### FILE="Main.annotation" ## Copyright: Public domain. ## Filename: P40-P47.agc ## Purpose: A section of Luminary revision 163. ## It is part of the reconstructed source code for the first ## (unflown) release of the flight software for the Lunar ## Module's (LM) Apollo Guidance Computer (AGC) for Apollo 14. ## The code has been recreated from a reconstructed copy of ## Luminary 173, as well as Luminary memos 157 amd 158. ## It has been adapted such that the resulting bugger words ## exactly match those specified for Luminary 163 in NASA ## drawing 2021152N, which gives relatively high confidence ## that the reconstruction is correct. ## Reference: pp. 738-770 ## Assembler: yaYUL ## Contact: Ron Burkey . ## Website: www.ibiblio.org/apollo/index.html ## Mod history: 2019-08-21 MAS Created from Luminary 173. Removed S40RET tag ## in UPDATEVG. Changed references to S40RET to ## QPRET. Removed GOFIND tag in ALARMIT, changed ## the CALL FINDCDUW -2 to GOTO, and removed the ## GOTO S40RET. Moved ALARMIT back to bank 27. ## Changed reference to GOFIND to FINDCDUW -2. ## 2021-05-30 ABS TGDCALC -> TGOCALC ## Page 738 # PROGRAM DESCRIPTION P40BOTH DECEMBER 22, 1966 # MOD 03 BY PETER ADLER MARCH 3, 1967 # CALLED VIA JOB FROM V37E # FUNCTIONAL DESCRIPTION # 1) TO COMPUTE A PREFERRED IMU ORIENTATION AND A PREFERRED VEHICLE ATTITUDE FOR A LM DPS # THRUSTING MANEUVER. ## (There is no item #2 in the original program listing.) # 3) TO DO THE VEHICLE MANEUVER TO THE THRUSTING ATTITUDE. # 4) TO CONTROL THE PGNCS DURING COUNTDOWN, IGNITION, THRUSTING, AND THRUST TERMINATION OF A # PGNCS CONTROLLED DPS MANEUVER. # 5) IN POSTBURN--ZERO RENDEZVOUS COUNTER, MAINTAIN VG CALCULATIONS FOR POSSIBLE RCS MANEUVER, # SET MAXIMUM DEADBAND IN DAP, RESET STEERLAW CSTEER TO ZERO. # NOTE: P42, WHICH IS IN THIS LOG SECTION, DOES THE SAME FOR AN APS BURN, AND P41 DOES 1-3 FOR # RCS PLUS DISPLAYS PARAMETERS FOR MANUAL CONTROL. # SUBROUTINES USED # R02 IMU STATUS CHECK # S40.1 COMPUTATION OF THRUST DIRECTION # S40.13 LENGTH OF BURN # S40.2,3 PREFERRED IMU ORIENATTION # S40.8 X PRODUCT STEERING # S40.9 LAMBERT VTOGAIN # R60LEM ATTITUDE MANEUVER # LEMPREC EXTRAPOLATE STATE VECTOR # PREREAD AVERAGE G, SERVICER # ALLCOAST DAP COASTING INITIALIZATION # CLOKTASK ERGO CLOCKJOB--COUNT DOWN # PHASCHNG, INTPRET, FLAGUP, FLAGDOWN, WAITLIST, LONGCALL, GOFLASH, GOFLASHR, GOPERF1, ALARM, # PRIOLARM, GOTOPOOH, ENDOFJOB, BANKCALL, SETMAXDB, SETMINDB, CHECKMM, FLATOUT, OUTFLAT, # KILLTASK, SGNAGREE, TPAGREE, ETC. # RESTARTS VIA GROUP 4 # DISPLAYS # V50N25 203 A/P TO PGNCS, AUTO THROTTLE MODE, AUTO ATTITUDE CONTROL # V06N40 TTI, VG, DELTAVM (DISPLAYED ONCE/SECOND BY CLOKTASK) # V50N99 PLEASE PERFORM ENGINE ON ENABLE # V06N40 TG (TIME TO GO TO CUTOFF), VG, DELTAVM--ONCE/SECOND # V16N40 FINAL VALUES OF TG, VG, DELTAVM # V16N85 COMP OF VG (BODY AXES) FOR POSS. RCS MANUAL MANEUVER # V05N09 POSSIBLE ALARMS # V50N07 PLEASE SELECT P00 ## Page 739 # VIA R30 # # V06N44 HAPO, PERI, TFF # V06N35 TIME TO PERIGEE, HMS # ALARM OR ABORT EXIT MODES # PROGRAM ALARM, FLASHING DISPLAY OF ALARM CODE 1706 IF P40 SELECTED WITH DESCENT UNIT STAGED. # V34E (TERMINATE) IS THE ONLY RESPONSE ACCEPTED. TC GOTOPOOH. # PROGRAM ALARM, FLASH CODE 1703: TIG LESS THAN 45 SECS AWAY. V34E= GOTOPOOH OR V33E= SLIP # TIG BY 45 SECS. # ERASABLE INITIALIZATION # DEBRIS # OUTPUT # SEE SUBROUTINES E.G.: S40.1, S40.2,3, S40.13, S40.8, S40.9, TRIMGIMB # XDELVFLG = 1 FOR EXT DELV COMPUTATION # = 0 FOR AIMPT (LAMBERT) COMP COUNT* $$/P40 EBANK= WHICH BANK 36 SETLOC P40S BANK P40LM TC PHASCHNG OCT 04024 CAF P40ADRES # INITIALIZATION FOR BURNBABY. TS WHICH CA FLGWRD10 MASK APSFLBIT CCS A TCF P40ALM TC BANKCALL # GO DO IMU STATUS CHECK ROUTINE. CADR R02BOTH CS DAPBOOLS # INITIALIZE DVMON MASK CSMDOCKD CCS A CAF THRESH1 AD THRESH3 TS DVTHRUSH CAF FOUR TS DVCNTR ## Page 740 TC INTPRET # LOAD CONSTANTS FOR DPS BURN VLOAD CLEAR # LOAD F, MDOT, TDECAY FDPS NOTHROTL STORE F SLOAD DPSVEX P40IN DCOMP SR1 STCALL VEX # LOAD EXHAUST VELOCITY FOR TGO COMP. S40.1 # COMPUTES UT AND VGTIG CALL S40.2,3 # COMPUTES PREFERRED IMU ORIENTATION EXIT INHINT TC IBNKCALL CADR PFLITEDB # ZERO ATTITUDE ERRORS, SET DB TO ONE DEG. TC P40SXT4 # *********************** TCF BURNBABY # *********************** P40SXT4 EXTEND QXCH P40/RET P41MANU RELINT TC DOWNFLAG # CLEAR 3AXISFLG -- R60 WILL USE VECPOINT. ADRES 3AXISFLG TC BANKCALL CADR R60LEM # DO ATTITUDE MANEUVER ROUTINE TC P40/RET EBANK= TRKMKCNT POSTBURN CA Z TS DISPDEX EXTEND DCA ACADN85 DXCH AVEGEXIT CAF V16N40 TC BANKCALL CADR GOFLASHR TC TERM40 TCF TIGNOW TC POSTBURN ## Page 741 P40PHS1 TC PHASCHNG OCT 00014 TCF ENDOFJOB TIGNOW INHINT TC IBNKCALL CADR ZATTEROR TC IBNKCALL CADR SETMINDB RELINT CAF V16N85B TC BANKCALL CADR REFLASHR TC TERM40 TCF TERM40 TC -5 TCF P40PHS1 TERM40 EXTEND DCA SERVCADR DXCH AVEGEXIT CAF ZERO TS TRKMKCNT # ZERO RENDZVS CNTERS CA Z TS DISPDEX INHINT TC IBNKCALL CADR RESTORDB RELINT TC GOTOPOOH EBANK= WHICH COUNT* $$/P41 P41LM CAF P41ADRES # INITIALIZATION FOR BURNBABY TS WHICH TC BANKCALL CADR R02BOTH CA ZERO # ZERO DVTOTAL FOR NOUN 40 DISPLAY TS DVTOTAL TS DVTOTAL +1 CAF PRIO5 TS DISPDEX # FOR SAFETY TC FINDVAC EBANK= VGPREV 2CADR DYNMDISP TC 2PHSCHNG ## Page 742 OCT 00116 # GROUP 6 RESTART AT FKP5RST, PRIO 17 OCT 04024 # GROUP 4 RESTART HERE, PRIO 13 TC INTPRET # BOTH LM BON DLOAD # IF NJETSFLAG IS SET, LOAD 2 JET F NJETSFLG P41FJET1 FRCS4 # IF NJETSFLAG IS CLEAR, LOAD 4 JET F P41FJET STCALL F P41IN P41FJET1 DLOAD FRCS2 STORE F P41IN CALL S40.1 # BOTH P41NORM CALL S40.2,3 # CALCULATE PREFERRED IMU ORIENTATION AND EXIT # SET PFRATFLG. INHINT TC IBNKCALL CADR ZATTEROR # ZERO ATTITUDE ERRORS TC IBNKCALL CADR SETMINDB # SET 0.3 DEGREE DEADBAND TC P40SXT4 TC INTPRET VLOAD CALL # TRANSFORM VELOCITY-TO-BE-GAINED AT TIG VGTIG # FROM REFERENCE COORDINATES TO LM BODY- S41.1 # AXIS COORDINATES FOR V16N85 DISPLAY. STORE VGBODY # (SCALED AT 2 (+7) METERS/CENTISECOND) EXIT CAF V16N85B TC BANKCALL CADR GODSPRET TC 2PHSCHNG OCT 00076 # GROUP 6 RESTARTS AT REDO6.7 OCT 04024 # GROUP 4 RESTARTS HERE # *********************** TCF B*RNB*B* # *********************** ## Page 743 BLNKWAIT CAF 1SEC TC BANKCALL CADR DELAYJOB REDO6.7 CA DISPDEX # ON A RESTART, DO NOT PUT UP DISPLAY IF AD TWO # BLANKING (BETWEEN TIG-35 AND TIG-30) # *********************** EXTEND BZF BLNKWAIT CAF V16N85B TC BANKCALL CADR GODSPRET FKP5RST CAF PRIO5 TC PRIOCHNG DYNMDISP CA DISPDEX # A NON-POSITIVE DISPDEX INDICATES PAST EXTEND # TIG-35, SO SERVICER WILL BE DOING THE BZMF ENDOFJOB # UPDATING OF NOUN 85. STOP DYNMDISP. EXTEND DCS TIG DXCH TTOGO # UPDATE TFI DISPLAY (NOUN 40) EXTEND DCA TIME2 DAS TTOGO TC INTPRET VLOAD CALL VGPREV S41.1 # CONVERT VG FROM REF TO BODY STORE VGBODY EXIT CAF 1SEC TC BANKCALL CADR DELAYJOB TCF DYNMDISP # RECYCLE ONCE A SECOND COUNT $$/P41 BANK 32 SETLOC P40S4 BANK CALCN85 TC INTPRET CALL UPDATEVG VLOAD CALL VGPREV ## Page 744 S41.1 STORE VGBODY EXIT TC POSTJUMP CADR SERVEXIT BANK 36 SETLOC P40S BANK COUNT* $$/P42 EBANK= WHICH P42LM TC PHASCHNG OCT 04024 CAF P42ADRES # INITIALIZATION FOR BURNBABY. TS WHICH CS FLGWRD10 MASK APSFLBIT CCS A TC P40ALM P42STAGE TC BANKCALL CADR R02BOTH CAF THRESH2 # INITIALIZE DVMON TS DVTHRUSH CAF FOUR TS DVCNTR TC INTPRET SET VLOAD # LOAD FAPS, MDOTAPS, AND ATDECAY INTO AVFLAG # F, MDOT, AND TDECAY BY VECTOR LOAD. FAPS STORE F SLOAD GOTO APSVEX P40IN EBANK= WHICH COUNT* $$/P47 P47LM TC BANKCALL CADR R02BOTH TC INTPRET CALRB MIDTOAV2 CA MPAC +1 TC TWIDDLE ## Page 745 ADRES STARTP47 TCF ENDOFJOB STARTP47 TC PHASCHNG OCT 05014 OCT 77777 EXTEND DCA ACADN83 DXCH AVEGEXIT CAF PRIO20 TC FINDVAC EBANK= DELVIMU 2CADR P47BODY TCF REDO4.2 # CHECKS PHASE 5 AND GOES TO PREREAD # SEE TIG-30 IN BURNBABY. CALCN83 TC INTPRET VLOAD VAD DELVCTL DELVREF STORE DELVSIN # TEMP STORAGE FOR RESTARTS CALL S41.1 STORE DELVIMU EXIT TC PHASCHNG OCT 10035 # REREADAC AND HERE TC INTPRET VLOAD DELVSIN STORE DELVCTL EXIT TC POSTJUMP CADR SERVEXIT P47BOD CAF V1683 TC BANKCALL CADR GOFLASHR TC GOTOPOOH TC GOTOPOOH TCF P47BODY TCF P40PHS1 P47BODY TC INTPRET VLOAD ## Page 746 HI6ZEROS STORE DELVIMU STORE DELVCTL EXIT TC P47BOD COUNT* $$/P40 IMPLBURN CA TGO +1 TC GETDT TC TWIDDLE ADRES ENGOFTSK TC DOWNFLAG # TURN OFF IGNFLAG ADRES IGNFLAG TC DOWNFLAG # TURN OFF ASTNFLG ADRES ASTNFLAG TC DOWNFLAG # TURN OFF IMPULSW ADRES IMPULSW TC PHASCHNG # RESTART PROTECT ENGOFTSK (ENGINOFF) OCT 40114 TC FIXDELAY # WAIT HALF A SECOND DEC 50 TC NOULLAGE # TURN OFF ULLAGE TC TASKOVER ENGOFTSK TC IBNKCALL # THIS CODING ALLOWS ENGINOFF ET AL TO BE CADR ENGINOFF # USED BOTH BY WAITLIST AND BY TC IBNKCALL TC TASKOVER ENGINOFF CAF PRIO12 # MUST BE LOWER PRIO THAN CLOCKJOB TC FINDVAC EBANK= TRKMKCNT 2CADR POSTBURN ENGINOF2 CAF BIT1 TC WAITLIST EBANK= OMEGAQ 2CADR COASTSET ENGINOF1 CS FLAGWRD7 # SET THE IDLE BIT. MASK IDLEFBIT ADS FLAGWRD7 TC NOULLAGE ENGINOF4 EXTEND DCA TIME2 ## Page 747 DXCH TEVENT ENGINOF3 CS ENGONBIT # INSURE ENGONFLG IS CLEAR. MASK FLAGWRD5 TS FLAGWRD5 CS PRIO30 # ENGINOF3 IS USED AS A PRE-ENGINE ARM EXTEND # SUBROUTINE. RAND DSALMOUT AD PRIO20 # TURN OFF THE ENGINE - DPS OR APS EXTEND WRITE DSALMOUT CS DAPBOOLS # TURN OFF TRIM GIMBAL MASK USEQRJTS ADS DAPBOOLS CS HIRTHROT # ZERO AUTO-THROTTLE WHENEVER THE ENGINE TS THRUST # IS TURNED OFF. CAF BIT4 # THE HARDWARE DOES SO ONLY WHEN THE EXTEND # ENGINE IS DISARMED. WOR CHAN14 TC ISWRETRN COASTSET TC IBNKCALL # DO DAP COASTING INITIALIZATION CADR ALLCOAST TC TASKOVER EBANK= OMEGAQ UPDATEVG STQ CALL QTEMP1 S40.8 # X-PRODUCT STEERING BON BON # WILL RETURN HERE FROM S40.8 XDELVFLG QTEMP1 NORMSW 180SETUP DLOAD DSU PIPTIME TIGSAVE DSU BMN TNEWA GETRANS DLOAD DAD TIGSAVE TNEWA STORE TIGSAVEP 180SETUP EXIT CCS PHASE2 TCF NO.9 CAF PRIO10 ## Page 748 INHINT TC FINDVAC EBANK= VG 2CADR S40.9 # LAMBERT VTOGAIN TC 2PHSCHNG OCT 00172 # 2.17SPOT FOR S40.9 OCT 10035 # HERE AND REREADAC AFTER RESTART ENDSTEER TC INTPRET DLOAD TIGSAVEP STOVL TIGSAVE RN STOVL RINIT VN STORE VINIT GETRANS DLOAD DSU TPASS4 PIPTIME STCALL DELLT4 QTEMP1 NO.9 TC INTPRET GOTO QTEMP1 STEERING TC INTPRET CALL UPDATEVG EXIT EBANK= DVCNTR NSTEER INHINT CA EBANK7 TS EBANK CS FLAGWRD2 # CHECK IMPULSE SWITCH. IT IS SET EITHER MASK IMPULBIT # BY S40.13 IF TBURN<6 SECS OR BY S40.8 IF CCS A # STEERING IS ALMOST DONE. TCF +5 # IMPULSW = 0 EXIT CS FLAGWRD7 # IMPULSW = 1 WHY? CHECK IDLEFLAG MASK IDLEFBIT # (IDLEFLAG = 0 --> DVMON ON) CCS A TCF +3 # DVMON ON-->THRUSTING-->IMPULSW VIA S40.8 TC POSTJUMP # DVMON OFF-->IMPULSW ON VIA S40.13-->EXIT CADR SERVEXIT TC IBNKCALL CADR STOPRATE ## Page 749 TC DOWNFLAG # TURN OFF IMPULSW ADRES IMPULSW TC UPFLAG ADRES IDLEFLAG # TURN OFF DVMON INHINT EXTEND DCA TIG DXCH MPAC EXTEND DCS TIME2 DAS MPAC TC TPAGREE CAE MPAC +1 TC GETDT TC TWIDDLE ADRES ENGOFTSK TC 2PHSCHNG OCT 40114 # ENGOFTSK (ENGINOFF) OCT 00035 # SERVICER--REREADAC TCF ENDOFJOB GETDT CCS A TCF +3 TCF +2 CAF ZERO AD ONE XCH L CAF ZERO DXCH TGO CA TGO +1 TC Q # ************************************************************************ 5SECDP OCT 00000 # DON'T MOVE FROM JUST BEFORE 5SEC 5SEC DEC 500 V16N40 VN 1640 V16N85B VN 1685 V1683 VN 1683 SEC01 = 1SEC ACADN85 = P41TABLE +2 EBANK= DELVIMU ACADN83 2CADR CALCN83 # ************************************************* ## Page 750 # PROGRAM DESCRIPTION S40.1 DATE15NOV66 # MOD N02 LOG SECTION P40-P47 # MOD BY ZELDIN AND ADAPTED BY TALAYCO # FUNCTIONAL DESCRIPTION # COMPUTE INITIAL THRUST DIRECTION(UT) AND INITIAL VALUE OF VG # VECTOR(VGTIG). # CALLING SEQUENCE # L CALL # L+1 S40.1 # NORMAL EXIT MODE # AT L+2 OF CALLING SEQUENCE (GOTO L+2) NORMAL RETURN OR # ERROR RETURN IF NOSOFLAG =1 # SUBROUTINES CALLED # LEMPREC # INITVEL # CALCGRAV # MIDGIM # ALARM OR ABORT EXIT MODES # L+2 OF CALLING SEQUENCE,UNSOLVABLE CONIC IF NOSOFLAG=1 # ERASABLE INITIALIZATION REQUIRED # WEIGHT/G ANTICIPATED VEHICLE MASS DP B16KGM # XDELVFLG 1=DELTA-V MANEUVER,0=AIMPT STEER # F THRUST FOR ENGINE USED # IF DELTA-V MANEUVER # DELVSIN SPECIFIED DELTA-V REQUIRED IN # INERTIAL COORDS. OF ACTIVE VEHICLE # AT TIME OF IGNITION VECTOR B7M/CS # DELVSAB MAG. OF DELVSIN DP B7M/CS # RTIG POSITION AT TIME OF IGNITION VECTOR B29M # VTIG VELOCITY AT TIME OF IGNITION VECTOR B7M/CS # IF AIMPT STEER # TIG TIME OF IGNITION DP B28CS # RTARG POSITION TARGET TIME VECTOR B29M # CSTEER C FOR STEER LAW DP B2 # DLTARG TARGET TIME-IGNITION TIME DP B28CS # OUTPUT # UT DESIRED THRUST DIRECTION VECT. B2M/(CS.CS) # VGTIG INITIAL VALUE OF VELOCITY # TO BE GAINED (INERT. COORD.) VECTOR B7M/CS # DELVLVC VGTIG IN LOC. VERT. COORDS. B7M/CS # BDT V REQUIRED AT TIG -V REQUIRED AT (TIG-2SEC) # -GDT FOR S40.13 VECT B7M/CS # RTIG CALC IN S40.1B(AIMPT) FOR S40.2,3 VECTOR B29M # POSITION AT TIME OF IGNITION # DEBRIS QTEMP1 # MPAC, QPRET # PUSHLIST BANK 14 SETLOC P40S1 BANK ## Page 751 COUNT* $$/S40.1 S40.1 STQ DLOAD QTEMP TIG STORE TIGSAVE DELVTEST BOFF XDELVFLG S40.1B CALCTHET SETPD VLOAD 0 VTIG STORE VINIT VXV UNIT RTIG STOVL UT # UP IN UT RTIG STORE RINIT VSQ PDDL 36D DMP DDV THETACON DMP DMP DELVSAB WEIGHT/G DDV F STOVL 14D DELVSIN DOT VXSC UT UT VSL2 PUSH # (DELTAV.UP)UP SCALED AT 2(+7) P.D.L. 0 BVSU PDDL # DELTA VP SCALED AT 2(+7) P.D.L. 6 DELVSIN 14D SIN PDVL 6D VXV UNIT UT VXSC STADR STOVL VGTIG # UNIT(VPXUP)SIN(THETAT/2) IN VGTIG. UNIT PDDL # UNIT(DELTA VP) IN P.D.L. 6 14D COS VXSC VAD VXSC VGTIG 36D VSL2 VAD STADR ## Page 752 STORE VGTIG # VG IGNITION SCALED AT 2(+7)M/CS UNIT STOVL UT # THRUST DIRECTION SCALED AT 2(+1) VGTIG PUSH CALL GET.LVC # VGTIG IN LV COOR AT 2(+7) M/CS IN DELVLVC GOTO QTEMP S40.1B DLOAD TIG STORE TDEC1 BDSU TPASS4 STCALL DELLT4 # INTERCEPT TIME - TIG. LEMPREC VLOAD SETPD # LOAD STATE VECTOR AT TIG FOR INITVEL. RATT 0 STORE RTIG STORE RINIT UNIT STOVL UNIT/R/ VATT STORE VTIG STORE VINIT DLOAD PDDL # NUMIT = 0 ZEROVECS EPS1 BOFF DAD NORMSW SMALLEPS EPS2 # EPSILON4 = 10 DEGREES OR 45 DEGREES. SMALLEPS PUSH SXA,1 RTX1 SXA,2 CALL RTX2 INITVEL VLOAD PUSH DELVEET3 # VGTIG = VR - VN. STORE VGTIG UNIT # UT = UNIT (VGTIG) STODL UT 36D STCALL VGDISP # CONVERT VGTIG (IN PUSHLIST ) TO LOCAL GET.LVC # VERTICAL COORDINATES. GOTO QTEMP EPS1 2DEC* 2.777777778 E-2* # 10 DEGREES AT 1 REVOLUTION. ## Page 753 EPS2 2DEC* 9.722222222 E-2* # 35 DEGREES AT 1 REVOLUTION. THETACON 2DEC .31830989 B-8 ## Page 754 # SUBROUTINE NAME: S40.2,3 MOD. NO. 3 DATE: APRIL 4, 1967 # MODIFICATION BY: JONATHAN D. ADDELSTON (ADAMS ASSOCIATES) # MOD. NO. 4: JULY 18, 1967: PETER ADLER (MIT/IL) # MOD. NO. 5: OCTOBER 18, 1967: PETER ADLER (MIT/IL) # ORIGINALLY BY: SAYDEAN ZELDIN (MIT INSTRUMENTATION LAB) AND RICHARD TALAYCO (SYSTEM DEVELOPMENT CORP) # S40.2,3 COMPUTES "POINTVSM" WHICH IS THE HALF-UNIT DESIRED THRUST VECTOR IN STABLE-MEMBER COORDINATES FROM "UT" # WHICH IS THE SAME VECTOR IN REFERENCE COORDINATES. IT DETERMINES THE CORRECT VALUES FOR "SCAXIS" USING THE +X # AXIS FOR DPS, APS, AND RCS BURNS. THE "WINGS-LEVEL HEADS-UP" LM ORIENTATION IS THEN COMPUTED IN REFERENCE # COORDINATES. THESE VECTORS ALSO DEFINE THE "PREFERRED IMU ORIENTATION". UPON COMPLETION OF THIS CALCULATION, # THE "PREFERRED ATTITUDE COMPUTED" FLAG IS SET (PFRATFLG). # CALLING SEQUENCE: # L CALL INTERPRETIVE CALL. # L +1 S40.2,3 # L +2 (RETURN) GIMBAL ANGLE VECTOR IN MPAC. # SUBROUTINES CALLED: NONE. # NORMAL RETURN: L +2 (SEE CALLING SEQUENCE ABOVE). # ALARM/ABORT MODES: NONE. # INPUT: # 1. REFSMMAT MATRIX FROM REFERENCE TO STABLE-MEMBER COORDINATES SCALED AT 2. # 2. UT HALF-UNIT DESIRED THRUST DIRECTION. # 3. RTIG POSITION AT TIG IN REFERENCE COORDINATES. # # OUTPUT: # 1. : XSCREF : WINGS-LEVEL HEADS-UP LM ORIENTATION # : YSCREF : IN REFERENCE COORDINATES # : ZSCREF : (PREFERRED IMU ORIENTATION). # 2. POINTVSM DESIRED THRUST DIRECTION IN STABLE-MEMBER COORDINATES. # 3. SCAXIS HALF-UNIT OF AXIS TO ALIGN IN STABLE-MEMBER COORDINATES. # 4. PFRATFLG INTERPRETIVE FLAG. ON: PREFERRED ORIENTATION COMPUTED; OFF: NOT COMPUTED. # DEBRIS: NONE. ## Page 755 COUNT* $$/S40.2 S40.2,3 VLOAD # UT: DESIRED THRUST DIRECTION (HALF-UNIT) UT # (PUT INTO TOP OF PUSH-DOWN-LIST.) MXV VSL1 # TRANSFORM THRUST DIRECTION TO STABLE- REFSMMAT # MEMBER FROM REFERENCE COORDS (RESCALE). STOVL POINTVSM # SAVE FOR "VECPOINT" ROUTINE (LEMMANU). UNITX # SCAXIS SET TO +X, FOR P40 AND P42 AND STOVL SCAXIS # FOR P41 IF RCS NOT -X,+Y,-Y,+Z,-Z. UT # ASSUME +X BURN ALWAYS, EVEN FOR RCS. PLUSX STORE XSCREF # XSCREF = UT (DESIRED THRUST DIRECTION.) VXV UNIT # RTIG = POSITION AT TIME-OF-IGNITION. RTIG # YSCREF = UNIT(UT X RTIG) PDDL BHIZ 36D # TEST MAGNITUDE OF UT X RTIG FIXY # IF SMALL, USE UT X VTIG AS YSC STORY VLOAD STADR STORE YSCREF VXV VSL1 # COMPUTE (YSCREF X XSCREF),BUT FOR A XSCREF # RIGHT HANDED SYSTEM, NEED (X CROSS Y). VCOMP # ZSCREF = - (YSCREF X XSCREF) STORE ZSCREF # = + (XSCREF X YSCREF) SET RVQ PFRATFLG FIXY VLOAD VXV # IN THIS CASE, XSCREF # YSCREF = UNIT(XSCREF X VTIG) VTIG UNIT PUSH GOTO STORY ## Page 756 # SUBROUTINE S40.8 # MODIFIED APRIL 3, 1968 BY PETER ADLER MIT/IL # DESCRIPTION # S40.8 UPDATES THE VELOCITY-TO-BE-GAINED VECTOR, VG, (AND FOR LAMBERT TARGETTED BURNS ALSO EXTRAPOLATES VG # USING THE BDT VECTOR) COMPUTES THE TIME FOR ISSUING THE ENGINE OFF COMMAND, TGO, AND CALLS THE ROUTINE # "FINDCDUW", WHICH GENERATES THE STEERING COMMANDS FOR THE DAP. # CALLING SEQUENCE # L-1 CALL # L S40.8 # L+1 INTERPRETIVE RETURN # ALARM # IF VG . DELVREF IS NEGATIVE (VG AND DELVREF OVER 90 DEGREES APART), BYPASS TGO AND STEERING COMPUTATIONS # AND SET ALARM 1407. RETURN TO CALLER NORMALLY. # INPUT AND INITIALIZATION # VGPREV REFERENCE 2(7) M/CS # DELVREF REFERENCE 2(7) M/CS # BDT REFERENCE 2(7) M/CS # TDECAY TAIL-OFF TIME 2(28) CS # XDELVFLG 1 = EXTERNAL DELTA-V; 0 = LAMBERT (AIMPOINT) # STEERSW 1 = DO STEERING AND TGO COMPUTATIONS; 0 = VG UPDATE ONLY # FIRSTFLG 1 = GONE TO LAMBERT AT LEAST ONCE; 0 = HAVEN'T GONE TO LAMBERT YET # NOTE: VGTIG EQUALS VGPREV # OUTPUT # STEERSW SEE INPUT # IMPULSW 1 = ENGINE OFF IN TGO CENTISECONDS; 0 = CONTINUE BURN # TGO TIME TO CUT-OFF 2(28) CS # SEE FINDCDUW FOR STEERING OUTPUTS. # SUBROUTINE CALLED # FINDCDUW # DEBRIS # MPACS, PUSHLIST COUNT* $$/S40.8 ## Page 757 S40.8 BOF # GENERATE VR IF NOT EXTERNAL DELTA-V BURN XDELVFLG RASTEER1 VLOAD VSU VGPREV DELVREF VGAIN* STORE VG # VELOCITY TO BE GAINED SCALED AT (7)M/CS MXV VSL1 REFSMMAT STORE UNFC/2 BDTOK VLOAD ABVAL VG STORE VGDISP EXIT TC PHASCHNG OCT 10035 TC INTPRET TGOCALC SETPD VLOAD 0 VG STOVL VGPREV DELVREF BOFF VCOMP STEERSW QPRET UNIT DOT PUSH VG BPL DDV ALARMIT # DELV IS MORE THAN 90 DEGREES FROM VG. VEX DAD DMP DPHALF SR DDV 10D 36D DMP DAD -FOURDT TDECAY STORE TGO DAD PIPTIME STODL TIG TGO DSU BPL FOURSECS # 400 CS FINDCDUW -2 SET CLRGO IMPULSW STEERSW QPRET ## Page 758 ALARMIT EXIT TC ALARM OCT 01407 TC INTPRET GOTO FINDCDUW -2 -FOURDT 2DEC -800 B-18 # -4 (200 CS.) B (-18) FOURSECS 2DEC 400 # 400 CS SCALED AT 2(+28) CS 2VEXHUST = VEX ## Page 759 # NAME S40.13 - TIMEBURN # FUNCTION (1) DETERMINE WHETHER A GIVEN COMBINATION OF VELOCITY TO # BE GAINED AND ENGINE CHOICE RESULT IN A BURN TIME # SUFFICIENT TO ALLOW STEERING AT THE VEHICLE DURING THE # BURN # (2) THE MAGNITUDE OF THE RESULTING BURN TIME -- IF IT # IS SHORT -- AND THE ASSOCIATED TIME OF THE ENGINE OFF # SIGNAL # CALLING SEQUENCE VIA FINDVAC AS A NEW JOB # INPUT VGTIG VELOCITY TO BE GAINED VECTOR (METERS/CS) AT +7 # WEIGHT/G MASS OF VEHICLE IN KGM AT +16 # F APS ENGINE THRUST IN M.NEWTONS AT +7 # AND ALSO FOR RCS ENGINE # MDOT RATE OF DECREASE OF VEHICLE MASS DURING ENGINE # BURN IN KILOGRAMS/CS AT +3 . THIS SCALING MAY # REQUIRE MODIFICATION FOR SATURN BURNS. # ENG1FLAG SWITCH TO DECIDE WHETHER APS OR DPS ENGINE IS USED # =0 DPS # =1 APS # OUTPUT IMPULSW ZERO FOR STEERING # ONE FOR ATTITUDE HOLD # NOTHROTL ZERO FOR THROTTLING # ONE TO INHIBIT THROTTLING # TGO TIME TO BURN IN CS # THE QUANTITY M.NEWTON = 10000 NEWTONS WILL BE USED TO EXPRESS # FORCE EBANK= TGO COUNT* $$/40.13 S40.13 TC INTPRET SETPD CLEAR 00D IMPULSW # ASSUME NO STEERING UNTIL FOUND OTHERWISE VLOAD ABVAL VGTIG # VELOCITY TO BE GAINED AT +7 PDDL DMP # 00D = MAG OF VGTIG AT +7 4SEC(17) # CORRECT VG FOR 4 SECS OF 2 JET ULLAGE FRCS2 DDV SL1 # SCALE WEIGHT/G BDSU PUSH BOFF SET APSFLAG S40.13D # FOR DPS ENGINE NOTHROTL DLOAD DDV # 00D = MAG OF VGTIG CORRECTED K1VAL # M.NEWTONS-CS AT +24 WEIGHT/G BDSU BMN ## Page 760 00D S40.131 # TGO LESS THAN 100 CS PDDL DMP # 02D = TEMP1 AT +7 MDOT # MDOT REPRESENTS THE RATE OF DECREASE OF VEHICLE MASS DURING ENGINE # BURN IN KILOGRAMS/CS . WHEN SATURN IS USED , THE SCALING MAY # REQUIRE ADJUSTMENT 3.5SEC # 350 CS AT +14 BDSU PDDL WEIGHT/G F DMP SR2 # SCALE 5SECS DDV PUSH # 04D = TEMP2 BDSU BPL 02D S40.13D DLOAD BDDV DMP DAD 5SECS 1SEC2D # 100 CS AT +14 GOTO S40.132 S40.131 DLOAD DMP WEIGHT/G SR1 PUSH DAD DDV K2VAL # M.NEWTON CS AT +24 K3VAL # M.NEWTON CS AT +10 S40.132 SET EXIT IMPULSW S40.132* TC TPAGREE CA MPAC XCH L CA ZERO DXCH TGO TCF S40.134 S40.13D DLOAD DMP # FOR DPS ENGINE 00D WEIGHT/G PUSH BON APSFLAG APSTGO DDV CLEAR S40.136 NOTHROTL BOV PUSH ## Page 761 S40.130V S40.137 DSU BPL 6SEC # 600.0 CS AT +14 S40.138 DAD GOTO 6SEC S40.132 S40.133 EXIT S40.134 TC PHASCHNG OCT 00003 TC ENDOFJOB S40.130V DLOAD SR4 # RECOMPUTE TGO IN TIME2 UNITS DDV S40.136_ # S40.136 SHIFTED LEFT 10 STORE TGO EXIT TCF S40.134 # REJOIN COMMON CODING FOR RESTART PROTECT S40.138 DSU BPL 89SECS STORETGO SET NOTHROTL STORETGO DLOAD # LOAD TGO AT 2(14) EXIT TCF S40.132* APSTGO DDV SL2 FAPS GOTO STORETGO +1 1SEC2D 2DEC 100.0 B-14 # 100.0 CS AT +14 3.5SEC 2DEC 350.0 B-13 # 350 CS AT +13 5SECS 2DEC 500.0 B-14 # 500.0 CS AT +14 6SEC 2DEC 600.0 B-14 # 600.0 CS AT +14 89SECS 2DEC 8900.0 B-14 # FUNCTION (1) GENERATES REQUIRED VELOCITY AND VELOCITY-TO-BE-GAINED # VECTORS FOR USE DURING AIMPOINT MANEUVERS EVERY TWO # COMPUTATION CYCLES (4 SECONDS). # (2) UPDATES THE B VECTOR WHICH IS USED IN THE FINAL # CALCULATION OF EXTRAPOLATING THE VELOCITY-TO-BE-GAINED # THROUGH ONE 2-SECOND INTERVAL INTO THE FUTURE. # CALLING SEQ VIA FINDVAC AS NEW JOB. ## Page 762 # INPUT RN - ACTIVE VEHICLE RADIUS VECTOR IN METERS AT +29. # VN - ACTIVE VEHICLE VELOCITY VECTOR IN METERS/CS AT +7 # VRPREV - LAST COMPUTED VELOCITY REQUIRED VECTOR IN # METERS/CS AT +7. # TIG - TIME OF IGNITION IN CS AT +28. # DLTARG - COMPUTATION CYCLE INTERVAL = 200 CS AT +28. # PIPTIME - TIME OF RN AND VN IN CS AT +28. # GDT/2 - HALF OF VELOCITY GAINED IN DELTA T TIME DUE TO # ACCERERATION OF GRAVITY IN METERS/CS AT +7. # DELVREF - CHANGE IN VELOCITY DURING LAST 2 SEC IN # METERS/CS AT +7. # OUTPUT VGPREV - VELOCITY TO BE GAINED VECTOR IN METERS/CS AT +7. # VGDISP - MAG OF VGPREV FOR DISPLAY PURPOSES. # VRPREV - VELOCITY REQUIRED VECTOR IN METERS/CS AT +7. # BDT - B VECTOR IN METERS/CS AT +7. # SUBROUTINES USED - INITVEL EBANK= VGPREV COUNT* $$/S40.9 S40.9 TC INTPRET SETPD 00D SET DLOAD AVFLAG # SET AVFLAG FOR LEM ACTIVE HI6ZEROS PDDL EPS1 BOFF DAD # EPSILON4 = 10 OR 45 DEGREES. NORMSW EPSSMALL EPS2 EPSSMALL PUSH CALL HAVEGUES ENDS40.9 EXIT TC PHASCHNG OCT 2 TCF ENDOFJOB RASTEER1 VLOAD ABVAL RN LXC,2 SL* RTX2 0,2 STOVL RMAG RTARG VSU RTB RN NORMUNX1 STODL IC 36D # C(36D) = ABVAL(C) ## Page 763 XAD,2 SL* X1 0,2 STORE 30D NORM DMP X2 RMAG NORM XAD,2 X1 X1 SXA,2 MUSCALE STODL R1C # 2(+58 -X) 30D SR1 PDDL RMAG SR1 PDDL RTMAG SR1 DAD DAD STADR STORE SS # SS = (R1 + R2 +C )/2 DSU DMP 30D MU/A BDSU MUASTEER PDDL DSU SS RMAG NORM SR1 X1 DDV DMP R1C XSU,2 SL* X1 1,2 LXA,2 MUSCALE SQRT SIGN GEOMSGN STORE 32D # + OR - A DLOAD DMP SS MU/A BDSU MUASTEER PDDL DSU SS RTMAG NORM SR1 ## Page 764 X1 DDV DMP R1C XSU,2 SL* X1 1,2 SQRT PDDL # -B (NO SIGN) SS DSU DDV 30D SS SQRT PUSH SR1 ASIN DMP PDDL 2PI+3 PDDL DDV 30D SS BOV +1 SQRT DMP SR3 BDSU SIGN PDDL GEOMSGN 2PI+3 SR2 DSU DMP PDDL SS SS SR3 SQRT DMP PDDL SL3 MUASTEER SQRT BDDV DSU DAD TPASS4 PIPTIME STODL 30D SIGN 30D # B WITH SIGN STORE 30D BON VLOAD NORMSW 180MESS IC VSU UNIT UNIT/R/ VXSC PDVL 30D IC ## Page 765 VAD UNIT UNIT/R/ GETVRVG1 VXSC VAD 32D GETVRVG2 LXC,2 VSR* RTX2 0 -1,2 STORE VIPRIME GOTO ASTREND -2 180MESS VLOAD DOT IC UNIT/R/ BMN VLOAD NEGPROD IC VSR1 PDVL UNIT/R/ VSR1 VAD UNIT PUSH VCOMP # FOR A VXV SIGN UN GEOMSGN UNIT VXSC 30D PDVL # UNIT(IC-IR) +-B GOTO GETVRVG1 NEGPROD VLOAD VSR1 UNIT/R/ PDVL VSR1 IC VSU UNIT PUSH VXV SIGN UN # FOR B GEOMSGN UNIT VXSC 32D PDVL VXSC VAD 30D GOTO GETVRVG2 VSU VN1 ASTREND STORE DELVEET3 FIRSTTME SLOAD BZE RTX2 ## Page 766 GETGOBL VLOAD GOTO # NO OBLATENESS COMP IF IN MOON SPHERE DELVEET3 NOGOBL GETGOBL VLOAD UNIT # CALCULATE OBLATENESS TERM. RN DLOAD DSU PIPTIME # 2 GOBLTIME # G = -(MU/R )(UNITGOBL)(T - TIG) DMP DDV # OBL EARTHMU 34D # 34D = /RN/ (2) FROM UNIT OPERATION. VXSC VAD UNITGOBL DELVEET3 # OUTPUT FROM INITVEL VG = VR - VN NOGOBL STORE DELVEET3 # VG = VR + GOBL - VN GOTO VGAIN* 2PI+3 2DEC 3.141592653 B-2 ## Page 767 # TRIMGIMB (FORMERLY S40.6) # MOD 0 24 FEB 67 PETER ADLER # FUNCTION: # TRIMS DPS ENGINE TO MINIMIZE THRUST/CG OFFSET. ENGINE IS GIMBALLED TO FULL + PITCH AND + ROLL (TO LOCK) # FOR REFERENCE AND IS THEN BROUGHT BACK TO TRIM POSITION BY RUNNING FOR THE PROPER TIMES (TO BE # SPECIFIED BY GAEC) IN - PITCH AND - ROLL. # CALLING SEQUENCE: # VIA WAITLIST FROM R03 # INPUT: # PITTIME TIME TO RUN FROM FULL + PITCH TO TRIM (CS) # ROLLTIME TIME TO RUN FROM FULL + ROLL TO TRIM (CS) # SUBROUTINES USED: # WAITLIST, FIXDELAY, VARDELAY, FLAGUP, FLAGDOWN, NOVAC COUNT* $$/S40.6 EBANK= ROLLTIME # OCTAL MASKS: PRIO5=05000 EBANK5=02400 TRIMGIMB TC DOWNFLAG # GMBDRVSW FLAG IS SET WHEN EITHER ROLL OR ADRES GMBDRVSW # PITCH IS COMPLETED, WHICHEVER IS FIRST. CS PRIO5 # TURN OFF - PITCH, - ROLL, IF ON. EXTEND WAND CHAN12 CAF EBANK5 # TURN ON + PITCH, + ROLL. EXTEND WOR CHAN12 TC FIXDELAY # WAIT ONE MINUTE TO MAKE SURE ENGINE IS DEC 6000 # AT FULL + PITCH AND FULL + ROLL CS EBANK5 # TURN OFF + PITCH, + ROLL. EXTEND WAND CHAN12 CAF PRIO5 # TURN ON - PITCH, - ROLL. EXTEND WOR CHAN12 CAE PITTIME # GET TIME TO SHUT OFF - PITCH AND SET UP TC TWIDDLE # TWIDDLE-TASK TO TURN IT OFF THEN ADRES PITCHOFF CAE ROLLTIME # GET TIME TO SHUT OFF - ROLL AND GO AWAY TC VARDELAY # UNTIL THEN CS BIT12 EXTEND WAND CHAN12 # SHUT OFF ROLL ROLLOVER CA FLAGWRD6 # IF HERE INLINE (ROLL DONE) IS PITCH DONE MASK GMBDRBIT # IF HERE FROM PITCHOFF, IS ROLL DONE? EXTEND BZF PITCHOFF +4 # NO. SET FLAG, ROLL OR PITCH DONE. CAF PRIO10 # RETURN TO R03 TC NOVAC EBANK= WHOCARES ## Page 768 2CADR TRIMDONE TC TASKOVER PITCHOFF CS BIT10 EXTEND WAND CHAN12 # SHUT OFF PITCH TCF ROLLOVER # SEE IF ROLL HAS FINISHED ALSO. TC UPFLAG # ROLL DONE; OR PITCH DONE; BUT NOT BOTH. ADRES GMBDRVSW TC TASKOVER ## Page 769 # SUBROUTINE NAME: S41.1 MOD. NO. 0 DATE: FEBRUARY 28, 1967 # MOD. NO. 1 DATE: JANUARY 23, 1968: BY PETER ADLER (MIT/IL) # AUTHOR: JONATHAN D. ADDELSTON (ADAMS ASSOCIATES) # S41.1 PERFORMS THE COORDINATE SYSTEM TRANFORMATION FROM THE REFERENCE FRAME TO THE BODY OF THE LM. # SPECIFICALLY, IT IS USED TO TRANSFORM A VELOCITY (SCALED AT 2(+7) METERS/CENTISECOND) FROM REFERENCE TO LM AXIS # COORDINATES. FIRST THE VECTOR IS TRANSFORMED TO THE STABLE MEMBER COORDINATES BY THE MATRIX REFSMMAT. THIS # LEAVES THE VECTOR IN MPAC, SCALED AT 2(+8) METERS/CENTISECOND. THEN # THE SUBROUTINE CDUTRIG IS CALLED TO SET UP THE DOUBLE-PRECISION CDU VECTOR ALONG WITH ITS SINES AND COSINES. # THE VECTOR IS THEN TRANSFORMED FROM STABLE MEMBER COORDINATES TO SPACECRAFT (OR LM) COORDINATES BY THE # SUBROUTINE *SMNB*. FINALLY( THE VECTOR IS RESCALED TO 2(+7) METERS/CENTISECOND, AND CONTROL IS RETURNED TO THE # CALLER WITH C(MPAC) = VELOCITY(LM). # CALLING SEQUENCE: # L VLOAD CALL # L +1 VELOCITY(REF) SCALED AT 2(+7)M/CS IN REFERENCE COORDS. # L +2 S41.1 # L +3 STORE VELOCITY(LM) SCALED AT 2(+7)M/CS IN LM BODY AXIS SYS. # SUBROUTINES CALLED: # 1. CDUTRIG, # WHICH CALLS CDULOGIC. # 2. *SMNB* # NORMAL RETURN: L +3 (SEE CALLING SEQUENCE, ABOVE.) # ALARM/ABORT MODES: NONE. # RESTART PROTECTION: NONE. ## Page 770 # INPUT: # 1. REFSMMAT. # 2. CDUX, CDUY, CDUZ. # 3. VELOCITY (REF) IN MPAC. # OUTPUT: # 1. CDUSPOT: DOUBLE PRECISION CDU VECTOR, ORDERED Y,Z,X. # 2. SINCDU: HALF SINES OF CDUSPOT COMPONENTS. # 3. COSCDU: HALF COSINES OF CDUSPOT COMPONENTS. # 4. MPAC: VELOCITY(LM) (SCALED AT 2(+7) METERS/CENTISECOND) # # DEBRIS: NONE. # CHECKOUT STATUS: CODED. COUNT* $$/S41.1 S41.1 MXV VSL1 # CONVERT VECTOR IN MPAC FROM REF AT 2(+7) REFSMMAT # TO SM AND RESCALE DUE TO HALFUNIT MATRIX GOTO # CONVERT TO BODY AT 2(+7) USING PRESENT CDU*SMNB # CDU ANGLES. CDU*SMNB WILL RETURN # VIA RVQ TO THE CALLER OF S41.1