Source Code

037080,000001: # Copyright: Public domain. 037081,000002: # Filename: ENTRY_LEXICON.agc 037082,000003: # Purpose: Part of the source code for Comanche, build 055. It 037083,000004: # is part of the source code for the Command Module's 037084,000005: # (CM) Apollo Guidance Computer (AGC), Apollo 11. 037085,000006: # Assembler: yaYUL 037086,000007: # Reference: pp. 837-843 037087,000008: # Contact: Ron Burkey <info@sandroid.org> 037088,000009: # Website: http://www.ibiblio.org/apollo. 037089,000010: # Mod history: 2009-05-12 RSB Adapted from Colossus249 file of the same 037090,000011: # name and Comanche 055 page images. 037091,000012: 037092,000013: # The contents of the "Comanche055" files, in general, are transcribed 037093,000014: # from scanned documents. 037094,000015: 037095,000016: # Assemble revision 055 of AGC program Comanche by NASA 037096,000017: # 2021113-051. April 1, 1969. 037097,000018: 037098,000019: # This AGC program shall also be referred to as Colossus 2A 037099,000020: 037100,000021: # Prepared by 037101,000022: # Massachusetts Institute of Technology 037102,000023: # 75 Cambridge Parkway 037103,000024: # Cambridge, Massachusetts 037104,000025: 037105,000026: # under NASA contract NAS 9-4065. 037106,000027: 037107,000028: # Refer directly to the online document mentioned above for further 037108,000029: # information. Please report any errors to info@sandroid.org. 037109,000030: 037110,000031: # Page 837 037111,000032: # VARIABLE DESCRIPTION MAXIMUM VALUE * COMPUTER NAME 037112,000033: # -------- ----------- --------------- ------------- 037113,000034: # _ 037114,000035: # URT0 INITIAL TARGET VECTOR 2 (UNIT VECTOR) = RTINIT 037115,000036: # _ 037116,000037: # UZ UNIT VECTOR NORTH 1 = UNITW 037117,000038: # _ 037118,000039: # V VELOCITY VECTOR 2 VSAT = VEL 037119,000040: # _ 037120,000041: # R POSITION VECTOR 2 EXP 29 METERS = RN 037121,000042: # _ 037122,000043: # VI INERTIAL VELOCITY 128 M/CENTISEC = VN 037123,000044: # _ 037124,000045: # RTE VECTOR EAST AT INITIAL TARGET 2 = RTEAST 037125,000046: # _ 037126,000047: # UTR NORMAL TO RTE AND UZ 2 = RTNORM 037127,000048: # _ 037128,000049: # URT TARGET VECTOR 2 = RT 037129,000050: # _ 037130,000051: # UNI UNIT NORMAL TO TRAJECTORY PLANE 2 037131,000052: # _ 037132,000053: # DELV INTEGRATED ACCEL. FROM PIPAS 5.85 16384 CM/S 037133,000054: # _ 037134,000055: # G GRAVITY VECTOR 128 M/CENTISEC = GDT/2 037135,000056: 037136,000057: # A0 INITIAL DRAG FOR UPCONTRL 805 FPSS FPSS=FT/SEC/SEC 037137,000058: 037138,000059: # AHOOKDV TERM IN GAMMAL CALC. = AHOOK DVL 16 037139,000060: 037140,000061: # A1 DRAG VALUE IN FACTOR CALCULATION 805 FPSS 037141,000062: 037142,000063: # ALP CONST FOR UPCONTRL 1 037143,000064: 037144,000065: # ASKEP KEPLER RANGE 21600 NM NM = NAUTICAL MILE 037145,000066: 037146,000067: # ASP1 FINAL PHASE RANGE 21600 NM 037147,000068: 037148,000069: # ASPUP UP-RANGE 21600 NM 037149,000070: 037150,000071: # ASP3 GAMMA CORRECTION 21600 NM 037151,000072: 037152,000073: # ASPDWN RANGE DOWN TO PULL-UP 21600 NM 037153,000074: 037154,000075: # ASP PREDICTED RANGE 21600 NM NOT STORED 037155,000076: 037156,000077: # COSG COSINE(GAMMAL) 2 = COSG/2 037157,000078: 037158,000079: # C/D0 RECIPROCAL DRAG, -4/D0 B-8 64/FPSS 037159,000080: 037160,000081: # D TOTAL ACCELERATION 805 FPSS 037161,000082: 037162,000083: # D0 CONTROLLED CONSTANT D 805 FPSS 037163,000084: 037164,000085: # DHOOK TERM IN GAMMAL COMPUTATION 805 FPSS 037165,000086: 037166,000087: # DIFF THETNM-ASP (RANGE DIFFERENCE) 21600 NM 037167,000088: 037168,000089: # DIFFOLD PREVIOUS VALUE OF DIFF 21600 NM 037169,000090: 037170,000091: # DLEWD CHANGE IN LEWD 1 037171,000092: 037172,000093: # DR REFERENCE DRAG FOR DOWNCONTROL 805 FPSS NOT STORED 037173,000094: 037174,000095: # DREFR REFERENCE DRAG 805 FPSS NOT STORED 037175,000096: 037176,000097: # DVL VS1-VL 2 VSAT 037177,000098: 037178,000099: # E ECCENTRICITY 4 NOT STORED 037179,000100: 037180,000101: # F1 DRANGE/D DRAG (FINAL PHASE) 2700/805 = FX +5 037181,000102: 037182,000103: # F2 DRANGE/D RDOT (FINAL PHASE) 2700/2VS NM/FPS = FX +4 037183,000104: # Page 838 037184,000105: 037185,000106: # F3 DRANGE/D (L/D) 2700 NM = FX 037186,000107: 037187,000108: # FACT1 CONST FOR UPCONTRL 805 FPSS 037188,000109: 037189,000110: # FACT2 CONST FOR UPCONTRL 1/805 FPSS 037190,000111: 037191,000112: # FACTOR USED IN UPCONTRL 1 * MAXIMUM VALUE DENOTES UNSCALED 037192,000113: # VARIABLE VALUE WHEN SCALED 037193,000114: # GAMMAL FLIGHT PATH ANGLE AT VL 1 RADIAN VARIABLE HAS MAXIMUM VALUE OF ONE. 037194,000115: 037195,000116: # GAMMAL1 SIMPLE FORM OF GAMMAL 1 RADIAN 037196,000117: # Page 839 037197,000118: 037198,000119: # HEADSUP INDICATOR FOR INITIAL ROLL 1 037199,000120: 037200,000121: # KA DRAG TO LIFT UP IF DOWN 805 FPSS = KAT 037201,000122: 037202,000123: # KLAT LATERAL SWITCH GAIN 1 (NOM = .0125) 037203,000124: 037204,000125: # K2ROLL INDICATOR FOR ROLL SWITCH 037205,000126: 037206,000127: # LAD MAX L/D (MIN ACTUAL VEHICLE L/D) 1 037207,000128: 037208,000129: # LADPAD NOMINAL VEHICLE L/D, SP PAD LOAD 1 (NOM = 0.3) 037209,000130: 037210,000131: # LATANG LATERAL RANGE 4 RADIANS 037211,000132: 037212,000133: # LEQ EXCESS C.F. OVER GRAV=(VSQ-1)GS 128.8 FPSS 037213,000134: 037214,000135: # LEWD UPCONTROL REFERENCE L/D 1 037215,000136: 037216,000137: # LOD FINAL PHASE L/D 1 (NOM = 0.18) 037217,000138: 037218,000139: # LODPAD FINAL PHASE L/D, SP PAD LOAD 1 037219,000140: 037220,000141: # L/D DESIRED LIFT TO DRAG RATIO 1 037221,000142: # (VERTICAL PLANE) 037222,000143: # 037223,000144: # L/D1 TEMP STORAGE FOR L/D IN LATERAL 1 037224,000145: 037225,000146: # L/DCMINR LAD COS(15DEG) 1 (NOM = 0.2895) 037226,000147: 037227,000148: # PREDANGLE PREDICTED RANGE (FINAL PHASE) 2700 NM = PREDANG 037228,000149: 037229,000150: # Q2 FINAL PHASE RANGE -23500 Q3 21600 NM 037230,000151: # Q2 = FCN(LAD) 037231,000152: 037232,000153: # Q7 MINIMUM DRAG FOR UPCONTROL 805FPSS 037233,000154: 037234,000155: # RDOT ALTITUDE RATE 2 VSAT 037235,000156: 037236,000157: # RDOTREF REFERENCE RDOT FOR UPCONTROL 2 VSAT 037237,000158: 037238,000159: # RDTR REFERENCE RDOT FOR DOWNCONT 2 VSAT NOT SAVED 037239,000160: 037240,000161: # ROLLC ROLL COMMAND 1 REVOLUTION 037241,000162: 037242,000163: # RTOGO RANGE TO GO (FINAL PHASE) 2700 NM = FX +2 037243,000164: 037244,000165: # SL SINE OF LATITUDE 1 NOT SAVED 037245,000166: 037246,000167: # T TIME B 28 CENTISEC = TIME2,TIME1 037247,000168: 037248,000169: # THETA DESIRED RANGE (RADIANS) 2 PI RADIANS = THETAH 037249,000170: 037250,000171: # THETNM DESIRED RANGE (NM) 21600 NM NON EXISTENT 037251,000172: 037252,000173: # V VELOCITY MAGNITUDE 2 VSAT 037253,000174: # 037254,000175: # V1 INITIAL VELOCITY FOR UPCONTROL 2 VSAT 037255,000176: 037256,000177: # VL EXIT VELOCITY FOR UPCONTROL 2 VSAT 037257,000178: 037258,000179: # VREF REFERENCE VELOCITY FOR UPCONTROL 2 VSAT 037259,000180: 037260,000181: # VS1 VSAT OR V1, WHICHEVER IS SMALLER 2 VSAT 037261,000182: # 2 2 037262,000183: # VBARS VL /VSAT 4 037263,000184: # 2 2 037264,000185: # VSQ NORMALIZED VEL. SQUARED = V /VSAT 4 = VSQUARE 037265,000186: 037266,000187: # WT EARTH RATE TIMES TIME 1 REVOLUTION NOT SAVED 037267,000188: 037268,000189: # X INTERMEDIATE VARIABLE IN G-LIMITER 2 VSAT NOT SAVED 037269,000190: 037270,000191: # Y LATERAL MISS LIMIT 4 RADIANS NOT SAVED 037271,000192: 037272,000193: # Page 840 037273,000194: # EXTRA COMPUTER ERASABLE LOCATIONS NOT SHOWN ON FLOW CHARTS 037274,000195: # ---------------------------------------------------------- 037275,000196: 037276,000197: # VARIABLE DESCRIPTION MAXIMUM VALUE 037277,000198: # -------- ----------- ------------- 037278,000199: 037279,000200: # GOTOADDR ADDRESS SELECTED BY SEQUENCER 037280,000201: 037281,000202: # XPIPBUF BUFFER TO STORE X PIPA COUNTS 037282,000203: 037283,000204: # YPIPBUF BUFFER TO STORE Y PIPA COUNTS 037284,000205: 037285,000206: # ZPIPBUF BUFFER TO STORE Z PIPA COUNTS 037286,000207: 037287,000208: # PIPCTR COUNTS PASSES THRU PIPA READ ROUTINE 037288,000209: 037289,000210: # JJ INDEX IN FINAL PHASE TABLE LOOK-UP 037290,000211: 037291,000212: # MM INDEX IN FINAL PHASE TABLE LOOK-U 037292,000213: 037293,000214: # GRAD INTERPOLATION FACTOR IN FINAL PHASE 037294,000215: 037295,000216: # FX DRANGE/D L/D = F3 2700 NM 037296,000217: 037297,000218: # FX +1 AREF 805 FPSS 037298,000219: 037299,000220: # FX +2 RTOGO 2700 NM 037300,000221: 037301,000222: # FX +3 RDOTREF VSAT/4 037302,000223: 037303,000224: # FX +4 DRANGE/D RDOT = F2 21600/2VS NM/FPS 037304,000225: 037305,000226: # FX +5 DRANGE/D DRAG = F1 2700/805 NM/FPSS 037306,000227: 037307,000228: # TEM1B TEMPORARY LOCATION 037308,000229: 037309,000230: # TIME/RTO TIME OF INITIAL TARGET RTINIT B 28 CENTISEC 037310,000231: 037311,000232: # DTEAROT EST TIME BETWEEN RTINIT AND RT B 28 CENTISEC 037312,000233: # _ 037313,000234: # UNITV UNIT V VECTOR 2 037314,000235: # _ 037315,000236: # UNITR UNIT R VECTOR 2 037316,000237: # _ 037317,000238: # -VREL NEGATIVE VELOCITY REL TO ATMOSP 2 VSAT 037318,000239: 037319,000240: # COMPUTER SWITCHES INITIAL STATE CM/FLAGS = STATE +6 037320,000241: # ----------------- ------------- ------------------- 037321,000242: 037322,000243: # ENTRYDSP DO ENTRY DISPLAY, IF SET NON-BRANCH (1) 92D, BIT 13 037323,000244: # GONEPAST INDICATES OVERSHOOT OF TARGET NON-BRANCH (0) 95D, BIT 10 037324,000245: # RELVELSW RELATIVE VELOCITY SWITCH NON-BRANCH (0) 96D, BIT 9 037325,000246: # EGSW FINAL PHASE SWITCH NON-BRANCH (0) 97D, BIT 8 037326,000247: # FIRSTPAS INITIAL PASS THRU HUNTEST NON-BRANCH (0) 98D, BIT 7 037327,000248: # HIND INDICATES ITERATION IN HUNTEST NON-BRANCH (0) 99D, BIT 6 037328,000249: # INRLSW INDICATES INIT ROLL ATTITUDE SET NON-BRANCH (0) 100D, BIT 5 037329,000250: # LATSW INHIBIT DOWNLIFT SWITCH IF NOT SET BRANCH (1) 101D, BIT 4 037330,000251: # .05GSW INDICATES DRAG EXCEEDS .05 GS BRANCH (0) 102D, BIT 3 037331,000252: 037332,000253: # GONEBY INDICATES GONE PAST TARGET (SET) SELF-INITIALIZING 112D, BIT 8 037333,000254: 037334,000255: # Page 841 037335,000256: # CONSTANTS AND GAINS VALUE 037336,000257: # ------------------- ----- 037337,000258: 037338,000259: # C1 FACTOR IN ALP COMPUTATION 1.25 037339,000260: # C16 CONSTD GAIN ON DRAG .01 037340,000261: # C17 CONSTD GAIN ON RDOT .001 037341,000262: # C18 BIAS VEL. FOR FINAL PHASE START 500 FPS 037342,000263: # C20 MAX DRAG FOR DOWN-LIFT 175 FPSS 037343,000264: # CHOOK FACTOR IN AHOOK COMPUTATION .25 037344,000265: # CH1 FACTOR IN GAMMAL COMPUTATION 1.0 037345,000266: # COS15 COS( 15 DEG ) .965 037346,000267: # DLEWD0 INITIAL VARIATION IN LEWD -.05 037347,000268: # D2 DRAG TO CHANGE LEWD 175 FPSS 037348,000269: # DT COMPUTATION CYCLE TIME INTERVAL 2 SEC. 037349,000270: # GMAX MAXIMUM ACCELERATION 257.6 FPSS (8 G'S) 037350,000271: # KA1 FACTOR IN KA CALC 1.3 GS 037351,000272: # KA2 FACTOR IN KA CALC .2 GS 037352,000273: # KA3 FACTOR IN D0 CALC 90 FPSS 037353,000274: # KA4 FACTOR IN D0 CALC 40 FPSS 037354,000275: # KB1 OPTIMIZED UPCONTROL GAIN 3.4 037355,000276: # KB2 OPTIMIZED UPCONTROL GAIN .0034 037356,000277: # KDMIN INCREMENT ON Q7 TO DETECT END OF KEPLER PHASE .5 FPSS 037357,000278: # KTETA TIME OF FLIGHT CONSTANT 1000 037358,000279: # KLAT1 FACTOR IN KLAT CALC 1/24 037359,000280: # K44 GAIN USED IN INITIAL ROLL SECTION 19749550 FPS 037360,000281: # LATBIAS LATERAL SWITCH BIAS TERM .41252961 NM 037361,000282: # LEWD1 NOMINAL UPCONTROL L/D .15 037362,000283: # POINT1 FACTOR TO REDUCE UPCONTROL GAIN .1 037363,000284: # Q2 FINAL PHASE RANGE - 23500 Q3 -1002 NM 037364,000285: # Q3 FINAL PHASE DRANGE/D V .07 NM/FPS 037365,000286: # Q5 FINAL PHASE DRANGE/D GAMMA 7050 NM/RAD 037366,000287: # Q6 FINAL PHASE INITIAL FLIGHT PATH ANGLE .0349 RAD 037367,000288: # Q7F MIN DRAG FOR UPCONTROL 6 FPSS 037368,000289: # Q7MIN IN VALUE FOR Q7 IN FACTOR CALCULATION 40 FPSS 037369,000290: # Q19 FACTOR IN GAMMAL1 CALCULATION .5 037370,000291: # Q21 FACTOR IN Q2 CALCULATION 1000 NM 037371,000292: # Q22 FACTOR IN Q2 CALCULATION -1302 NM 037372,000293: # VFINAL1 VELOCITY TO START FINAL PHASE ON INITIAL ENTRY 27000 FPS 037373,000294: # VFINAL FACTOR IN INITIAL UP-DOWN CALC 26600 FPS 037374,000295: # VLMIN MINIMUM VL 18000 FPS 037375,000296: # VMIN VELOCITY TO SWITCH TO RELATIVE VEL VSAT/2 037376,000297: # VRCONTRL RDOT TO START INTO HUNTEST 700 FPS 037377,000298: # VRCONT=COMPUTER NAME 037378,000299: # 25NM TOLERANCE TO STOP RANGE ITERATION 25 NM 037379,000300: # VQUIT VELOCITY TO STOP STEERING 1000 FPS 037380,000301: 037381,000302: # Page 842 037382,000303: # CONVERSION FACTORS AND SCALING CONSTANTS 037383,000304: # ---------------------------------------- 037384,000305: 037385,000306: # ATK ANGLE IN RAD TO NM 3437.7468 NM/RAD 037386,000307: # G5 NOMINAL G VALUE FOR SCALING 32.2 FPSS 037387,000308: # H5 ATMOSPHERE SCALE HEIGHT 28500 FT 037388,000309: # J GRAVITY HARMONIC COEFFICIENT .00162346 037389,000310: # KWE EQUATORIAL EARTH RATE 1546.10168 FPS 037390,000311: # MUE EARTH GRAVITATIONAL CONSTANT 3.986032233 E14 CUBIC M/ SEC SEC 037391,000312: # RE EARTH RADIUS 21202900 FT 037392,000313: # REQ EARTH EQUATORIAL RADIUS 20925738.2 FT 037393,000314: # VSAT SATELLITE VELOCITY AT RE 25766.1973 FPS 037394,000315: # WIE EARTH RATE .0000729211505 RAD/SEC 037395,000316: 037396,000317: # (END GSOP AS-278, VOL 1, FIG. 5.6-3 CONSTANTS, GAINS, ETC.) 037397,000318: 037398,000319: # DISPLAY QUANTITIES 037399,000320: # ------------------ 037400,000321: 037401,000322: # (SEE SECTION 4 OF THE GSOP FOR SIGN CONVENTIONS.) 037402,000323: 037403,000324: # VARIABLE DESCRIPTION MAXIMUM VALUE 037404,000325: # -------- ----------- ------------- 037405,000326: 037406,000327: # QMAX PREDICTED MAXIMUM ENTRY ACCEL 163.84 GS N 60 037407,000328: # VPRED PREDICTED VELOCITY AT ALTITUDE 128 M/CENTISEC N 60 037408,000329: # 400K FT ABOVE FISCHER RADIUS. 037409,000330: # GAMMAEI PREDICTED GAMMA AT ALTITUDE 1 REVOLUTION N 60 037410,000331: # 400K FT ABOVE FISCHER RADIUS 037411,000332: # D DRAG ACCELERATION 805 FPSS N 64 037412,000333: # VMAGI INERTIAL VELOCITY MAGNITUDE 128 M/CENTISEC N 64, N 68 037413,000334: # THETAH DESIRED RANGE ANGLE NM 1 REVOLUTION N 64, N 67 037414,000335: # LAT PRESENT LATITUDE 1 REVOLUTION N 67 037415,000336: # LONG PRESENT LONGITUDE 1 REVOLUTION N 67 037416,000337: # RTOGO RANGE ANGLE TO SPLASH FROM 1 REVOLUTION N 67 037417,000338: # EMSALT FT ABOVE FISCHER RADIUS (IN NM) 037418,000339: # VIO PREDICTED VELOCITY AT ALTITUDE 128 M/CENTISEC N 63 037419,000340: # EMSALT FT ABOVE FISCHER RADIUS. 037420,000341: # TTE TIME OF FREE FALL TO ALT B 28 CENTISEC N 63 037421,000342: # EMSALT FT ABOVE FISCHER RADIUS 037422,000343: # ROLLC ROLL COMMAND 1 REVOLUTION N 68, N 68, N 69 037423,000344: # LATANG CROSS-RANGE ERROR (XRNGERR) 4 RADIANS N 66 037424,000345: # DNRNGERR DOWN RANGE ERROR 1 REVOLUTION N 66 037425,000346: # (PREDANG - THETAH IN NM) 037426,000347: # HDOT ALTITUDE RATE 128 M/CENTISEC N 68 037427,000348: # QT MINIMUM DRAG FOR UPCONTROL 805 FPSS N 69 037428,000349: # VL EXIT VELOCITY FOR UP-CONTROL 2 VSAT N 69 037429,000350: 037430,000351: # Page 843 037431,000352: # BODY ATTITUDE QUANTITIES (CM/POSE) 037432,000353: # ---------------------------------- 037433,000354: 037434,000355: # VARIABLE DECRIPTION MAXIMUM VALUE 037435,000356: # -------- ---------- ------------- 037436,000357: # _ 037437,000358: # -VREL NEGATIVE VELOCITY REL TO ATMOS. 2 VSAT 037438,000359: # _ 037439,000360: # OLDUYA USED FOR UYA BELOW 1000 FPS 2 037440,000361: # _ 037441,000362: # UXA/2 UNIT VECTOR TRIAD 2 037442,000363: # _ 037443,000364: # UYA/2 BASED ON 2 037444,000365: # _ 037445,000366: # UZA/2 THE TRAJECTORY 2 037446,000367: # _ 037447,000368: # UBX/2 UNIT VECTOR 2 037448,000369: # _ 037449,000370: # UBY/2 BODY TRIAD 2 037450,000371: # _ 037451,000372: # UBZ/2 FOR CM. 2 037452,000373: End of include-file ENTRY_LEXICON.agc. Parent file is MAIN.agc