR SDELF
053816,000591: 27,3703           00045                                    TFFTEM                                #  1/Z  E:(11) M:(10)
053817,000592: 27,3704           00015                                    RMAG1                                 #  E:(-29) M:(-27)
053818,000593: 27,3705           43312                           SL2      DAD                                   
053819,000594: 27,3706           00017                                    TFFQ1                                 #  Q1  E:(-16) M:(-15)
053820,000595: 27,3707           14045                           STODL    TFFTEM                                #  (Q1+R 1/Z) =SGN OF SDELF  E:(-16) M:(-15
053821,000596: 27,3710           00035                                    TFFNP                                 #  LC P  E:(-38+2NR) M:(-36+2NR)
053822,000597: 27,3711           53605                           DMP      SL*                                   #  CALC FOR ARG FOR TFF/TRIG.

Page 1281

053824,000599: 27,3712           00027                                    TFF1/ALF                              #  1/ALFA  E:(-22-2NA) M:(-20-2NA)
053825,000600: 27,3713           57575                                    1,2                                   #  X2=-NA
053826,000601: 27,3714           53765                           SIGN     SL*                                   
053827,000602: 27,3715           00045                                    TFFTEM                                #  AFFIX SIGN FOR SDELF
053828,000603: 27,3716           57576                                    0,2                                   
053829,000604: 27,3717           14045                           STODL    TFFTEM                                #  P/ALFA  E:(-59+2NR) M:(-55+2NR)
053830,000605:                                                                                                  #  (ARG FOR USE IN TFF/TRIG)
053831,000606: 27,3720           00027                                    TFF1/ALF                              #  1/ALFA  E:(-22-2NA) M:(-20-2NA)
053832,000607: 27,3721           41366                           SQRT     DMP                                   
053833,000608: 27,3722           17755                                    PI/16                                 #  PI (-4)
053834,000609: 27,3723           77615                           DAD                                            
053835,000610:                                                                                                  #  2(XT(X)-1)/Z ALFA FROM PDL    E:(-15-NA)
053836,000611:                                                                                                  #                                M:(-14-NA)
053837,000612: 27,3724           45257                           SL*      DSU                                   
053838,000613: 27,3725           57577                                    0          -1,2                       
053839,000614: 27,3726           00013                                    TFFDELQ                               #  Q2-Q1  E:(-16) M:(-15)
053840,000615: 27,3727           53605                           DMP      SL*                                   
053841,000616: 27,3730           00027                                    TFF1/ALF                              #  1/ALFA  E:(-22-2NA) M:(-20-2NA)
053842,000617: 27,3731           57601                                    0          -3,2                       
053843,000618: 27,3732           52057                           SL*      GOTO                                  
053844,000619: 27,3733           57602                                    0          -4,2                       
053845,000620: 27,3734           57641                                    ENDTFF                                #  TFF SQRT(MU) IN MPAC E:(-45) M:(-42)
053846,000621: 

Page 1282

053848,000623:                                                                                                  #  PROGRAM NAME:  T(X)                           DATE:  01.17.67
053849,000624:                                                                                                  #  MOD NO:  0                                    LOG SECTION:  TIME OF FREE FALL
053850,000625:                                                                                                  #  MOD BY:  RR BAIRNSFATHER
053851,000626: 
053852,000627:                                                                                                  #  FUNCTIONAL DESCRIPTION:  THE POLYNOMIAL T(X) IS USED BY TIME OF FLIGHT SUBROUTINES CALCTFF AND
053853,000628:                                                                                                  #        CALCTPER TO APPROXIMATE THE SERIES
053854,000629:                                                                                                  #                           2     3
053855,000630:                                                                                                  #                1/3 -X/5 +X /7 -X /9 ...
053856,000631: 
053857,000632:                                                                                                  #        WHERE   X = ALFA Z Z            IF ALFA Z Z LEQ 1
053858,000633:                                                                                                  #                X = 1/(ALFA Z Z)        IF ALFA Z Z G 1
053859,000634: 
053860,000635:                                                                                                  #        ALSO    X IS NEG FOR HYPERBOLIC ORBITS
053861,000636:                                                                                                  #                X = 0 FOR PARABOLIC ORBITS
053862,000637:                                                                                                  #                X IS POSITIVE FOR ELLIPTIC ORBITS
053863,000638: 
053864,000639:                                                                                                  #        FOR FLIGHT 278, THE POLYNOMIAL T(X) IS FITTED OVER THE RANGE (0,+1) AND HAS A MAXIMUM
053865,000640:                                                                                                  #        DEVIATION FROM THE SERIES OF 2 E-5   (T(X) IS A CHEBYCHEV TYPE FIT AND WAS OBTAINED USING
053866,000641:                                                                                                  #        MAC PROGRAM AUTCURFIT294RRB AND IS VALID TO THE SAME TOLERANCE OVER THE RANGE (-.08,+1).)
053867,000642: 
053868,000643:                                                                                                  #  CALLING SEQUENCE:     RTB
053869,000644:                                                                                                  #                                T(X)
053870,000645:                                                                                                  #        C(MPAC) = X
053871,000646: 
053872,000647:                                                                                                  #  SUBROUTINES CALLED:  NONE
053873,000648: 
053874,000649:                                                                                                  #  NORMAL EXIT MODE:  TC   DANZIG
053875,000650: 
053876,000651:                                                                                                  #  ALARMS:  NONE
053877,000652: 
053878,000653:                                                                                                  #  OUTPUT:  C(MPAC) = T(X)
053879,000654: 
053880,000655:                                                                                                  #  ERASABLE INITIALIZATION REQUIRED:
053881,000656:                                                                                                  #        C(MPAC) = X
053882,000657: 
053883,000658:                                                                                                  #  DEBRIS:  NONE
053884,000659: 
053885,000660: 27,3735           07222        T(X)               TC       POLY                                  
053886,000661: 27,3736           00004                           DEC      4          B-14                       #  N-1
053887,000662: 27,3737           12525 12525                     2DEC     3.333333333 E-1                        
053888,000663: 
053889,000664: 27,3741           71463 57703                     2DEC*    -1.999819135 E-1*                       
053890,000665: 
053891,000666: 27,3743           04423 17645                     2DEC*    1.418148467 E-1*                       
053892,000667: 
053893,000668: 27,3745           74604 43667                     2DEC*    -1.01310997 E-1*                       
053894,000669: 
053895,000670: 27,3747           01626 37256                     2DEC*    5.609004986 E-2*                       
053896,000671: 
053897,000672: 27,3751           77404 52071                     2DEC*    -1.536156925 E-2*                       
053898,000673: 
053899,000674: 27,3753           06061        ENDT(X)            TC       DANZIG                                
053900,000675: 
053901,000676: 27,3754  27,3753               TCDANZIG           =        ENDT(X)                               
053902,000677: 

Page 1283

053904,000679:                                                                                                  #  TFF CONSTANTS
053905,000680: 
053906,000681: 32,3773                                           BANK     32                                    
053907,000682: 
053908,000683: 27,2000                                           SETLOC   TOF-FF1                               
053909,000684: 27,2000                                           BANK                                           
053910,000685: 
053911,000686:                                                                                                  #                                                NOTE _  NOTE _  ADJUSTED MUE FOR NEAR EARTH TRAJ.
053912,000687:                                                                                                  # MUE            =       3.990815471 E10         M CUBE/CS SQ
053913,000688:                                                                                                  # RTMUE          =       1.997702549 E5 B-18*    MODIFIED EARTH MU
053914,000689: 
053915,000690:                                                                                                  #                                                NOTE _  NOTE _  ADJUSTED MUE FOR NEAR EARTH TRAJ.
053916,000691:                                                                                                  # MUM            =       4.902778 E8             M CUBE/CS SQ
053917,000692:                                                                                                  # RTMUM          2DEC*   2.21422176 E4 B-18*
053918,000693: 
053919,000694: 27,3754           06220 37553  PI/16              2DEC     3.141592653 B-4                        
053920,000695: 
053921,000696: 27,3756           37777 37700  LIM(-22)           2OCT     3777737700                            #  1.0 -B(-22)
053922,000697: 
053923,000698: 27,3760           00000 00100  DP(-22)            2OCT     0000000100                            #  B(-22)
053924,000699: 
053925,000700: 27,3762           04000 00000  DP2(-3)            2DEC     1          B-3                        
053926,000701: 
053927,000702: 27,3764           02000 00000  DP2(-4)            2DEC     1          B-4                        #  1/16
053928,000703: 
053929,000704:                                                                                                  #  RPAD1         2DEC    6373338 B-29            M (-29) = 20909901.57 FT
053930,000705: 
053931,000706: 27,3766  23,2314               RPAD1              =        RPAD                                  
053932,000707: 
053933,000708: 27,3766           00305 11205  R300K              2DEC     6464778    B-29                       #  (-29) M
053934,000709: 
053935,000710: 27,3770           37777 37777  NEARONE            2DEC     .999999999                            
053936,000711: 
053937,000712: 27,3772  23,2521               TFFZEROS           EQUALS   HI6ZEROS                              
053938,000713: 27,3772  23,2511               TFF1/4             EQUALS   HIDP1/4                               
053939,000714: 

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