Source Code
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These source-code files are part of a reconstructed copy of Comanche 51, the
initial release (though not the final mission release) of the Apollo 11
Command Module (CM) Apollo Guidance Computer (AGC) software. The flown, final
release was Comanche 55. The reconstruction is believed to be exactly accurate,
but in the absence of an actual Apollo-era listing of Comanche 51, some
explanation of the reconstruction process is needed to insure confidence in
that accuracy.
The starting point was the source code of Comanche 55, whose original source code
is available. Comanche 55 source code was then modified by undoing changes known
to have been made between revisions 51 and 55. The most-significant steps involved
reverting changes related to the R-2 lunar potential model, the details of which
were known from the previous, separate, independent reconstruction of the Apollo 10
Lunar Module software Luminary 69/2. The now-reconstructed
Comanche 51 source code was verified by assembling it and checking that the assembled
code had the expected known-correct memory-bank checksums. Note that page numbers in
the reconstructed code match those on the Comanche 55 or Luminary 69 printouts, although
the source code would likely have different page numbers in a contemporary Comanche 51 listing.
Annotations that were not present in the contemporary source code have been added to
the reconstructed code to justify each change relative to Comanche 55. Here's a guide
to some of the Apollo documentation relevant to those annotations:
Among documentation not actually referenced in the annotations, there is
a short writeup about the reconstruction process in our software repository
that may be helpful in understanding it from a different perspective. There's also
a handy table
that lists what the number of memory-words should be for each routine in Comanche 51,
which could make a nice double-check; however, we've not performed that double-check ourselves.
Comments expected to have been present in 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.
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058370,000002: ## Copyright: Public domain.
058371,000003: ## Filename: TIME_OF_FREE_FALL.agc
058372,000004: ## Purpose: A section of Comanche revision 051.
058373,000005: ## It is part of the reconstructed source code for the
058374,000006: ## original release of the flight software for the Command
058375,000007: ## Module's (CM) Apollo Guidance Computer (AGC) for Apollo 11.
058376,000008: ## The code has been recreated from a copy of Comanche 055. It
058377,000009: ## has been adapted such that the resulting bugger words
058378,000010: ## exactly match those specified for Comanche 51 in NASA drawing
058379,000011: ## 2021153D, which gives relatively high confidence that the
058380,000012: ## reconstruction is correct.
058381,000013: ## Reference: pp. 1373-1388
058382,000014: ## Assembler: yaYUL
058383,000015: ## Contact: Ron Burkey <info@sandroid.org>.
058384,000016: ## Website: www.ibiblio.org/apollo/index.html
058385,000017: ## Mod history: 2019-07-30 MAS Created from Comanche 55.
058386,000018:
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Page 1373
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058388,000020: # THE TFF SUBROUTINES MAY BE USED IN EITHER EARTH OR MOON CENTERED COORDINATES. THE TFF ROUTINES NEVER
058389,000021: # KNOW WHICH ORIGIN APPLIES. IT IS THE USER WHO KNOWS, AND WHO SUPPLIES RONE, VONE AND 1/SQRT(MU) AT THE
058390,000022: # APPROPRIATE SCALE LEVEL FOR THE PROPER PRIMARY BODY.
058391,000023:
058392,000024: # EARTH ORIGIN POSITION -29 METERS
058393,000025: # VELOCITY -7 METERS/CENTISECOND
058394,000026: # 1/SQRT(MU) +17 SQRT(CS SQ/METERS CUBED)
058395,000027:
058396,000028: # MOON ORIGIN POSITION -27 METERS
058397,000029: # VELOCITY -5 METERS/CENTISECONDS
058398,000030: # 1/SQRT(MU) +14 SQRT(CS SQ/METERS CUBED)
058399,000031:
058400,000032: # ALL DATA PROVIDED TO AND RECEIVED FROM ANY TFF SUBROUTINE WILL BE AT ONE OF THE LEVELS ABOVE. IN ALL CASES,
058401,000033: # THE FREE FALL TIME IS RETURNED IN CENTISECONDS AT (-28). PROGRAM TFF/CONIC WILL GENERATE VONE/RTMU AND
058402,000034: # LEAVE IT IN VONE' AT (+10) IF EARTH ORIGIN AND (+9) IF MOON ORIGIN.
058403,000035:
058404,000036: # THE USER MUST STORE THE STATE VECTOR IN RONE, VONE AND MU IN THE FORM 1/SQRT(MU) IN TFF/RTMU
058405,000037: # AT THE PROPER SCALE BEFORE CALLING TFF/CONIC. SINCE RONE, VONE ARE IN THE EXTENDED VERB STORAGE AREA,
058406,000038: # THE USER MUST ALSO LOCK OUT THE EXTENDED VERBS, AND RELEASE THEM WHEN FINISHED.
058407,000039:
058408,000040: # PROGRAMS CALC/TFF AND CALC/TPER ASSUME THAT THE TERMINAL RADIUS IS LESS THAN THE PRESENT
058409,000041: # RADIUS. THIS RESTRICTION CAN BE REMOVED BY A 15 W CODING CHANGE, BUT AT PRESENT IT IS NOT DEEMED NECESSARY.
058410,000042:
058411,000043: # THE FOLLOWING ERASABLE QUANTITIES ARE USED BY THE TFF ROUTINES, AND ARE LOCATED IN THE PUSH LIST.
058412,000044:
058413,000045: # BELOW E: IS USED FOR EARTH ORIGIN SCALE
058414,000046: # M: IS USED FOR MOON ORIGIN SCALE
058415,000047:
058416,000048: # TFFSW = 119D BIT1 0 = CALCTFF 1 = CALCTPER
058417,000049: 23,3772 TFFDELQ = 10D # Q2-Q1 E: (-16) M: (-15)
058418,000050: 23,3772 RMAG1 = 12D # ABVAL(RN) M E: (-29) M: (-27)
058419,000051: # RPER = 14D PERIGEE RADIUS M E: (-29) M: (-27)
058420,000052: 23,3772 TFFQ1 = 14D # R.V / SQRT(MUE) E: (-16) M: (-15)
058421,000053: # SDELF/2 SIN(THETA) /2
058422,000054: 23,3772 CDELF/2 = 14D # COS(THETA) /2
058423,000055: # RAPO = 16D APOGEE RADIUS M E: (-29) M: (-27)
058424,000056: 23,3772 NRTERM = 16D # TERMINAL RADIUS M E: (-29+NR)
058425,000057: # M: (-27+NR)
058426,000058: 23,3772 RTERM = 18D # TERMINAL RADIUS M E: (-29) M: (-27)
058427,000059: 23,3772 TFFVSQ = 20D # -(V SQUARED/MU) 1/M E: (20) M: (18)
058428,000060: 23,3772 TFF1/ALF = 22D # SEMI MAJ AXIS M E: (-22-2 NA)
058429,000061: # M: (-20-2 NA)
058430,000062: 23,3772 TFFRTALF = 24D # SQRT(ALFA) E:(10+NA) M: (9+NA)
058431,000063: 23,3772 TFFALFA = 26D # ALFA 1/M E:(26-NR) M: (24-NR)
058432,000064: 23,3772 TFFNP = 28D # SEMI LATUS RECTUM M E: (-38+2 NR)
058433,000065: # M: (-36+2 NR)
058434,000066: 23,3772 TFF/RTMU = 30D # 1/SQRT(MU) E: (17) M: (14)
058435,000067: 23,3772 NRMAG = 32D # PRESENT RADIUS M E: (-29+NR)
058436,000068: # M: (-27+NR)
058437,000069: 23,3772 TFFX = 34D
058438,000070: 23,3772 TFFTEM = 36D # TEMPORARY
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Page 1374
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058440,000072: # REGISTERS S1, S2 ARE UNTOUCHED BY ANY TFF SUBROUTINE
058441,000073: # INDEX REGISTERS X1, X2 ARE USED BY ALL TFF SUBROUTINES. THEY ARE ESTAB-
058442,000074: # LISHED IN TFF/CONIC AND MUST BE PRESERVED BETWEEN CALLS TO SUBSEQUENT
058443,000075: # SUBROUTINES.
058444,000076: # -NR C(X1) = NORM COUNT OF RMAG
058445,000077: # -NA C(X2) = NORM COUNT OF SQRT(ABS(ALFA))
058446,000078:
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Page 1375
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058448,000080: # SUBROUTINE NAME: TFFCONIC DATE: 01.29.67
058449,000081: # MOD NO: 0 LOG SECTION: TIME OF FREE FALL
058450,000082: # MOD BY: RR BAIRNSFATHER
058451,000083: # MOD NO: 1 MOD BY: RR BAIRNSFATHER DATE: 11 APR 67
058452,000084: # MOD NO: 2 MOD BY: RR BAIRNSFATHER DATE: 21 NOV 67 ADD MOON MU.
058453,000085: # MOD NO: 3 MOD BY: RR BAIRNSFATHER DATE: 21 MAR 68 ACCEPT DIFFERENT EARTH/MOON SCALES
058454,000086:
058455,000087: # FUNCTIONAL DESCRIPTION: THIS SUBROUTINE IS CALLED TO COMPUTE THOSE CONIC PARAMETERS REQUIRED BY THE TFF
058456,000088: # SUBROUTINES AND TO ESTABLISH THEM IN THE PUSH LIST AREA. THE PARAMETERS ARE LISTED UNDER OUTPUT.
058457,000089: # THE EQUATIONS ARE
058458,000090: # - - -
058459,000091: # H = RN*VN ANGULAR MOMENTUM
058460,000092: # - -
058461,000093: # LCP = H.H / MU SEMI LATUS RECTUM
058462,000094: # - -
058463,000095: # ALFA = 2/RN - VN.VN / MU RECIPROCAL SEMI MAJ AXIS, SIGNED
058464,000096:
058465,000097: # AND ALFA IS POS FOR ELLIPTIC ORBITS
058466,000098: # 0 FOR PARABOLIC ORBITS
058467,000099: # NEG FOR HYPERBOLIC ORBITS.
058468,000100: # SUBROUTINE ALSO COMPUTES AND SAVES RMAG.
058469,000101:
058470,000102: # CALLING SEQUENCE:
058471,000103: # TFFCONIC EXPECTS CALLER TO ENTER WITH CORRECT GRAVITATIONAL CONSTANT IN MPAC, IN THE FORM
058472,000104: # 1/SQRT(MU). PROGRAM WILL SAVE IN TFF/RTMU. THE SCALE IS DETERMINED BY WHETHER EARTH OR MOON
058473,000105: # ORIGIN IS USED. THE CALLER MUST LOCK OUT THE EXTENDED VERBS BEFORE PROVIDING STATE VECTOR IN RONE,
058474,000106: # VONE AT PROPER SCALE. THE EXTENDED VERBS MUST BE RESTORED WHEN THE CALLER IS FINISHED USING THE
058475,000107: # TFF ROUTINES.
058476,000108:
058477,000109: # ENTRY POINT TFFCONMU EXPECTS THAT TFF/RTMU IS ALREADY LOADED.
058478,000110:
058479,000111: # TO SPECIFY MU: DLOAD CALL IF MU ALREADY STORED: CALL
058480,000112: # YOURMU 1/RTMU E:(17) M:(14) TFFCONMU
058481,000113: # TFFCONIC
058482,000114: # PUSHLOC = PDL+0, ARBITRARY IF LEQ 18D
058483,000115:
058484,000116: # SUBROUTINES CALLED: NONE
058485,000117:
058486,000118: # NORMAL EXIT MODES: RVQ
058487,000119:
058488,000120: # ALARMS: NONE
058489,000121:
058490,000122: # OUTPUT: THE FOLLOWING ARE STORED IN THE PUSH LIST AREA.
058491,000123: # RMAG1 E:(-29) M:(-27) M RN, PRESENT RADIUS LENGTH.
058492,000124: # NRMAG E:(-29+NR) M RMAG, NORMALIZED
058493,000125: # M:(-27+NR)
058494,000126: # X1 -NR, NORM COUNT
058495,000127: # TFFNP E:(-38+2NR) M LCP, SEMI LATUS RECTUM, WEIGHTED BY NR. FOR VGAMCALC
058496,000128: # M:(-36+2NR)
058497,000129: # TFF/RTMU E:(17) M:(14) 1/SQRT(MU)
058498,000130: # TFFVSQ E:(20) M:(18) 1/M -(V SQ/MU): PRESENT VELOCITY, NORMLIZED. FOR VGAMCALC
058499,000131: # TFFALFA E:(26-NR) 1/M ALFA, WEIGHTED BY NR
058500,000132: # M:(24-NR)
058501,000133: # TFFRTALF E:(10+NA) SQRT(ALFA), NORMALIZED
058502,000134: # M:(9+NA)
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Page 1376
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058504,000136: # X2 -NA, NORM COUNT
058505,000137: # TFF1/ALF E:(-22-2NA) SIGNED SEMI MAJ AXIS, WEIGHTED BY NA
058506,000138: # M:(-20-2NA)
058507,000139: # PUSHLOC AT PDL+0
058508,000140:
058509,000141: # THE FOLLOWING IS STORED IN GENERAL ERASABLE
058510,000142: # VONE' E:(10) M:(9) V/RT(MU), NORMALIZED VELOCITY
058511,000143:
058512,000144: # ERASABLE INITIALIZATION REQUIRED:
058513,000145: # RONE E:(-29) M:(-27) M STATE VECTOR LEFT BY CALLER
058514,000146: # VONE E:(-7) M:(-5) M/CS STATE VECTOR LEFT BY CALLER
058515,000147: # TFF/RTMU E:(17) M:(14) 1/RT(CS SQ/M CUBE) IF ENTER VIA TFFCONMU.
058516,000148:
058517,000149: # DEBRIS: QPRET, PDL+0 ... PDL+3
058518,000150:
058519,000151: 33,3776 BANK 33
058520,000152: 27,2000 SETLOC TOF-FF
058521,000153: 27,2000 BANK
058522,000154:
058523,000155: 27,2757 COUNT* $$/TFF
058524,000156:
058525,000157: 27,2757 00037 TFFCONIC STORE TFF/RTMU # 1/SQRT(MU) E:(17) M:(14)
058526,000158:
058527,000159: 27,2760 53575 TFFCONMU VLOAD UNIT # COME HERE WITH TFFRTMU LOADED.
058528,000160: 27,2761 02327 RONE # SAVED RN. M E:(-29) M:(-27)
058529,000161: 27,2762 77725 PDDL # UR/2 TO PDL+0, +5
058530,000162: 27,2763 00045 36D # MAGNITUDE
058531,000163: 27,2764 00015 STORE RMAG1 # M E:(-29) M:(-27)
058532,000164:
058533,000165: 27,2765 77701 NORM
058534,000166: 27,2766 00047 X1 # -NR
058535,000167: 27,2767 24041 STOVL NRMAG # RMAG M E:(-29+NR) M:(-27+NR)
058536,000168: 27,2770 02335 VONE # SAVED VN. M/CS E:(-7) M:(-5)
058537,000169: 27,2771 77761 VXSC
058538,000170: 27,2772 00037 TFF/RTMU # E:(17) M:(14)
058539,000171: 27,2773 02372 STORE VONE' # VN/SQRT(MU) E:(10) M:(9)
058540,000172:
058541,000173: 27,2774 47361 VXSC VXV
058542,000174: 27,2775 00041 NRMAG # E:(-29+NR) M:(-27+NR)
058543,000175: # UR/2 FROM PDL
058544,000176: 27,2776 47572 VSL1 VSQ # BEFORE: E:(-19+NR) M:(-18+NR)
058545,000177: 27,2777 14035 STODL TFFNP # LC P M E:(-38+2NR) M:(-36+2NR)
058546,000178: # SAVE ALSO FOR VGAMCALC
058547,000179: 27,3000 15325 TFF1/4
058548,000180: 27,3001 63271 DDV PDVL # (2/RMAG) 1/M E:(26-NR) M:(24-NR)
058549,000181: 27,3002 00041 NRMAG # RMAG M E:(-29+NR) M:(-27+NR)
058550,000182: 27,3003 02372 VONE' # SAVED VN. E:(10) M:(9)
058551,000183: 27,3004 57436 VSQ DCOMP # KEEP MPAC+2 HONEST FOR SQRT.
058552,000184: 27,3005 00025 STORE TFFVSQ # -(V SQ/MU) E:(20) M:(18)
058553,000185: # SAVE FOR VGAMCALC
058554,000186: 27,3006 43257 SR* DAD
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Page 1377
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058556,000188: 27,3007 20573 0 -6,1 # GET -VSQ/MU E:(26-NR) M:(24-NR)
058557,000189: 27,3010 77626 STADR
058558,000190: # 2/RMAG FROM PDL+2
058559,000191: 27,3011 77744 STORE TFFALFA # ALFA 1/M E:(26-NR) M:(24-NR)
058560,000192: 27,3012 41457 SL* PUSH # TEMP SAVE ALFA E:(20) M:(18)
058561,000193: 27,3013 20173 0 -6,1
058562,000194: 27,3014 75446 ABS SQRT # E:(10) M:(9)
058563,000195: 27,3015 77701 NORM
058564,000196: 27,3016 00050 X2 # X2 = -NA
058565,000197: 27,3017 00031 STORE TFFRTALF # SQRT( ABS(ALFA) ) E:(10+NA) M:(9+NA)
058566,000198: 27,3020 75316 DSQ SIGN # NOT SO ACCURATE, BUT OK
058567,000199: # ALFA FROM PDL+2 E:(20) M:(18)
058568,000200: 27,3021 55254 BZE BDDV # SET 1/ALFA =0, TO SHOW SMALL ALFA
058569,000201: 27,3022 57024 +2
058570,000202: 27,3023 15325 TFF1/4
058571,000203: 27,3024 00027 +2 STORE TFF1/ALF # 1/ALFA E:(-22-2NA) M:(-20-2NA)
058572,000204: 27,3025 77616 DUMPCNIC RVQ
058573,000205: # 39 W
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Page 1378
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058575,000207: # SUBROUTINE NAME: TFFRP/RA DATE: 01.17.67
058576,000208: # MOD NO: 0 LOG SECTION: TIME OF FREE FALL
058577,000209: # MOD BY: RR BAIRNSFATHER
058578,000210: # MOD NO: 1 MOD BY: RR BAIRNSFATHER DATE: 11 APR 67
058579,000211: # MOD NO: 2 MOD BY: RR BAIRNSFATHER DATE: 21 MAR 68 ACCEPT DIFFERENT EARTH/MOON SCALES
058580,000212: # ALSO IMPROVE ACCURACY OF RAPO.
058581,000213:
058582,000214: # FUNCTIONAL DESCRIPTION: USED BY CALCTPER AND TFF DISPLAYS TO CALCULATE PERIGEE RADIUS AND ALSO
058583,000215: # APOGEE RADIUS FOR A GENERAL CONIC.
058584,000216: # PROGRAM GIVES PERIGEE RADIUS AS APOGEE RADIUS IS GIVEN BY
058585,000217: # RP = P/(1+E) RA = (1+E) / ALFA
058586,000218: # WHERE 2
058587,000219: # E = 1 - P ALFA
058588,000220: # IF RA IS NEGATIVE OR SHOWS DIVIDE OVERFLOW, THEN RA = POSMAX BECAUSE
058589,000221: # 1. APOGEE RADIUS IS NOT MEANINGFUL FOR HYPERBOLA
058590,000222: # 2. APOGEE RADIUS IS NOT DEFINED FOR PARABOLA
058591,000223: # 3. APOGEE RADIUS EXCEEDS THE SCALING FOR ELLIPSE.
058592,000224:
058593,000225: # THIS SUBROUTINE REQUIRES THE SIGNED RECIPROCAL SEMI MAJ AXIS, ALFA, AND SEMI LATUS RECTUM AS DATA.
058594,000226:
058595,000227: # CALLING SEQUENCE: CALL
058596,000228: # TFFRP/RA
058597,000229: # PUSHLOC = PDL+0, ARBITRARY IF LEQ 10D
058598,000230: # C(MPAC) UNSPECIFIED
058599,000231:
058600,000232: # SUBROUTINES CALLED: NONE
058601,000233:
058602,000234: # NORMAL EXIT MODE: RVQ
058603,000235: # IF ELLIPSE, WITHIN NORMAL SCALING, RAPO IS CORRECT.
058604,000236: # OTHERWISE, RAPO = POSMAX.
058605,000237:
058606,000238: # ALARMS: NONE
058607,000239:
058608,000240: # OUTPUT: STORED IN PUSH LIST AREA. SCALE OF OUTPUT AGREES WITH DATA SUPPLIED TO TFF/CONIC.
058609,000241: # RPER E:(-29) M:(-27) M PERIGEE RADIUS DESTROYED BY CALCTFF/CALCTPER, TFFTRIG.
058610,000242: # RAPO E:(-29) M:(-27) M APOGEE RADIUS WILL BE DESTROYED BY CALCTFF/CALCTPER
058611,000243: # PUSHLOC AT PDL+0
058612,000244:
058613,000245: # ERASABLE INITIALIZATION REQUIRED:
058614,000246: # TFFALFA E:(26-NR) M 1/SEMI MAJ AXIS LEFT BY TFFCONIC
058615,000247: # M:(24-NR)
058616,000248: # TFFNP E:(-38+2NR) M LC P, SEMI LATUS RECTUM LEFT BY TFFCONIC
058617,000249: # M:(-36+2NR)
058618,000250: # X1 -NR, NORM COUNT OF RMAG LEFT BY TFFCONIC
058619,000251: # X2 -NA, NORM COUNT OF ALFA LEFT BY TFFCONIC
058620,000252:
058621,000253: # DEBRIS: QPRET, PDL+0 ... PDL+1
058622,000254:
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Page 1379
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058624,000256: 27,3026 RAPO = 16D # APOGEE RADIUS M E:(-29) M:(-27)
058625,000257: 27,3026 RPER = 14D # PERIGEE RADIUS M E:(-29) M:(-27)
058626,000258:
058627,000259: 27,3026 41345 TFFRP/RA DLOAD DMP
058628,000260: 27,3027 00033 TFFALFA # ALFA 1/M E:(26-NR) M:(24-NR)
058629,000261: 27,3030 00035 TFFNP # LC P M E:(-38+2NR) M:(-36+2NR)
058630,000262: 27,3031 57457 SR* DCOMP # ALFA P (-12+NR)
058631,000263: 27,3032 20571 0 -8D,1 # ALFA P (-4)
058632,000264: 27,3033 51415 DAD ABS # (DCOMP GIVES VALID TP RESULT FOR SQRT)
058633,000265: # (ABS PROTECTS SQRT IF E IS VERY NEAR 0)
058634,000266: 27,3034 17366 DP2(-4)
058635,000267: 27,3035 43366 SQRT DAD # E SQ = (1- P ALFA) (-4)
058636,000268: 27,3036 15325 TFF1/4
058637,000269: 27,3037 55206 PUSH BDDV # (1+E) (-2) TO PDL+0
058638,000270: 27,3040 00035 TFFNP # LCP M E:(-38+2NR) M:(-36+2NR)
058639,000271: 27,3041 53657 SR* SR* # (DOES SR THEN SL TO AVOID OVFL)
058640,000272: 27,3042 20601 0,1 # X1=-NR
058641,000273: 27,3043 20572 0 -7,1 # (EFFECTIVE SL)
058642,000274: 27,3044 14017 STODL RPER # PERIGEE RADIUS M E:(-29) M:(-27)
058643,000275: # (1+E) (-2) FROM PDL+0
058644,000276: 27,3045 41005 DMP BOVB
058645,000277: 27,3046 00027 TFF1/ALF # E:(-22-2NA) M:(-20-2NA)
058646,000278: 27,3047 57352 TCDANZIG # CLEAR OVFIND, IF ON.
058647,000279: 27,3050 53654 BZE SL*
058648,000280: 27,3051 57060 MAXRA # SET POSMAX, IF ALFA=0
058649,000281: 27,3052 57603 0 -5,2 # -5+NA
058650,000282: 27,3053 40057 SL* BOV
058651,000283: 27,3054 57576 0,2
058652,000284: 27,3055 57060 MAXRA # SET POSMAX IF OVFL.
058653,000285: 27,3056 77644 BPL # CONTINUE WITH VALID RAPO.
058654,000286: 27,3057 57062 +3
058655,000287: 27,3060 77745 MAXRA DLOAD # RAPO CALC IS NOT VALID. SET RAPO =
058656,000288: 27,3061 17372 NEARONE # POSMAX AS A TAG.
058657,000289: 27,3062 00021 +3 STORE RAPO # APOGEE RADIUS M E:(-29) M:(-27)
058658,000290: 27,3063 77616 DUMPRPRA RVQ
058659,000291: # 30 W
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Page 1380
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058661,000293: # SUBROUTINE NAME: CALCTPER / CALCTFF DATE: 01.29.67
058662,000294: # MOD NO: 0 LOG SECTION: TIME OF FREE FALL
058663,000295: # MOD BY: RR BAIRNSFATHER
058664,000296: # MOD NO: 1 MOD BY: RR BAIRNSFATHER DATE: 21 MAR 67
058665,000297: # MOD NO: 2 MOD BY: RR BAIRNSFATHER DATE: 14 APR 67
058666,000298: # MOD NO: 3 MOD BY: RR BAIRNSFATHER DATE: 8 JUL 67 NEAR EARTH MUE AND NEG TFF (GONEPAST)
058667,000299: # MOD NO: 4 MOD BY: RR BAIRNSFATHER DATE: 21 NOV 67 ADD VARIABLE MU.
058668,000300: # MOD NO: 5 MOD BY: RR BAIRNSFATHER DATE: 21 MAR 68 ACCEPT DIFFERENT EARTH/MOON SCALES
058669,000301:
058670,000302: # FUNCTIONAL DESCRIPTION: PROGRAM CALCULATES THE FREE-FALL TIME OF FLIGHT FROM PRESENT POSITION RN AND
058671,000303: # VELOCITY VN TO A RADIUS LENGTH SPECIFIED BY RTERM, SUPPLIED BY THE USER. THE POSITION VECTOR
058672,000304: # RN MAY BE ON EITHER SIDE OF THE CONIC, BUT RTERM IS CONSIDERED ON THE INBOUND SIDE.
058673,000305: # THE EQUATIONS ARE
058674,000306:
058675,000307: # Q2 = -SQRT(RTERM (2-RTERM ALFA) - LCP) (INBOUND SIDE)) LEQ +- LCE/SQRT(ALFA)
058676,000308: # - -
058677,000309: # Q1 = RN.VN / SQRT(MU) LEQ +- LCE/SQRT(ALFA)
058678,000310:
058679,000311: # Z = NUM / DEN LEQ +- 1/SQRT(ALFA)
058680,000312:
058681,000313: # WHERE, IF INBOUND
058682,000314: # NUM = RTERM -RN LEQ +- 2 LCE/ALFA
058683,000315: # DEN = Q2+Q1 LEQ +- 2 LCE/SQRT(ALFA)
058684,000316:
058685,000317: # AND, IF OUTBOUND
058686,000318: # NUM = Q2-Q1 LEQ +- 2 LCE/SQRT(ALFA)
058687,000319: # DEN = 2 - ALFA (RTERM + RN). LEQ +- 2 LCE
058688,000320:
058689,000321: # IF ALFA ZZ < 1.0 (FOR ALL CONICS EXCEPT ELLIPSES HAVING ABS(DEL ECC ANOM) G 90 DEG)
058690,000322: # THEN X = ALFA Z Z
058691,000323: # AND TFF = (RTERM +RN -2 ZZ T(X) ) Z/SQRT(MU)
058692,000324: # EXCEPT IF ALFA PNZ, AND IF TFF NEG,
058693,000325: # THEN TFF = 2 PI /(ALFA SQRT(ALFA)) + TFF
058694,000326: # OR IF ALFA ZZ GEQ 1.0 (FOR ELLIPSES HAVING ABS(DEL ECC ANOM) GEQ 90 DEG)
058695,000327: # THEN X = 1/ALFA Z Z
058696,000328: # AND TFF = (PI/SQRT(ALFA) -Q2 +Q1 +2(X T(X) -1) /ALFA Z) /ALFA SQRT(MU)
058697,000329: # WHERE T(X) IS A POLYNOMIAL APPROXIMATION TO THE SERIES
058698,000330: # 2 3 2
058699,000331: # 1/3 - X/5 + X /7 - X /9 ... (X < 1.0)
058700,000332:
058701,000333: # CALLING SEQUENCE: TIME TO RTERM TIME TO PERIGEE
058702,000334: # CALL CALL
058703,000335: # CALCTFF CALCTPER
058704,000336: # C(MPAC) = TERMNL RAD M C(MPAC) = PERIGEE RAD M
058705,000337: # FOR EITHER, E:(-29) M:(-27)
058706,000338: # FOR EITHER, PUSHLOC = PDL+0, ARBITRARY IF LEQ 8D.
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|
Page 1381
|
058708,000340:
058709,000341: # SUBROUTINES CALLED: T(X), VIA RTB
058710,000342:
058711,000343: # NORMAL EXIT MODE: RVQ
058712,000344: # HOWEVER, PROGRAM EXITS WITH ONE OF THE FOLLOWING VALUES FOR TFF (-28) CS IN MPAC. USER MUST STORE.
058713,000345: # A. TFF = FLIGHT TIME. NORMAL CASE FOR POSITIVE FLIGHT TIME LESS THAN ONE ORBITAL PERIOD.
058714,000346: # B. (THIS OPTION IS NO LONGER USED.)
058715,000347: # C. TFF = POSMAX. THIS INDICATES THAT THE CONIC FROM THE PRESENT POSITION WILL NOT RETURN TO
058716,000348: # THE SPECIFIED ALTITUDE. ALSO INDICATES OUTBOUND PARABOLA OR HYPERBOLA.
058717,000349:
058718,000350: # OUTPUT: C(MPAC) (-28) CS TIME OF FLIGHT, OR TIME TO PERIGEE
058719,000351: # TFFX (0) X, LEFT FOR ENTRY DISPLAY TFF ROUTINES
058720,000352: # NRTERM E:(-29+NR) M RTERM, WEIGHTED BY NR LEFT FOR ENTRY DISPLAY TFF ROUTINES
058721,000353: # M:(-27+NR)
058722,000354: # TFFTEM E:(-59+2NR) LCP Z Z SGN(SDELF) LEFT FOR ENTRY DISPLAY TFF ROUTINES
058723,000355: # M:(-55+2NR) LCP /ALFA SGN(SDELF) LEFT FOR ENTRY DISPLAY TFF ROUTINES
058724,000356: # NOTE: TFFTEM = PDL 36D AND WILL BE DESTROYED BY .:UNIT:.
058725,000357: # RMAG1 E:(-29) M:(-27) PDL 12 NOT TOUCHED.
058726,000358: # TFFQ1 E:(-16) M:(-15) PDL 14D
058727,000359: # TFFDELQ E:(-16) M:(-15) PDL 10D
058728,000360: # PUSHLOC AT PDL+0
058729,000361:
058730,000362: # ERASABLE INITIALIZATION REQUIRED:
058731,000363: # RONE E:(-29) M:(-27) M STATE VECTOR LEFT BY USER
058732,000364: # VONE' E:(+10) M:(+9) VN/SQRT(MU) LEFT BY TFF/CONIC
058733,000365: # RMAG1 E:(-29) M:(-27) PRESENT RADIUS, M LEFT BY TFFCONIC
058734,000366: # C(MPAC) E:(-29) M:(-27) RTERM, TERMINAL RADIUS LENGTH, M LEFT BY USER
058735,000367:
058736,000368: # THE FOLLOWING ARE STORED IN THE PUSH LIST AREA.
058737,000369: # TFF/RTMU E:(17) M:(14) 1/SQRT(MU) LEFT BY TFFCONIC.
058738,000370: # NRMAG E:(-29+NR) M RMAG, NORMALIZED LEFT BY TFFCONIC
058739,000371: # M:(-27+NR)
058740,000372: # X1 -NR, NORM COUNT LEFT BY TFFCONIC
058741,000373: # TFFNP E:(-38+2NR) M LCP, SEMI LATUS RECTUM, WEIGHT NR LEFT BY TFFCONIC
058742,000374: # M:(-36+2NR)
058743,000375: # TFFALFA E:(26-NR) 1/M ALFA, WEIGHT NR LEFT BY TFFCONIC
058744,000376: # M:(24-NR)
058745,000377: # TFFRTALF E:(10+NA) SQRT(ALFA), NORMALIZED LEFT BY TFFCONIC
058746,000378: # M:(9+NA)
058747,000379: # X2 -NA, NORM COUNT LEFT BY TFFCONIC
058748,000380: # TFF1/ALF E:(-22-2NA) SIGNED SEMIMAJ AXIS, WEIGHTED BY NA LEFT BY TFFCONIC
058749,000381: # M:(-20-2NA)
058750,000382:
058751,000383: # DEBRIS: QPRET, PDL+0 ... PDL+3
058752,000384: # RTERM E:(-29) M:(-27) RTERM, TERMINAL RADIUS LENGTH
058753,000385: # RAPO E:(-29) M:(-27) PDL 16D (=NRTERM)
058754,000386: # RPER E:(-29) M:(-27) PDL 14D (=TFFQ1)
058755,000387:
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|
Page 1382
|
058757,000389: 27,3064 77614 CALCTPER SETGO # ENTER WITH RPER IN MPAC
058758,000390: 27,3065 03436 TFFSW
058759,000391: 27,3066 57071 +3
058760,000392: 27,3067 77614 CALCTFF CLEAR # ENTER WITH RTERM IN MPAC
058761,000393: 27,3070 03676 TFFSW
058762,000394: 27,3071 00023 +3 STORE RTERM # E:(-29) M:(-27)
058763,000395: 27,3072 77657 SL*
058764,000396: 27,3073 20201 0,1 # X1=-NR
058765,000397: 27,3074 00021 STORE NRTERM # RTERM E:(-29+NR) M:(-27+NR)
058766,000398: 27,3075 44205 DMP BDSU
058767,000399: 27,3076 00033 TFFALFA # ALFA E:(26-NR) M:(24-NR)
058768,000400: 27,3077 15325 TFF1/4
058769,000401: 27,3100 41206 PUSH DMP # (2-ALFA RTERM) (-3) TO PDL+0
058770,000402: 27,3101 00021 NRTERM # E:(-29+NR) M:(-27+NR)
058771,000403: 27,3102 53725 PDDL SR* # RTERM(2-ALFA RTERM) TO PDL+2
058772,000404: # E:(-32+NR) M:(-30+NR)
058773,000405: 27,3103 00035 TFFNP # LC P E:(-38+2NR) M:(-36+2NR)
058774,000406: 27,3104 20573 0 -6,1 # X1 = -NR
058775,000407: 27,3105 43276 DCOMP DAD # DUE TO SHIFTS, KEEP PRECISION FOR SQRT
058776,000408: # RTERM(2-ALFA RTERM) FROM PDL +2
058777,000409: # E:(-32+NR) M:(-30+NR)
058778,000410: 27,3106 77657 SR* # LEAVE E:(-32) M:(-30)
058779,000411: 27,3107 20601 0,1 # X1 = -NR
058780,000412: 27,3110 71214 BOFF DLOAD # CHECK TFF /TPER SWITCH
058781,000413: 27,3111 03756 TFFSW
058782,000414: 27,3112 57114 +2 # IF TFF, CONTINUE
058783,000415: 27,3113 15335 TFFZEROS # IF TPER, SET Q2 = 0
058784,000416: 27,3114 75440 +2 BMN SQRT # E:(-16) M:(-15)
058785,000417: 27,3115 57247 MAXTFF1 # NO FREE FALL CONIC TO RTERM FROM HERE
058786,000418: # RESET PDL, SET TFF=POSMAX, AND EXIT.
058787,000419:
058788,000420: 27,3116 41076 DCOMP BOVB # RT IS ON INBOUND SIDE. ASSURE OVFIND=0
058789,000421: 27,3117 57352 TCDANZIG # ANY PORT IN A STORM.
058790,000422: 27,3120 24045 STOVL TFFTEM # Q2 E:(-16) M:(-15)
058791,000423: 27,3121 02372 VONE' # VN/SQRT(MU) E:(10) M:(9)
058792,000424: 27,3122 52441 DOT SL3
058793,000425: 27,3123 02327 RONE # SAVED RN. E:(-29) M:(-27)
058794,000426: 27,3124 00017 STORE TFFQ1 # Q1, SAVE FOR GONEPAST TEST.
058795,000427: # E:(-16) M:(-15)
058796,000428: 27,3125 44240 BMN BDSU
058797,000429: 27,3126 57147 INBOUND # USE ALTERNATE Z
058798,000430: 27,3127 00045 TFFTEM # Q2 E:(-16) M:(-15)
058799,000431:
058800,000432: # OUTBOUND Z CALC CONTINUES HERE
058801,000433:
058802,000434: 27,3130 14043 STODL TFFX # NUM=Q2-Q1 E:(-16) M:(-15)
058803,000435: 27,3131 00033 TFFALFA # ALFA E:(26-NR) M:(24-NR)
058804,000436: 27,3132 44205 DMP BDSU
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|
Page 1383
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058806,000438: 27,3133 00041 NRMAG # RMAG E:(-29+NR) M:(-27+NR)
058807,000439: # (2-RTERM ALFA) (-3) FROM PDL+0
058808,000440: 27,3134 51406 SAVEDEN PUSH ABS # DEN TO PDL+0 E:(-3) OR (-16)
058809,000441: # M:(-3) OR (-15)
058810,000442: 27,3135 40015 DAD BOV # INDETERMINANCY TEST
058811,000443: 27,3136 17360 LIM(-22) # =1.0-B(-22)
058812,000444: 27,3137 57160 TFFXTEST # GO IF DEN >/= B(-22)
058813,000445: 27,3140 65345 DLOAD PDDL # SET DEN=0 OTHERWISE
058814,000446: 27,3141 15335 TFFZEROS
058815,000447: # XCH ZERO WITH PDL+0
058816,000448: 27,3142 57545 DLOAD DCOMP
058817,000449: 27,3143 00033 TFFALFA # ALFA E:(26-NR) M:(24-NR)
058818,000450: 27,3144 71240 BMN DLOAD # FOR TPER: Z INDET AT DELE/2=0 AND 90.
058819,000451: 27,3145 57254 TFFEL1 # ASSUME 90, AND LEAVE 0 IN PDL: 1/Z=D/N
058820,000452:
058821,000453: # Z INDET. AT PERIGEE FOR PARAB OR HYPERB.
058822,000454: 27,3146 77616 DUMPTFF1 RVQ # RETURN TFF =0
058823,000455:
058824,000456: # INBOUND Z CALC CONTINUES HERE
058825,000457:
058826,000458: 27,3147 77745 INBOUND DLOAD # RESET PDL+0
058827,000459: 27,3150 45345 DLOAD DSU # ALTERNATE Z CALC
058828,000460: 27,3151 00023 RTERM # E:(-29) M:(-27)
058829,000461: 27,3152 00015 RMAG1 # E:(-29) M:(-27)
058830,000462: 27,3153 14043 STODL TFFX # NUM=RTERM-RN E:(-29) M:(-27)
058831,000463: 27,3154 00045 TFFTEM # Q2 E:(-16) M:(-15)
058832,000464: 27,3155 52015 DAD GOTO
058833,000465: 27,3156 00017 TFFQ1 # Q1 E:(-16) M:(-15)
058834,000466: 27,3157 57134 SAVEDEN # DEN = Q2+Q1 E:(-16) M:(-15)
058835,000467:
058836,000468: 27,3160 65215 TFFXTEST DAD PDDL # (ABS(DEN) TO PDL+2)) E:(-3) OR (-16)
058837,000469: # M:(-3) OR (-15)
058838,000470: 27,3161 17362 DP(-22) # RESTORE ABS(DEN) TO MPAC
058839,000471: 27,3162 00043 TFFX # NUM E:(-16) OR (-29) M:(-15) OR (-27)
058840,000472: 27,3163 53605 DMP SR*
058841,000473: 27,3164 00031 TFFRTALF # SQRT(ALFA) E:(10+NA) M:(9+NA)
058842,000474: 27,3165 57201 0 -3,2 # X2=-NA
058843,000475: 27,3166 77671 DDV # C(MPAC) =NUM SQRT(ALFA) E:(-3) OR (-16)
058844,000476: # M:(-3) OR (-15)
058845,000477: # ABS(DEN) FROM PDL+2 E:(-3) OR (-16)
058846,000478: # M:(-3) OR (-15)
058847,000479: 27,3167 40145 DLOAD BOV # (THE DLOAD IS SHARED WITH TFFELL)
058848,000480: 27,3170 00043 TFFX # NUM E:(-16) OR (-29) M:(-15) OR (-27)
058849,000481: 27,3171 57252 TFFELL # USE EQN FOR DELE GEQ 90, LEQ -90
058850,000482:
058851,000483: # OTHERWISE, CONTINUE FOR GENERAL CONIC FOR TFF EQN
058852,000484:
058853,000485: 27,3172 45471 DDV STADR
058854,000486: # DEN FROM PDL+0 E:(-3) OR (-16)
058855,000487: # M:(-3) OR (-15)
058856,000488: 27,3173 77732 STORE TFFTEM # Z SAVE FOR SIGN OF SDELF.
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Page 1384
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058858,000490: # E:(-13) M:(-12)
058859,000491: 27,3174 63406 PUSH DSQ # Z TO PDL+0
058860,000492: 27,3175 41206 PUSH DMP # Z SQ TO PDL+2 E:(-26) M:(-24)
058861,000493: 27,3176 00035 TFFNP # LC P E:(-38+2NR) M:(-36+2NR)
058862,000494: 27,3177 75261 SL SIGN
058863,000495: 27,3200 20206 5
058864,000496: 27,3201 00045 TFFTEM # AFFIX SIGN FOR SDELF (ENTRY DISPLAY)
058865,000497: 27,3202 14045 STODL TFFTEM # P ZSQ E:(-59+2NR) M:(-55+2NR)
058866,000498: # (ARG IS USED IN TFF/TRIG)
058867,000499: # ZSQ FROM PDL+2 E:(-26) M:(-24)
058868,000500: 27,3203 41206 PUSH DMP # RESTORE PUSH LOC
058869,000501: 27,3204 00033 TFFALFA # ALFA E:(26-NR) M:(24-NR)
058870,000502: 27,3205 77657 SL*
058871,000503: 27,3206 20201 0,1 # X1=-NR
058872,000504: 27,3207 00043 STORE TFFX # X
058873,000505: 27,3210 41234 RTB DMP
058874,000506: 27,3211 57334 T(X) # POLY
058875,000507: # ZSQ FROM PDL+2 E:(-26) M:(-24)
058876,000508: 27,3212 44302 SR2 BDSU # 2 ZSQ T(X) E:(-29) M:(-27)
058877,000509: 27,3213 00023 RTERM # RTERM E:(-29) M:(-27)
058878,000510: 27,3214 41215 DAD DMP
058879,000511: 27,3215 00015 RMAG1 # E:(-29) M:(-27)
058880,000512: # Z FROM PDL+0 E:(-13) M:(-12)
058881,000513: 27,3216 51042 SR3 BPL # TFF SQRT(MU) E:(-45) M:(-42)
058882,000514: 27,3217 57240 ENDTFF # (NO PUSH UP)
058883,000515: 27,3220 75206 PUSH SIGN # TFF SQRT(MU) TO PDL+0
058884,000516: 27,3221 00017 TFFQ1 # Q1 FOR GONEPAST TEST
058885,000517: 27,3222 71244 BPL DLOAD # GONE PAST ?
058886,000518: 27,3223 57244 NEGTFF # YES. TFF < 0.
058887,000519: 27,3224 00027 TFF1/ALF # 1/ALFA E:(-22-2NA) M:(-20-2NA)
058888,000520: 27,3225 51076 DCOMP BPL # ALFA > 0 ?
058889,000521: 27,3226 57244 NEGTFF # NO. TFF IS NEGATIVE.
058890,000522:
058891,000523: # CORRECT FOR ORBITAL PERIOD.
058892,000524:
058893,000525: 27,3227 77676 DCOMP # YES. CORRECT FOR ORB PERIOD.
058894,000526: 27,3230 56205 DMP DDV
058895,000527: 27,3231 17356 PI/16 # 2 PI (-5)
058896,000528: 27,3232 00031 TFFRTALF # SQRT(ALFA) E:(10+NA) M:(9+NA)
058897,000529: 27,3233 53657 SL* SL*
058898,000530: 27,3234 57602 0 -4,2 # X2=-NA
058899,000531: 27,3235 57602 0 -4,2
058900,000532: 27,3236 43257 SL* DAD
058901,000533: 27,3237 57576 0,2
058902,000534: # TFF SQRT(MU) FROM PDL+0 E:(-45) M:(-42)
058903,000535: 27,3240 40005 ENDTFF DMP BOV # TFF SQRT(MU) IN MPAC E:(-45) M:(-42)
058904,000536: 27,3241 00037 TFF/RTMU # E:(17) M:(14)
058905,000537: 27,3242 57250 MAXTFF # SET POSMAX IF OVFL.
058906,000538:
058907,000539: 27,3243 77616 DUMPTFF2 RVQ # RETURN TFF (-28) CS IN MPAC.
058908,000540:
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Page 1385
|
058910,000542: 27,3244 77745 NEGTFF DLOAD
058911,000543: # TFF SQRT(MU) FROM PDL+0, NEGATIVE.
058912,000544: 27,3245 77650 GOTO
058913,000545: 27,3246 57240 ENDTFF
058914,000546:
058915,000547: 27,3247 77745 MAXTFF1 DLOAD # RESET PDL
058916,000548: 27,3250 43545 MAXTFF DLOAD RVQ
058917,000549: 27,3251 17372 NEARONE
058918,000550:
058919,000551: # TIME OF FLIGHT ELLIPSE WHEN DEL (ECCENTRIC ANOM) GEQ 90 AND LEQ -90.
058920,000552:
058921,000553: # NUM FROM TFFX. E:(-16) OR (-29)
058922,000554: # M:(-15) OR (-27)
058923,000555: 27,3252 77712 TFFELL SL2 # NUM E:(-14) OR (-27) M:(-13) OR (-25)
058924,000556: 27,3253 41465 BDDV PUSH # TEMP SAVE D/N IN PDL+0
058925,000557: # DEN FROM PDL+0 E:(-3)/( 16) M:(-3)/(-15)
058926,000558: # N/D TO PDL+0 E:(11) M:(10)
058927,000559: 27,3254 45345 TFFEL1 DLOAD DSU # (ENTER WITH D/N=0 IN PDL+0)
058928,000560: 27,3255 00045 TFFTEM # Q2 E:(-16) M:(-15)
058929,000561: 27,3256 00017 TFFQ1 # Q1 E:(-16) M:(-15)
058930,000562: 27,3257 14013 STODL TFFDELQ # Q2-Q1 E:(-16) M:(-15)
058931,000563: # D/N FROM PDL+0
058932,000564: 27,3260 77626 STADR
058933,000565: 27,3261 77732 STORE TFFTEM # D/N E:(11) M:(10)
058934,000566: 27,3262 53605 DMP SL*
058935,000567: 27,3263 00027 TFF1/ALF # 1/ALFA E:(-22-2NA) M:(-20-2NA)
058936,000568: 27,3264 57576 0,2 # 1/ALFA Z E:(-11-NA) M:(-10-NA)
058937,000569: 27,3265 41206 PUSH DMP # TO PDL+0
058938,000570: 27,3266 00045 TFFTEM # 1/Z E:(11) M:(10)
058939,000571: 27,3267 41057 SL* BOVB
058940,000572: 27,3270 57576 0,2 # X2= -NA
058941,000573: 27,3271 45712 SIGNMPAC # IN CASE X= 1.0, CONTINUE
058942,000574: 27,3272 00043 STORE TFFX # X=1/ALFA ZSQ
058943,000575: 27,3273 41234 RTB DMP
058944,000576: 27,3274 57334 T(X) # POLY
058945,000577: 27,3275 00043 TFFX
058946,000578: 27,3276 45242 SR3 DSU
058947,000579: 27,3277 17364 DP2(-3)
058948,000580: 27,3300 41405 DMP PUSH # 2(X T(X)-1) /Z ALFA E:(-15-NA)
058949,000581: # M:(-14-NA)
058950,000582: # 1/ALFA Z FROM PDL+0 E:(-11-NA)
058951,000583: # M:(-10-NA)
058952,000584: 27,3301 41345 DLOAD DMP # GET SIGN FOR SDELF
058953,000585: 27,3302 00045 TFFTEM # 1/Z E:(11) M:(10)
058954,000586: 27,3303 00015 RMAG1 # E:(-29) M:(-27)
058955,000587: 27,3304 43312 SL2 DAD
058956,000588: 27,3305 00017 TFFQ1 # Q1 E:(-16) M:(-15)
058957,000589: 27,3306 14045 STODL TFFTEM # (Q1+R 1/Z) =SGN OF SDELF E:(-16) M:(-15
058958,000590: 27,3307 00035 TFFNP # LC P E:(-38+2NR) M:(-36+2NR)
058959,000591: 27,3310 53605 DMP SL* # CALC FOR ARG FOR TFF/TRIG.
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|
Page 1386
|
058961,000593: 27,3311 00027 TFF1/ALF # 1/ALFA E:(-22-2NA) M:(-20-2NA)
058962,000594: 27,3312 57575 1,2 # X2=-NA
058963,000595: 27,3313 53765 SIGN SL*
058964,000596: 27,3314 00045 TFFTEM # AFFIX SIGN FOR SDELF
058965,000597: 27,3315 57576 0,2
058966,000598: 27,3316 14045 STODL TFFTEM # P/ALFA E:(-59+2NR) M:(-55+2NR)
058967,000599: # (ARG FOR USE IN TFF/TRIG)
058968,000600: 27,3317 00027 TFF1/ALF # 1/ALFA E:(-22-2NA) M:(-20-2NA)
058969,000601: 27,3320 41366 SQRT DMP
058970,000602: 27,3321 17356 PI/16 # PI (-4)
058971,000603: 27,3322 77615 DAD
058972,000604: # 2(XT(X)-1)/Z ALFA FROM PDL E:(-15-NA)
058973,000605: # M:(-14-NA)
058974,000606: 27,3323 45257 SL* DSU
058975,000607: 27,3324 57577 0 -1,2
058976,000608: 27,3325 00013 TFFDELQ # Q2-Q1 E:(-16) M:(-15)
058977,000609: 27,3326 53605 DMP SL*
058978,000610: 27,3327 00027 TFF1/ALF # 1/ALFA E:(-22-2NA) M:(-20-2NA)
058979,000611: 27,3330 57601 0 -3,2
058980,000612: 27,3331 52057 SL* GOTO
058981,000613: 27,3332 57602 0 -4,2
058982,000614: 27,3333 57240 ENDTFF # TFF SQRT(MU) IN MPAC E:(-45) M:(-42)
058983,000615:
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|
Page 1387
|
058985,000617: # PROGRAM NAME: T(X) DATE: 01.17.67
058986,000618: # MOD NO: 0 LOG SECTION: TIME OF FREE FALL
058987,000619: # MOD BY: RR BAIRNSFATHER
058988,000620:
058989,000621: # FUNCTIONAL DESCRIPTION: THE POLYNOMIAL T(X) IS USED BY TIME OF FLIGHT SUBROUTINES CALCTFF AND
058990,000622: # CALCTPER TO APPROXIMATE THE SERIES
058991,000623: # 2 3
058992,000624: # 1/3 -X/5 +X /7 -X /9 ...
058993,000625:
058994,000626: # WHERE X = ALFA Z Z IF ALFA Z Z LEQ 1
058995,000627: # X = 1/(ALFA Z Z) IF ALFA Z Z G 1
058996,000628:
058997,000629: # ALSO X IS NEG FOR HYPERBOLIC ORBITS
058998,000630: # X = 0 FOR PARABOLIC ORBITS
058999,000631: # X IS POSITIVE FOR ELLIPTIC ORBITS
059000,000632:
059001,000633: # FOR FLIGHT 278, THE POLYNOMIAL T(X) IS FITTED OVER THE RANGE (0,+1) AND HAS A MAXIMUM
059002,000634: # DEVIATION FROM THE SERIES OF 2 E-5 (T(X) IS A CHEBYCHEV TYPE FIT AND WAS OBTAINED USING
059003,000635: # MAC PROGRAM AUTCURFIT294RRB AND IS VALID TO THE SAME TOLERANCE OVER THE RANGE (-.08,+1).)
059004,000636:
059005,000637: # CALLING SEQUENCE: RTB
059006,000638: # T(X)
059007,000639: # C(MPAC) = X
059008,000640:
059009,000641: # SUBROUTINES CALLED: NONE
059010,000642:
059011,000643: # NORMAL EXIT MODE: TC DANZIG
059012,000644:
059013,000645: # ALARMS: NONE
059014,000646:
059015,000647: # OUTPUT: C(MPAC) = T(X)
059016,000648:
059017,000649: # ERASABLE INITIALIZATION REQUIRED:
059018,000650: # C(MPAC) = X
059019,000651:
059020,000652: # DEBRIS: NONE
059021,000653:
059022,000654: 27,3334 07171 T(X) TC POLY
059023,000655: 27,3335 00004 DEC 4 B-14 # N-1
059024,000656: 27,3336 12525 12525 2DEC 3.333333333 E-1
059025,000657: 27,3340 71463 57703 2DEC* -1.999819135 E-1*
059026,000658: 27,3342 04423 17645 2DEC* 1.418148467 E-1*
059027,000659: 27,3344 74604 43667 2DEC* -1.01310997 E-1*
059028,000660: 27,3346 01626 37256 2DEC* 5.609004986 E-2*
059029,000661: 27,3350 77404 52071 2DEC* -1.536156925 E-2*
059030,000662:
059031,000663: 27,3352 06030 ENDT(X) TC DANZIG
059032,000664:
059033,000665: 27,3353 27,3352 TCDANZIG = ENDT(X)
059034,000666:
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Page 1388
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059036,000668: # TFF CONSTANTS
059037,000669:
059038,000670: 32,3770 BANK 32
059039,000671:
059040,000672: 27,2000 SETLOC TOF-FF1
059041,000673: 27,2000 BANK
059042,000674:
059043,000675: # NOTE _ NOTE _ ADJUSTED MUE FOR NEAR EARTH TRAJ.
059044,000676: # MUE = 3.990815471 E10 M CUBE/CS SQ
059045,000677: # RTMUE = 1.997702549 E5 B-18* MODIFIED EARTH MU
059046,000678:
059047,000679: 27,3353 24775 30424 1/RTMU 2DEC* .5005750271 E-5 B17* # MODIFIED EARTH MU
059048,000680:
059049,000681: # NOTE _ NOTE _ ADJUSTED MUE FOR NEAR EARTH TRAJ.
059050,000682: # MUM = 4.902778 E8 M CUBE/CS SQ
059051,000683: # RTMUM 2DEC* 2.21422176 E4 B-18*
059052,000684: 27,3355 06220 37553 PI/16 2DEC 3.141592653 B-4
059053,000685: 27,3357 37777 37700 LIM(-22) 2OCT 3777737700 # 1.0 -B(-22)
059054,000686: 27,3361 00000 00100 DP(-22) 2OCT 0000000100 # B(-22)
059055,000687: 27,3363 04000 00000 DP2(-3) 2DEC 1 B-3
059056,000688: 27,3365 02000 00000 DP2(-4) 2DEC 1 B-4 # 1/16
059057,000689:
059058,000690: # RPAD1 2DEC 6373338 B-29 M (-29) = 20909901.57 FT
059059,000691: 27,3367 22,3151 RPAD1 = RPAD
059060,000692:
059061,000693: 27,3367 00305 11205 R300K 2DEC 6464778 B-29 # (-29) M
059062,000694: 27,3371 37777 37777 NEARONE 2DEC .999999999
059063,000695: 27,3373 26,3334 TFFZEROS EQUALS HI6ZEROS
059064,000696: 27,3373 26,3324 TFF1/4 EQUALS HIDP1/4
End of include-file TIME_OF_FREE_FALL.agc. Parent file is MAIN.agc