Source Code
034887,000001: # Copyright: Public domain.
034888,000002: # Filename: LUNAR_AND_SOLAR_EPHEMERIDES_SUBROUTINES.agc
034889,000003: # Purpose: Part of the source code for Comanche, build 055. It
034890,000004: # is part of the source code for the Command Module's
034891,000005: # (CM) Apollo Guidance Computer (AGC), Apollo 11.
034892,000006: # Assembler: yaYUL
034893,000007: # Reference: pp. 785-788
034894,000008: # Contact: Ron Burkey <info@sandroid.org>
034895,000009: # Website: http://www.ibiblio.org/apollo.
034896,000010: # Mod history: 2009-05-12 RSB Adapted from Colossus249 file of the same
034897,000011: # name and Comanche 055 page images.
034898,000012: # 2009-07-26 RSB Added annotations related to computation
034899,000013: # of the ephemeral(?) polynomials.
034900,000014:
034901,000015: # The contents of the "Comanche055" files, in general, are transcribed
034902,000016: # from scanned documents.
034903,000017:
034904,000018: # Assemble revision 055 of AGC program Comanche by NASA
034905,000019: # 2021113-051. April 1, 1969.
034906,000020:
034907,000021: # This AGC program shall also be referred to as Colossus 2A
034908,000022:
034909,000023: # Prepared by
034910,000024: # Massachussets Institute of Technology
034911,000025: # 75 Cambridge Parkway
034912,000026: # Cambridge, Massachusetts
034913,000027:
034914,000028: # under NASA contract NAS 9-4065.
034915,000029:
034916,000030: # Refer directly to the online document mentioned above for further
034917,000031: # information. Please report any errors to info@sandroid.org.
034918,000032:
034919,000033: # Page 785
034920,000034: # LUNAR AND SOLAR EPHEMERIDES SUBROUTINES
034921,000035:
034922,000036: # FUNCTIONAL DESCRIPTION
034923,000037:
034924,000038: # THESE SUBROUTINES ARE USED TO DETERMINE THE POSITION AND VELOCITY
034925,000039: # VECTORS OF THE SUN AND THE MOON RELATIVE TO THE EARTH AT THE
034926,000040: # SPECIFIED GROUND ELAPSED TIME INPUT BY THE USER.
034927,000041:
034928,000042: # THE POSITION OF THE MOON IS STORED IN THE COMPUTER IN THE FORM OF
034929,000043: # A NINTH DEGREE POLYNOMIAL APPROXIMATION WHICH IS VALID OVER A 15
034930,000044: # DAY INTERVAL BEGINNING SHORTLY BEFORE LAUNCH. THEREFORE THE TIME
034931,000045: # INPUT BY THE USER SHOULD FALL WITHIN THIS 15 DAY INTERVAL.
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The 9th-degree polynomial spoken of here is a pad load, meaning that it is not actually hardcoded into the software. Additional information about calculating the polynomial can be found on the Orbiter NASSP wiki, as well as information about calculation of the solar ephemerides. |
034939,000053:
034940,000054: # LSPOS COMPUTES THE POSITION VECTORS OF THE SUN AND THE MOON.
034941,000055:
034942,000056: # LUNPOS COMPUTES THE POSITION VECTOR OF THE MOON.
034943,000057:
034944,000058: # LUNVEL COMPUTES THE VELOCITY VECTOR OF THE MOON.
034945,000059:
034946,000060: # SOLPOS COMPUTES THE POSITION VECTOR OF THE SUN.
034947,000061:
034948,000062: # CALLING SEQUENCE
034949,000063:
034950,000064: # DLOAD CALL
034951,000065: # TIME GROUND ELAPSED TIME
034952,000066: # SUBROUTINE LSPOS OR LUNPOS OR LUNVEL OR SOLPOS
034953,000067:
034954,000068: # INPUT
034955,000069:
034956,000070: # 1) SPECIFIED GROUND ELAPSED TIME IN CS x B-28 LOADED IN MPAC.
034957,000071:
034958,000072: # 2) TIMEMO -- TIME AT THE CENTER OF THE RANGE OVER WHICH THE LUNAR
034959,000073: # POSITION POLYNOMIAL IS VALID IN CS x B-42.
034960,000074:
034961,000075: # 3) VECOEM -- VECTOR COEFFICIENTS OF THE LUNAR POSITION POLYNOMIAL
034962,000076: # LOADED IN DESCENDING SEQUENCE IN METERS/CS**N x B-2
034963,000077:
034964,000078: # 4) RESO -- POSITION VECTOR OF THE SUN RELATIVE TO THE EARTH AT
034965,000079: # TIMEMO IN METERS x B-38
034966,000080:
034967,000081: # 5) VESO -- VELOCITY VECTOR OF THE SUN RELATIVE TO THE EARTH AT
034968,000082: # TIMEMO IN METERS/CS x B-9
034969,000083: #
034970,000084: # 6) OMEGAES -- ANGULAR VELOCITY OF THE VECTOR RESO AT TIMEMO IN
034971,000085: # REV/CS x B+26
034972,000086:
034973,000087: # ALL EXCEPT THE FIRST INPUT ARE INCLUDED IN THE PRE-LAUNCH
034974,000088: # ERASABLE DATA LOAD.
034975,000089:
034976,000090: # OUTPUT -- LSPOS
034977,000091: # Page 786
034978,000092:
034979,000093: # 1) 2D OF VAC AREA CONTAINS THE POSITION VECTOR OF THE SUN RELATIVE
034980,000094: # TO THE EARTH AT TIME INPUT BY THE USER IN METERS x B-38.
034981,000095:
034982,000096: # 2) MPAC CONTAINS THE POSITION VECTOR OF THE MOON RELATIVE TO THE
034983,000097: # EARTH AT TIME INPUT BY THE USER IN METERS x B-29
034984,000098:
034985,000099: # OUTPUT -- LUNPOS
034986,000100:
034987,000101: # MPAC CONTAINS THE POSITION VECTOR OF THE MOON RELATIVE TO THE
034988,000102: # EARTH AT THE TIME INPUT BY USER IN METERS x B-29
034989,000103:
034990,000104: # OUTPUT -- LUNVEL
034991,000105:
034992,000106: # MPAC CONTAINS THE VELOCITY VECTOR OF THE MOON RELATIVE TO THE
034993,000107: # EARTH AT THE TIME INPUT BY THE USER IN METERS/CS x B-7
034994,000108:
034995,000109: # OUTPUT -- SOLPOS
034996,000110:
034997,000111: # MPAC CONTAINS THE POSITION VECTOR OF THE SUN RELATIVE TO THE EARTH
034998,000112: # AT TIME INPUT BY THE USER IN METERS x B-38.
034999,000113:
035000,000114: # SUBROUTINES USED
035001,000115:
035002,000116: # NONE
035003,000117:
035004,000118: # REMARKS
035005,000119:
035006,000120: # THE VAC AREA IS USED FOR STORAGE OF INTERMEDIATE AND FINAL RESULTS
035007,000121: # OF COMPUTATIONS.
035008,000122:
035009,000123: # S1, X1, AND X2 ARE USED BY THESE SUBROUTINES.
035010,000124:
035011,000125: # PRELAUNCH ERASABLE DATA LOAD ARE ONLY ERASABLE STORAGE USED BY
035012,000126: # THESE SUBROUTINES.
035013,000127:
035014,000128: # RESTARTS DURING OPERATION OF THESE SUBROUTINES MUST BE HANDLED BY
035015,000129: # THE USER.
035016,000130:
035017,000131: 36,2466 BANK 36
035018,000132: 26,2000 SETLOC EPHEM
035019,000133: 26,2000 BANK
035020,000134:
035021,000135: 26,2110 COUNT* $$/EPHEM
035022,000136: 26,2110 E7,1777 EBANK= END-E7
035023,000137: 26,2110 77774 LSPOS AXT,2 # COMPUTES POSITION VECTORS OF BOTH THE
035024,000138: 26,2111 54161 RESA # SUN AND THE MOON. THE POSITION VECTOR
035025,000139: 26,2112 52170 AXT,1 GOTO # OF THE SUN IS STORED IN 2D OF THE VAC
035026,000140: 26,2113 54143 RES # AREA. THE POSITION VECTOR OF THE MOON
035027,000141: 26,2114 54126 LSTIME # IS STORED IN MPAC.
035028,000142: 26,2115 52170 LUNPOS AXT,1 GOTO # COMPUTES THE POSITION VECTOR OF THE MOON
035029,000143: 26,2116 54162 REM # AND STORES IT IN MPAC.
035030,000144: 26,2117 54126 LSTIME
035031,000145: # Page 787
035032,000146: 26,2120 52170 LUNVEL AXT,1 GOTO # COMPUTES THE VELOCITY VECTOR OF THE MOON
035033,000147: 26,2121 54173 VEM # AND STORES IT IN MPAC.
035034,000148: 26,2122 54126 LSTIME
035035,000149: 26,2123 76020 SOLPOS STQ AXT,1 # COMPUTES THE POSITION VECTOR OF THE SUN
035036,000150: 26,2124 00047 X2 # AND STORES IT IN MPAC.
035037,000151: 26,2125 54143 RES
035038,000152: 26,2126 54201 LSTIME SETPD SR
035039,000153: 26,2127 00001 0D
035040,000154: 26,2130 20617 14D
035041,000155: 26,2131 57571 TAD DCOMP
035042,000156: 26,2132 01707 TEPHEM
035043,000157: 26,2133 57571 TAD DCOMP
035044,000158: 26,2134 02034 TIMEMO
035045,000159: 26,2135 66261 SL SSP
035046,000160: 26,2136 20221 16D
035047,000161: 26,2137 00051 S1
035048,000162: 26,2140 00006 6D
035049,000163: 26,2141 77650 GOTO
035050,000164: 26,2142 00046 X1
035051,000165: 26,2143 41206 RES PUSH DMP # PD- 2
035052,000166: 26,2144 02147 OMEGAES
035053,000167: 26,2145 71406 PUSH COS # PD- 4
035054,000168: 26,2146 65361 VXSC PDDL # PD- 8
035055,000169: 26,2147 02133 RESO
035056,000170: 26,2150 63356 SIN PDVL # PD-10
035057,000171: 26,2151 02133 RESO
035058,000172: 26,2152 53406 PUSH UNIT # PD-16
035059,000173: 26,2153 53435 VXV UNIT
035060,000174: 26,2154 02141 VESO
035061,000175: 26,2155 76435 VXV VSL1 # PD-10
035062,000176: 26,2156 53361 VXSC VAD # PD-02
035063,000177: 26,2157 52172 VSL1 GOTO # RES IN METERS x B-38 IN MPAC.
035064,000178: 26,2160 00047 X2
035065,000179: 26,2161 14003 RESA STODL 2D # RES IN METERS x B-38 IN 2D OF VAC. PD- 0
035066,000180: 26,2162 63370 REM AXT,1 PDVL # PD- 2
035067,000181: 26,2163 00066 54D
035068,000182: 26,2164 02037 VECOEM
035069,000183: 26,2165 52761 REMA VXSC VAD*
035070,000184: 26,2166 00001 0D
035071,000185: 26,2167 02133 VECOEM +60D,1
035072,000186: 26,2170 72500 TIX,1 VSL2 # REM IN METERS x B-29 IN MPAC.
035073,000187: 26,2171 54165 REMA
035074,000188: 26,2172 77616 RVQ
035075,000189: 26,2173 65370 VEM AXT,1 PDDL # PD- 2
035076,000190: 26,2174 00060 48D
035077,000191: 26,2175 14214 NINEB4
035078,000192: 26,2176 74206 PUSH VXSC # PD- 4
035079,000193: 26,2177 02037 VECOEM
035080,000194: 26,2200 77761 VEMA VXSC
035081,000195: 26,2201 00001 0D
035082,000196: # Page 788
035083,000197: 26,2202 14005 STODL 4D # PD- 2
035084,000198: 26,2203 41425 DSU PUSH # PD- 4
035085,000199: 26,2204 14216 ONEB4
035086,000200: 26,2205 53357 VXSC* VAD
035087,000201: 26,2206 02125 VECOEM +54D,1
035088,000202: 26,2207 00005 4D
035089,000203: 26,2210 72500 TIX,1 VSL2 # VEM IN METERS/CS x B-7 IN MPAC.
035090,000204: 26,2211 54200 VEMA
035091,000205: 26,2212 77616 RVQ
035092,000206: 26,2213 22000 00000 NINEB4 2DEC 9.0 B-4
035093,000207:
035094,000208: 26,2215 02000 00000 ONEB4 2DEC 1.0 B-4
035095,000209:
035096,000210:
035097,000211:
End of include-file LUNAR_AND_SOLAR_EPHEMERIDES_SUBROUTINES.agc. Parent file is MAIN.agc