Source Code

027857,000001: # Copyright: Public domain. 027858,000002: # Filename: LAMBERT_AIMPOINT_GUIDANCE.agc 027859,000003: # Purpose: Part of the source code for Luminary 1A build 099. 027860,000004: # It is part of the source code for the Lunar Module's (LM) 027861,000005: # Apollo Guidance Computer (AGC), for Apollo 11. 027862,000006: # Assembler: yaYUL 027863,000007: # Contact: Ron Burkey <info@sandroid.org>. 027864,000008: # Website: www.ibiblio.org/apollo. 027865,000009: # Pages: 651-653 027866,000010: # Mod history: 2009-05-18 RSB Transcribed from Luminary 099 027867,000011: # page images. 027868,000012: # 2009-06-05 RSB Corrected 4 typos. 027869,000013: # 2009-06-07 RSB Fixed a typo. 027870,000014: 027871,000015: # This source code has been transcribed or otherwise adapted from 027872,000016: # digitized images of a hardcopy from the MIT Museum. The digitization 027873,000017: # was performed by Paul Fjeld, and arranged for by Deborah Douglas of 027874,000018: # the Museum. Many thanks to both. The images (with suitable reduction 027875,000019: # in storage size and consequent reduction in image quality as well) are 027876,000020: # available online at www.ibiblio.org/apollo. If for some reason you 027877,000021: # find that the images are illegible, contact me at info@sandroid.org 027878,000022: # about getting access to the (much) higher-quality images which Paul 027879,000023: # actually created. 027880,000024: 027881,000025: # Notations on the hardcopy document read, in part: 027882,000026: 027883,000027: # Assemble revision 001 of AGC program LMY99 by NASA 2021112-61 027884,000028: # 16:27 JULY 14, 1969 027885,000029: 027886,000030: # Page 651 027887,000031: 027888,000032: # GENERAL LAMBERT AIMPOINT GUIDANCE ** 027889,000033: # WRITTEN BY RAMA M AIYAWAR 027890,000034: 027891,000035: # PROGRAM P-31 DESCRIPTION ** 027892,000036: 027893,000037: # 1. TO ACCEPT TARGETING PARAMETERS OBTAINED FROM A SOURCE EXTERNAL 027894,000038: # TO THE LEM AND COMPUTE THERE FROM THE REQUIRED-VELOCITY AND 027895,000039: # OTHER INITIAL CONDITIONS REQUIRED BY LM FOR DESIRED MANEUVER. 027896,000040: # THE TARGETING PARAMETERS ARE TIG (TIME OF IGNITION), TARGET 027897,000041: # VECTOR (RTARG), AND THE TIME FROM TIG UNTIL THE TARGET IS 027898,000042: # REACHED (DELLT4), DESIRED TIME OF FLIGHT FROM RINIT TO RTARG. 027899,000043: 027900,000044: # ASSUMPTIONS ** 027901,000045: 027902,000046: # 1. THE TARGET PARAMETERS MAY HAVE BEEN LOADED PRIOR TO THE 027903,000047: # EXECUTION OF THIS PROGRAM. 027904,000048: # 2. THIS PROGRAM IS APPLICABLE IN EITHER EARTH OR LUNAR ORBIT. 027905,000049: # 3. THIS PROGRAM IS DESIGNED FOR ONE-MAN OPERATION, AND SHOULD 027906,000050: # BE SELECTED BY THE ASTRONAUT BY DSKY ENTRY V37 E31. 027907,000051: 027908,000052: # SUBROUTINES USED ** 027909,000053: # 027910,000054: # MANUPARM, TTG/N35, R02BOTH, MIDGIM, DISPMGA, FLAGDOWN, BANKCALL, 027911,000055: # GOTOPOOH, ENDOFJOB, PHASCHNG, GOFLASHR, GOFLASH. 027912,000056: 027913,000057: # MANUPARM CALCULATES APOGEE, PERIGEE ALTITUDES AND DELTAV DESIRED 027914,000058: # FOR THE MANEUVER. 027915,000059: 027916,000060: # TTG/N35 CLOCKTASK - UPDATES CLOCK. 027917,000061: 027918,000062: # MIDGIM CALCULATES MIDDLE GIMBAL ANGLE FOR DISPLAY. 027919,000063: 027920,000064: # R02BOTH IMU - STATUS CHECK ROUTINE. 027921,000065: 027922,000066: # DISPLAYS USED IN P-31LM ** 027923,000067: 027924,000068: # V06N33 DISPLAY SOTRED TIG (IN HRS. MINS. SECS.) 027925,000069: # V06N42 DISPLAY APOGEE, PERIGEE, DELTAV. 027926,000070: # V16N35 DISPLAY TIME FROM TIG. 027927,000071: # V06N45 TIME FROM IGNITION AND MIDDLE GIMBAL ANGLE. 027928,000072: 027929,000073: # ERASABLE INITIALIZATION REQUIRED ** 027930,000074: 027931,000075: # TIG TIME OF IGNITION DP (B+28) CS. 027932,000076: 027933,000077: # DELLT4 DESIRED TIME OF FLIGHT DP (B+28) CS 027934,000078: # FROM RINIT TO RTARG. 027935,000079: 027936,000080: # RTARG RADIUS VECTOR OF TARGET POSITION VECTOR 027937,000081: # RADIUS VECTOR SCALED TO (B+29)METERS IF EARTH ORBIT 027938,000082: # Page 652 027939,000083: # RADIUS VECTOR SCALED TO (B+27)METERS IF MOON ORBIT 027940,000084: 027941,000085: # OUTPUT ** 027942,000086: 027943,000087: # HAPO APOGEE ALTITUDE 027944,000088: # HPER PERIGEE ALTITUDE 027945,000089: # VGDISP MAG. OF DELTAV FOR DISPLAY, SCALING B+7 M/CS EARTH 027946,000090: # MAG. OF DELTAV FOR DISPLAY, SCALING B+5 M/CS MOON 027947,000091: # MIDGIM MIDDLE GIMBAL ANGLE 027948,000092: # XDELVFLG RESETS XDELVFLG FOR LAMBERT VG COMPUTATIONS 027949,000093: 027950,000094: # ALARMS OR ABORTS NONE ** 027951,000095: 027952,000096: # RESTARTS ARE VIA GROUP 4 ** 027953,000097: 027954,000098: 35,2000 SETLOC GLM 027955,000099: 35,2000 BANK 027956,000100: 027957,000101: 35,2450 E7,1470 EBANK= SUBEXIT 027958,000102: 027959,000103: 35,2450 COUNT* $$/P31 027960,000104: 35,2450 02361 P31 TC P20FLGON 027961,000105: 35,2451 32025 CAF V06N33 # T16 027962,000106: 35,2452 03712 TC VNP00H 027963,000107: 35,2453 06037 TC INTPRET 027964,000108: 35,2454 71214 CLEAR DLOAD 027965,000109: 35,2455 00670 UPDATFLG 027966,000110: 35,2456 03442 TIG 027967,000111: 35,2457 34041 STCALL TDEC1 # INTEGRATE STATE VECTORS TO TIG 027968,000112: 35,2460 27057 LEMPREC 027969,000113: 35,2461 40375 VLOAD SETPD 027970,000114: 35,2462 00001 RATT 027971,000115: 35,2463 00001 0D 027972,000116: 35,2464 03642 STORE RTIG 027973,000117: 35,2465 26323 STOVL RINIT 027974,000118: 35,2466 00007 VATT 027975,000119: 35,2467 03650 STORE VTIG 027976,000120: 35,2470 16331 STODL VINIT 027977,000121: 35,2471 32420 P30ZERO 027978,000122: 35,2472 65206 PUSH PDDL # E4 AND NUMIT = 0 027979,000123: 35,2473 03452 DELLT4 027980,000124: 35,2474 66015 DAD SXA,1 027981,000125: 35,2475 03442 TIG 027982,000126: 35,2476 02776 RTX1 027983,000127: 35,2477 03631 STORE TPASS4 027984,000128: 35,2500 45134 SXA,2 CALL 027985,000129: 35,2501 02777 RTX2 027986,000130: 35,2502 22000 INITVEL 027987,000131: 35,2503 41575 VLOAD PUSH 027988,000132: # Page 653 027989,000133: 35,2504 02366 DELVEET3 027990,000134: 35,2505 03656 STORE DELVSIN 027991,000135: 35,2506 43046 ABVAL CLEAR 027992,000136: 35,2507 01267 XDELVFLG 027993,000137: 35,2510 37664 STCALL VGDISP 027994,000138: 35,2511 15733 GET.LVC 027995,000139: 35,2512 63375 VLOAD PDVL 027996,000140: 35,2513 03642 RTIG 027997,000141: 35,2514 02337 VIPRIME 027998,000142: 35,2515 77624 CALL 027999,000143: 35,2516 46316 PERIAPO1 028000,000144: 35,2517 77624 CALL 028001,000145: 35,2520 46426 SHIFTR1 028002,000146: 35,2521 77624 CALL # LIMIT DISPLAY TO 9999.9 N. MI. 028003,000147: 35,2522 45636 MAXCHK 028004,000148: 35,2523 16321 STODL HPER 028005,000149: 35,2524 00005 4D 028006,000150: 35,2525 77624 CALL 028007,000151: 35,2526 46426 SHIFTR1 028008,000152: 35,2527 77624 CALL # LIMIT DISPLAY TO 9999.9 N. MI. 028009,000153: 35,2530 45636 MAXCHK 028010,000154: 35,2531 02317 STORE HAPO 028011,000155: 35,2532 77776 EXIT 028012,000156: 35,2533 33727 CAF V06N81 # DELVLVC 028013,000157: 35,2534 03712 TC VNP00H 028014,000158: 35,2535 32026 CAF V06N42 # HAPO, HPER, VGDISP 028015,000159: 35,2536 03712 TC VNP00H 028016,000160: 35,2537 06037 TC INTPRET 028017,000161: 35,2540 45014 REVN1645 SET CALL # TRKMKCNT, TTOGO, +MGA 028018,000162: 35,2541 01071 FINALFLG 028019,000163: 35,2542 73606 VN1645 028020,000164: 35,2543 77650 GOTO 028021,000165: 35,2544 72540 REVN1645 028022,000166: 028023,000167: 028024,000168: # *** END OF LEMP30S .103 *** 028025,000169: End of include-file LAMBERT_AIMPOINT_GUIDANCE.agc. Parent file is MAIN.agc