Source Code
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These source-code files are part of a reconstructed copy of Comanche 72/3 (AKA Manche72 revision 3),
the final, flown mission release of the Apollo Guidance Computer (AGC) Command Module (CM) software
for Apollo 13.
The starting point was the source code of Comanche 72 (itself previously reconstructed). Comanche 72
source code was then modified by incorporating changes known from contemporary documentation to have
been made between revisions 72 and 72/3. The resulting code assembles to have identical
memory-bank checksums as those specified in NASA drawing 2021153G; this gives reasonably
high confidence that the changes that have been made are correct. In places where
ambiguity exists, this ambiguity is discussed in "## Reconstruction:" comments.
Since no contemporary listings of Comanche 72/3 are available as source material,
all comments and labels are approximate.
They have been taken from other AGC programs where possible, or, in some places, written
from scratch to match what we believe would have been in the original listing.
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057236,000002: ## Copyright: Public domain.
057237,000003: ## Filename: TIME_OF_FREE_FALL.agc
057238,000004: ## Purpose: A section of Manche72 revision 3.
057239,000005: ## It is part of the reconstructed source code for the final, flown
057240,000006: ## release of the software for the Command Module's (CM) Apollo
057241,000007: ## Guidance Computer (AGC) for Apollo 13. No original listings
057242,000008: ## of this program are available; instead, this file was recreated
057243,000009: ## from a reconstructed copy of Comanche 072. It has been adapted
057244,000010: ## such that the resulting bugger words exactly match those
057245,000011: ## specified for Manche72 revision 3 in NASA drawing 2021153G,
057246,000012: ## which gives relatively high confidence that the reconstruction
057247,000013: ## is correct.
057248,000014: ## Assembler: yaYUL
057249,000015: ## Contact: Ron Burkey <info@sandroid.org>.
057250,000016: ## Website: www.ibiblio.org/apollo/index.html
057251,000017: ## Mod history: 2024-05-19 MAS Created from Comanche 072.
057252,000018:
057253,000019: # THE TFF SUBROUTINES MAY BE USED IN EITHER EARTH OR MOON CENTERED COORDINATES. THE TFF ROUTINES NEVER
057254,000020: # KNOW WHICH ORIGIN APPLIES. IT IS THE USER WHO KNOWS, AND WHO SUPPLIES RONE, VONE AND 1/SQRT(MU) AT THE
057255,000021: # APPROPRIATE SCALE LEVEL FOR THE PROPER PRIMARY BODY.
057256,000022:
057257,000023: # EARTH ORIGIN POSITION -29 METERS
057258,000024: # VELOCITY -7 METERS/CENTISECOND
057259,000025: # 1/SQRT(MU) +17 SQRT(CS SQ/METERS CUBED)
057260,000026:
057261,000027: # MOON ORIGIN POSITION -27 METERS
057262,000028: # VELOCITY -5 METERS/CENTISECONDS
057263,000029: # 1/SQRT(MU) +14 SQRT(CS SQ/METERS CUBED)
057264,000030:
057265,000031: # ALL DATA PROVIDED TO AND RECEIVED FROM ANY TFF SUBROUTINE WILL BE AT ONE OF THE LEVELS ABOVE. IN ALL CASES,
057266,000032: # THE FREE FALL TIME IS RETURNED IN CENTISECONDS AT (-28). PROGRAM TFF/CONIC WILL GENERATE VONE/RTMU AND
057267,000033: # LEAVE IT IN VONE' AT (+10) IF EARTH ORIGIN AND (+9) IF MOON ORIGIN.
057268,000034:
057269,000035: # THE USER MUST STORE THE STATE VECTOR IN RONE, VONE AND MU IN THE FORM 1/SQRT(MU) IN TFF/RTMU
057270,000036: # AT THE PROPER SCALE BEFORE CALLING TFF/CONIC. SINCE RONE, VONE ARE IN THE EXTENDED VERB STORAGE AREA,
057271,000037: # THE USER MUST ALSO LOCK OUT THE EXTENDED VERBS, AND RELEASE THEM WHEN FINISHED.
057272,000038:
057273,000039: # PROGRAMS CALC/TFF AND CALC/TPER ASSUME THAT THE TERMINAL RADIUS IS LESS THAN THE PRESENT
057274,000040: # RADIUS. THIS RESTRICTION CAN BE REMOVED BY A 15 W CODING CHANGE, BUT AT PRESENT IT IS NOT DEEMED NECESSARY.
057275,000041:
057276,000042: # THE FOLLOWING ERASABLE QUANTITIES ARE USED BY THE TFF ROUTINES, AND ARE LOCATED IN THE PUSH LIST.
057277,000043:
057278,000044: # BELOW E: IS USED FOR EARTH ORIGIN SCALE
057279,000045: # M: IS USED FOR MOON ORIGIN SCALE
057280,000046:
057281,000047: # TFFSW = 119D BIT1 0 = CALCTFF 1 = CALCTPER
057282,000048: 23,3774 TFFDELQ = 10D # Q2-Q1 E: (-16) M: (-15)
057283,000049: 23,3774 RMAG1 = 12D # ABVAL(RN) M E: (-29) M: (-27)
057284,000050: # RPER = 14D PERIGEE RADIUS M E: (-29) M: (-27)
057285,000051: 23,3774 TFFQ1 = 14D # R.V / SQRT(MUE) E: (-16) M: (-15)
057286,000052: # SDELF/2 SIN(THETA) /2
057287,000053: 23,3774 CDELF/2 = 14D # COS(THETA) /2
057288,000054: # RAPO = 16D APOGEE RADIUS M E: (-29) M: (-27)
057289,000055: 23,3774 NRTERM = 16D # TERMINAL RADIUS M E: (-29+NR)
057290,000056: # M: (-27+NR)
057291,000057: 23,3774 RTERM = 18D # TERMINAL RADIUS M E: (-29) M: (-27)
057292,000058: 23,3774 TFFVSQ = 20D # -(V SQUARED/MU) 1/M E: (20) M: (18)
057293,000059: 23,3774 TFF1/ALF = 22D # SEMI MAJ AXIS M E: (-22-2 NA)
057294,000060: # M: (-20-2 NA)
057295,000061: 23,3774 TFFRTALF = 24D # SQRT(ALFA) E:(10+NA) M: (9+NA)
057296,000062: 23,3774 TFFALFA = 26D # ALFA 1/M E:(26-NR) M: (24-NR)
057297,000063: 23,3774 TFFNP = 28D # SEMI LATUS RECTUM M E: (-38+2 NR)
057298,000064: # M: (-36+2 NR)
057299,000065: 23,3774 TFF/RTMU = 30D # 1/SQRT(MU) E: (17) M: (14)
057300,000066: 23,3774 NRMAG = 32D # PRESENT RADIUS M E: (-29+NR)
057301,000067: # M: (-27+NR)
057302,000068: 23,3774 TFFX = 34D
057303,000069: 23,3774 TFFTEM = 36D # TEMPORARY
057304,000070: # REGISTERS S1, S2 ARE UNTOUCHED BY ANY TFF SUBROUTINE
057305,000071: # INDEX REGISTERS X1, X2 ARE USED BY ALL TFF SUBROUTINES. THEY ARE ESTAB-
057306,000072: # LISHED IN TFF/CONIC AND MUST BE PRESERVED BETWEEN CALLS TO SUBSEQUENT
057307,000073: # SUBROUTINES.
057308,000074: # -NR C(X1) = NORM COUNT OF RMAG
057309,000075: # -NA C(X2) = NORM COUNT OF SQRT(ABS(ALFA))
057310,000076:
057311,000077: # SUBROUTINE NAME: TFFCONIC DATE: 01.29.67
057312,000078: # MOD NO: 0 LOG SECTION: TIME OF FREE FALL
057313,000079: # MOD BY: RR BAIRNSFATHER
057314,000080: # MOD NO: 1 MOD BY: RR BAIRNSFATHER DATE: 11 APR 67
057315,000081: # MOD NO: 2 MOD BY: RR BAIRNSFATHER DATE: 21 NOV 67 ADD MOON MU.
057316,000082: # MOD NO: 3 MOD BY: RR BAIRNSFATHER DATE: 21 MAR 68 ACCEPT DIFFERENT EARTH/MOON SCALES
057317,000083:
057318,000084: # FUNCTIONAL DESCRIPTION: THIS SUBROUTINE IS CALLED TO COMPUTE THOSE CONIC PARAMETERS REQUIRED BY THE TFF
057319,000085: # SUBROUTINES AND TO ESTABLISH THEM IN THE PUSH LIST AREA. THE PARAMETERS ARE LISTED UNDER OUTPUT.
057320,000086: # THE EQUATIONS ARE
057321,000087: # - - -
057322,000088: # H = RN*VN ANGULAR MOMENTUM
057323,000089: # - -
057324,000090: # LCP = H.H / MU SEMI LATUS RECTUM
057325,000091: # - -
057326,000092: # ALFA = 2/RN - VN.VN / MU RECIPROCAL SEMI MAJ AXIS, SIGNED
057327,000093:
057328,000094: # AND ALFA IS POS FOR ELLIPTIC ORBITS
057329,000095: # 0 FOR PARABOLIC ORBITS
057330,000096: # NEG FOR HYPERBOLIC ORBITS.
057331,000097: # SUBROUTINE ALSO COMPUTES AND SAVES RMAG.
057332,000098:
057333,000099: # CALLING SEQUENCE:
057334,000100: # TFFCONIC EXPECTS CALLER TO ENTER WITH CORRECT GRAVITATIONAL CONSTANT IN MPAC, IN THE FORM
057335,000101: # 1/SQRT(MU). PROGRAM WILL SAVE IN TFF/RTMU. THE SCALE IS DETERMINED BY WHETHER EARTH OR MOON
057336,000102: # ORIGIN IS USED. THE CALLER MUST LOCK OUT THE EXTENDED VERBS BEFORE PROVIDING STATE VECTOR IN RONE,
057337,000103: # VONE AT PROPER SCALE. THE EXTENDED VERBS MUST BE RESTORED WHEN THE CALLER IS FINISHED USING THE
057338,000104: # TFF ROUTINES.
057339,000105:
057340,000106: # ENTRY POINT TFFCONMU EXPECTS THAT TFF/RTMU IS ALREADY LOADED.
057341,000107:
057342,000108: # TO SPECIFY MU: DLOAD CALL IF MU ALREADY STORED: CALL
057343,000109: # YOURMU 1/RTMU E:(17) M:(14) TFFCONMU
057344,000110: # TFFCONIC
057345,000111: # PUSHLOC = PDL+0, ARBITRARY IF LEQ 18D
057346,000112:
057347,000113: # SUBROUTINES CALLED: NONE
057348,000114:
057349,000115: # NORMAL EXIT MODES: RVQ
057350,000116:
057351,000117: # ALARMS: NONE
057352,000118:
057353,000119: # OUTPUT: THE FOLLOWING ARE STORED IN THE PUSH LIST AREA.
057354,000120: # RMAG1 E:(-29) M:(-27) M RN, PRESENT RADIUS LENGTH.
057355,000121: # NRMAG E:(-29+NR) M RMAG, NORMALIZED
057356,000122: # M:(-27+NR)
057357,000123: # X1 -NR, NORM COUNT
057358,000124: # TFFNP E:(-38+2NR) M LCP, SEMI LATUS RECTUM, WEIGHTED BY NR. FOR VGAMCALC
057359,000125: # M:(-36+2NR)
057360,000126: # TFF/RTMU E:(17) M:(14) 1/SQRT(MU)
057361,000127: # TFFVSQ E:(20) M:(18) 1/M -(V SQ/MU): PRESENT VELOCITY, NORMLIZED. FOR VGAMCALC
057362,000128: # TFFALFA E:(26-NR) 1/M ALFA, WEIGHTED BY NR
057363,000129: # M:(24-NR)
057364,000130: # TFFRTALF E:(10+NA) SQRT(ALFA), NORMALIZED
057365,000131: # M:(9+NA)
057366,000132: # X2 -NA, NORM COUNT
057367,000133: # TFF1/ALF E:(-22-2NA) SIGNED SEMI MAJ AXIS, WEIGHTED BY NA
057368,000134: # M:(-20-2NA)
057369,000135: # PUSHLOC AT PDL+0
057370,000136:
057371,000137: # THE FOLLOWING IS STORED IN GENERAL ERASABLE
057372,000138: # VONE' E:(10) M:(9) V/RT(MU), NORMALIZED VELOCITY
057373,000139:
057374,000140: # ERASABLE INITIALIZATION REQUIRED:
057375,000141: # RONE E:(-29) M:(-27) M STATE VECTOR LEFT BY CALLER
057376,000142: # VONE E:(-7) M:(-5) M/CS STATE VECTOR LEFT BY CALLER
057377,000143: # TFF/RTMU E:(17) M:(14) 1/RT(CS SQ/M CUBE) IF ENTER VIA TFFCONMU.
057378,000144:
057379,000145: # DEBRIS: QPRET, PDL+0 ... PDL+3
057380,000146:
057381,000147: 33,3776 BANK 33
057382,000148: 27,2000 SETLOC TOF-FF
057383,000149: 27,2000 BANK
057384,000150:
057385,000151: 27,2760 COUNT* $$/TFF
057386,000152:
057387,000153: 27,2760 00037 TFFCONIC STORE TFF/RTMU # 1/SQRT(MU) E:(17) M:(14)
057388,000154:
057389,000155: 27,2761 53575 TFFCONMU VLOAD UNIT # COME HERE WITH TFFRTMU LOADED.
057390,000156: 27,2762 02327 RONE # SAVED RN. M E:(-29) M:(-27)
057391,000157: 27,2763 77725 PDDL # UR/2 TO PDL+0, +5
057392,000158: 27,2764 00045 36D # MAGNITUDE
057393,000159: 27,2765 00015 STORE RMAG1 # M E:(-29) M:(-27)
057394,000160:
057395,000161: 27,2766 77701 NORM
057396,000162: 27,2767 00047 X1 # -NR
057397,000163: 27,2770 24041 STOVL NRMAG # RMAG M E:(-29+NR) M:(-27+NR)
057398,000164: 27,2771 02335 VONE # SAVED VN. M/CS E:(-7) M:(-5)
057399,000165: 27,2772 77761 VXSC
057400,000166: 27,2773 00037 TFF/RTMU # E:(17) M:(14)
057401,000167: 27,2774 02372 STORE VONE' # VN/SQRT(MU) E:(10) M:(9)
057402,000168:
057403,000169: 27,2775 47361 VXSC VXV
057404,000170: 27,2776 00041 NRMAG # E:(-29+NR) M:(-27+NR)
057405,000171: # UR/2 FROM PDL
057406,000172: 27,2777 47572 VSL1 VSQ # BEFORE: E:(-19+NR) M:(-18+NR)
057407,000173: 27,3000 14035 STODL TFFNP # LC P M E:(-38+2NR) M:(-36+2NR)
057408,000174: # SAVE ALSO FOR VGAMCALC
057409,000175: 27,3001 15324 TFF1/4
057410,000176: 27,3002 63271 DDV PDVL # (2/RMAG) 1/M E:(26-NR) M:(24-NR)
057411,000177: 27,3003 00041 NRMAG # RMAG M E:(-29+NR) M:(-27+NR)
057412,000178: 27,3004 02372 VONE' # SAVED VN. E:(10) M:(9)
057413,000179: 27,3005 57436 VSQ DCOMP # KEEP MPAC+2 HONEST FOR SQRT.
057414,000180: 27,3006 00025 STORE TFFVSQ # -(V SQ/MU) E:(20) M:(18)
057415,000181: # SAVE FOR VGAMCALC
057416,000182: 27,3007 43257 SR* DAD
057417,000183: 27,3010 20573 0 -6,1 # GET -VSQ/MU E:(26-NR) M:(24-NR)
057418,000184: 27,3011 77626 STADR
057419,000185: # 2/RMAG FROM PDL+2
057420,000186: 27,3012 77744 STORE TFFALFA # ALFA 1/M E:(26-NR) M:(24-NR)
057421,000187: 27,3013 41457 SL* PUSH # TEMP SAVE ALFA E:(20) M:(18)
057422,000188: 27,3014 20173 0 -6,1
057423,000189: 27,3015 75446 ABS SQRT # E:(10) M:(9)
057424,000190: 27,3016 77701 NORM
057425,000191: 27,3017 00050 X2 # X2 = -NA
057426,000192: 27,3020 00031 STORE TFFRTALF # SQRT( ABS(ALFA) ) E:(10+NA) M:(9+NA)
057427,000193: 27,3021 75316 DSQ SIGN # NOT SO ACCURATE, BUT OK
057428,000194: # ALFA FROM PDL+2 E:(20) M:(18)
057429,000195: 27,3022 55254 BZE BDDV # SET 1/ALFA =0, TO SHOW SMALL ALFA
057430,000196: 27,3023 57025 +2
057431,000197: 27,3024 15324 TFF1/4
057432,000198: 27,3025 00027 +2 STORE TFF1/ALF # 1/ALFA E:(-22-2NA) M:(-20-2NA)
057433,000199: 27,3026 77616 DUMPCNIC RVQ
057434,000200: # 39 W
057435,000201: # SUBROUTINE NAME: TFFRP/RA DATE: 01.17.67
057436,000202: # MOD NO: 0 LOG SECTION: TIME OF FREE FALL
057437,000203: # MOD BY: RR BAIRNSFATHER
057438,000204: # MOD NO: 1 MOD BY: RR BAIRNSFATHER DATE: 11 APR 67
057439,000205: # MOD NO: 2 MOD BY: RR BAIRNSFATHER DATE: 21 MAR 68 ACCEPT DIFFERENT EARTH/MOON SCALES
057440,000206: # ALSO IMPROVE ACCURACY OF RAPO.
057441,000207:
057442,000208: # FUNCTIONAL DESCRIPTION: USED BY CALCTPER AND TFF DISPLAYS TO CALCULATE PERIGEE RADIUS AND ALSO
057443,000209: # APOGEE RADIUS FOR A GENERAL CONIC.
057444,000210: # PROGRAM GIVES PERIGEE RADIUS AS APOGEE RADIUS IS GIVEN BY
057445,000211: # RP = P/(1+E) RA = (1+E) / ALFA
057446,000212: # WHERE 2
057447,000213: # E = 1 - P ALFA
057448,000214: # IF RA IS NEGATIVE OR SHOWS DIVIDE OVERFLOW, THEN RA = POSMAX BECAUSE
057449,000215: # 1. APOGEE RADIUS IS NOT MEANINGFUL FOR HYPERBOLA
057450,000216: # 2. APOGEE RADIUS IS NOT DEFINED FOR PARABOLA
057451,000217: # 3. APOGEE RADIUS EXCEEDS THE SCALING FOR ELLIPSE.
057452,000218:
057453,000219: # THIS SUBROUTINE REQUIRES THE SIGNED RECIPROCAL SEMI MAJ AXIS, ALFA, AND SEMI LATUS RECTUM AS DATA.
057454,000220:
057455,000221: # CALLING SEQUENCE: CALL
057456,000222: # TFFRP/RA
057457,000223: # PUSHLOC = PDL+0, ARBITRARY IF LEQ 10D
057458,000224: # C(MPAC) UNSPECIFIED
057459,000225:
057460,000226: # SUBROUTINES CALLED: NONE
057461,000227:
057462,000228: # NORMAL EXIT MODE: RVQ
057463,000229: # IF ELLIPSE, WITHIN NORMAL SCALING, RAPO IS CORRECT.
057464,000230: # OTHERWISE, RAPO = POSMAX.
057465,000231:
057466,000232: # ALARMS: NONE
057467,000233:
057468,000234: # OUTPUT: STORED IN PUSH LIST AREA. SCALE OF OUTPUT AGREES WITH DATA SUPPLIED TO TFF/CONIC.
057469,000235: # RPER E:(-29) M:(-27) M PERIGEE RADIUS DESTROYED BY CALCTFF/CALCTPER, TFFTRIG.
057470,000236: # RAPO E:(-29) M:(-27) M APOGEE RADIUS WILL BE DESTROYED BY CALCTFF/CALCTPER
057471,000237: # PUSHLOC AT PDL+0
057472,000238:
057473,000239: # ERASABLE INITIALIZATION REQUIRED:
057474,000240: # TFFALFA E:(26-NR) M 1/SEMI MAJ AXIS LEFT BY TFFCONIC
057475,000241: # M:(24-NR)
057476,000242: # TFFNP E:(-38+2NR) M LC P, SEMI LATUS RECTUM LEFT BY TFFCONIC
057477,000243: # M:(-36+2NR)
057478,000244: # X1 -NR, NORM COUNT OF RMAG LEFT BY TFFCONIC
057479,000245: # X2 -NA, NORM COUNT OF ALFA LEFT BY TFFCONIC
057480,000246:
057481,000247: # DEBRIS: QPRET, PDL+0 ... PDL+1
057482,000248:
057483,000249: 27,3027 RAPO = 16D # APOGEE RADIUS M E:(-29) M:(-27)
057484,000250: 27,3027 RPER = 14D # PERIGEE RADIUS M E:(-29) M:(-27)
057485,000251:
057486,000252: 27,3027 41345 TFFRP/RA DLOAD DMP
057487,000253: 27,3030 00033 TFFALFA # ALFA 1/M E:(26-NR) M:(24-NR)
057488,000254: 27,3031 00035 TFFNP # LC P M E:(-38+2NR) M:(-36+2NR)
057489,000255: 27,3032 57457 SR* DCOMP # ALFA P (-12+NR)
057490,000256: 27,3033 20571 0 -8D,1 # ALFA P (-4)
057491,000257: 27,3034 51415 DAD ABS # (DCOMP GIVES VALID TP RESULT FOR SQRT)
057492,000258: # (ABS PROTECTS SQRT IF E IS VERY NEAR 0)
057493,000259: 27,3035 17367 DP2(-4)
057494,000260: 27,3036 43366 SQRT DAD # E SQ = (1- P ALFA) (-4)
057495,000261: 27,3037 15324 TFF1/4
057496,000262: 27,3040 55206 PUSH BDDV # (1+E) (-2) TO PDL+0
057497,000263: 27,3041 00035 TFFNP # LCP M E:(-38+2NR) M:(-36+2NR)
057498,000264: 27,3042 53657 SR* SR* # (DOES SR THEN SL TO AVOID OVFL)
057499,000265: 27,3043 20601 0,1 # X1=-NR
057500,000266: 27,3044 20572 0 -7,1 # (EFFECTIVE SL)
057501,000267: 27,3045 14017 STODL RPER # PERIGEE RADIUS M E:(-29) M:(-27)
057502,000268: # (1+E) (-2) FROM PDL+0
057503,000269: 27,3046 41005 DMP BOVB
057504,000270: 27,3047 00027 TFF1/ALF # E:(-22-2NA) M:(-20-2NA)
057505,000271: 27,3050 57353 TCDANZIG # CLEAR OVFIND, IF ON.
057506,000272: 27,3051 53654 BZE SL*
057507,000273: 27,3052 57061 MAXRA # SET POSMAX, IF ALFA=0
057508,000274: 27,3053 57603 0 -5,2 # -5+NA
057509,000275: 27,3054 40057 SL* BOV
057510,000276: 27,3055 57576 0,2
057511,000277: 27,3056 57061 MAXRA # SET POSMAX IF OVFL.
057512,000278: 27,3057 77644 BPL # CONTINUE WITH VALID RAPO.
057513,000279: 27,3060 57063 +3
057514,000280: 27,3061 77745 MAXRA DLOAD # RAPO CALC IS NOT VALID. SET RAPO =
057515,000281: 27,3062 17373 NEARONE # POSMAX AS A TAG.
057516,000282: 27,3063 00021 +3 STORE RAPO # APOGEE RADIUS M E:(-29) M:(-27)
057517,000283: 27,3064 77616 DUMPRPRA RVQ
057518,000284: # 30 W
057519,000285: # SUBROUTINE NAME: CALCTPER / CALCTFF DATE: 01.29.67
057520,000286: # MOD NO: 0 LOG SECTION: TIME OF FREE FALL
057521,000287: # MOD BY: RR BAIRNSFATHER
057522,000288: # MOD NO: 1 MOD BY: RR BAIRNSFATHER DATE: 21 MAR 67
057523,000289: # MOD NO: 2 MOD BY: RR BAIRNSFATHER DATE: 14 APR 67
057524,000290: # MOD NO: 3 MOD BY: RR BAIRNSFATHER DATE: 8 JUL 67 NEAR EARTH MUE AND NEG TFF (GONEPAST)
057525,000291: # MOD NO: 4 MOD BY: RR BAIRNSFATHER DATE: 21 NOV 67 ADD VARIABLE MU.
057526,000292: # MOD NO: 5 MOD BY: RR BAIRNSFATHER DATE: 21 MAR 68 ACCEPT DIFFERENT EARTH/MOON SCALES
057527,000293:
057528,000294: # FUNCTIONAL DESCRIPTION: PROGRAM CALCULATES THE FREE-FALL TIME OF FLIGHT FROM PRESENT POSITION RN AND
057529,000295: # VELOCITY VN TO A RADIUS LENGTH SPECIFIED BY RTERM, SUPPLIED BY THE USER. THE POSITION VECTOR
057530,000296: # RN MAY BE ON EITHER SIDE OF THE CONIC, BUT RTERM IS CONSIDERED ON THE INBOUND SIDE.
057531,000297: # THE EQUATIONS ARE
057532,000298:
057533,000299: # Q2 = -SQRT(RTERM (2-RTERM ALFA) - LCP) (INBOUND SIDE)) LEQ +- LCE/SQRT(ALFA)
057534,000300: # - -
057535,000301: # Q1 = RN.VN / SQRT(MU) LEQ +- LCE/SQRT(ALFA)
057536,000302:
057537,000303: # Z = NUM / DEN LEQ +- 1/SQRT(ALFA)
057538,000304:
057539,000305: # WHERE, IF INBOUND
057540,000306: # NUM = RTERM -RN LEQ +- 2 LCE/ALFA
057541,000307: # DEN = Q2+Q1 LEQ +- 2 LCE/SQRT(ALFA)
057542,000308:
057543,000309: # AND, IF OUTBOUND
057544,000310: # NUM = Q2-Q1 LEQ +- 2 LCE/SQRT(ALFA)
057545,000311: # DEN = 2 - ALFA (RTERM + RN). LEQ +- 2 LCE
057546,000312:
057547,000313: # IF ALFA ZZ < 1.0 (FOR ALL CONICS EXCEPT ELLIPSES HAVING ABS(DEL ECC ANOM) G 90 DEG)
057548,000314: # THEN X = ALFA Z Z
057549,000315: # AND TFF = (RTERM +RN -2 ZZ T(X) ) Z/SQRT(MU)
057550,000316: # EXCEPT IF ALFA PNZ, AND IF TFF NEG,
057551,000317: # THEN TFF = 2 PI /(ALFA SQRT(ALFA)) + TFF
057552,000318: # OR IF ALFA ZZ GEQ 1.0 (FOR ELLIPSES HAVING ABS(DEL ECC ANOM) GEQ 90 DEG)
057553,000319: # THEN X = 1/ALFA Z Z
057554,000320: # AND TFF = (PI/SQRT(ALFA) -Q2 +Q1 +2(X T(X) -1) /ALFA Z) /ALFA SQRT(MU)
057555,000321: # WHERE T(X) IS A POLYNOMIAL APPROXIMATION TO THE SERIES
057556,000322: # 2 3 2
057557,000323: # 1/3 - X/5 + X /7 - X /9 ... (X < 1.0)
057558,000324:
057559,000325: # CALLING SEQUENCE: TIME TO RTERM TIME TO PERIGEE
057560,000326: # CALL CALL
057561,000327: # CALCTFF CALCTPER
057562,000328: # C(MPAC) = TERMNL RAD M C(MPAC) = PERIGEE RAD M
057563,000329: # FOR EITHER, E:(-29) M:(-27)
057564,000330: # FOR EITHER, PUSHLOC = PDL+0, ARBITRARY IF LEQ 8D.
057565,000331:
057566,000332: # SUBROUTINES CALLED: T(X), VIA RTB
057567,000333:
057568,000334: # NORMAL EXIT MODE: RVQ
057569,000335: # HOWEVER, PROGRAM EXITS WITH ONE OF THE FOLLOWING VALUES FOR TFF (-28) CS IN MPAC. USER MUST STORE.
057570,000336: # A. TFF = FLIGHT TIME. NORMAL CASE FOR POSITIVE FLIGHT TIME LESS THAN ONE ORBITAL PERIOD.
057571,000337: # B. (THIS OPTION IS NO LONGER USED.)
057572,000338: # C. TFF = POSMAX. THIS INDICATES THAT THE CONIC FROM THE PRESENT POSITION WILL NOT RETURN TO
057573,000339: # THE SPECIFIED ALTITUDE. ALSO INDICATES OUTBOUND PARABOLA OR HYPERBOLA.
057574,000340:
057575,000341: # OUTPUT: C(MPAC) (-28) CS TIME OF FLIGHT, OR TIME TO PERIGEE
057576,000342: # TFFX (0) X, LEFT FOR ENTRY DISPLAY TFF ROUTINES
057577,000343: # NRTERM E:(-29+NR) M RTERM, WEIGHTED BY NR LEFT FOR ENTRY DISPLAY TFF ROUTINES
057578,000344: # M:(-27+NR)
057579,000345: # TFFTEM E:(-59+2NR) LCP Z Z SGN(SDELF) LEFT FOR ENTRY DISPLAY TFF ROUTINES
057580,000346: # M:(-55+2NR) LCP /ALFA SGN(SDELF) LEFT FOR ENTRY DISPLAY TFF ROUTINES
057581,000347: # NOTE: TFFTEM = PDL 36D AND WILL BE DESTROYED BY .:UNIT:.
057582,000348: # RMAG1 E:(-29) M:(-27) PDL 12 NOT TOUCHED.
057583,000349: # TFFQ1 E:(-16) M:(-15) PDL 14D
057584,000350: # TFFDELQ E:(-16) M:(-15) PDL 10D
057585,000351: # PUSHLOC AT PDL+0
057586,000352:
057587,000353: # ERASABLE INITIALIZATION REQUIRED:
057588,000354: # RONE E:(-29) M:(-27) M STATE VECTOR LEFT BY USER
057589,000355: # VONE' E:(+10) M:(+9) VN/SQRT(MU) LEFT BY TFF/CONIC
057590,000356: # RMAG1 E:(-29) M:(-27) PRESENT RADIUS, M LEFT BY TFFCONIC
057591,000357: # C(MPAC) E:(-29) M:(-27) RTERM, TERMINAL RADIUS LENGTH, M LEFT BY USER
057592,000358:
057593,000359: # THE FOLLOWING ARE STORED IN THE PUSH LIST AREA.
057594,000360: # TFF/RTMU E:(17) M:(14) 1/SQRT(MU) LEFT BY TFFCONIC.
057595,000361: # NRMAG E:(-29+NR) M RMAG, NORMALIZED LEFT BY TFFCONIC
057596,000362: # M:(-27+NR)
057597,000363: # X1 -NR, NORM COUNT LEFT BY TFFCONIC
057598,000364: # TFFNP E:(-38+2NR) M LCP, SEMI LATUS RECTUM, WEIGHT NR LEFT BY TFFCONIC
057599,000365: # M:(-36+2NR)
057600,000366: # TFFALFA E:(26-NR) 1/M ALFA, WEIGHT NR LEFT BY TFFCONIC
057601,000367: # M:(24-NR)
057602,000368: # TFFRTALF E:(10+NA) SQRT(ALFA), NORMALIZED LEFT BY TFFCONIC
057603,000369: # M:(9+NA)
057604,000370: # X2 -NA, NORM COUNT LEFT BY TFFCONIC
057605,000371: # TFF1/ALF E:(-22-2NA) SIGNED SEMIMAJ AXIS, WEIGHTED BY NA LEFT BY TFFCONIC
057606,000372: # M:(-20-2NA)
057607,000373:
057608,000374: # DEBRIS: QPRET, PDL+0 ... PDL+3
057609,000375: # RTERM E:(-29) M:(-27) RTERM, TERMINAL RADIUS LENGTH
057610,000376: # RAPO E:(-29) M:(-27) PDL 16D (=NRTERM)
057611,000377: # RPER E:(-29) M:(-27) PDL 14D (=TFFQ1)
057612,000378:
057613,000379: 27,3065 77614 CALCTPER SETGO # ENTER WITH RPER IN MPAC
057614,000380: 27,3066 03436 TFFSW
057615,000381: 27,3067 57072 +3
057616,000382: 27,3070 77614 CALCTFF CLEAR # ENTER WITH RTERM IN MPAC
057617,000383: 27,3071 03676 TFFSW
057618,000384: 27,3072 00023 +3 STORE RTERM # E:(-29) M:(-27)
057619,000385: 27,3073 77657 SL*
057620,000386: 27,3074 20201 0,1 # X1=-NR
057621,000387: 27,3075 00021 STORE NRTERM # RTERM E:(-29+NR) M:(-27+NR)
057622,000388: 27,3076 44205 DMP BDSU
057623,000389: 27,3077 00033 TFFALFA # ALFA E:(26-NR) M:(24-NR)
057624,000390: 27,3100 15324 TFF1/4
057625,000391: 27,3101 41206 PUSH DMP # (2-ALFA RTERM) (-3) TO PDL+0
057626,000392: 27,3102 00021 NRTERM # E:(-29+NR) M:(-27+NR)
057627,000393: 27,3103 53725 PDDL SR* # RTERM(2-ALFA RTERM) TO PDL+2
057628,000394: # E:(-32+NR) M:(-30+NR)
057629,000395: 27,3104 00035 TFFNP # LC P E:(-38+2NR) M:(-36+2NR)
057630,000396: 27,3105 20573 0 -6,1 # X1 = -NR
057631,000397: 27,3106 43276 DCOMP DAD # DUE TO SHIFTS, KEEP PRECISION FOR SQRT
057632,000398: # RTERM(2-ALFA RTERM) FROM PDL +2
057633,000399: # E:(-32+NR) M:(-30+NR)
057634,000400: 27,3107 77657 SR* # LEAVE E:(-32) M:(-30)
057635,000401: 27,3110 20601 0,1 # X1 = -NR
057636,000402: 27,3111 71214 BOFF DLOAD # CHECK TFF /TPER SWITCH
057637,000403: 27,3112 03756 TFFSW
057638,000404: 27,3113 57115 +2 # IF TFF, CONTINUE
057639,000405: 27,3114 15334 TFFZEROS # IF TPER, SET Q2 = 0
057640,000406: 27,3115 75440 +2 BMN SQRT # E:(-16) M:(-15)
057641,000407: 27,3116 57250 MAXTFF1 # NO FREE FALL CONIC TO RTERM FROM HERE
057642,000408: # RESET PDL, SET TFF=POSMAX, AND EXIT.
057643,000409:
057644,000410: 27,3117 41076 DCOMP BOVB # RT IS ON INBOUND SIDE. ASSURE OVFIND=0
057645,000411: 27,3120 57353 TCDANZIG # ANY PORT IN A STORM.
057646,000412: 27,3121 24045 STOVL TFFTEM # Q2 E:(-16) M:(-15)
057647,000413: 27,3122 02372 VONE' # VN/SQRT(MU) E:(10) M:(9)
057648,000414: 27,3123 52441 DOT SL3
057649,000415: 27,3124 02327 RONE # SAVED RN. E:(-29) M:(-27)
057650,000416: 27,3125 00017 STORE TFFQ1 # Q1, SAVE FOR GONEPAST TEST.
057651,000417: # E:(-16) M:(-15)
057652,000418: 27,3126 44240 BMN BDSU
057653,000419: 27,3127 57150 INBOUND # USE ALTERNATE Z
057654,000420: 27,3130 00045 TFFTEM # Q2 E:(-16) M:(-15)
057655,000421:
057656,000422: # OUTBOUND Z CALC CONTINUES HERE
057657,000423:
057658,000424: 27,3131 14043 STODL TFFX # NUM=Q2-Q1 E:(-16) M:(-15)
057659,000425: 27,3132 00033 TFFALFA # ALFA E:(26-NR) M:(24-NR)
057660,000426: 27,3133 44205 DMP BDSU
057661,000427: 27,3134 00041 NRMAG # RMAG E:(-29+NR) M:(-27+NR)
057662,000428: # (2-RTERM ALFA) (-3) FROM PDL+0
057663,000429: 27,3135 51406 SAVEDEN PUSH ABS # DEN TO PDL+0 E:(-3) OR (-16)
057664,000430: # M:(-3) OR (-15)
057665,000431: 27,3136 40015 DAD BOV # INDETERMINANCY TEST
057666,000432: 27,3137 17361 LIM(-22) # =1.0-B(-22)
057667,000433: 27,3140 57161 TFFXTEST # GO IF DEN >/= B(-22)
057668,000434: 27,3141 65345 DLOAD PDDL # SET DEN=0 OTHERWISE
057669,000435: 27,3142 15334 TFFZEROS
057670,000436: # XCH ZERO WITH PDL+0
057671,000437: 27,3143 57545 DLOAD DCOMP
057672,000438: 27,3144 00033 TFFALFA # ALFA E:(26-NR) M:(24-NR)
057673,000439: 27,3145 71240 BMN DLOAD # FOR TPER: Z INDET AT DELE/2=0 AND 90.
057674,000440: 27,3146 57255 TFFEL1 # ASSUME 90, AND LEAVE 0 IN PDL: 1/Z=D/N
057675,000441:
057676,000442: # Z INDET. AT PERIGEE FOR PARAB OR HYPERB.
057677,000443: 27,3147 77616 DUMPTFF1 RVQ # RETURN TFF =0
057678,000444:
057679,000445: # INBOUND Z CALC CONTINUES HERE
057680,000446:
057681,000447: 27,3150 77745 INBOUND DLOAD # RESET PDL+0
057682,000448: 27,3151 45345 DLOAD DSU # ALTERNATE Z CALC
057683,000449: 27,3152 00023 RTERM # E:(-29) M:(-27)
057684,000450: 27,3153 00015 RMAG1 # E:(-29) M:(-27)
057685,000451: 27,3154 14043 STODL TFFX # NUM=RTERM-RN E:(-29) M:(-27)
057686,000452: 27,3155 00045 TFFTEM # Q2 E:(-16) M:(-15)
057687,000453: 27,3156 52015 DAD GOTO
057688,000454: 27,3157 00017 TFFQ1 # Q1 E:(-16) M:(-15)
057689,000455: 27,3160 57135 SAVEDEN # DEN = Q2+Q1 E:(-16) M:(-15)
057690,000456:
057691,000457: 27,3161 65215 TFFXTEST DAD PDDL # (ABS(DEN) TO PDL+2)) E:(-3) OR (-16)
057692,000458: # M:(-3) OR (-15)
057693,000459: 27,3162 17363 DP(-22) # RESTORE ABS(DEN) TO MPAC
057694,000460: 27,3163 00043 TFFX # NUM E:(-16) OR (-29) M:(-15) OR (-27)
057695,000461: 27,3164 53605 DMP SR*
057696,000462: 27,3165 00031 TFFRTALF # SQRT(ALFA) E:(10+NA) M:(9+NA)
057697,000463: 27,3166 57201 0 -3,2 # X2=-NA
057698,000464: 27,3167 77671 DDV # C(MPAC) =NUM SQRT(ALFA) E:(-3) OR (-16)
057699,000465: # M:(-3) OR (-15)
057700,000466: # ABS(DEN) FROM PDL+2 E:(-3) OR (-16)
057701,000467: # M:(-3) OR (-15)
057702,000468: 27,3170 40145 DLOAD BOV # (THE DLOAD IS SHARED WITH TFFELL)
057703,000469: 27,3171 00043 TFFX # NUM E:(-16) OR (-29) M:(-15) OR (-27)
057704,000470: 27,3172 57253 TFFELL # USE EQN FOR DELE GEQ 90, LEQ -90
057705,000471:
057706,000472: # OTHERWISE, CONTINUE FOR GENERAL CONIC FOR TFF EQN
057707,000473:
057708,000474: 27,3173 45471 DDV STADR
057709,000475: # DEN FROM PDL+0 E:(-3) OR (-16)
057710,000476: # M:(-3) OR (-15)
057711,000477: 27,3174 77732 STORE TFFTEM # Z SAVE FOR SIGN OF SDELF.
057712,000478: # E:(-13) M:(-12)
057713,000479: 27,3175 63406 PUSH DSQ # Z TO PDL+0
057714,000480: 27,3176 41206 PUSH DMP # Z SQ TO PDL+2 E:(-26) M:(-24)
057715,000481: 27,3177 00035 TFFNP # LC P E:(-38+2NR) M:(-36+2NR)
057716,000482: 27,3200 75261 SL SIGN
057717,000483: 27,3201 20206 5
057718,000484: 27,3202 00045 TFFTEM # AFFIX SIGN FOR SDELF (ENTRY DISPLAY)
057719,000485: 27,3203 14045 STODL TFFTEM # P ZSQ E:(-59+2NR) M:(-55+2NR)
057720,000486: # (ARG IS USED IN TFF/TRIG)
057721,000487: # ZSQ FROM PDL+2 E:(-26) M:(-24)
057722,000488: 27,3204 41206 PUSH DMP # RESTORE PUSH LOC
057723,000489: 27,3205 00033 TFFALFA # ALFA E:(26-NR) M:(24-NR)
057724,000490: 27,3206 77657 SL*
057725,000491: 27,3207 20201 0,1 # X1=-NR
057726,000492: 27,3210 00043 STORE TFFX # X
057727,000493: 27,3211 41234 RTB DMP
057728,000494: 27,3212 57335 T(X) # POLY
057729,000495: # ZSQ FROM PDL+2 E:(-26) M:(-24)
057730,000496: 27,3213 44302 SR2 BDSU # 2 ZSQ T(X) E:(-29) M:(-27)
057731,000497: 27,3214 00023 RTERM # RTERM E:(-29) M:(-27)
057732,000498: 27,3215 41215 DAD DMP
057733,000499: 27,3216 00015 RMAG1 # E:(-29) M:(-27)
057734,000500: # Z FROM PDL+0 E:(-13) M:(-12)
057735,000501: 27,3217 51042 SR3 BPL # TFF SQRT(MU) E:(-45) M:(-42)
057736,000502: 27,3220 57241 ENDTFF # (NO PUSH UP)
057737,000503: 27,3221 75206 PUSH SIGN # TFF SQRT(MU) TO PDL+0
057738,000504: 27,3222 00017 TFFQ1 # Q1 FOR GONEPAST TEST
057739,000505: 27,3223 71244 BPL DLOAD # GONE PAST ?
057740,000506: 27,3224 57245 NEGTFF # YES. TFF < 0.
057741,000507: 27,3225 00027 TFF1/ALF # 1/ALFA E:(-22-2NA) M:(-20-2NA)
057742,000508: 27,3226 51076 DCOMP BPL # ALFA > 0 ?
057743,000509: 27,3227 57245 NEGTFF # NO. TFF IS NEGATIVE.
057744,000510:
057745,000511: # CORRECT FOR ORBITAL PERIOD.
057746,000512:
057747,000513: 27,3230 77676 DCOMP # YES. CORRECT FOR ORB PERIOD.
057748,000514: 27,3231 56205 DMP DDV
057749,000515: 27,3232 17357 PI/16 # 2 PI (-5)
057750,000516: 27,3233 00031 TFFRTALF # SQRT(ALFA) E:(10+NA) M:(9+NA)
057751,000517: 27,3234 53657 SL* SL*
057752,000518: 27,3235 57602 0 -4,2 # X2=-NA
057753,000519: 27,3236 57602 0 -4,2
057754,000520: 27,3237 43257 SL* DAD
057755,000521: 27,3240 57576 0,2
057756,000522: # TFF SQRT(MU) FROM PDL+0 E:(-45) M:(-42)
057757,000523: 27,3241 40005 ENDTFF DMP BOV # TFF SQRT(MU) IN MPAC E:(-45) M:(-42)
057758,000524: 27,3242 00037 TFF/RTMU # E:(17) M:(14)
057759,000525: 27,3243 57251 MAXTFF # SET POSMAX IF OVFL.
057760,000526:
057761,000527: 27,3244 77616 DUMPTFF2 RVQ # RETURN TFF (-28) CS IN MPAC.
057762,000528:
057763,000529: 27,3245 77745 NEGTFF DLOAD
057764,000530: # TFF SQRT(MU) FROM PDL+0, NEGATIVE.
057765,000531: 27,3246 77650 GOTO
057766,000532: 27,3247 57241 ENDTFF
057767,000533:
057768,000534: 27,3250 77745 MAXTFF1 DLOAD # RESET PDL
057769,000535: 27,3251 43545 MAXTFF DLOAD RVQ
057770,000536: 27,3252 17373 NEARONE
057771,000537:
057772,000538: # TIME OF FLIGHT ELLIPSE WHEN DEL (ECCENTRIC ANOM) GEQ 90 AND LEQ -90.
057773,000539:
057774,000540: # NUM FROM TFFX. E:(-16) OR (-29)
057775,000541: # M:(-15) OR (-27)
057776,000542: 27,3253 77712 TFFELL SL2 # NUM E:(-14) OR (-27) M:(-13) OR (-25)
057777,000543: 27,3254 41465 BDDV PUSH # TEMP SAVE D/N IN PDL+0
057778,000544: # DEN FROM PDL+0 E:(-3)/( 16) M:(-3)/(-15)
057779,000545: # N/D TO PDL+0 E:(11) M:(10)
057780,000546: 27,3255 45345 TFFEL1 DLOAD DSU # (ENTER WITH D/N=0 IN PDL+0)
057781,000547: 27,3256 00045 TFFTEM # Q2 E:(-16) M:(-15)
057782,000548: 27,3257 00017 TFFQ1 # Q1 E:(-16) M:(-15)
057783,000549: 27,3260 14013 STODL TFFDELQ # Q2-Q1 E:(-16) M:(-15)
057784,000550: # D/N FROM PDL+0
057785,000551: 27,3261 77626 STADR
057786,000552: 27,3262 77732 STORE TFFTEM # D/N E:(11) M:(10)
057787,000553: 27,3263 53605 DMP SL*
057788,000554: 27,3264 00027 TFF1/ALF # 1/ALFA E:(-22-2NA) M:(-20-2NA)
057789,000555: 27,3265 57576 0,2 # 1/ALFA Z E:(-11-NA) M:(-10-NA)
057790,000556: 27,3266 41206 PUSH DMP # TO PDL+0
057791,000557: 27,3267 00045 TFFTEM # 1/Z E:(11) M:(10)
057792,000558: 27,3270 41057 SL* BOVB
057793,000559: 27,3271 57576 0,2 # X2= -NA
057794,000560: 27,3272 45712 SIGNMPAC # IN CASE X= 1.0, CONTINUE
057795,000561: 27,3273 00043 STORE TFFX # X=1/ALFA ZSQ
057796,000562: 27,3274 41234 RTB DMP
057797,000563: 27,3275 57335 T(X) # POLY
057798,000564: 27,3276 00043 TFFX
057799,000565: 27,3277 45242 SR3 DSU
057800,000566: 27,3300 17365 DP2(-3)
057801,000567: 27,3301 41405 DMP PUSH # 2(X T(X)-1) /Z ALFA E:(-15-NA)
057802,000568: # M:(-14-NA)
057803,000569: # 1/ALFA Z FROM PDL+0 E:(-11-NA)
057804,000570: # M:(-10-NA)
057805,000571: 27,3302 41345 DLOAD DMP # GET SIGN FOR SDELF
057806,000572: 27,3303 00045 TFFTEM # 1/Z E:(11) M:(10)
057807,000573: 27,3304 00015 RMAG1 # E:(-29) M:(-27)
057808,000574: 27,3305 43312 SL2 DAD
057809,000575: 27,3306 00017 TFFQ1 # Q1 E:(-16) M:(-15)
057810,000576: 27,3307 14045 STODL TFFTEM # (Q1+R 1/Z) =SGN OF SDELF E:(-16) M:(-15
057811,000577: 27,3310 00035 TFFNP # LC P E:(-38+2NR) M:(-36+2NR)
057812,000578: 27,3311 53605 DMP SL* # CALC FOR ARG FOR TFF/TRIG.
057813,000579: 27,3312 00027 TFF1/ALF # 1/ALFA E:(-22-2NA) M:(-20-2NA)
057814,000580: 27,3313 57575 1,2 # X2=-NA
057815,000581: 27,3314 53765 SIGN SL*
057816,000582: 27,3315 00045 TFFTEM # AFFIX SIGN FOR SDELF
057817,000583: 27,3316 57576 0,2
057818,000584: 27,3317 14045 STODL TFFTEM # P/ALFA E:(-59+2NR) M:(-55+2NR)
057819,000585: # (ARG FOR USE IN TFF/TRIG)
057820,000586: 27,3320 00027 TFF1/ALF # 1/ALFA E:(-22-2NA) M:(-20-2NA)
057821,000587: 27,3321 41366 SQRT DMP
057822,000588: 27,3322 17357 PI/16 # PI (-4)
057823,000589: 27,3323 77615 DAD
057824,000590: # 2(XT(X)-1)/Z ALFA FROM PDL E:(-15-NA)
057825,000591: # M:(-14-NA)
057826,000592: 27,3324 45257 SL* DSU
057827,000593: 27,3325 57577 0 -1,2
057828,000594: 27,3326 00013 TFFDELQ # Q2-Q1 E:(-16) M:(-15)
057829,000595: 27,3327 53605 DMP SL*
057830,000596: 27,3330 00027 TFF1/ALF # 1/ALFA E:(-22-2NA) M:(-20-2NA)
057831,000597: 27,3331 57601 0 -3,2
057832,000598: 27,3332 52057 SL* GOTO
057833,000599: 27,3333 57602 0 -4,2
057834,000600: 27,3334 57241 ENDTFF # TFF SQRT(MU) IN MPAC E:(-45) M:(-42)
057835,000601:
057836,000602: # PROGRAM NAME: T(X) DATE: 01.17.67
057837,000603: # MOD NO: 0 LOG SECTION: TIME OF FREE FALL
057838,000604: # MOD BY: RR BAIRNSFATHER
057839,000605:
057840,000606: # FUNCTIONAL DESCRIPTION: THE POLYNOMIAL T(X) IS USED BY TIME OF FLIGHT SUBROUTINES CALCTFF AND
057841,000607: # CALCTPER TO APPROXIMATE THE SERIES
057842,000608: # 2 3
057843,000609: # 1/3 -X/5 +X /7 -X /9 ...
057844,000610:
057845,000611: # WHERE X = ALFA Z Z IF ALFA Z Z LEQ 1
057846,000612: # X = 1/(ALFA Z Z) IF ALFA Z Z G 1
057847,000613:
057848,000614: # ALSO X IS NEG FOR HYPERBOLIC ORBITS
057849,000615: # X = 0 FOR PARABOLIC ORBITS
057850,000616: # X IS POSITIVE FOR ELLIPTIC ORBITS
057851,000617:
057852,000618: # FOR FLIGHT 278, THE POLYNOMIAL T(X) IS FITTED OVER THE RANGE (0,+1) AND HAS A MAXIMUM
057853,000619: # DEVIATION FROM THE SERIES OF 2 E-5 (T(X) IS A CHEBYCHEV TYPE FIT AND WAS OBTAINED USING
057854,000620: # MAC PROGRAM AUTCURFIT294RRB AND IS VALID TO THE SAME TOLERANCE OVER THE RANGE (-.08,+1).)
057855,000621:
057856,000622: # CALLING SEQUENCE: RTB
057857,000623: # T(X)
057858,000624: # C(MPAC) = X
057859,000625:
057860,000626: # SUBROUTINES CALLED: NONE
057861,000627:
057862,000628: # NORMAL EXIT MODE: TC DANZIG
057863,000629:
057864,000630: # ALARMS: NONE
057865,000631:
057866,000632: # OUTPUT: C(MPAC) = T(X)
057867,000633:
057868,000634: # ERASABLE INITIALIZATION REQUIRED:
057869,000635: # C(MPAC) = X
057870,000636:
057871,000637: # DEBRIS: NONE
057872,000638:
057873,000639: 27,3335 07171 T(X) TC POLY
057874,000640: 27,3336 00004 DEC 4 B-14 # N-1
057875,000641: 27,3337 12525 12525 2DEC 3.333333333 E-1
057876,000642: 27,3341 71463 57703 2DEC* -1.999819135 E-1*
057877,000643: 27,3343 04423 17645 2DEC* 1.418148467 E-1*
057878,000644: 27,3345 74604 43667 2DEC* -1.01310997 E-1*
057879,000645: 27,3347 01626 37256 2DEC* 5.609004986 E-2*
057880,000646: 27,3351 77404 52071 2DEC* -1.536156925 E-2*
057881,000647:
057882,000648: 27,3353 06030 ENDT(X) TC DANZIG
057883,000649:
057884,000650: 27,3354 27,3353 TCDANZIG = ENDT(X)
057885,000651:
057886,000652: # TFF CONSTANTS
057887,000653:
057888,000654: 32,3770 BANK 32
057889,000655:
057890,000656: 27,2000 SETLOC TOF-FF1
057891,000657: 27,2000 BANK
057892,000658:
057893,000659: # NOTE _ NOTE _ ADJUSTED MUE FOR NEAR EARTH TRAJ.
057894,000660: # MUE = 3.990815471 E10 M CUBE/CS SQ
057895,000661: # RTMUE = 1.997702549 E5 B-18* MODIFIED EARTH MU
057896,000662:
057897,000663: 27,3354 24775 30424 1/RTMU 2DEC* .5005750271 E-5 B17* # MODIFIED EARTH MU
057898,000664:
057899,000665: # NOTE _ NOTE _ ADJUSTED MUE FOR NEAR EARTH TRAJ.
057900,000666: # MUM = 4.902778 E8 M CUBE/CS SQ
057901,000667: # RTMUM 2DEC* 2.21422176 E4 B-18*
057902,000668: 27,3356 06220 37553 PI/16 2DEC 3.141592653 B-4
057903,000669: 27,3360 37777 37700 LIM(-22) 2OCT 3777737700 # 1.0 -B(-22)
057904,000670: 27,3362 00000 00100 DP(-22) 2OCT 0000000100 # B(-22)
057905,000671: 27,3364 04000 00000 DP2(-3) 2DEC 1 B-3
057906,000672: 27,3366 02000 00000 DP2(-4) 2DEC 1 B-4 # 1/16
057907,000673:
057908,000674: # RPAD1 2DEC 6373338 B-29 M (-29) = 20909901.57 FT
057909,000675: 27,3370 22,3151 RPAD1 = RPAD
057910,000676:
057911,000677: 27,3370 00305 11205 R300K 2DEC 6464778 B-29 # (-29) M
057912,000678: 27,3372 37777 37777 NEARONE 2DEC .999999999
057913,000679: 27,3374 26,3333 TFFZEROS EQUALS HI6ZEROS
057914,000680: 27,3374 26,3323 TFF1/4 EQUALS HIDP1/4
End of include-file TIME_OF_FREE_FALL.agc. Parent file is MAIN.agc