Apollo-11/Comanche055/REENTRY_CONTROL.agc

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# Copyright: Public domain.
# Filename: REENTRY_CONTROL.agc
# Purpose: Part of the source code for Colossus 2A, AKA Comanche 055.
# It is part of the source code for the Command Module's (CM)
# Apollo Guidance Computer (AGC), for Apollo 11.
# Assembler: yaYUL
# Contact: Ron Burkey <info@sandroid.org>.
# Website: www.ibiblio.org/apollo.
# Pages: 844-882
# Mod history: 2009-05-08 RSB Adapted from the Colossus249/ file of the
# same name, using Comanche055 page images.
# 2009-05-23 RSB In a couple of 2OCT statements, removed the
# space between the first and second octal words.
#
# 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 055 of AGC program Comanche by NASA
# 2021113-051. 10:28 APR. 1, 1969
#
# This AGC program shall also be referred to as
# Colossus 2A
# Page 844
# ENTRY INITIALIZATION ROUTINE
# ----------------------------
BANK 25
SETLOC REENTRY
BANK
COUNT* $$/ENTRY
EBANK= RTINIT
EBENTRY = EBANK7
EBAOG EQUALS EBANK6
NTRYPRIO EQUALS PRIO20 # (SERVICER)
CM/FLAGS EQUALS STATE +6
STARTENT EXIT # MM = 63
# COME HERE FROM CM/POSE. RESTARTED IN CM/POSE.
CS ENTMASK # INITIALIZE ALL SWITCHES TO ZERO
# EXCEPT LATSW, ENTRYDSP, AND GONEPAST.
# GONEBY 112D BIT8 FLAG7, SELF-INITIALIZING.
INHINT
MASK CM/FLAGS
# ENTRYDSP = 92D B13
# GONEPAST=95D B10 RELVELSW=96D B9
# EGSW = 97D B8
# HIND=99D B6 INRLSW=100D B5
# LATSW=101D B4 .05GSW=102D B3
AD ENTRYSW
TS CM/FLAGS
RELINT
TC INTPRET
SLOAD
LODPAD
STORE LOD
SLOAD
LADPAD
STORE LAD
DMP # L/DCMINR = LAD COS(15)
COS15
STODL L/DCMINR
LATSLOPE
DMP SR1 # KLAT = LAD/24
LAD
# Page 845
STODL KLAT
Q7F
STODL Q7 # Q7 = Q7F
NEARONE # 1.0 -1BIT
STODL FACTOR
LAD
SIGN DCOMP
HEADSUP # MAY BE NOISE FOR DISPLAY P61
STCALL L/D # L/D = - LAD SGN(HEADSUP)
STARTEN1 # RETURN VIA GOTOADDR
VLOAD VXV
VN # (-7) M/CS
UNITR # .5 UNIT REF COORDS
UNIT DOT
RT # RT/2 TARGET VECTOR REF COORDS
STORE LATANG # LATANG = UNI.RT /4
DCOMP RTB
SIGNMPAC
STODL K2ROLL # K2ROLL = -SGN(LATANG)
LAD
DMP DAD
Q21
Q22
STORE Q2 # Q2 = -1152 + 500 LAD
SSP SSP
GOTOADDR # SET SELECTOR FOR INITIAL PASS
INITROLL
POSEXIT
SCALEPOP # SET CM/POSE TO CONTINUE AT SCALEPOP
RTB
SERVNOUT # OMIT INITIAL DISPLAY, SINCE 1ST GUESSBAD
# CALCULATE THE INITIAL TARGET VECTOR: RTINIT, ALSO RTEAST, RTNORM, AND RT. ALL ARE .5 UNIT AND IN
# REFERENCE COORDINATES.
STARTEN1 STQ VLOAD
GOTOADDR
LAT(SPL) # TARGET COORDINATES
CLEAR CLEAR # DO CALL USING PAD RADIUS. WILL UNIT IT.
ERADFLAG # ANYWAY.
LUNAFLAG
STODL LAT
3ZEROS
STODL LAT +4 # SET ALT=0.
PIPTIME # ESTABLISH RTINIT AT TIME OF PRESENT
# Page 846
# RN AND VN.
STCALL TIME/RTO # SAVE TIME BASE OF RTINIT.
LALOTORV # C(MPAC) =TIME (PIPTIME)
UNIT # ANSWER IN ALPHAV ALSO
STODL RTINIT # .5 UNIT TARGET REF COORDS
500SEC # NOMINAL ENTRY TIME FOR P63
# TIME/RTO = PIPTIME, STILL.
STCALL DTEAROT # INITIALIZE EARROT
EARROT1 # GET R5
DOT SL1
UNITR # RT/2 IN MPAC
ACOS
STCALL THETAH # RANGE ANGLE /360
GOTOADDR # RETURN TO CALLER
500SEC 2DEC 50000 B-28 # CS.
ENTMASK OCT 11774
ENTRYSW OCT 11010 # ENTRYDSP B13. GONEPAST B10. LATSW B4
# Page 847
SCALEPOP CALL
TARGETNG
EXIT
REFAZE10 TC PHASCHNG
OCT 10035 # SERVICER 5.3 RESTART AT REFAZE10
TC INTPRET
# JUMP TO PARTICULAR RE-ENTRY PHASE:
# SEQUENCE
GOTO
GOTOADDR
# GOTOADDR CONTAINS THE ADDRESS OF THE ROLL COMMAND EQUATIONS TO THE CURRENT PHASE OF
# RE-ENTRY. SEQUENCING IS AS FOLLOWS:
#
# INITROLL ADDRESS IS SET HERE INITIALLY. HOLDS INITIAL ROLL ATTITUDE UNTIL KAT IS EXCEEDED. THEN HOLDS NEW ROLL
# ATTITUDE UNTIL VRTHRESH IS EXCEEDED. THEN BRANCHES TO
#
# HUNTEST THIS SECTION CHECKS TO SEE IF THE PREDICTED RANGE AT NOMINAL L/D FROM PRESENT CONDITIONS IS LESS
# THAN THE DESIRED RANGE.
# IF NOT --- A ROLL COMMAND IS GENERATED BY THE CONSTANT DRAG CONTROLLER.
# IF SO --- CONTROL AND GOTOADDR ARE SET TO UPCONTRL.
# USUALLY NO ITERATION IS INVOLVED EXCEPT IF THE RANGE DESIRED IS TOO LONG ON THE FIRST PASS THROUGH
# HUNTEST.
#
# UPCONTRL CONTROLS ROLL DURING THE SUPER-CIRCULAR PHASE. UPCONTRL IS TERMINATED EITHER
# (A) WHEN THE DRAG (AS MEASURED BY THE PIPAS) FALLS BELOW Q7, OR
# (B) IF RDOT IS NEGATIVE AND REFERENCE VL EXCEEDS V.
# IN CASE (A), GOTOADDR IS SET TO KEP2 AND IN CASE (B), TO PREDICT3 SKIPPING THE KEPLER PHASE OF
# ENTRY.
#
# KEP2 GOTOADDR IS SET HERE DURING THE KEPLER PHASE TO MONITOR DRAG. THE SPACECRAFT IS INSTANTANEOUSLY
# TRIMMED IN PITCH AND YAW TO THE COMPUTED RELATIVE VELOCITY. THE LAST COMPUTED ROLL ANGLE IS MAINTAINED.
# WHEN THE MEASURED DRAG EXCEEDS Q7 +0.5, GOTOADDR IS SET TO
#
# PREDICT3 THIS CONTROLS THE FINAL SUB-ORBITAL PHASE. ROLL COMMANDS CEASE
# WHEN V IS LESS THAN VQUIT . AN EXIT IS MADE TO
#
# P67.1 THE LAST COMPUTED ROLL ANGLE IS MAINTAINED. RATE DAMPING IS DONE IN PITCH AND YAW. PRESENT LATITUDE
# AND LONGITUDE ARE COMPUTED FOR DISPLAY.
# ENTRY IS TERMINATED WHEN DISKY RESPONSE IS MADE TO THIS FINAL FLASHING DISPLAY.
# Page 848
# PROCESS AVERAGE G OUTPUT...SCALE IT AND GET INPUT DATA
# * START TARGETING ...
EBANK= RTINIT
# TARGETNG IS CALLED BY P61, FROM GROUP 4.
# TARGETNG IS CALLED BY ENTRY, FROM GROUP 5.
# ALL MM COME HERE.
TARGETNG BOFF VLOAD # ENTER WITH PROPER EB FROM CM/POSE(TEST)
RELVELSW # RELVELSW = 96D BIT9
GETVEL # WANT INERTIAL VEL. GO GET IT.
-VREL # NEW V IS RELATIVE, CONTINUE
VCOMP GOTO # (VREL) = (V) + KWE UNITR*UNITW
GETUNITV -1 # - VREL WAS LEFT BY CM/POSE
GETVEL VLOAD VXSC # INERTIAL V WANTED
VN # KVSCALE = (12800 / .3048) / 2VS
KVSCALE # KVSCALE = .81491944
STORE VEL # V/2 VS
GETUNITV UNIT STQ
60GENRET
STODL UNITV
34D
STORE VSQUARE # VSQ/4
DSU # LEQ = VSQUARE - 1
FOURTH # 4 G'S FULL SCALE
STODL LEQ # LEQ/4
36D
STOVL V # V/2 VS = VEL/2 VS
VEL
DOT SL1 # RDOT= V.UNITR
UNITR
STOVL RDOT # RDOT /2 VS
DELV # PIPA COUNTS IN PLATFORM COORDS.
ABVAL DMP
KASCALE
SL1 BZE
SETMIND
DSTORE STOVL D # ACCELERATION USED TO APPROX DRAG
VEL
VXV UNIT # UNI = UNIT(V*R)
# Page 849
UNITR
STORE UNI # .5 UNI REF COORDS.
BOFF DLOAD
RELVELSW
GETETA
3ZEROS
UPDATERT DSU DAD # PIPTIME-TIME/RTO =ELAPSED TIME SINCE
# RTINIT WAS ESTABLISHED.
TIME/RTO
PIPTIME
STCALL DTEAROT # GET PREDICTED TARGET VECTOR RT
EARROT2
DOT SETPD # SINCE (RT) UNIT VECT, THIS IS 1/4 MAX
UNI # LATANG = RT.UNI
0
STOVL LATANG # LATANG = MAC LATANG / 4
RT
CLEAR
GONEBY # SHOW HAVE NOT GONE PAST TARGET.
VXV DOT # IF RT*UNITR.UNI NEG, GONEBY=1
UNITR # GONEPAST IS CONDITIONAL SW SET IN
UNI # FINAL PHASE.
BPL SET
+2
GONEBY # SHOW HAVE GONE PAST TARGET.
VLOAD
RT
GETANGLE DOT DSU # THETA = ARCCOS(RT.UNITR)
UNITR
NEAR1/4 # TO IMPROVE ACCURACY, CALC RANGE BY
BPL DAD # TINYTHET IF HIGH ORDER PART OF
TINYTHET # ARCCOS ARGUMENT IS ZERO
NEAR1/4
SL1 ACOS
THETDONE STORE THETAH # THETAH/360
# HI WORD, LO BIT =1.32 NM=360 60/16384
BON DCOMP
GONEBY # =1 IF HAVE GONE PAST TARGET.
# (SIGN MAY BECOME ERRATIC VERY NEAR
# TARGET DUE TO LOSS OF PRECISION.)
+1
STODL RTGON67 # RANGE ERROR: NEG IF WILL FALL SHORT.
D
DSU BMN
# Page 850
.05G
NO.05G
SET VLOAD
.05GSW
DELVREF
PUSH DOT
UXA/2
SL1 DSQ
PDVL VSQ # EXCHANGE WITH PDL.
DSU DDV
0
BOV SQRT
NOLDCALC # OVFL LAST CLEARED IN EARROT2 ABOVE.
STORE L/DCALC
NOLDCALC GOTO
60GENRET
NO.05G CLEAR GOTO # THIS WAY FOR DAP. (MAY INTERRUPT)
.05GSW # .05GSW = 102D B3
NOLDCALC # KEEP SINGLE EXIT FOR TARGETING
# Page 851
# SUBROUTINES CALLED BY SCALEPOP (TARGETING):
BANK 26
SETLOC REENTRY1
BANK
COUNT* $$/ENTRY
GETETA DLOAD DDV # D = D +D(-RDOT/HS -2D/V) DT/2
# DT/2 = 2/2 =1
RDOT
-HSCALED
PDDL DMP
D
-KSCALE
DDV DAD
V
# -RDOT/HS FROM PDL.
DMP DAD
D
D
STORE D
BON DLOAD # EGSW INDICATES FINAL PHASE
EGSW
SUBETA
THETAH
DMP GOTO
KTETA # = 1000x2PI/(2)E14 163.84
UPDATERT
SUBETA DLOAD DSU # SWITCH FROM INERTIAL TO RELATIVE VEL.
V
VMIN
BPL SET
SUBETA2
RELVELSW
SUBETA2 DLOAD DMP
THETAH
KT1 # KT1 = KT
DDV GOTO
V # KT = RE(2 PI)/2 VS 16384 163.84/ 2 VSAT
UPDATERT
SETMIND DLOAD GOTO
1BITDP
DSTORE
# Page 852
TINYTHET DSU ABS # ENTER WITH X-.249
1BITDP +1 # GET 1/4 - MPAC
SL SQRT # SCALE UP BEFORE SQRT
13D # HAS FACTOR FOR UP SCALING
DMP GOTO
KACOS
THETDONE
# Page 853
# * START INITIAL ROLL ...
BANK 25
SETLOC REENTRY
BANK
COUNT* $$/ENTRY
# MM = 63, 64, ...
INITROLL BON BOFF # IF D- .05G NEG, GO TO LIMITL/D
INRLSW
INITRL1
.05GSW
LIMITL/D
# MM = 64, NOW
# 3
# KA = KA1 LEG + KA2
DLOAD DSQ
LEQ
DMP DDV
LEQ
1/KA1 # = 25 /(64 1.8)
DAD RTB
KA2 # = .2
P64 # ROLLC VI RDOT
# XXX.XX DEG XXXXX. FPS XXXXX. FPS
STORE KAT
DSU BMN
KALIM
+4
DLOAD
KALIM
STORE KAT
DLOAD DSU # IF V-VFINAL1 NEG, GO TO FINAL PHASE.
V
VFINAL1
CLEAR BPL # (CAN'T CLEAR INRLSW AFTER HERE: RESTARTS)
GONEPAST # GONEPAST WAS INITIALLY SET=1 TO FORCE
# ROLLC TO REMAIN AS DEFINED BY HEADSUP
# UNTIL START OF P64. (UNTIL D > .05G)
D0EQ
SSP GOTO
GOTOADDR
KEP2 # AND IDLE UNTIL D > 0.2 G. (NO P66 HERE)
INROLOUT # GO TO LIMITL/D AFTER SETTING INRLSW.
D0EQ DLOAD DMP # D0 = KA3 LEQ + KA4
# Page 854
LEQ
KA3
DAD
KA4
STORE D0 # D0/805
BDDV BOV
C001 # (-4/25 G) B-8
+1 # CLEAR OVFIND, IF ON.
STODL C/D0 # (-4/D0) B-8
LAD # IF V-VFINAL +K(RDOT/V)CUBED POS,L/D=-LAD
STODL L/D
RDOT
DDV PUSH
V
DSQ DMP
DDV DSU
1/K44
VFINAL
# 3
# V-VFINAL +(RDOT/V) / K44 OVFL $
DAD BOV
V
INROLOUT # GO TO LIMITL/D AFTER SETTING INRLSW.
BMN DLOAD
INROLOUT # GO TO LIMITL/D AFTER SETTING INRLSW.
LAD
DCOMP
STORE L/D
# SET INRLSW AT END FOR RESTART PROTECTION
INROLOUT BOFSET # END OF PRE .05G PATH OF INITROLL.
INRLSW # SWITCH IS ZERO INITIALLY.
LIMITL/D # (GO TO)
KATEST DLOAD DSU # IF KAT - D POS, GO TO CONSTD
KAT
D # IF POS, OUT WITH COMMAND VIA LIMITL/D
BPL GOTO
LIMITL/D
CONSTD
INITRL1 DLOAD DAD # IF RDOT + VRCONT POS, GO TO HUNTEST
RDOT
VRCONT
BMN CALL # IF POSITIVE, FALL INTO HUNTEST.
KATEST
FOREHUNT # INITIALIZE HUNTEST.
# Page 855
# * START HUNT TEST ...
# MM = 64
SSP # INITIALIZE HUNTEST ON FIRST PASS
GOTOADDR
HUNTEST # MUST GO AFTER FOREHUNT FOR RESTARTS.
HUNTEST DLOAD
D
STODL A1 # A1/805 = A1/25G
LAD
STODL TEM1B
RDOT
BMN DLOAD # IF RDOT NEG,TEM1B=LAD, OTHERWISE = LEWD
A0CALC
LEWD
STODL TEM1B
RDOT
A0CALC DDV DAD # V1 = V + RDOT/TEM1B
TEM1B
V
STODL V1 # V1/2 VS
RDOT
DSQ DDV # A0=(V1/V)SQ(D+RDOT SQ/(TEM1B 2 C1 HS)
TEM1B
DDV DAD
2C1HS
D
DMP DMP
V1
V1
DDV
VSQUARE
STODL A0 # A0/805 = A0/25G
RDOT
BPL DLOAD
V1LEAD
A0
STORE A1 # A1/25G
V1LEAD DLOAD BPL # IF L/D NEG, V1=V1 - 1000
L/D
HUNTEST1
DLOAD DSU
V1
# Page 856
VQUIT
STORE V1
HUNTEST1 DLOAD DMP # ALP = 2 C1 HS A0/LEWD V1 V1
A0
2C1HS
DDV SETPD
V1
0
DDV DDV
V1
LEWD
STORE ALP
BDSU BDDV # FACT1 = V1 / (1 - ALP)
BARELY1
V1
STODL FACT1 # FACT1 / 2VS
ALP
DSU DMP # FACT2 = ALP(ALP - 1) / A0
BARELY1
ALP
DDV
A0
STORE FACT2 # FACT2 (25G)
DMP DAD
Q7 # Q7 / 805 = Q7 / 25G
ALP # VL=FACT1 (1-SQRT(Q7 FACT2 +ALP) )
SQRT BDSU
BARELY1
DMP
FACT1
STORE VL # VL / 2 VS
BDSU DMP # GAMMAL1 = LEWD (V1-VL)/VL
V1
LEWD
DDV
VL
STODL GAMMAL1 # GAMMAL1 USED IN UPCONTROL.
# GAMMAL1 = PDL 22D.
VL
DSU BMN # IF VL-VLMIN NEG, GO TO PREFINAL
VLMIN
PREFINAL
DLOAD DSQ
# Page 857
VL
STODL VBARS # VBARS / 4 VS VS
HALVE # IF VSAT-VL NEG, GO TO CONSTD
DSU BMN
VL
BECONSTD # SET MODE=HUNTEST, CONTINUE IN CONSTD
STODL DVL # DVL / 2VS
HALVE
STORE VS1 # VS1 = VSAT
DSU BMN # IF V1 GREATER THAN VSAT, GO ON
V1
GETDHOOK
BDSU
DVL
STODL DVL # DVL = DVL - (VSAT-V1) = V1 - VL
V1
STORE VS1 # VS1 = V1, IN THIS CASE
GETDHOOK DLOAD CALL # DHOOK=((1-VS1/FACT1) SQ -ALP)/FACT2
VS1 # VS1 / 2 VS
DHOOKYQ7 # GO CALC DHOOK
STORE DHOOK # DHOOK / 25G
SR DDV
6 # CHOOK
Q7
DSU
CHOOK # = .25/16 = (-6)
STORE AHOOKDV
DAD DMP # GAMMAL= GAMMAL1-CH1 DVL SQ(1+AHOOK DVL)
1/16TH
CH1
DMP DMP
DVL
DVL
DDV DDV
DHOOK
VBARS
BDSU BMN
GAMMAL1
NEGAMA
HUNTEST3 STORE GAMMAL
DSU # GAMMAL1=GAMMAL1 +Q19 (GAMMAL-GAMMAL1)
GAMMAL1
DMP DAD
# Page 858
Q19
GAMMAL1
STODL GAMMAL1
GAMMAL
# Page 859
# *START RANGE PREDICTION ...
# C(MPAC) = GAMMAL.
RANGER DSQ SR2 # COSG = 1-GAMMAL SQ/2, TRUNCATED SERIES
BDSU
HALVE
STODL COSG/2
VBARS # E=SQRT(1+VBARS........
DSU DMP
HALVE
VBARS
DMP DMP
COSG/2
COSG/2
SL2 DAD
C1/16 # C1/16 = 1/16
SQRT PDDL # E/4 INTO PDL
VBARS
DMP DMP # ASKEP/2 = ARCSIN(VBARS COSG SING/E)
COSG/2
GAMMAL
DDV ASIN
SL1 PUSH # ASKEP TO PDL 0.
STODL ASKEP # BALLISTIC RANGE ASKEP/2PI
# FOR TM, STORE RANGE COMPONENTS OVERLAPPING (SP)
VL
DMP DAD # ASP1 = Q2 + Q3 VL
Q3
Q2
STORE ASP1 # FINAL PHASE RANGE ASP1/2 PI
PDDL DSQ # ASP1 TO PDL 2.
V1
# 2
# ASPUP= -C12 LOG(V1 Q7/VBARS A0)/GAMMAL1
DMP DDV
Q7
VBARS
DDV CALL
A0
LOG # RETURN WITH -LOG IN MPAC
DMP DDV
C12
GAMMAL1
STORE ASPUP # UP PHASE RANGE ASPUP / 2 PI
# Page 860
PDDL DMP # ASPUP TO PDL 4.
KC3 # KC3 = -4 VS VS / 2 PI 805 RE
# ASPDWN = KC3 RDOT V / A0
RDOT
DMP DDV
V
A0
DDV PUSH # ASPDWN TO PDL 6.
LAD
STODL ASPDWN # RANGE TO PULL OUT ASPDWN /2 PI
Q6
DSU DMP # ASP3 = Q5(Q6-GAMMAL)
GAMMAL
Q5
STOVL ASP3 # GAMMA CORRECTION ASP3/2PI
ASKEP # GET HI-WD AND
STODL ASPS(TM) # SAVE HI-WORD OF ASP'S FOR TM.
ASP3
DAD DAD
# ASPDWN FROM PDL 6.
# ASPUP FROM PDL 4.
DAD DAD
# ASP1 FROM PDL 2.
# ASKEP FROM PDL 0.
DSU BOVB # CLEAR OVFIND.
THETAH
TCDANZIG
STORE DIFF # DIFF = (ASP-THETAH) / 2 PI
# ASP=ASKEP+ASP1+ASPUP+ASP3+ASPDWN = TOTAL RANGE
ABS DSU # IF ABS(THETAH-ASP) -25NM NEG, GO TO UPSY
25NM
BMN BON
GOTOUPSY
HIND
GETLEWD
DLOAD BPL
DIFF
DCONSTD # EVENTUALLY SETS MODE = HUNTEST.
GETLEWD DLOAD DMP
# DLEWD = DLEWD (DIFF/(DIFFOLD-DIFF))
DLEWD
DIFF
PDDL DSU
DIFFOLD
DIFF
# Page 861
BDDV
LWDSTORE STADR
STORE DLEWD
DAD BMN # IF LEWD+DLEWD NEG, DLEWD=-LEWD/2
LEWD
LEWDPTR
BOV
LEWDOVFL
STORE LEWD
SIDETRAK EXIT
CA EBENTRY
TS EBANK
CA PRIO16 # DROP GRP 5 RESTART PRIO TO 1 LESS THAN
TS PHSPRDT5 # GRP 4.
TC PHASCHNG
OCT 00474 # RESTART GRP 4 AT PRE-HUN.
# FORCE RESTART TO PICK UP IN GRP 4:
# USE PRIO 17 FOR GRP 4 (< SERVICER PRIO)
CA PRIO16 # CONTINUE GRP 5 AT LOWER PRIO THAN EITHER
# GRP 4 OR SERVICER.
TC PRIOCHNG
CAF ADENDEXT # SIDETRACK NEXT PASS UNTIL THIS ONE DONE.
TS GOTOADDR # ONLY AFTER RESTART IS LEFT AFTER DETOUR.
TC INTPRET
DLOAD SET
DIFF
HIND
STODL DIFFOLD # DIFFOLD / 2 PI
Q7F
STCALL Q7 # Q7 / 805 FPSS
HUNTEST # (GO TO)
LEWDOVFL DLOAD
NEARONE
STCALL LEWD
DCONSTD # (GO TO) ALSO WILL SET MODE = HUNTEST
LEWDPTR DLOAD SR1
LEWD
DCOMP GOTO
LWDSTORE
# Page 862
NEGAMA DMP DMP # ENTER WITH GAMMAL IN MPAC
VL
1/3RD
PDDL DMP # PUSH GAMMAL VL/3
LEWD
1/3RD
PDDL DAD # PUSH LEWD/3
AHOOKDV
1/24TH
DMP DMP # DEL VL = (GAMMAL VL/3)/(LEWD/3-DVL
DVL # (2/3 + AHOOKDV)(CH1 GS/DHOOK VL))
CH1
DDV DDV
DHOOK
VL
BDSU BDDV
# LEWD/3
# GAMMAL VL /3
DAD
VL
STCALL VL # VL/2 VS
DHOOKYQ7 # GO CALC Q7
# Q7=((1-VL/FACT1)SQ - ALP)/FACT2
STODL Q7 # Q7 / 25G
VL
DSQ
STODL VBARS # VBARS / 4 VS VS
3ZEROS
GOTO # SET GAMMAL = 0
HUNTEST3
DHOOKYQ7 SR1 DDV # SUBROUTINE TO CALC DHOOK OR Q7
FACT1
BDSU SL1
HALVE
DSQ DSU
ALP
DDV RVQ
FACT2
# Page 863
# COME TO PRE-HUNT WHEN RESTART OCCURS AFTER
# HUNTEST IS SIDE-TRACKED AT SIDETRAK.
# PICK UP IN GROUP 4.
PRE-HUNT TC INTPRET
CLEAR CALL
HIND # HIND 99D BIT 6 FLAG 6
FOREHUNT # RE-INITIALIZE HUNTEST AFTER RE-START.
GOTO
HUNTEST
FOREHUNT DLOAD # INITIALIZE HUNTEST.
3ZEROS
STODL DIFFOLD
DLEWD0
STODL DLEWD
LEWD1
STORE LEWD
RVQ
ADENDEXT CADR ENDEXIT
# Page 864
# * START UP CONTROL ...
# MM = 65
GOTOUPSY RTB # END OF HUNTEST
P65 # HUNTEST USE OF GRP4 IS DISABLED BY P65
# USE FOR DISPLAY.
# SET MODE = UPCONTRL.
# RETURN FROM P65 DIRECTLY TO UPDONTRL
# VIA THE GOTOADDR AT REFAZE10.
UPCONTRL DLOAD DSU # IF D-140 POS, NOSWITCH =1
D # (SUPPRESS LATERAL SWITCH)
C21
BMN SET
+2
NOSWITCH
DLOAD DSU # IF V-V1 POS, GO TO DOWN CONTROL.
V
V1
BPL DLOAD
DOWNCNTL
D
DSU BMN # IF D- Q7 NEG, GO TO KEP
Q7
KEP
DLOAD BPL # IF RDOT NEG, DO VLTEST
RDOT
CONT1
VLTEST DLOAD DSU # IF V-VL-C18 NEG,EGSW=1,MODE=PREDICT3
V
VL
DSU BMN
C18
PREFINAL
CONT1 DLOAD # IF D-A0 POS, L/D = LAD, GO TO LIMITL/D
D
DSU BMN
A0
CONT3
DLOAD GOTO
LAD
STOREL/D
CONT3 DLOAD DMP # VREF=FACT1(1-SQRT(FACT2 D + ALP))
D
FACT2
# Page 865
DAD SQRT
ALP
BDSU DMP
BARELY1
FACT1
STORE VREF # VREF / 2VS
BDSU DMP # RDOTREF = LEWD(V1-VREF)
V1
LEWD
STODL RDOTREF # RDOTREF / 2VS
VS1
DSU BMN # IF VSAT-VREF NEG, GO TO CONTINU2
VREF
CONTINU2
PUSH PUSH # VS1-VREF TO PDL TWICE
DMP DDV # RDHOOK=CHI1(1+DV AHOOKDV/DVL) DV DV
AHOOKDV # /DHOOK VREF
DVL # WHERE DV = (VS1-VREF)
DAD DMP
1/16TH
CH1
DMP DMP
# VS1-VREF FROM PDL TWICE.
DDV
DHOOK
DDV BDSU
VREF
RDOTREF # C(RDOTREF)= LEWD (V1-VREF)
STORE RDOTREF # RDOTREF = RDOTREF - RDHOOK
CONTINU2 DLOAD DSU
D
Q7MIN
BOVB BMN
TCDANZIG # CLEAR OVFL IND, IF ON.
UPCNTRL3
DLOAD DSU
A1
Q7
PDDL DSU
D
Q7
DDV STADR
STORE FACTOR # FACTOR / 25G
# Page 866
# SKIPPER
# DELTA L/D=-((RDOT-RDOTREF)F1 KB1+V-VREF)F1 KB2
# WHERE F1 = FACTOR
UPCNTRL3 DLOAD
RDOT
DSU DMP # L/D = LEWD
RDOTREF # -((RDOT-RDOTREF)F1/KB1+V-VREF)F1/KB2
FACTOR
DDV DAD
1/KB1
V
DSU DMP
VREF
FACTOR
DDV PUSH
-1/KB2 # DELTA L/D INTO PDL
BOV ABS # NONLINEAR CIRCUIT FOR REDUCING HIGH GAIN
GOMAXL/D
DSU BMN
PT1/16
NEXT1
DMP DAD
POINT1
PT1/16
SIGN PUSH # ATTACH SIGN OF PUSH TO MPAC THEN PUSH
NEXT1 DLOAD SL4
# DELTA L/D FROM PDL.
DAD
LEWD
NEGTESTS BOV PUSH # L/D TO PDL FOR USE IN NEGTESTS.
GOMAXL/D
STODL L/D
# IF D-C20 POS, LATSW =0
# AND IF L/D NEG, L/D = 0.
D
DSU BMN
C20
LIMITL/D
CLEAR DLOAD
LATSW # =21D. ROLL OVER TOP, REGARDLESS.
# L/D FROM PDL.
BPL DLOAD
LIMITL/D
3ZEROS
STCALL L/D
LIMITL/D # (GO TO)
# Page 867
DCONSTD DLOAD # TWO RANGER ENTRIES TO CONSTD HERE
DIFF
# SAVE OLD VALUE OF DIFF FOR NEXT PASS.
STODL DIFFOLD # DIFFOLD / 2 PI
Q7F
STORE Q7
BECONSTD SSP RTB # A HUNTEST ENTRY INTO CONSTD.
GOTOADDR # RESET MODE TO HUNTEST
HUNTEST
KILLGRP4 # DEACTIVATE GRP4 FROM HUNTEST.
CONSTD BOVB
TCDANZIG # CLEAR OVF IND IF ON.
DLOAD DMP
LEQ
C/D0 # C/D0 = -4/D0 B-8
PDDL DMP # LEQ C/D0 INTO PDL
2HS # 2HS / 4 VS VS
D0
DDV DAD # RDOTREF = -2 HS D0/V
V
RDOT
DMP DAD
K2D # C/D0 LEQ + K2D(RDOT-RDOTREF) INTO PD
PDDL
D0 # D0 /805
CONSTD1 BDSU # ENTER WITH DREF IN MPAC
D
DMP DAD
K1D # K2D TERM FROM PUSH
SL GOTO
8D
NEGTESTS # (GO TO)
DOWNCNTL BOVB # INITIAL PART OF UPCONTROL.
TCDANZIG # CLEAR OVFIND, IF ON.
DLOAD SR
LAD
8D
PDDL DSU # RDTR = LAD(V1-V)
V
V1
DMP DAD
LAD
# Page 868
RDOT
DMP DAD
K2D
# PUSH UP LAD.
PDDL DSU # LAD + K2D(RDOT-RDTR) INTO PD
V1
V
DSQ DMP
LAD
DDV PDDL # (V1-V)SQ LAD/(2 C1 HS) INTO PD
2C1HS
V1
DSQ DDV
VSQUARE
BDDV DSU # DREF = (V/V1)SQ A0 - PD
A0
# PUSH UP HERE
GOTO # C(MPAC) = DREF
CONSTD1
# 2 2
# DREF = (V/V1) A0 -(V-V1) LAD/2 C1 HS
# Page 869
# * START BALLISTIC PHASE ...
# MM = 66 UPCONTRL ENTRY INTO KEP2
KEP RTB SSP
P66 # DISPLAY TRIM GIMBAL ANGLE VALUES.
GOTOADDR # SET GOTOADDR TO KEPLER PHASE.
KEP2
# KEP2 CAN ALSO BE STARTED UP DIRECTLY FROM INITROLL
# IN P64. PROGRAM WILL IDLE IN P64 UNTIL D EXCEEDS
# .2 G BEFORE GOING ON TO P67.
KEP2 DLOAD DSU # IF Q7F+KDMIN -D NEG, GO TO FINAL PHASE.
Q7FKDMIN # (Q7F + KDMIN)/805
D
BMN TLOAD
PREFINAL
# SET ROLLHOLD = ROLLC, IN CASE CMDAPMOD
ROLLC # = +1 EVER ENTERED.
BON TLOAD # IF D > .05G, KEEP PRESENT ROLL COMMAND.
.05GSW # IF D < .06G, SET ROLL COMMAND = 0.
+2
3ZEROS # SET ROLLC & ROLLHOLD =0.
+2 STCALL ROLLC # (SP ROLLHOLD FOLLOWS DP ROLLC)
P62.3 # CALC DESIRED GIMBAL ANGLES AT PRESENT
# RN, VN TO YIELD TRIM ATTITUDE.
# AVAILABLE IN CPHI'S FOR N22.
# Page 870
# START FINAL PHASE ...
# MM = 67
PREFINAL SSP RTB
GOTOADDR # RESTART PROTECT: RESET GOTOADDR IF CAME
PREFINAL # FROM HUNTEST.
P67 # DISABLES GRP4. FINE IF FROM HUNTEST, BUT
# MAY ALSO REMOVE RESTART PROTECTION OF
# N69 (P65).
# ROLLC XRNGERR DNRNGERR
# XXX.XX DEG XXXX.X NM XXXX.XX NM
SET SSP
EGSW
GOTOADDR
PREDICT3
PREDICT3 DLOAD DSU # IF V-VQUIT NEG, STOP STEERING
V
VQUIT
BMN EXIT
STEEROFF
CA EBENTRY # PRECAUTIONARY.
TS EBANK
CA TWELVE
BACK TS JJ
CS V
INDEX JJ
AD VREFER # VREF - V, HIGHEST VREF AT END OF TABLE.
CCS A # IF VREF-V POS LOOP BACK
CCS JJ # DECREMENT JJ, JJ CANNOT BE ZERO
TCF BACK
AD ONE
TS TEM1B # V-VREF IN TEM1B (MUST BE POSITIVE NUM)
INDEX JJ
CS VREFER
INDEX JJ
AD VREFER +1 # V(K+1) - V(K) (POS NUM)
XCH TEM1B
ZL
EXTEND
DV TEM1B
TS GRAD # GRAD = (V-VREF)/(VK+1 - VK) (POS NUM)
CAF FIVE
# Page 871
BACK2 TS MM
CAF THIRTEEN
ADS JJ
INDEX A
CS VREFER
INDEX JJ
AD VREFER +1 # X(K+1) - X(K)
EXTEND
MP GRAD
INDEX JJ
AD VREFER
INDEX MM
TS FX # FX = AK + GRAD (AK+1 - AK)
CCS MM
TCF BACK2
XCH FX +1 # ZERO FX +1 AND GET DREFR
AD D
EXTEND
MP FX +5 # F1
DXCH MPAC # MPAC = F1(D-DREF)
EXTEND
DCS RDOT # FORM RDOTREF - RDOT
DDOUBL
DDOUBL
DDOUBL # SCALE UP BY 8 FOR THIS PHASE.
AD FX +3 # RDOTREF
EXTEND
MP FX +4 # F2
AD FX +2 # RTOGO
DAS MPAC # ADD F2(DADV1-DADVR)
CA MPAC
TS PREDANG
# L/D = LOD + (THETA- PREDANG)/ Y
TC INTPRET
SR3 DSU
THETAH
BON BOFF
GONEPAST
GONEGLAD
GONEBY
HAVDNRNG
DLOAD SET # SET GONEPAST IF GONEBY SET & LATCH IN-PLACE
MAXRNG # DISPLAY = 9999.9 IF GONEBY
GONEPAST
STCALL DNRNGERR
GONEGLAD
HAVDNRNG STORE DNRNGERR # = (PREDANG - THETA) /360
# Page 872
DCOMP # FALLS SHORT IF NEG, OVERSHOOT IF POS
BOVB DDV
TCDANZIG # CLEAR OVFIND IF ON.
FX # FX= DRANGE/D L/D = Y
SL BOV
5
GOMAXL/D
DAD BOV
LOD
GOMAXL/D
STCALL L/D
GLIMITER # (GO TO)
# GONEGLAD AND GOPOSMAX ENTRY POINTS FOR GLIMITER ...
GONEGLAD DLOAD # SET L/D = -LAD
GONEGLAD # (ANY NEGATIVE NUMBER WILL DO)
GOMAXL/D RTB DMP L/D = LAD SIGN(MPAC)
SIGNMPAC
LAD
STORE L/D # AND FALL INTO GLIMITER SECTION
GLIMITER DLOAD DSU # IF GMAX/2-D POS, GO TO LIMITL/D
GMAX/2
D
BPL DAD # IF GMAX -D NEG, GO TO GOPOSLAD
LIMITL/D
GMAX/2
BMN DMP
GOPOSLAD
2HS
PDDL DMP # 2HS(GMAX-D) INTO PD
LEQ
1/GMAX
DAD DMP
LAD
PDDL DDV # 2HS(GMAX-D) (LEQ/GMAX+LAD) INTO PD
2HSGMXSQ
VSQUARE
DAD SQRT # XLIM = SQRT(PD+(2HSGMAX/V)SQ)
DAD BPL # IF RDOT+XLIM POS, GO TO LIMITL/D
RDOT
LIMITL/D
GOPOSLAD DLOAD
LAD
STOREL/D STORE L/D
# Page 873
LIMITL/D DLOAD
L/D
STODL L/D1
VSQUARE
BON # NO LATERAL CONTROL IF PAST TARGET
GONEPAST
L355
DMP DAD # Y= KLAT VSQUARE + LATBIAS
KLAT
LATBIAS # Y INTO PD
L350 PDDL ABS # IF ABS(L/D)-L/DCMINR NEG, GO TO L353
L/D
DSU BMN
L/DCMINR
L353
DLOAD SIGN # IF K2ROLL LATANG NEG, GO TO L357
LATANG
K2ROLL
BMN DLOAD
L357
SR1 PUSH # Y = Y/2
L353 DLOAD SIGN # IF LATANG SIGN(K2ROLL)-Y POS, SWITCH
LATANG
K2ROLL
DSU
BMN DLOAD
L355
K2ROLL
BONCLR DCOMP # IF NOSWITCH =1, K2ROLL= K2ROLL
NOSWITCH
L355
STORE K2ROLL # K2ROLL = -K2ROLL
L355 DLOAD DDV # ROLLC = ACOS( (L/D1) / LAD)
L/D1
LAD # MPAC SET TO +-1 IF OVERFLOW***
SR1 ACOS
SIGN CLEAR
K2ROLL
NOSWITCH
STORE ROLLC
ENDEXIT EXIT
OVERNOUT CA BIT13 # ENTRYDSP =92D B13
MASK CM/FLAGS
EXTEND
BZF NODISKY # OMIT DISPLAY.
# Page 874
CA ENTRYVN # ALL ENTRY DISPLAYS ARE DONE HERE.
TC BANKCALL
CADR REGODSPR # NO ABORT IF DISKY IN USE
NODISKY INHINT
CCS NEWJOB # PROTECT READACCS GRP 5, IF SIDETRACKED.
TC CHANG1
SERVNOUT TC POSTJUMP # ( COME HERE FROM P67.3 )
CADR SERVEXIT # AND END AVERAGEG JOB VIA ENDOJOB.
# Page 875
# DISPLAY WHEN V IS LESS THAN VQUIT.
STEEROFF EXIT
CA EBENTRY # PRECAUTIONARY.
TS EBANK
CA PRIO16 # 2 LESS THAN NTRYPRIO.
TC NOVAC
EBANK= AOG # ANY EB HERE
2CADR P67.1 # START UP REMAINDER OF P67
# RTOGO LAT LONG
# XXXX.X NM XXX.XX DEG XXX.XX DEG
TC 2PHSCHNG # INHINT/RELINT DONE.
OCT 00414 # 4.41 RESTART FOR P67.1 DISPLAY JOB.
OCT 10035 # SERVICER 5.3 RESTART.
CA P67.2CAD # HEREAFTER, DO LAT, LONG.
TS GOTOADDR
TC INTPRET
GOTO
P67.2CAD P67.2 # CONTINUE FOR LAT, LONG THIS TIME.
L357 DLOAD SIGN # L/D = L/DCMINR SIGN(L/D)
L/DCMINR
L/D
STCALL L/D1
L355 # (GO TO)
# Page 876
# TABLE USED FOR SUB-ORBITAL REFERENCE TRAJECTORY CONTROL.
VREFER DEC .019288 # REFERENCE VELOCITY SCALED V/51532.3946
DEC .040809 # 13 POINTS ARE STORED AS THE INDEPENDENT
DEC .076107 # VARIABLE AND THEN SIX 13-POINT FUNCTIONS
DEC .122156 # OF V ARE STORED CONSECUTIVELY
DEC .165546
DEC .196012
DEC .271945
DEC .309533
DEC .356222
DEC .404192
DEC .448067
DEC .456023
DEC .67918 # HIGHVELOCITY FOR SAFETY.
DEC -.010337 # DRANGE/DA SCALED DRDA/(2700/805)
DEC -.016550
DEC -.026935
DEC -.042039
DEC -.058974
DEC -.070721
DEC -.098538
DEC -.107482
DEC -.147762
DEC -.193289
DEC -.602557
DEC -.99999
DEC -.99999
DEC -.0478599 B-3 # -DRANGE/DRDOT
DEC -.0683663 B-3 # SCALED ((2VS/8 2700) DR/DRDOT)
DEC -.1343468 B-3
DEC -.2759846 B-3
DEC -.4731437 B-3
DEC -.6472087 B-3
DEC -1.171693 B-3
DEC -1.466382 B-3
DEC -1.905171 B-3
DEC -2.547990 B-3
DEC -4.151220 B-3
DEC -5.813617 B-3
DEC -5.813617 B-3
# Page 877
DEC -.0134001 B3 # RDOTREF SCALED (8 RDT/2VS)
DEC -.013947 B3
DEC -.013462 B3
DEC -.011813 B3
DEC -.0095631 B3
DEC -.00806946 B3
DEC -.006828 B3
DEC -.00806946 B3
DEC -.0109791 B3
DEC -.0151498 B3
DEC -.0179817 B3
DEC -.0159061 B3
DEC -.0159061 B3
DEC .0008067 # RANGE TO GO SCALED RTOGO/2700
DEC .0032963 # 8.9
DEC .0081852 # 22.1
DEC .017148
DEC .027926
DEC .037
DEC .063298
DEC .077889
DEC .098815
DEC .127519
DEC .186963
DEC .238148
DEC .294185185
DEC -.051099 # -AREF/805
DEC -.074534
DEC -.101242
DEC -.116646
DEC -.122360
DEC -.127081
DEC -.147453
DEC -.155528
DEC -.149565
DEC -.118509
DEC -.034907
DEC -.007950
DEC -.007950
# Page 878
DEC .004491 # DRANGE/D L/D SCALED Y/2700
DEC .008081
DEC .016030
DEC .035815
DEC .069422
DEC .104519
DEC .122
DEC .172407
DEC .252852
DEC .363148
DEC .512963
DEC .558519
DEC .558519 # END OF STORED REFERENCE
# Page 879
# REENTRY CONSTANTS.
# DEFINED BY EQUALS
DEC15 = LOW4
#GAMMAL1 = 22D
MAXRNG 2OCT 1663106755 # DNRNGERR = 9999.9 IF GONEPAST=1
BANK 26
SETLOC REENTRY1
BANK
COUNT* $$/ENTRY
BARELY1 = NEARONE # COMMON TO BOTH DISK,DANCE, DEFND IN TFF
#1BITDP # COMMON TO BOTH DISK AND DANCE. DEFND IN VECPOINT.
1/12TH DEC .083333 # DP 1/12 USES HI WORD IN 1/3 BELOW
1/3RD 2DEC .3333333333 # DP 1/3
1/16TH = DP2(-4)
# BELOW: VS = VSAT = 25766.1973 FT/SEC
# RE = 21,202,900 FEET
LEWD1 2DEC .15
POINT1 2DEC .1
POINT2 2DEC .2 # .2
DLEWD0 2DEC -.05 # -.05
GMAX/2 2DEC .16 # 8 GS / 2
3ZEROS EQUALS HI6ZEROS
NEAR1/4 2OCT 0777700000 # 1/4 LESS 1 BIT IN UPPER PART.
C18 2DEC .0097026346 # 500/2VS
Q7FKDMIN 2DEC .0080745342 # 6.5/805 (Q7F +KDMIN) = 6 + .5)
C1/16 = DP2(-4)
Q3 2DEC .167003132 # .07 2VS/21600
# Page 880
Q5 2DEC .326388889 # .3 23500/21600
Q6 2DEC .0349 # 2 DEG. APPROX 820/23500
Q7F 2DEC .0074534161 # 6/805 (VALUE OF Q7 IN FIXED MEM.)
Q19 = HALVE # Q19 = .5
Q21 2DEC .0231481481 # 500/21600
Q22 2DEC -.053333333 # -1152/21600
VLMIN 2DEC .34929485 # 18000/2 VS
VMIN = FOURTH # (VS/2) / 2VS
C12 2DEC .00684572901 # 32 28500/(21202900 2 PI)
1/KB1 2DEC .29411765 # 1 / 3.4
-1/KB2 2DEC -.0057074322 B4 # - 1/(.0034 2 VS) EXP +4
VQUIT 2DEC .019405269 # 1000 /2VS
C20 2DEC .21739130 # (175 FPSS) LIFT UP IF ABOVE C20
C21 2DEC .17391304 # 140/805
25NM 2DEC .0011574074 # 25/21600 (25 NAUT MILES)
K1D 2DEC .0314453125 # =C16 805/256 = .01 805/256
K2D 2DEC -.201298418 # -C17 2VS/256 = -.001 2VS/256
KVSCALE 2DEC .81491944 # 12800/(2 VS .3048)
KASCALE 2DEC .97657358 # 5.85 16384/(4 .3048 100 805)
KTETA 2DEC* .383495203 E2 B-14* # 1000 2PI/16384(163.84)
KT1 2DEC* .157788327 E2 B-14* # RE(2PI)/2 VS(16384) 163.84
.05G 2DEC .002 # .05/25
LATBIAS 2DEC .00003 # APPRX .5 NM/ 4(21600/2 PI)
KWE 2DEC .120056652 B-1
KACOS 2DEC .004973592 # 1/32(2PI)
CHOOK 2DEC 1 B-6 # .25/16
# Page 881
1/24TH 2DEC .0833333333 B-1
CH1 2DEC .32 B1 # 16 CH1/25 = 16 (1) /25
KC3 2DEC -.0247622232 # -(4 VS VS/ 2 PI 805 RE)
VRCONT 2DEC .0135836886 # 700/2 VSAT
HALVE EQUALS HIDPHALF
FOURTH EQUALS HIDP1/4
1/GMAX EQUALS HALVE # 4/GMAX = 4 / 8
2HS 2DEC .0172786611 # 2 28500 25 32.2/(4 VS VS)
2HSGMXSQ 2DEC .0000305717 # (2 28500 8 32.2/ 4 VS VS)SQ
C001 2DEC -.000625 # -(4/25)/256 LEQ/D0 CONST
POINT8 2DEC .8
2C1HS 2DEC .0215983264 # 2 1.25 28500 805/(2 VS)SQ
PT1/16 2DEC .1 B-4
1/K44 2DEC .00260929464 # 2 VS/19749550
VFINAL 2DEC .51618016 # 26600/2 VS
VFINAL1 2DEC .523942273 # = 27000 / 2 VS
1/KA1 2DEC .30048077 # 25/(1.3 64)
KA2 2DEC .008 # .2/25
KA3 2DEC .44720497 # = 90 4/805
KA4 2DEC .049689441 # 40/805
KALIM 2DEC .06 # 1.5/25
Q7MIN = KA4 # = 40/805 = .049689441
-HSCALED 2DEC -.55305018 # -28500/2 VS
-KSCALE 2DEC -.0312424837 # -805/VS
COS15 2DEC .965
LATSLOPE EQUALS 1/12TH
# ... END OF RE-ENTRY CONSTANTS ...