374 lines
11 KiB
Plaintext
374 lines
11 KiB
Plaintext
# Copyright: Public domain.
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# Filename: ENTRY_LEXICON.agc
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# Purpose: Part of the source code for Comanche, build 055. It
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# is part of the source code for the Command Module's
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# (CM) Apollo Guidance Computer (AGC), Apollo 11.
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# Assembler: yaYUL
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# Reference: pp. 837-843
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# Contact: Ron Burkey <info@sandroid.org>
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# Website: http://www.ibiblio.org/apollo.
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# Mod history: 2009-05-12 RSB Adapted from Colossus249 file of the same
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# name and Comanche 055 page images.
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#
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# The contents of the "Comanche055" files, in general, are transcribed
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# from scanned documents.
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#
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# Assemble revision 055 of AGC program Comanche by NASA
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# 2021113-051. April 1, 1969.
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#
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# This AGC program shall also be referred to as Colossus 2A
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#
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# Prepared by
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# Massachusetts Institute of Technology
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# 75 Cambridge Parkway
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# Cambridge, Massachusetts
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#
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# under NASA contract NAS 9-4065.
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#
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# Refer directly to the online document mentioned above for further
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# information. Please report any errors to info@sandroid.org.
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# Page 837
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# VARIABLE DESCRIPTION MAXIMUM VALUE * COMPUTER NAME
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# -------- ----------- --------------- -------------
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# _
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# URT0 INITIAL TARGET VECTOR 2 (UNIT VECTOR) = RTINIT
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# _
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# UZ UNIT VECTOR NORTH 1 = UNITW
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# _
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# V VELOCITY VECTOR 2 VSAT = VEL
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# _
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# R POSITION VECTOR 2 EXP 29 METERS = RN
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# _
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# VI INERTIAL VELOCITY 128 M/CENTISEC = VN
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# _
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# RTE VECTOR EAST AT INITIAL TARGET 2 = RTEAST
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# _
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# UTR NORMAL TO RTE AND UZ 2 = RTNORM
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# _
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# URT TARGET VECTOR 2 = RT
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# _
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# UNI UNIT NORMAL TO TRAJECTORY PLANE 2
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# _
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# DELV INTEGRATED ACCEL. FROM PIPAS 5.85 16384 CM/S
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# _
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# G GRAVITY VECTOR 128 M/CENTISEC = GDT/2
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#
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# A0 INITIAL DRAG FOR UPCONTRL 805 FPSS FPSS=FT/SEC/SEC
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#
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# AHOOKDV TERM IN GAMMAL CALC. = AHOOK DVL 16
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#
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# A1 DRAG VALUE IN FACTOR CALCULATION 805 FPSS
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#
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# ALP CONST FOR UPCONTRL 1
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#
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# ASKEP KEPLER RANGE 21600 NM NM = NAUTICAL MILE
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#
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# ASP1 FINAL PHASE RANGE 21600 NM
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#
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# ASPUP UP-RANGE 21600 NM
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#
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# ASP3 GAMMA CORRECTION 21600 NM
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#
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# ASPDWN RANGE DOWN TO PULL-UP 21600 NM
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#
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# ASP PREDICTED RANGE 21600 NM NOT STORED
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#
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# COSG COSINE(GAMMAL) 2 = COSG/2
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#
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# C/D0 RECIPROCAL DRAG, -4/D0 B-8 64/FPSS
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#
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# D TOTAL ACCELERATION 805 FPSS
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#
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# D0 CONTROLLED CONSTANT D 805 FPSS
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#
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# DHOOK TERM IN GAMMAL COMPUTATION 805 FPSS
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#
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# DIFF THETNM-ASP (RANGE DIFFERENCE) 21600 NM
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#
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# DIFFOLD PREVIOUS VALUE OF DIFF 21600 NM
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#
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# DLEWD CHANGE IN LEWD 1
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#
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# DR REFERENCE DRAG FOR DOWNCONTROL 805 FPSS NOT STORED
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#
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# DREFR REFERENCE DRAG 805 FPSS NOT STORED
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#
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# DVL VS1-VL 2 VSAT
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#
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# E ECCENTRICITY 4 NOT STORED
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#
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# F1 DRANGE/D DRAG (FINAL PHASE) 2700/805 = FX +5
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#
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# F2 DRANGE/D RDOT (FINAL PHASE) 2700/2VS NM/FPS = FX +4
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# Page 838
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#
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# F3 DRANGE/D (L/D) 2700 NM = FX
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#
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# FACT1 CONST FOR UPCONTRL 805 FPSS
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#
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# FACT2 CONST FOR UPCONTRL 1/805 FPSS
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#
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# FACTOR USED IN UPCONTRL 1 * MAXIMUM VALUE DENOTES UNSCALED
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# VARIABLE VALUE WHEN SCALED
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# GAMMAL FLIGHT PATH ANGLE AT VL 1 RADIAN VARIABLE HAS MAXIMUM VALUE OF ONE.
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#
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# GAMMAL1 SIMPLE FORM OF GAMMAL 1 RADIAN
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# Page 839
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#
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# HEADSUP INDICATOR FOR INITIAL ROLL 1
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#
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# KA DRAG TO LIFT UP IF DOWN 805 FPSS = KAT
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#
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# KLAT LATERAL SWITCH GAIN 1 (NOM = .0125)
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#
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# K2ROLL INDICATOR FOR ROLL SWITCH
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#
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# LAD MAX L/D (MIN ACTUAL VEHICLE L/D) 1
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#
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# LADPAD NOMINAL VEHICLE L/D, SP PAD LOAD 1 (NOM = 0.3)
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#
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# LATANG LATERAL RANGE 4 RADIANS
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#
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# LEQ EXCESS C.F. OVER GRAV=(VSQ-1)GS 128.8 FPSS
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#
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# LEWD UPCONTROL REFERENCE L/D 1
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#
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# LOD FINAL PHASE L/D 1 (NOM = 0.18)
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#
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# LODPAD FINAL PHASE L/D, SP PAD LOAD 1
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#
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# L/D DESIRED LIFT TO DRAG RATIO 1
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# (VERTICAL PLANE)
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#
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# L/D1 TEMP STORAGE FOR L/D IN LATERAL 1
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#
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# L/DCMINR LAD COS(15DEG) 1 (NOM = 0.2895)
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#
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# PREDANGLE PREDICTED RANGE (FINAL PHASE) 2700 NM = PREDANG
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#
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# Q2 FINAL PHASE RANGE -23500 Q3 21600 NM
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# Q2 = FCN(LAD)
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#
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# Q7 MINIMUM DRAG FOR UPCONTROL 805FPSS
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#
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# RDOT ALTITUDE RATE 2 VSAT
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#
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# RDOTREF REFERENCE RDOT FOR UPCONTROL 2 VSAT
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#
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# RDTR REFERENCE RDOT FOR DOWNCONT 2 VSAT NOT SAVED
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#
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# ROLLC ROLL COMMAND 1 REVOLUTION
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#
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# RTOGO RANGE TO GO (FINAL PHASE) 2700 NM = FX +2
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#
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# SL SINE OF LATITUDE 1 NOT SAVED
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#
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# T TIME B 28 CENTISEC = TIME2,TIME1
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#
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# THETA DESIRED RANGE (RADIANS) 2 PI RADIANS = THETAH
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#
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# THETNM DESIRED RANGE (NM) 21600 NM NON EXISTENT
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#
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# V VELOCITY MAGNITUDE 2 VSAT
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#
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# V1 INITIAL VELOCITY FOR UPCONTROL 2 VSAT
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#
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# VL EXIT VELOCITY FOR UPCONTROL 2 VSAT
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#
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# VREF REFERENCE VELOCITY FOR UPCONTROL 2 VSAT
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#
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# VS1 VSAT OR V1, WHICHEVER IS SMALLER 2 VSAT
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# 2 2
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# VBARS VL /VSAT 4
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# 2 2
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# VSQ NORMALIZED VEL. SQUARED = V /VSAT 4 = VSQUARE
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#
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# WT EARTH RATE TIMES TIME 1 REVOLUTION NOT SAVED
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#
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# X INTERMEDIATE VARIABLE IN G-LIMITER 2 VSAT NOT SAVED
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#
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# Y LATERAL MISS LIMIT 4 RADIANS NOT SAVED
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# Page 840
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# EXTRA COMPUTER ERASABLE LOCATIONS NOT SHOWN ON FLOW CHARTS
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# ----------------------------------------------------------
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#
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# VARIABLE DESCRIPTION MAXIMUM VALUE
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# -------- ----------- -------------
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#
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# GOTOADDR ADDRESS SELECTED BY SEQUENCER
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#
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# XPIPBUF BUFFER TO STORE X PIPA COUNTS
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#
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# YPIPBUF BUFFER TO STORE Y PIPA COUNTS
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#
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# ZPIPBUF BUFFER TO STORE Z PIPA COUNTS
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#
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# PIPCTR COUNTS PASSES THRU PIPA READ ROUTINE
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#
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# JJ INDEX IN FINAL PHASE TABLE LOOK-UP
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#
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# MM INDEX IN FINAL PHASE TABLE LOOK-U
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#
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# GRAD INTERPOLATION FACTOR IN FINAL PHASE
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#
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# FX DRANGE/D L/D = F3 2700 NM
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#
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# FX +1 AREF 805 FPSS
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#
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# FX +2 RTOGO 2700 NM
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#
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# FX +3 RDOTREF VSAT/4
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#
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# FX +4 DRANGE/D RDOT = F2 21600/2VS NM/FPS
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#
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# FX +5 DRANGE/D DRAG = F1 2700/805 NM/FPSS
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#
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# TEM1B TEMPORARY LOCATION
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#
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# TIME/RTO TIME OF INITIAL TARGET RTINIT B 28 CENTISEC
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#
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# DTEAROT EST TIME BETWEEN RTINIT AND RT B 28 CENTISEC
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# _
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# UNITV UNIT V VECTOR 2
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# _
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# UNITR UNIT R VECTOR 2
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# _
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# -VREL NEGATIVE VELOCITY REL TO ATMOSP 2 VSAT
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# COMPUTER SWITCHES INITIAL STATE CM/FLAGS = STATE +6
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# ----------------- ------------- -------------------
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#
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# ENTRYDSP DO ENTRY DISPLAY, IF SET NON-BRANCH (1) 92D, BIT 13
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# GONEPAST INDICATES OVERSHOOT OF TARGET NON-BRANCH (0) 95D, BIT 10
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# RELVELSW RELATIVE VELOCITY SWITCH NON-BRANCH (0) 96D, BIT 9
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# EGSW FINAL PHASE SWITCH NON-BRANCH (0) 97D, BIT 8
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# FIRSTPAS INITIAL PASS THRU HUNTEST NON-BRANCH (0) 98D, BIT 7
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# HIND INDICATES ITERATION IN HUNTEST NON-BRANCH (0) 99D, BIT 6
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# INRLSW INDICATES INIT ROLL ATTITUDE SET NON-BRANCH (0) 100D, BIT 5
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# LATSW INHIBIT DOWNLIFT SWITCH IF NOT SET BRANCH (1) 101D, BIT 4
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# .05GSW INDICATES DRAG EXCEEDS .05 GS BRANCH (0) 102D, BIT 3
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#
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# GONEBY INDICATES GONE PAST TARGET (SET) SELF-INITIALIZING 112D, BIT 8
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# Page 841
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# CONSTANTS AND GAINS VALUE
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# ------------------- -----
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#
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# C1 FACTOR IN ALP COMPUTATION 1.25
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# C16 CONSTD GAIN ON DRAG .01
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# C17 CONSTD GAIN ON RDOT .001
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# C18 BIAS VEL. FOR FINAL PHASE START 500 FPS
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# C20 MAX DRAG FOR DOWN-LIFT 175 FPSS
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# CHOOK FACTOR IN AHOOK COMPUTATION .25
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# CH1 FACTOR IN GAMMAL COMPUTATION 1.0
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# COS15 COS( 15 DEG ) .965
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# DLEWD0 INITIAL VARIATION IN LEWD -.05
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# D2 DRAG TO CHANGE LEWD 175 FPSS
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# DT COMPUTATION CYCLE TIME INTERVAL 2 SEC.
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# GMAX MAXIMUM ACCELERATION 257.6 FPSS (8 G'S)
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# KA1 FACTOR IN KA CALC 1.3 GS
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# KA2 FACTOR IN KA CALC .2 GS
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# KA3 FACTOR IN D0 CALC 90 FPSS
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# KA4 FACTOR IN D0 CALC 40 FPSS
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# KB1 OPTIMIZED UPCONTROL GAIN 3.4
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# KB2 OPTIMIZED UPCONTROL GAIN .0034
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# KDMIN INCREMENT ON Q7 TO DETECT END OF KEPLER PHASE .5 FPSS
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# KTETA TIME OF FLIGHT CONSTANT 1000
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# KLAT1 FACTOR IN KLAT CALC 1/24
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# K44 GAIN USED IN INITIAL ROLL SECTION 19749550 FPS
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# LATBIAS LATERAL SWITCH BIAS TERM .41252961 NM
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# LEWD1 NOMINAL UPCONTROL L/D .15
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# POINT1 FACTOR TO REDUCE UPCONTROL GAIN .1
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# Q2 FINAL PHASE RANGE - 23500 Q3 -1002 NM
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# Q3 FINAL PHASE DRANGE/D V .07 NM/FPS
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# Q5 FINAL PHASE DRANGE/D GAMMA 7050 NM/RAD
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# Q6 FINAL PHASE INITIAL FLIGHT PATH ANGLE .0349 RAD
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# Q7F MIN DRAG FOR UPCONTROL 6 FPSS
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# Q7MIN IN VALUE FOR Q7 IN FACTOR CALCULATION 40 FPSS
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# Q19 FACTOR IN GAMMAL1 CALCULATION .5
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# Q21 FACTOR IN Q2 CALCULATION 1000 NM
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# Q22 FACTOR IN Q2 CALCULATION -1302 NM
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# VFINAL1 VELOCITY TO START FINAL PHASE ON INITIAL ENTRY 27000 FPS
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# VFINAL FACTOR IN INITIAL UP-DOWN CALC 26600 FPS
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# VLMIN MINIMUM VL 18000 FPS
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# VMIN VELOCITY TO SWITCH TO RELATIVE VEL VSAT/2
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# VRCONTRL RDOT TO START INTO HUNTEST 700 FPS
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# VRCONT=COMPUTER NAME
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# 25NM TOLERANCE TO STOP RANGE ITERATION 25 NM
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# VQUIT VELOCITY TO STOP STEERING 1000 FPS
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# Page 842
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# CONVERSION FACTORS AND SCALING CONSTANTS
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# ----------------------------------------
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#
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# ATK ANGLE IN RAD TO NM 3437.7468 NM/RAD
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# G5 NOMINAL G VALUE FOR SCALING 32.2 FPSS
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# H5 ATMOSPHERE SCALE HEIGHT 28500 FT
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# J GRAVITY HARMONIC COEFFICIENT .00162346
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# KWE EQUATORIAL EARTH RATE 1546.10168 FPS
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# MUE EARTH GRAVITATIONAL CONSTANT 3.986032233 E14 CUBIC M/ SEC SEC
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# RE EARTH RADIUS 21202900 FT
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# REQ EARTH EQUATORIAL RADIUS 20925738.2 FT
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# VSAT SATELLITE VELOCITY AT RE 25766.1973 FPS
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# WIE EARTH RATE .0000729211505 RAD/SEC
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# (END GSOP AS-278, VOL 1, FIG. 5.6-3 CONSTANTS, GAINS, ETC.)
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# DISPLAY QUANTITIES
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# ------------------
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#
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# (SEE SECTION 4 OF THE GSOP FOR SIGN CONVENTIONS.)
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#
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# VARIABLE DESCRIPTION MAXIMUM VALUE
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# -------- ----------- -------------
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#
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# QMAX PREDICTED MAXIMUM ENTRY ACCEL 163.84 GS N 60
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# VPRED PREDICTED VELOCITY AT ALTITUDE 128 M/CENTISEC N 60
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# 400K FT ABOVE FISCHER RADIUS.
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# GAMMAEI PREDICTED GAMMA AT ALTITUDE 1 REVOLUTION N 60
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# 400K FT ABOVE FISCHER RADIUS
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# D DRAG ACCELERATION 805 FPSS N 64
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# VMAGI INERTIAL VELOCITY MAGNITUDE 128 M/CENTISEC N 64, N 68
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# THETAH DESIRED RANGE ANGLE NM 1 REVOLUTION N 64, N 67
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# LAT PRESENT LATITUDE 1 REVOLUTION N 67
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# LONG PRESENT LONGITUDE 1 REVOLUTION N 67
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# RTOGO RANGE ANGLE TO SPLASH FROM 1 REVOLUTION N 67
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# EMSALT FT ABOVE FISCHER RADIUS (IN NM)
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# VIO PREDICTED VELOCITY AT ALTITUDE 128 M/CENTISEC N 63
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# EMSALT FT ABOVE FISCHER RADIUS.
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# TTE TIME OF FREE FALL TO ALT B 28 CENTISEC N 63
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# EMSALT FT ABOVE FISCHER RADIUS
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# ROLLC ROLL COMMAND 1 REVOLUTION N 68, N 68, N 69
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# LATANG CROSS-RANGE ERROR (XRNGERR) 4 RADIANS N 66
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# DNRNGERR DOWN RANGE ERROR 1 REVOLUTION N 66
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# (PREDANG - THETAH IN NM)
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# HDOT ALTITUDE RATE 128 M/CENTISEC N 68
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# QT MINIMUM DRAG FOR UPCONTROL 805 FPSS N 69
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# VL EXIT VELOCITY FOR UP-CONTROL 2 VSAT N 69
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# Page 843
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# BODY ATTITUDE QUANTITIES (CM/POSE)
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# ----------------------------------
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#
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# VARIABLE DECRIPTION MAXIMUM VALUE
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# -------- ---------- -------------
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# _
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# -VREL NEGATIVE VELOCITY REL TO ATMOS. 2 VSAT
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# _
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# OLDUYA USED FOR UYA BELOW 1000 FPS 2
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# _
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# UXA/2 UNIT VECTOR TRIAD 2
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# _
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# UYA/2 BASED ON 2
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# _
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# UZA/2 THE TRAJECTORY 2
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# _
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# UBX/2 UNIT VECTOR 2
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# _
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# UBY/2 BODY TRIAD 2
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# _
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# UBZ/2 FOR CM. 2
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