Source Code

These source-code files were obtained by digitally photographing an Artemis 72 program listing from a private collection and then modifying pre-existing Comanche 55 (Apollo 11) source files to incorporate changes. Note that the page images presented online are of reduced quality, and that additional images may be available. Report any conversion errors or legibility problems in page images to info@sandroid.org. Notations on the program listing read, in part:

	GAP: ASSEMBLE REVISION 072 OF AGC PROGRAM ARTEMIS 
	BY NASA 2021114-011 11:40 FEB. 26, 1971

	THIS AGC PROGRAM SHALL ALSO BE REFERRED TO AS
				COLOSSUS 3
	THIS PROGRAM IS INTENDED FOR USE IN THE CM AS SPECIFIED
	IN REPORT R-577.  THIS PROGRAM WAS PREPARED UNDER OSR
	PROJECT 55-23890, SPONSORED BY THE MANNED SPACECRAFT
	CENTER OF THE NATIONAL AERONAUTICS AND SPACE
	ADMINISTRATION THROUGH CONTRACT NAS 9-4065 WITH THE
	CHARLES STARK DRAPER LABORATORY, MASSACHUSETTS INSTITUTE OF
	TECHNOLOGY, CAMBRIDGE, MASS.

034979,000002:                                                                                                 #  Copyright:     Public domain.
034980,000003:                                                                                                 #  Filename:      LUNAR_AND_SOLAR_EPHEMERIDES_SUBROUTINES.agc
034981,000004:                                                                                                 #  Purpose:       Part of the source code for Artemis (i.e., Colossus 3),
034982,000005:                                                                                                 #                 build 072.  This is for the Command Module's (CM)
034983,000006:                                                                                                 #                 Apollo Guidance Computer (AGC), we believe for
034984,000007:                                                                                                 #                 Apollo 15-17.
034985,000008:                                                                                                 #  Assembler:     yaYUL
034986,000009:                                                                                                 #  Contact:       Jim Lawton <jim DOT lawton AT gmail DOT com>
034987,000010:                                                                                                 #  Website:       www.ibiblio.org/apollo/index.html
034988,000011:                                                                                                 #  Page scans:    www.ibiblio.org/apollo/ScansForConversion/Artemis072/
034989,000012:                                                                                                 #  Mod history:   2009-08-11 JL   Adapted from corresponding Comanche 055 file.
034990,000013:                                                                                                 #                 2010-02-20 RSB  Un-##'d this header.
034991,000014: 

Page 789

034993,000016: 
034994,000017:                                                                                                 #  LUNAR AND SOLAR EPHEMERIDES SUBROUTINES
034995,000018: 
034996,000019:                                                                                                 #  FUNCTIONAL DESCRIPTION
034997,000020: 
034998,000021:                                                                                                 #         THESE SUBROUTINES ARE USED TO DETERMINE THE POSITION AND VELOCITY
034999,000022:                                                                                                 #         VECTORS OF THE SUN AND THE MOON RELATIVE TO THE EARTH AT THE
035000,000023:                                                                                                 #         SPECIFIED GROUND ELAPSED TIME INPUT BY THE USER.
035001,000024: 
035002,000025:                                                                                                 #         THE POSITION OF THE MOON IS STORED IN THE COMPUTER IN THE FORM OF
035003,000026:                                                                                                 #         A NINTH DEGREE POLYNOMIAL APPROXIMATION WHICH IS VALID OVER A 15
035004,000027:                                                                                                 #         DAY INTERVAL BEGINNING SHORTLY BEFORE LAUNCH.  THEREFORE THE TIME
035005,000028:                                                                                                 #         INPUT BY THE USER SHOULD FALL WITHIN THIS 15 DAY INTERVAL.
035006,000029:                                                                                                 #  

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.

035014,000037: 
035015,000038:                                                                                                 #         LSPOS COMPUTES THE POSITION VECTORS OF THE SUN AND THE MOON.
035016,000039: 
035017,000040:                                                                                                 #         LUNPOS COMPUTES THE POSITION VECTOR OF THE MOON.
035018,000041: 
035019,000042:                                                                                                 #         LUNVEL COMPUTES THE VELOCITY VECTOR OF THE MOON.
035020,000043: 
035021,000044:                                                                                                 #  CALLING SEQUENCE
035022,000045: 
035023,000046:                                                                                                 #         DLOAD   CALL
035024,000047:                                                                                                 #                 TIME            GROUND ELAPSED TIME
035025,000048:                                                                                                 #                 SUBROUTINE      LSPOS OR LUNPOS OR LUNVEL
035026,000049: 
035027,000050:                                                                                                 #  INPUT
035028,000051: 
035029,000052:                                                                                                 #         1) SPECIFIED GROUND ELAPSED TIME IN CS x B-28 LOADED IN MPAC.
035030,000053: 
035031,000054:                                                                                                 #         2) TIMEMO - TIME AT THE CENTER OF THE RANGE OVER WHICH THE LUNAR
035032,000055:                                                                                                 #            POSITION POLYNOMIAL IS VALID IN CS x B-42.
035033,000056: 
035034,000057:                                                                                                 #         3) VECOEM - VECTOR COEFFICIENTS OF THE LUNAR POSITION POLYNOMIAL
035035,000058:                                                                                                 #            LOADED IN DESCENDING SEQUENCE IN METERS/CS**N x B-2
035036,000059: 
035037,000060:                                                                                                 #         4) RESO - POSITION VECTOR OF THE SUN RELATIVE TO THE EARTH AT
035038,000061:                                                                                                 #            TIMEMO IN METERS x B-38
035039,000062: 
035040,000063:                                                                                                 #         5) VESO - VELOCITY VECTOR OF THE SUN RELATIVE TO THE EARTH AT
035041,000064:                                                                                                 #            TIMEMO IN METERS/CS x B-9
035042,000065:                                                                                                 #  
035043,000066:                                                                                                 #         6) OMEGAES - ANGULAR VELOCITY OF THE VECTOR RESO AT TIMEMO IN
035044,000067:                                                                                                 #            REV/CS x B+26.
035045,000068: 
035046,000069:                                                                                                 #         ALL EXCEPT THE FIRST INPUT ARE INCLUDED IN THE PRE-LAUNCH
035047,000070:                                                                                                 #         ERASABLE DATA LOAD.
035048,000071: 
035049,000072:                                                                                                 #  OUTPUT - LSPOS
035050,000073: 
035051,000074:                                                                                                 #         1) 2D OF VAC AREA CONTAINS THE POSITION VECTOR OF THE SUN RELATIVE

Page 790

035053,000076:                                                                                                 #            TO THE EARTH AT TIME INPUT BY THE USER IN METERS x B-38.
035054,000077: 
035055,000078:                                                                                                 #         2) MPAC CONTAINS THE POSITION VECTOR OF THE MOON RELATIVE TO THE
035056,000079:                                                                                                 #            EARTH AT TIME INPUT BY THE USER IN METERS x B-29.
035057,000080: 
035058,000081:                                                                                                 #  OUTPUT - LUNPOS
035059,000082: 
035060,000083:                                                                                                 #         MPAC CONTAINS THE POSITION VECTOR OF THE MOON RELATIVE TO THE
035061,000084:                                                                                                 #         EARTH AT THE TIME INPUT BY USER IN METERS x B-29.
035062,000085: 
035063,000086:                                                                                                 #  OUTPUT - LUNVEL
035064,000087: 
035065,000088:                                                                                                 #         MPAC CONTAINS THE VELOCITY VECTOR OF THE MOON RELATIVE TO THE
035066,000089:                                                                                                 #         EARTH AT THE TIME INPUT BY THE USER IN METERS/CS x B-7.
035067,000090: 
035068,000091:                                                                                                 #  SUBROUTINES USED
035069,000092: 
035070,000093:                                                                                                 #         NONE
035071,000094: 
035072,000095:                                                                                                 #  REMARKS
035073,000096: 
035074,000097:                                                                                                 #         THE VAC AREA IS USED FOR STORAGE OF INTERMEDIATE AND FINAL RESULTS
035075,000098:                                                                                                 #         OF COMPUTATIONS.
035076,000099: 
035077,000100:                                                                                                 #         S1, X1, AND X2 ARE USED BY THESE SUBROUTINES.
035078,000101:                                                                                                 #         PRELAUNCH ERASABLE DATA LOAD ARE ONLY ERASABLE STORAGE USED BY
035079,000102:                                                                                                 #         THESE SUBROUTINES.
035080,000103:                                                                                                 #         RESTARTS DURING OPERATION OF THESE SUBROUTINES MUST BE HANDLED BY
035081,000104:                                                                                                 #         THE USER.
035082,000105: 
035083,000106: 26,2000                                          SETLOC   EPHEM                                 
035084,000107: 26,2000                                          BANK                                           
035085,000108: 
035086,000109: 26,2136                                          COUNT*   $$/EPHEM                              
035087,000110: 26,2136  E7,1777                                 EBANK=   WHOCARES                              
035088,000111: 26,2136           52170        LSPOS             AXT,1    GOTO                                  
035089,000112: 26,2137           54163                                   RES                                   #  AREA.  THE POSITION VECTOR OF THE MOON
035090,000113: 26,2140           54146                                   LSTIME                                #  IS STORED IN MPAC.
035091,000114: 26,2141           52170        LUNPOS            AXT,1    GOTO                                  #  COMPUTES THE POSITION VECTOR OF THE MOON
035092,000115: 26,2142           54201                                   REM                                   #  AND STORES IT IN MPAC.
035093,000116: 26,2143           54146                                   LSTIME                                
035094,000117: 26,2144           77770        LUNVEL            AXT,1                                          
035095,000118: 26,2145           54212                                   VEM                                   #  AND STORES IT IN MPAC.
035096,000119: 26,2146           54201        LSTIME            SETPD    SR                                    
035097,000120: 26,2147           00001                                   0D                                    
035098,000121: 26,2150           20617                                   14D                                   
035099,000122: 26,2151           57571                          TAD      DCOMP                                 
035100,000123: 26,2152           01707                                   TEPHEM                                
035101,000124: 26,2153           57571                          TAD      DCOMP                                 
035102,000125: 26,2154           02034                                   TIMEMO                                

Page 791

035104,000127: 26,2155           66261                          SL       SSP                                   
035105,000128: 26,2156           20221                                   16D                                   
035106,000129: 26,2157           00051                                   S1                                    
035107,000130: 26,2160           00006                                   6D                                    
035108,000131: 26,2161           77650                          GOTO                                           
035109,000132: 26,2162           00046                                   X1                                    
035110,000133: 26,2163           41206        RES               PUSH     DMP                                   #                                         PD- 2
035111,000134: 26,2164           02147                                   OMEGAES                               
035112,000135: 26,2165           71406                          PUSH     COS                                   #                                         PD- 4
035113,000136: 26,2166           65361                          VXSC     PDDL                                  #                                         PD- 8
035114,000137: 26,2167           02133                                   RESO                                  
035115,000138: 26,2170           63356                          SIN      PDVL                                  #                                         PD-10
035116,000139: 26,2171           02133                                   RESO                                  
035117,000140: 26,2172           53406                          PUSH     UNIT                                  #                                         PD-16
035118,000141: 26,2173           53435                          VXV      UNIT                                  
035119,000142: 26,2174           02141                                   VESO                                  
035120,000143: 26,2175           76435                          VXV      VSL1                                  #                                         PD-10
035121,000144: 26,2176           53361                          VXSC     VAD                                   #                                         PD-02
035122,000145: 26,2177           77772                          VSL1                                           
035123,000146: 26,2200           14003        RESA              STODL    2D                                    #  RES IN METERS x B-38 IN 2D OF VAC.     PD- 0
035124,000147: 26,2201           63370        REM               AXT,1    PDVL                                  #                                         PD- 2
035125,000148: 26,2202           00066                                   54D                                   
035126,000149: 26,2203           02037                                   VECOEM                                
035127,000150: 26,2204           52761        REMA              VXSC     VAD*                                  
035128,000151: 26,2205           00001                                   0D                                    
035129,000152: 26,2206           02133                                   VECOEM     +60D,1                     
035130,000153: 26,2207           72500                          TIX,1    VSL2                                  #  REM IN METERS x B-29 IN MPAC.
035131,000154: 26,2210           54204                                   REMA                                  
035132,000155: 26,2211           77616                          RVQ                                            
035133,000156: 26,2212           65370        VEM               AXT,1    PDDL                                  #                                         PD- 2
035134,000157: 26,2213           00060                                   48D                                   
035135,000158: 26,2214           14233                                   NINEB4                                
035136,000159: 26,2215           74206                          PUSH     VXSC                                  #                                         PD- 4
035137,000160: 26,2216           02037                                   VECOEM                                
035138,000161: 26,2217           77761        VEMA              VXSC                                           
035139,000162: 26,2220           00001                                   0D                                    
035140,000163: 26,2221           14005                          STODL    4D                                    #                                         PD- 2
035141,000164: 26,2222           41425                          DSU      PUSH                                  #                                         PD- 4
035142,000165: 26,2223           31771                                   ONEB4                                 
035143,000166: 26,2224           53357                          VXSC*    VAD                                   
035144,000167: 26,2225           02125                                   VECOEM     +54D,1                     
035145,000168: 26,2226           00005                                   4D                                    
035146,000169: 26,2227           72500                          TIX,1    VSL2                                  #  VEM IN METERS/CS x B-7 IN MPAC.
035147,000170: 26,2230           54217                                   VEMA                                  
035148,000171: 26,2231           77616                          RVQ                                            
035149,000172: 26,2232           22000 00000  NINEB4            2DEC     9.0        B-4                        
035150,000173: 26,2234  34,3770               ONEB4             EQUALS   DP2(-4)                               #  1 B-4
035151,000174: 

End of include-file LUNAR_AND_SOLAR_EPHEMERIDES_SUBROUTINES.agc.  Parent file is MAIN.agc