Pre-launch Review
STABLE ORBIT
Scanned pages: 723-730
# Copyright: Public domain.# Filename: STABLE_ORBIT.agc# Purpose: Part of the source code for Luminary 1A build 099.# It is part of the source code for the Lunar Module's (LM)# Apollo Guidance Computer (AGC), for Apollo 11.# Assembler: yaYUL# Contact: Ron Burkey <info@sandroid.org>.# Website: www.ibiblio.org/apollo.# Pages: 723-730# Mod history: 2009-05-19 RSB Adapted from the corresponding# Colossus249 file (there being no corresponding# Luminary131 source-code file), using page# images from Luminary 1A.# 2009-06-07 RSB Eliminated an extraneous instruction.# 2011-01-06 JL Fixed pseudo-label indentation.## This source code has been transcribed or otherwise adapted from# digitized images of a hardcopy from the MIT Museum. The digitization# was performed by Paul Fjeld, and arranged for by Deborah Douglas of# the Museum. Many thanks to both. The images (with suitable reduction# in storage size and consequent reduction in image quality as well) are# available online at www.ibiblio.org/apollo. If for some reason you# find that the images are illegible, contact me at info@sandroid.org# about getting access to the (much) higher-quality images which Paul# actually created.## Notations on the hardcopy document read, in part:## Assemble revision 001 of AGC program LMY99 by NASA 2021112-061# 16:27 JULY 14, 1969
# Page 723# STABLE ORBIT RENDEZVOUS PROGRAMS (P38 AND P78)## MOD NO -1 LOG SECTION - STABLE ORBIT - P38-P39# MOD BY RUDNICKI.S DATE 25JAN68## FUNCTIONAL DESCRIPTION## P38 AND P78 CALCULATE THE REQUIRED DELTA V AND OTHER INITIAL# CONDITIONS REQUIRED BY THE AGC TO (1) PUT THE ACTIVE VEHICLE# ON A TRANSFER TRAJECTORY THAT INTERCEPTS THE PASSIVE VEHICLE# ORBIT A GIVEN DISTANCE, DELTA R, EITHER AHEAD OF OR BEHIND THE# PASSIVE VEHICLE AND (2) ACTUALLY PLACE THE ACTIVE VEHICLE IN THE# PASSIVE VEHICLE ORBIT WITH A DELTA R SEPARATION BETWEEN THE TWO# VEHICLES## CALLING SEQUENCE## ASTRONAUT REQUEST THRU DSKY## V37E38E IF THIS VEHICLE IS ACTIVE VEHICLE# V37E78E IF OTHER VEHICLE IS ACTIVE VEHICLE## INPUT## (1) SOI MANEUVER## (A) TIG TIME OF SOI MANEUVER# (B) CENTANG ORBITAL CENTRAL ANGLE OF THE PASSIVE VEHICLE# DURING THE TRANSFER FROM TIG TO TIME OF INTERCEPT# (C) DELTAR THE DESIRED SEPARATION OF THE TWO VEHICLES# SPECIFIED AS A DISTANCE ALONG THE PASSIVE VEHICLE# ORBIT# (D) OPTION EQUALS 1 FOR SOI## (2) SOR MANEUVER## (A) TIG TIME OF SOR MANEUVER# (B) CENTANG AN OPTIONAL RESPECIFICATION OF 1 (B) ABOVE# (C) OPTION EQUALS 2 FOR SOR# (D) DELTTIME THE TIME REQUIRED TO TRAVERSE DELTA R WHEN# TRAVELING AT A VELOCITY EQUAL TO THE HORIZONTAL# VELOCITY OF THE PASSIVE VEHICLE - SAVED FROM# SOI PHASE# (E) TINT TIME OF INTERCEPT (SOI) - SAVED FROM SOI PHASE## OUTPUT## (1) TRKMKCNT NUMBER OF MARKS# (2) TTOGO TIME TO GO# (3) +MGA MIDDLE GIMBAL ANGLE# Page 724# (4) DSPTEM1 TIME OF INTERCEPT OF PASSIVE VEHICLE ORBIT# (FOR SOI ONLY)# (5) POSTTPI PERIGEE ALTITUDE OF ACTIVE VEHICLE ORBIT AFTER# THE SOI (SOR) MANEUVER# (6) DELVTPI MAGNITUDE OF DELTA V AT SOI (SOR) TIME# (7) DELVTPF MAGNITUDE OF DELTA V AT INTERCEPT TIME# (8) DELVLVC DELTA VELOCITY AT SOI (AND SOR) - LOCAL VERTICAL# COORDINATES## SUBROUTINE USED## AVFLAGA# AVFLAGP# VNDSPLY# BANKCALL# GOFLASHR# GOTOPOOH# BLANKET# ENDOFJOB# PREC/TT# SELECTMU# INTRPVP# MAINRTNE
BANK 04 SETLOC STBLEORB BANK
EBANK= SUBEXIT COUNT* $$/P3879
P38 TC BANKCALL CADR AVFLAGA # THIS VEHICLE ACTIVE TC +3P78 TC BANKCALL CADR AVFLAGP # OTHER VEHICLE ACTIVE TC BANKCALL CADR P20FLGON # SET UPDATFLG, TRACKFLG CAF DECTWO TS NN CAF V06N33SR # DISPLAY TIG TC VNDSPLY CAF V06N55SR # DISPLAY CENTANG TCR BANKCALL CADR GOFLASHR TCF GOTOPOOH # TERMINATE TCF +5 # PROCEED TCF -5 # RECYCLE CAF THREE # IMMEDIATE RETURN - BLANK R1, R2 TCR BLANKET# Page 725 TCF ENDOFJOB CAF FIVE TS OPTION1 CAF ONE TS OPTION2 # OPTION CODE IS SET TO 1 CAF V04N06SR # DISPLAY OPTION CODE - 1 = SOI, 2 = SOR TCR BANKCALL CADR GOFLASHR TCF GOTOPOOH # TERMINATE TCF +5 # PROCEED TCF -5 # RECYCLE CAF BIT3 # IMMEDIATE RETURN - BLANK R3 TCR BLANKET TCF ENDOFJOB TC INTPRET SLOAD SR1 OPTION2 BHIZ DLOAD OPTN1 TINT STORE TINTSOI # STORE FOR SOR PHASE CLRGO OPTNSW # OPTNSW: ON = SOI, OFF = SOR JUNCTN1OPTN1 SET CLEAR # SOI OPTNSW UPDATFLG CALL PREC/TT DAD SET TIG UPDATFLG STORE TINT # TI = TIG + TF EXIT CAF V06N57SR # DISPLAY DELTA R TCR BANKCALL CADR GOFLASHR TCF GOTOPOOH # TERMINATE TCF +5 # PROCEED TCF -5 # RECYCLE CAF SIX # IMMEDIATE RETURN - BLANK R2, R3 TCR BLANKET TCF ENDOFJOB +5 EXTEND DCA TINT DXCH DSPTEM1 # FOR DISPLAY CAF V06N34SR # DISPLAY TIME OF INTERCEPT TC VNDSPLY TC INTPRETJUNCTN1 CLEAR CALL# Page 726 P39/79SW SELECTMU # SELECT MU, CLEAR FINALFLG, GO TO VN1645RECYCLE CALL PREC/TT BOFF DLOAD OPTNSW OPTN2 TINT STCALL TDEC1 # PRECISION UPDATE PASSIVE VEHICLE TO INTRPVP # INTERCEPT TIME VLOAD UNIT RATT # RP/(RP) PDVL VXV VATT ABVAL NORM # (VP X RP/(RP)) X1 PDDL DDV DELTAR SL* # DELTA R / (VP X RP/RP) 0 -7,1 STCALL DELTTIME # DELTA T = (RP) DELTA R / (VP X RP) JUNCTN2OPTN2 DLOAD DAD TINTSOI T STORE TINT # TI = TI + TFJUNCTN2 DLOAD DSU TINT DELTTIME STORE TARGTIME # TT = TI - DELTA T
# .... MAINRTNE ....# SUBROUTINES USED:## S3435.25# PERIAPO1# SHIFTR1# VNDSPLY# BANKCALL# GOFLASH# GOTOPOOH# VN1645
MAINRTNE STCALL TDEC1 # PRECISION UPDATE PASSIVE VEHICLE TO INTRPVP # TARGET TIME DLOAD TIG STORE INTIME SSP VLOAD SUBEXIT TEST3979# Page 727 RATT CALL S3435.25TEST3979 BOFF BON P39/79SW MAINRTN1 FINALFLG P39P79 SET UPDATFLGP39P79 EXIT TC DSPLY81 # FOR P39 AND P79MAINRTN1 VLOAD ABVAL DELVEET3 STOVL DELVTPI # DELTA V VPASS4 VSU ABVAL VTPRIME STOVL DELVTPF # DELTA V (FINAL) = V'T - VT RACT3 PDVL CALL VIPRIME PERIAPO1 # GET PERIGEE ALTITUDE CALL SHIFTR1 STORE POSTTPI BON SET FINALFLG DSPLY58 UPDATFLGDSPLY58 EXIT CAF V06N58SR # DISPLAY HP, DELTA V, DELTA V (FINAL) TC VNDSPLYDSPLY81 CAF V06N81SR # DISPLAY DELTA V (LV) TC VNDSPLY TC INTPRET CLEAR VLOAD XDELVFLG DELVEET3 STCALL DELVSIN VN1645 # DISPLAY TRKMKCNT, TTOGO, +MGA BON GOTO P39/79SW P39/P79B RECYCLE
# STABLE ORBIT MIDCOURSE PROGRAM (P39 AND P79)## MOD NO -1 LOG SECTION - STABLE ORBIT - P38-P39# MOD BY RUDNICKI.S DATE 25JAN68## Page 728# FUNCTIONAL DESCRIPTION## P39 AND P79 CALCULATE THE REQUIRED DELTA V AND OTHER INITIAL# CONDITIONS REQUIRED BY THE AGC TO MAKE A MIDCOURSE CORRECTION# MANEUVER AFTER COMPLETING THE SOI MANEUVER BUT BEFORE MAKING# THE SOR MANEUVER.## CALLING SEQUENCE## ASTRONAUT REQUEST THRU DSKY## V37E39E IF THIS VEHICLE IS ACTIVE VEHICLE# V37E79E IF OTHER VEHICLE IS ACTIVE VEHICLE## INPUT## (1) TPASS4 TIME OF INTERCEPT - SAVED FROM P38/P78# (2) TARGTIME TIME THAT PASSIVE VEHICLE IS AT INTERCEPT POINT -# SAVED FROM P38/P78## OUTPUT## (1) TRKMKCNT NUMBER OF MARKS.# (2) TTOGO TIME TO GO# (3) +MGA MIDDLE GIMBAL ANGLE# (4) DELVLVC DELTA VELOCITY AT MID - LOCAL VERTICAL COORDINATES## SUBROUTINES USED## AVFLAGA# AVFLAGP# LOADTIME# SELECTMU# PRECSET# S34/35.1# MAINRTNE
P39 TC BANKCALL CADR AVFLAGA # THIS VEHICLE ACTIVE EXTEND DCA ATIGINC TC P39/P79AP79 TC BANKCALL CADR AVFLAGP # OTHER VEHICLE ACTIVE EXTEND DCA PTIGINCP39/P79A DXCH KT # TIME TO PREPARE FOR BURN TC BANKCALL CADR P20FLGON # SET UPDATFLG, TRACKFLG TC INTPRET# Page 729 SET CALL P39/79SW SELECTMU # SELECT MU, CLEAR FINALFLG, GO TO VN1645P39/P79B RTB DAD LOADTIME KT STORE TIG # TIG = T (PRESENT) + PREPARATION TIME STCALL TDEC1 # PRECISION UPDATE ACTIVE AND PASSIVE PRECSET # VEHICLES TO TIG CALL S34/35.1 # GET UNIT NORMAL DLOAD GOTO TARGTIME MAINRTNE # CALCULATE DELTA V AND DELTA V (LV)
# .... PREC/TT ....# SUBROUTINES USED## PRECSET# TIMETHET# S34/35.1
PREC/TT STQ DLOAD RTRN TIG STCALL TDEC1 # PRECISION UPDATE ACTIVE AND PASSIVE PRECSET # VEHICLES TO TIG VLOAD VSR* RPASS3 0,2 STODL RVEC CENTANG PUSH COS STODL CSTH SIN SET RVSW STOVL SNTH VPASS3 VSR* 0,2 STCALL VVEC # GET TRANSFER TIME BASED ON CENTANG OF TIMETHET # PASSIVE VEHICLE CALL S34/35.1 # GET UNIT NORMAL DLOAD GOTO T RTRN
# .... INTRPVP ....# SUBROUTINES USED## CSMPREC# Page 730# LEMPREC
INTRPVP STQ BOFF # PRECISION UPDATE PASSIVE VEHICLE TO RTRN # TDEC1 AVFLAG OTHERV CALL CSMPREC GOTO RTRNOTHERV CALL LEMPREC GOTO RTRN
# .... VNDSPLY ....# SUBROUTINES USED## BANKCALL# GOFLASH# GOTOPOOH
VNDSPLY EXTEND # FLASH DISPLAY QXCH RTRN TS VERBNOUN CA VERBNOUN TCR BANKCALL CADR GOFLASH TCF GOTOPOOH # TERMINATE TC RTRN # PROCEED TCF -5 # RECYCLEV06N33SR VN 0633V06N55SR VN 0655V04N06SR VN 0406V06N57SR VN 0657V06N34SR VN 0634V06N58SR VN 0658V06N81SR VN 0681DECTWO OCT 2
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