Source Code

046916,000001: # Copyright: Public domain. 046917,000002: # Filename: PLANETARY_INERTIAL_ORIENTATION.agc 046918,000003: # Purpose: A section of Luminary 1C, revision 131. 046919,000004: # It is part of the source code for the Lunar Module's (LM) 046920,000005: # Apollo Guidance Computer (AGC) for Apollo 13 and Apollo 14. 046921,000006: # This file is intended to be a faithful transcription, except 046922,000007: # that the code format has been changed to conform to the 046923,000008: # requirements of the yaYUL assembler rather than the 046924,000009: # original YUL assembler. 046925,000010: # Reference: pp. 1139-1147 of 1729.pdf. 046926,000011: # Contact: Ron Burkey <info@sandroid.org>. 046927,000012: # Website: www.ibiblio.org/apollo/index.html 046928,000013: # Mod history: 06/01/03 RSB. Began transcribing. 046929,000014: # 05/14/05 RSB Corrected website reference above. 046930,000015: 046931,000016: # Page 1139 046932,000017: # PLANETARY INERTIAL ORIENTATION 046933,000018: 046934,000019: # ***** RP-TO-R SUBROUTINE ***** 046935,000020: # SUBROUTINE TO CONVERT RP (VECTOR IN PLANETARY COORDINATE SYSTEM, EITHER 046936,000021: # EARTH-FIXED OR MOON-FIXED) TO R (SAME VECTOR IN BASIC REF. SYSTEM) 046937,000022: # R = MT(T) * (RP + LP X RP) MT = M MATRIX TRANSPOSE 046938,000023: 046939,000024: # CALLING SEQUENCE 046940,000025: # L CALL 046941,000026: # L+1 RP-TO-R 046942,000027: 046943,000028: # SUBROUTINES USED 046944,000029: # EARTHMX, MOONMX, EARTHL 046945,000030: 046946,000031: # ITEMS AVAILABLE FROM LAUNCH DATA 046947,000032: # 504M = THE LIBRATION VECTOR L OF THE MOON AT TIME TIMSUBL, EXPRESSED 046948,000033: # IN THE MOON-FIXED COORD. SYSTEM RADIANS B0 046949,000034: 046950,000035: # ITEMS NECESSARY FOR SUBR. USED (SEE DESCRIPTION OF SUBR.) 046951,000036: 046952,000037: # INPUT 046953,000038: # MPAC = 0 FOR EARTH, NON-ZERO FOR MOON 046954,000039: # 0-5D = RP VECTOR 046955,000040: # 6-7D = TIME 046956,000041: 046957,000042: # OUTPUT 046958,000043: # MPAC = R VECTOR METERS B-29 FOR EARTH, B-27 FOR MOON 046959,000044: 046960,000045: 26,2000 SETLOC PLANTIN1 046961,000046: 26,2000 BANK 046962,000047: 046963,000048: 26,3716 COUNT* $$/LUROT 046964,000049: 046965,000050: 26,3716 46020 RP-TO-R STQ BHIZ 046966,000051: 26,3717 00050 RPREXIT 046967,000052: 26,3720 55733 RPTORA 046968,000053: 26,3721 77624 CALL # COMPUTE M MATRIX FOR MOON 046969,000054: 26,3722 51730 MOONMX # LP=LM FOR MOON RADIANS B0 046970,000055: 26,3723 77775 VLOAD 046971,000056: 26,3724 02013 504LM 046972,000057: 26,3725 53235 RPTORB VXV VAD 046973,000058: 26,3726 00001 504RPR 046974,000059: 26,3727 00001 504RPR 046975,000060: 26,3730 52105 VXM GOTO 046976,000061: 26,3731 00025 MMATRIX # MPAC=R=MT(T)*(RP+LPXRP) 046977,000062: 26,3732 51716 RPRPXXXX # RESET PUSHLOC TO 0 BEFORE EXITING 046978,000063: 26,3733 77624 RPTORA CALL # EARTH COMPUTATIONS 046979,000064: 26,3734 55743 EARTHMX # M MATRIX B-1 046980,000065: 26,3735 77624 CALL 046981,000066: 26,3736 15761 EARTHL # L VECTOR RADIANS B0 046982,000067: 26,3737 76521 MXV VSL1 # LP=M(T)*L RAD B-0 046983,000068: 26,3740 00025 MMATRIX 046984,000069: # Page 1140 046985,000070: 26,3741 77650 GOTO 046986,000071: 26,3742 55725 RPTORB 046987,000072: 24,2000 SETLOC PLANTIN 046988,000073: 24,2000 BANK 046989,000074: 24,3700 COUNT* $$/LUROT 046990,000075: 046991,000076: # Page 1141 046992,000077: # ***** R-TO-RP SUBROUTINE ***** 046993,000078: # SUBROUTINE TO CONVERT R (VECTOR IN REFERENCE COORD. SYSTEM) TO RP 046994,000079: # (VECTOR IN PLANETARY COORD SYSTEM) EITHER EARTH-FIXED OR MOON-FIXED 046995,000080: # RP = M(T) * (R - L X R) 046996,000081: 046997,000082: # CALLING SEQUENCE 046998,000083: # L CALL 046999,000084: # L+1 R-TO-RP 047000,000085: 047001,000086: # SUBROUTINES USED 047002,000087: # EARTHMX, MOONMX, EARTHL 047003,000088: 047004,000089: # INPUT 047005,000090: # MPAC = 0 FOR EARTH, NON-ZERO FOR MOON 047006,000091: # 0-5D = R VECTOR 047007,000092: # 6-7D = TIME 047008,000093: 047009,000094: # ITEMS AVAILABLE FROM LAUNCH DATA 047010,000095: # 504LM = THE LIBRATION VECTOR L OF THE MOON AT TIME TIMSUBL, EXPRESSED 047011,000096: # IN THE MOON-FIXED COORD. SYSTEM RADIANS B0 047012,000097: 047013,000098: # ITEMS NECESSARY FOR SUBROUTINES USED (SEE DESCRIPTION OF SUBR.) 047014,000099: 047015,000100: # OUTPUT 047016,000101: # MPAC = RP VECTOR METERS B-29 FOR EARTH, B-27 FOR MOON 047017,000102: 047018,000103: 24,3700 46020 R-TO-RP STQ BHIZ 047019,000104: 24,3701 00050 RPREXIT 047020,000105: 24,3702 51722 RTORPA 047021,000106: 24,3703 77624 CALL 047022,000107: 24,3704 51730 MOONMX 047023,000108: 24,3705 61375 VLOAD VXM 047024,000109: 24,3706 02013 504LM # LP=LM 047025,000110: 24,3707 00025 MMATRIX 047026,000111: 24,3710 77772 VSL1 # L = MT(T)*LP RADIANS B0 047027,000112: 24,3711 51235 RTORPB VXV BVSU 047028,000113: 24,3712 00001 504RPR 047029,000114: 24,3713 00001 504RPR 047030,000115: 24,3714 77721 MXV # M(T)*(R-LXR) B-2 047031,000116: 24,3715 00025 MMATRIX 047032,000117: 24,3716 40372 RPRPXXXX VSL1 SETPD 047033,000118: 24,3717 00001 0D 047034,000119: 24,3720 77650 GOTO 047035,000120: 24,3721 00050 RPREXIT 047036,000121: 24,3722 77624 RTORPA CALL # EARTH COMPUTATIONS 047037,000122: 24,3723 55743 EARTHMX 047038,000123: 24,3724 77624 CALL 047039,000124: 24,3725 15761 EARTHL 047040,000125: 24,3726 77650 GOTO # MPAC=L=(-AX,-AY,0) RAD B-0 047041,000126: 24,3727 51711 RTORPB 047042,000127: 047043,000128: # Page 1142 047044,000129: # ***** MOONMX SUBROUTINE ***** 047045,000130: # SUBROUTINE TO COMPUTE THE TRANSFORMATION MATRIX M FOR THE MOON 047046,000131: 047047,000132: # CALLING SEQUENCE 047048,000133: # L CALL 047049,000134: # L+1 MOONMX 047050,000135: 047051,000136: # SUBROUTINES USED 047052,000137: # NEWANGLE 047053,000138: 047054,000139: # INPUT 047055,000140: # 6-7D = TIME 047056,000141: 047057,000142: # ITEMS AVAILABLE FROM LAUNCH DATA 047058,000143: # BSUBO, BDOT 047059,000144: # TIMSUBO, NODIO, NODDOT, FSUBO, FDOT 047060,000145: # COSI = COS(I) B-1 047061,000146: # SINI = SIN(I) B-1 047062,000147: # I IS THE ANGLE BETWEEN THE MEAN LUNAR EQUATORIAL PLANE AND THE 047063,000148: # PLANE OF THE ECLIPTIC (1 DEGREE 32.1 MINUTES) 047064,000149: 047065,000150: # OUTPUT 047066,000151: # MMATRIX = 3X3 M MATRIX B-1 (STORED IN VAC AREA) 047067,000152: 047068,000153: 24,3730 40220 MOONMX STQ SETPD 047069,000154: 24,3731 00051 EARTHMXX 047070,000155: 24,3732 00011 8D 047071,000156: 24,3733 77770 AXT,1 # B REQUIRES SL 0, SL 5 IN NEWANGLE 047072,000157: 24,3734 00005 5 047073,000158: 24,3735 65345 DLOAD PDDL # PD 10D 8-9D=BSUBO 047074,000159: 24,3736 14017 BSUBO # 10-11D=BDOT 047075,000160: 24,3737 14011 BDOT 047076,000161: 24,3740 45006 PUSH CALL # PD 12D 047077,000162: 24,3741 53732 NEWANGLE # EXIT WITH PD 8D AND MPAC= B REVS B0 047078,000163: 24,3742 71406 PUSH COS # PD 10D 047079,000164: 24,3743 14041 STODL COB # PD 8D COS(B) B-1 047080,000165: 24,3744 77756 SIN # SIN(B) B-1 047081,000166: 24,3745 14043 STODL SOB # SETUP INPUT FOR NEWANGLE 047082,000167: 24,3746 14015 FSUBO # 8-9D=FSUBO 047083,000168: 24,3747 41525 PDDL PUSH # PD 10D THEN 12D 10-11D=FDOT 047084,000169: 24,3750 14007 FDOT 047085,000170: 24,3751 45170 AXT,1 CALL # F REQUIRES SL 1, SL 6 IN NEWANGLE. 047086,000171: 24,3752 00004 4 047087,000172: 24,3753 53732 NEWANGLE # EXIT WITH PD 8D AND MPAC= F REVS B0 047088,000173: 24,3754 14027 STODL AVECTR +2 # SAVE F TEMP 047089,000174: 24,3755 14013 NODIO # 8-9D=NODIO 047090,000175: 24,3756 41525 PDDL PUSH # PD 10D THEN 12D 10-11D=NODDOT 047091,000176: 24,3757 14005 NODDOT # MPAC=5 047092,000177: 24,3760 45170 AXT,1 CALL # NODE REQUIRES SL 0, SL 5 IN NEWANGLE 047093,000178: 24,3761 00005 5 047094,000179: 24,3762 53732 NEWANGLE # EXIT WITH PD 8D AND MPAC= NODI REVS B0 047095,000180: # Page 1143 047096,000181: 24,3763 71406 PUSH COS # PD 10D 8-9D= NODI REVS B0 047097,000182: 24,3764 77606 PUSH # PD 12D 10-11D= COS(NODI) B-1 047098,000183: 24,3765 00025 STORE AVECTR 047099,000184: 24,3766 76405 DMP SL1R 047100,000185: 24,3767 00041 COB # COS(NODI) B-1 047101,000186: 24,3770 14035 STODL BVECTR +2 # PD 10D 20-25D=AVECTR=COB*SIN(NODI) 047102,000187: 24,3771 76405 DMP SL1R # SOB*SIN(NODI) 047103,000188: 24,3772 00043 SOB 047104,000189: 24,3773 14037 STODL BVECTR +4 # PD 8D 047105,000190: 24,3774 41556 SIN PUSH # -SIN(NODI) B-1 047106,000191: 24,3775 52076 DCOMP GOTO # 26-31D=BVECTR=COV*COS(NODI) 047107,000192: 24,3776 53653 MOONMXA 047108,000193: 047109,000194: 25,3653 BANK 25 047110,000195: 25,2000 SETLOC PLANTIN3 047111,000196: 25,2000 BANK 047112,000197: 25,3653 COUNT* $$/LUROT 047113,000198: 047114,000199: 25,3653 14033 MOONMXA STODL BVECTR # PD 8D SOB*COS(NODI) 047115,000200: 25,3654 00027 AVECTR +2 # MOVE F FROM TEMP LOC. TO 504F 047116,000201: 25,3655 14007 STODL 504F 047117,000202: 25,3656 76405 DMP SL1R 047118,000203: 25,3657 00041 COB 047119,000204: 25,3660 14027 STODL AVECTR +2 047120,000205: 25,3661 00011 SINNODI # 8-9D=SIN(NODI) B-1 047121,000206: 25,3662 76405 DMP SL1R 047122,000207: 25,3663 00043 SOB 047123,000208: 25,3664 14031 STODL AVECTR +4 # 0 047124,000209: 25,3665 06524 HI6ZEROS # 8-13D= CVECTR= -SOB B-1 047125,000210: 25,3666 57525 PDDL DCOMP # PD 10D COB 047126,000211: 25,3667 00043 SOB 047127,000212: 25,3670 63325 PDDL PDVL # PD 12D THEN PD 14D 047128,000213: 25,3671 00041 COB 047129,000214: 25,3672 00033 BVECTR 047130,000215: 25,3673 63361 VXSC PDVL # PD 20D BVECTR*SINI B-2 047131,000216: 25,3674 14003 SINI 047132,000217: 25,3675 00011 CVECTR 047133,000218: 25,3676 53361 VXSC VAD # PD 14D CVECTR*COSI B-2 047134,000219: 25,3677 14001 COSI 047135,000220: 25,3700 77772 VSL1 047136,000221: 25,3701 24041 STOVL MMATRIX +12D # PD 8D M2=BVECTR*SINI+CVECTR*COSI B-1 047137,000222: 25,3702 63361 VXSC PDVL # PD 14D 047138,000223: 25,3703 14003 SINI # CVECTR*SINI B-2 047139,000224: 25,3704 00033 BVECTR 047140,000225: 25,3705 52361 VXSC VSU # PD 8D BVECTR*COSI B-2 047141,000226: 25,3706 14001 COSI 047142,000227: 25,3707 65372 VSL1 PDDL # PD 14D 047143,000228: 25,3710 00007 504F # 8-13D=DVECTR=BVECTR*COSI-CVECTR*SINI B-1 047144,000229: 25,3711 74346 COS VXSC 047145,000230: 25,3712 00011 DVECTR 047146,000231: 25,3713 73525 PDDL SIN # PD 20D 14-19D= DVECTR*COSF B-2 047147,000232: # Page 1144 047148,000233: 25,3714 00007 504F 047149,000234: 25,3715 52361 VXSC VSU # PD 14D AVECTR*SINF B-2 047150,000235: 25,3716 00025 AVECTR 047151,000236: 25,3717 77772 VSL1 047152,000237: 25,3720 14033 STODL MMATRIX +6 # M1= AVECTR*SINF-DVECTR*COSF B-1 047153,000238: 25,3721 00007 504F 047154,000239: 25,3722 74356 SIN VXSC # PD 8D 047155,000240: 25,3723 71525 PDDL COS # PD 14D 8-13D=DVECTR*SINF B-2 047156,000241: 25,3724 00007 504F 047157,000242: 25,3725 53361 VXSC VAD # PD 8D AVECTR*COSF B-2 047158,000243: 25,3726 00025 AVECTR 047159,000244: 25,3727 57572 VSL1 VCOMP 047160,000245: 25,3730 34025 STCALL MMATRIX # M0= -(AVECTR*COSF+DVECTR*SINF) B-1 047161,000246: 25,3731 00051 EARTHMXX 047162,000247: 047163,000248: # COMPUTE X=X0+(XDOT)(T+T0) 047164,000249: # 8-9D= X0 (REVS B-0), PUSHLOC SET AT 12D 047165,000250: # 10-11D=XDOT (REVS/CSEC) SCALED B+23 FOR WEARTH,B+28 FOR NODDOT AND BDOT 047166,000251: # AND B+27 FOR FDOT 047167,000252: # X1=DIFFERENCE IN 23 AND SCALING OF XDOT, =0 FOR WEARTH, 5 FOR NDDOT AND 047168,000253: # BDOT AND 4 FOR FDOT 047169,000254: # 6-7D=T (CSEC B-28), TIMSUBO= (CSEC B-42 TRIPLE PREC.) 047170,000255: 047171,000256: 25,3732 54345 NEWANGLE DLOAD SR # ENTER PD 12D 047172,000257: 25,3733 00007 6D 047173,000258: 25,3734 20617 14D 047174,000259: 25,3735 72371 TAD TLOAD # CHANGE MODE TO TP 047175,000260: 25,3736 01707 TIMSUBO 047176,000261: 25,3737 00155 MPAC 047177,000262: 25,3740 14017 STODL TIMSUBM # T+T0 CSEC B-42 047178,000263: 25,3741 00020 TIMSUBM +1 047179,000264: 25,3742 77605 DMP # PD 10D MULT BY XDOT IN 10-11D 047180,000265: 25,3743 43257 SL* DAD # PD 8D ADD X0 IN 8-9D AFTER SHIFTING 047181,000266: 25,3744 20206 5,1 # SUCH THAT SCALING IS B-0 047182,000267: 25,3745 67206 PUSH SLOAD # PD 10D SAVE PARTIAL (X0+XDOT*T) IN 8-9D 047183,000268: 25,3746 00017 TIMSUBM 047184,000269: 25,3747 41261 SL DMP 047185,000270: 25,3750 20212 9D 047186,000271: 25,3751 00013 10D # XDOT 047187,000272: 25,3752 43257 SL* DAD # PD 8D SHIFT SUCH THAT THIS PART OF X 047188,000273: 25,3753 20213 10D,1 # IS SCALED REVS/CSEC B-0 047189,000274: 25,3754 77600 BOV # TURN OFF OVERFLOW IF SET BY SHIFT 047190,000275: 25,3755 53756 +1 # INSTRUCTION BEFORE EXITING. 047191,000276: 25,3756 77616 RVQ # MPAC=X= X0+(XDOT)(T+T0) REVS B0 047192,000277: 047193,000278: # Page 1145 047194,000279: # ***** EARTHMX SUBROUTINE ***** 047195,000280: # SUBROUTINE TO COMPUTE THE TRANSFORMATION MATRIX M FOR THE EARTH 047196,000281: 047197,000282: # CALLING SEQUENCE 047198,000283: # L CALL 047199,000284: # L+1 EARTHMX 047200,000285: 047201,000286: # SUBROUTINE USED 047202,000287: # NEWANGLE 047203,000288: 047204,000289: # INPUT 047205,000290: # INPUT AVAILABLE FROM LAUNCH DATA AZC REVS B-0 047206,000291: # TEPHEM CSEC B-42 047207,000292: # 6-7D= TIME CSEC B-28 047208,000293: 047209,000294: # OUTPUT 047210,000295: # MMATRIX= 3X3 M MATRIX B-1 (STORED IN VAC AREA) 047211,000296: 047212,000297: 26,3743 BANK 26 047213,000298: 26,2000 SETLOC PLANTIN1 047214,000299: 26,2000 BANK 047215,000300: 26,3743 COUNT* $$/LUROT 047216,000301: 047217,000302: 26,3743 40220 EARTHMX STQ SETPD # SET 8-9D=AZO 047218,000303: 26,3744 00051 EARTHMXX 047219,000304: 26,3745 00011 8D # 10-11D=WEARTH 047220,000305: 26,3746 77770 AXT,1 # FOR SL 5, AND SL 10 IN NEWANGLE 047221,000306: 26,3747 00000 0 047222,000307: 26,3750 65345 DLOAD PDDL # LEAVING PD SET AT 12D FOR NEWANGLE 047223,000308: 26,3751 01712 AZO 047224,000309: 26,3752 14021 WEARTH 047225,000310: 26,3753 45006 PUSH CALL 047226,000311: 26,3754 53732 NEWANGLE 047227,000312: 26,3755 41401 SETPD PUSH # 18-19D=504AZ 047228,000313: 26,3756 00023 18D # COS(AZ) SIN(AZ) 0 047229,000314: 26,3757 65346 COS PDDL # 20-37D= MMATRIX= -SIN(AZ) COS(AZ) 0 B-1 047230,000315: 26,3760 00023 504AZ # 0 0 1 047231,000316: 26,3761 65356 SIN PDDL 047232,000317: 26,3762 06524 HI6ZEROS 047233,000318: 26,3763 73525 PDDL SIN 047234,000319: 26,3764 00023 504AZ 047235,000320: 26,3765 65276 DCOMP PDDL 047236,000321: 26,3766 00023 504AZ 047237,000322: 26,3767 63346 COS PDVL 047238,000323: 26,3770 06524 HI6ZEROS 047239,000324: 26,3771 41525 PDDL PUSH 047240,000325: 26,3772 06522 HIDPHALF 047241,000326: 26,3773 77650 GOTO 047242,000327: 26,3774 00051 EARTHMXX 047243,000328: 047244,000329: # Page 1146 047245,000330: # ***** EARTH SUBROUTINE ***** 047246,000331: # SUBROUTINE TO COMPUTE L VECTOR FOR EARTH 047247,000332: 047248,000333: # CALLING SEQUENCE 047249,000334: # L CALL 047250,000335: # L+1 EARTHL 047251,000336: 047252,000337: # INPUT 047253,000338: # AXO,AYO SET AT LAUNCH TIME WITH AYO IMMEDIATELY FOLLOWING AXO IN CORE 047254,000339: 047255,000340: # OUTPUT 047256,000341: # -AX 047257,000342: # MPAC= -AY RADIANS B-0 047258,000343: # 0 047259,000344: 047260,000345: 06,3761 BANK 06 047261,000346: 06,2000 SETLOC EARTHLOC 047262,000347: 06,2000 BANK 047263,000348: 06,3761 COUNT* $$/LUROT 047264,000349: 047265,000350: 06,3761 57545 EARTHL DLOAD DCOMP 047266,000351: 06,3762 01716 AXO 047267,000352: 06,3763 14017 STODL 504LPL 047268,000353: 06,3764 01714 -AYO 047269,000354: 06,3765 14021 STODL 504LPL +2 047270,000355: 06,3766 24007 LO6ZEROS 047271,000356: 06,3767 24023 STOVL 504LPL +4 047272,000357: 06,3770 00017 504LPL 047273,000358: 06,3771 77616 RVQ 047274,000359: 047275,000360: # Page 1147 047276,000361: # CONSTANTS AND ERASABLE ASSIGNMENTS 047277,000362: 047278,000363: 06,3772 12,2004 1B1 = DP1/2 # 1 SCALED B-1 047279,000364: 06,3772 0000050 RPREXIT = S1 # R-TO-RP AND RP-TO-R SUBR EXIT 047280,000365: 06,3772 0000051 EARTHMXX = S2 # EARTHMX, MOONMX SUBR. EXITS 047281,000366: 06,3772 504RPR = 0D # 6 REGS R OR RP VECTOR 047282,000367: 06,3772 SINNODI = 8D # 2 SIN(NODI) 047283,000368: 06,3772 DVECTR = 8D # 6 D VECTOR MOON 047284,000369: 06,3772 CVECTR = 8D # 6 C VECTR MOON 047285,000370: 06,3772 504AZ = 18D # 2 AZ 047286,000371: 06,3772 TIMSUBM = 14D # 3 TIME SUB M (MOON) T+10 IN GETAZ 047287,000372: 06,3772 504LPL = 14D # 6 L OR LP VECTOR 047288,000373: 06,3772 AVECTR = 20D # 6 A VECTOR (MOON) 047289,000374: 06,3772 BVECTR = 26D # 6 B VECTOR (MOON) 047290,000375: 06,3772 MMATRIX = 20D # 18 M MATRIX 047291,000376: 06,3772 COB = 32D # 2 COS(B) B-1 047292,000377: 06,3772 SOB = 34D # 2 SIN(B) B-1 047293,000378: 06,3772 504F = 6D # 2 F(MOON) 047294,000379: End of include-file PLANETARY_INERTIAL_ORIENTATION.agc. Parent file is MAIN.agc