Proof Luminary099/TIME_OF_FREE_FALL

Fix two transcription errors found by comparing against scan pages 1275-1276:

- Page 1275 (R0293-R0295): MOD BY: 3/4/5 -> MOD NO: 3/4/5
  The modification number field was transcribed as MOD BY instead of MOD NO
  for entries 3, 4, and 5. MOD NO: 1 and MOD NO: 2 above them were correct.

- Page 1276 (R0393): M:(-36+2N4) -> M:(-36+2NR)
  The R in NR was misread as 4. Every other instance of this scale factor
  in the file correctly reads 2NR.

Partially resolves #647

Author: 0xDI

Luminary099/TIME_OF_FREE_FALL.agc

@@ -80,7 +80,7 @@ NRMAG		=	32D	#	PRESENT RADIUS  M	E: (-29+NR)
 TFFX		=	34D     #
 TFFTEM		=	36D	#	TEMPORARY
 # Page 1269
-#		REGISTERS S1, S2 ARE UNTOUCED BY ANY TFF SUBROUTINE
+#		REGISTERS S1, S2 ARE UNTOUCHED BY ANY TFF SUBROUTINE
 #		INDEX REGISTERS X1, X2 ARE USED BY ALL TFF SUBROUTINES.  THEY ARE ESTAB-
 #		LISHED IN TFF/CONIC AND MUST BE PRESERVED BETWEEN CALLS TO SUBSEQUENT
 #		SUBROUTINES.
@@ -233,7 +233,7 @@ DUMPCNIC	RVQ
 #		2. APOGEE RADIUS IS NOT DEFINED FOR PARABOLA
 #		3. APOGEE RADIUS EXCEEDS THE SCALING FOR ELLIPSE.
 #
-#	THIS SUBROUTINE REQUIRED THE SIGNED RECIPROCAL SEMI MAJ AXIS, ALFA, AND SEMI-LATUS RECTUM AS DATA.
+#	THIS SUBROUTINE REQUIRES THE SIGNED RECIPROCAL SEMI MAJ AXIS, ALFA, AND SEMI LATUS RECTUM AS DATA.
 #
 # CALLING SEQUENCE:	CALL
 #				TFFRP/RA
@@ -307,9 +307,9 @@ DUMPRPRA	RVQ
 # MOD BY:  RR BAIRNSFATHER
 # MOD NO:  1	MOD BY:  RR BAIRNSFATHER	DATE: 21 MAR 67
 # MOD NO:  2	MOD BY:  RR BAIRNSFATHER	DATE: 14 APR 67
-# MOD BY:  3	MOD BY:  RR BAIRNSFATHER	DATE: 8 JUL 67		NEAR EARTH MUE AND NEG TFF (GONEPAST)
-# MOD BY:  4	MOD BY:  RR BAIRNSFATHER	DATE: 21 NOV 67		ADD VARIABLE MU.
-# MOD BY:  5	MOD BY:  RR BAIRNSFATHER	DATE: 21 MAR 68		ACCEPT DIFFERENT EARTH/MOON SCALES
+# MOD NO:  3	MOD BY:  RR BAIRNSFATHER	DATE: 8 JUL 67		NEAR EARTH MUE AND NEG TFF (GONEPAST)
+# MOD NO:  4	MOD BY:  RR BAIRNSFATHER	DATE: 21 NOV 67		ADD VARIABLE MU.
+# MOD NO:  5	MOD BY:  RR BAIRNSFATHER	DATE: 21 MAR 68		ACCEPT DIFFERENT EARTH/MOON SCALES
 #
 # FUNCTIONAL DESCRIPTION:  PROGRAM CALCULATES THE FREE-FALL TIME OF FLIGHT FROM PRESENT POSITION RN AND
 #	VELOCITY VN TO A RADIUS LENGTH SPECIFIED BY RTERM, SUPPLIED BY THE USER.  THE POSITION VECTOR
@@ -340,7 +340,7 @@ DUMPRPRA	RVQ
 #	AND	TFF = (PI/SQRT(ALFA) -Q2 +Q1 +2(X T(X) -1) /ALFA Z) /ALFA SQRT(MU)
 #	WHERE	T(X) IS A POLYNOMIAL APPROXIMATION TO THE SERIES
 #		             2      3             2
-#		1/3 - X/5 + X /7 - X /8 ...	(X  < 1.0)
+#		1/3 - X/5 + X /7 - X /9 ...	(X  < 1.0)
 #
 # CALLING SEQUENC:	TIME TO RTERM			TIME TO PERIGEE
 #			CALL				CALL
@@ -383,7 +383,7 @@ DUMPRPRA	RVQ
 #				M:(-27+NR)
 #		X1				-NR, NORM COUNT				LEFT BY TFFCONIC
 #		TFFNP		E:(-38+2NR)	M  LCP, SEMI LATUS RECTUM, WEIGHT NR	LEFT BY TFFCONIC
-#				M:(-36+2N4)
+#				M:(-36+2NR)
 #		TFFALFA		E:(26-NR)	1/M  ALFA, WEIGHT NR			LEFT BY TFFCONIC
 #				M:(24-NR)
 #		TFFRTALF	E:(10+NA)	SQRT(ALFA), NORMALIZED			LEFT BY TFFCONIC