Here you'll find a collection of all the AGC, AGS, LVDC, and Gemini spacecraft computer documentation and software that I've managed to find whilst working on  Virtual AGC.  Every document on this page is archived here at Virtual AGC, regardless of whether it originated here or not.  In the early days I used to include only material I uncovered by my own efforts, but there have increasingly been contributions by readers, including some of the original AGC developers.  And there's material here that has been duplicated from other Apollo-centric websites for your convenience; see the FAQ page for a list of the fine Apollo and Gemini websites I raided. Now, there is some value-added in this process, since I add searchable text to those PDFs which are image-only, as well as adding metadata and bookmark panes where they don't exist.  My intention is to eventually provide one-stop-shopping for all of your Apollo and Gemini computing-system documentation needs. Note however, that I choose to duplicate only scanned or photographic images of the original documents.  In other words, I provide something as close to the "real thing" as I can.  On some sites, notably the Apollo Flight Journal and Apollo Lunar Surface Journal, great pains have been taken to produce HTML forms of the documents.  I do not duplicate those improved reformulations here, because that's original work for which I think credit is due; so you will have to visit those sites to use those improved versions.

Note:  Newest additions to the library (currently, July 2017 or later) are marked with the icon .

Document categories

AGC-related presentations

Various presentations presented at the MAPLD '04 conference, by AGC developers and other knowledgeable folks

 AGC software manuals and listings

AGC Users' Guides

This section pertains to a document (E-2448) called "Users' Guide to Apollo GN&CS Major Modes and Routines", presented in several different revisions.  While the document itself purports to be general purpose in nature rather than mission-specific, it was nevertheless maintained to remain current, and therefore can be roughly matched (from publication dates and internal information) particularly-relevant missions.

Guidance System Operations Plans (GSOP)

AGC quick-reference cards or data cards

AGC pad loads

AGC electrical schematics

Space Guidance Analysis (SGA) memos

If you are interested in the mathematical underpinnings of the AGC software, then this amazing series of memos from MIT's Instrumentation Lab is the place to look.  The memos are in roughly chronological order.  It is very interesting to reflect on the fact that these mathematical memos are often written by the very same people whose names you find as authors in the software.  The AGC software was written in a time ... or at least a place ... where software was regarded as the expression of mathematical knowledge as opposed to being a mere exercise in the expert employment of programming languages and tools as it is today.  It is interesting also to reflect on the nature of the software this approach produced.

LUMINARY Memos

This is a series of memos from the MIT Instrumentation Lab dealing with issues of Luminary software development.  Of particular interest, if you're concerned with the evolution of the AGC software, many of them memos are used to document the changes of the Luminary code from one revision to the next.  In theory, if you had all of them, you could use them to document the complete evolution of Luminary, or at any rate from LUMINARY 4 (memo #22) through LUMINARY 209 (memo #205).  Some of the gaps can also be filled in with SCB meeting reports, in the next section.

There are over 250 known LUMINARY Memos, of which we have (or are in the process of obtaining) the majority from Don Eyles's personal collection.  Here at the Virtual AGC site we are providing these memos in a convenient, readable quality, but higher-quality archival versions are available in our Virtual AGC collection at the Internet Archive.  In the table below, the lines which are grayed-out are not in Don's collection at all.

There is an equivalent series of COLOSSUS and DANCE (SUNDANCE) development memos, and probably others as well, but we have none of them except where they happen to coincide with LUMINARY memos.

LUMINARY Memo #

COLOSSUS or (SUN)DANCE Memo #

Date

Author

Subject

1

DANCE 2

11/7/67

J. Rhode

Nothing's Here to Stay — Not Even KKK

2

DANCE 7

11/15/67

Steve Copps

Tiger Team

3

DANCE 8

11/13/67

George Cherry

Minutes of MSC LM Digital Autopilot Design Review

4


11/29/67

George Cherry

LGC Computer Program Execution Time During Lunar Landing

5

DANCE 14

11/27/67

J. Saponaro

Synchronization of W-Matix and State Vector

6


1/12/68

George Cherry

Summary of Information from Level III Testing Status Reports for LUMINARY Development Plan, Week of 8 January 1968

7


1/16/68

George Cherry

LUMINARY GSOP Chapter 5 and Chapter 4 Review

8

DANCE 34

1/24/68

John Vella

Recent Changes to PINBALL Affecting DSKY Operation

9

COLOSSUS ?

2/6/68

A. Martorano

Minutes of PRC Meeting 2 February 1968

10

DANCE 37

2/9/68

George Cherry

RCS Jet Firings During Gyro Torquing in P52 on SUNDANCE

11

DANCE 38

2/12/68

J. S. Miller

Inhibition of DAP Operation in SUNDANCE and LUMINARY

12

DANCE 40

2/13/68

S. Davis

Hybrid Facility Procedures

13

DANCE 45

2/26/68

George Cherry

Deadband Setting PCR #86

14

DANCE 48

3/4/68

Alex Kosmala

Key Release Light

15


3/8/68

N. Neville

SETUP504

16

COLOSSUS 41

3/14/68

Alex Kosmala

ABORT

17

DANCE 51
COLOSSUS 42

3/15/68

J. Saponaro

AGC Time Dependent Constants

18


3/?/68

R. Tinkham

LUMINARY Downlist

19


3/4/68

Allan Klumpp

Comparison of Body Drive & Gimbal Drive FINDCDUW Routines

20

DANCE 57

4/1/68

Jim Kernan

SUNDANCE Revisions 280, 281 and 282 and LUMINARY Revision 0

21


4/8/68

Craig Schulenberg

LUMINARY Revisions 1, 2 and 3

22


4/15/68

Craig Schulenberg

LUMINARY Revisions 4, 5 and 6

23


4/22/68

Craig Schulenberg

LUMINARY Revisions 7 and 8

24

DANCE 69

4/24/68

C. Braunhardt

Standards for Verification Plans

25


4/30/68

Craig Schulenberg

LUMINARY Revisions 9, 10 and 11

26

COLOSSUS 26

5/13/68

Don Eyles

RTB

27


5/10/68

Allan Klumpp

FINDCDUW Guidance Autopiliot Interface Routine

28


5/14/68

Craig Schulenberg

LUMINARY Revisions 12 - 16

29


6/6/68

Craig Schulenberg

LUMINARY Revisions 17 and 18

30


6/7/68

Jim Kernan & Schulenberg

LUMINARY Level 4 Test Plan

31


6/12/68

Craig Schulenberg

LUMINARY Revisions 19 - 26

32


6/24/68

Peter Weissman

Undocumented Aspects of R03 (Verb 48)

33


6/24/68

George Cherry

Z-Axis Tracking in LUMINARY

34


7/15/68

Craig Schulenberg

LUMINARY Revisions 27 - 34

35


7/30/68

George Cherry

Don't Wrap Rendezvous Radar Around the Axle

36

DANCE 83

7/30/68

George Cherry

Computing the Lag Angles which Prevent Beginning and Supervised DAP Maneuvers

37


8/5/68

Craig Schulenberg

LUMINARY Revisions 35 - 38

38

DANCE 84

8/6/68

Craig Work

Restrictions to R03 (Verb 48) Inputs

39


8/27/68

George Cherry

Scheduling Proposed Modifications to the LUMINARY Digital Autopilot

40


9/5/68

Craig Schulenberg

LUMINARY Revisions 39 - 43

41


8/28/68

A. Laats & J. Shillingford

LUMINARY Level 3 Verification Plan

42


9/12/68

George Cherry

LUMINARY Program Changes Suggested at MSC/MIT Lunar Landing Co-Ordidation Meeting Held at MIT on 9/12/68

43


9/16/68

George Cherry

Implementation of One-Phase Descent Guidance Logic PCR

44


9/19/68

Don Eyles

Implementation of "One-Phase" Guidance in the AGC

45


9/24/68

Don Eyles

New Landing Initialization

46


10/15/68

George Cherry

LUMINARY Level IV Test Data Requirements for Pre-FACI Review

47


10/29/68

George Cherry

DPS and APS Engine Data

48


10/24/68

J. Connor

R65 Edit

49


11/1/68

Craig Schulenberg

LUMINARY Revisions 44 - 47

50


11/2/68

Craig Schulenberg

LUMINARY Revisions 48- 50

51


11/2/68

Craig Schulenberg

LUMINARY Revisions 51 - 53

52


11/3/68

Craig Schulenberg

LUMINARY Revisions 54 - 60

53


11/12/68

George Cherry

Final LUMINARY Tree-Shaking

54


11/18/68

George Cherry

LUMINARY Pre-Release Activities

55


12/4/68

Craig Schulenberg

LUMINARY Revisions 61

56

DANCE 86

12/4/68

George Cherry

DANCE & LUMINARY Program Activity Calendar

57


12/9/68

George Cherry

Report on LUMINARY FACI

58


12/17/68

Craig Schulenberg

LUMINARY Revisions 62 - 64

59

DANCE 87

1/3/69

Craig Work

SUNDANCE Edits for DAP and for Powered Descent

60


1/9/69

Jim Kernan, Peter Volante

LUMINARY Level 5 Test Plan

61


1/14/69

Craig Schulenberg

LUMINARY Revisions 65 - 69

62


1/24/69

George Cherry

A Set of Lunar Landing Guidance Equations which Compensate for Computation, Throttle, and Attitude-Control Lags

63


1/27/69

George Cherry

A Derivation of the Improved Lunar Landing Guidance Equations

64


2/4/69

Jim Kernan

Verb 85 — RR Antenna Line-of-Sight Display

65


2/7/69

George Cherry

A Variable Time Constant Velocity-Nulling Guidance Law

66


2/12/69

George Cherry

Aborts from the Lunar Landing & Nominal Lunar Ascent Targetting

67


2/17/69

Craig Schulenberg

LUMINARY Revisions 70 - 79

68


2/20/69

George Cherry

Lunar Landing Guidance Equations Program Alarms

69


3/10/69

Craig Work

LUMINARY 1A Edits for DAP and for Powered Descent

70

COLOSSUS 163

3/13/69

Joe Saponaro

Accuracy of Verb 83 (Range, Range Rate, Theta Display)

71


3/14/69

Peter Volante

LUMINARY TEDITS

72

COLOSSUS 167


Bill Ostanek

Use of V96 During State Vector / W Matrix Synchronization

73


3/27/69

Craig Schulenberg

LUMINARY Revisions 80 - 92

74


3/31/69

Peter Adler

Response to V99 & V97 in LUMINARY

75


4/1/69

George Cherry

R-2 Lunar Potential Model Added to LUM

76


4/1/69

Don Eyles

Variable Gains in Guidance Frame Erection

77


4/3/69

George Cherry

Let's Continue the LUMINARY 1A Test Results Review

78


4/10/69

Craig Schulenberg

LUMINARY Revisions 93 - 96

79

COLOSSUS 171

4/15/69

Jane Goode

Computation Cycle Timing in TPI, TPM Programs

80


4/24/69

Don Eyles

Abnormal Exit from Ignition Algorithm

81


4/28/69

Don Eyles

Landing Dependence on Platform Alignment

82


5/8/69

J.E. Jones

Suggestions for LUMINARY 1A Simulations

83


5/19/69

Jim Kernan

LUMINARY Revision 98

84


5/21/69

Don Eyles

Ignition Algorithm Convergence

85


5/21/69

Jim Kernan

LUMINARY Revision 99

86

COLOSSUS 183

5/21/69

Eugene Muller, Peter Kachmar

Affect of Radar (or the HF Ranging) AGC Interface Problem on F Mission Rendezvous Sequence

87


5/28/69

George Cherry

George Lowe's Decision at CCB Regarding LGC Radar Interface Problem

88


6/5/69

Don Eyles

Anomaly 64

89


6/23/69

Peter Adler, Dana Densmore

A Metaphysic of Downrupts

90

COLOSSUS 191

6/30/69

Jenny Flaherty

Memo Indexes

91


7/7/69

Craig Schulenberg

LUMINARY Revisions 100 - 105

92


7/10/69

Craig Schulenberg

LUMINARY Revisions 106

93


7/14/69

J.E. Jones

Intermediate Throttle-up of LM DPS During CSM-docked Burn

94


7/14/69

Bruce McCoy

Revision 107

95


7/9/69

Robert Covelli

Landing Radar Orientation

96


7/14/69

Bruce McCoy

Level 3 Test Plan for LUMINARY 1B

97


7/16/69

Don Eyles

Anomaly 79 Test Data

98

COLOSSUS 198

7/22/69

Margaret Hamilton

Review of Reduction of Coding Approval Procedures

99


7/23/69

George Cherry

LUMINARY Memo #96

100


7/31/69

Craig Schulenberg

Brief Summary of Verb, Noun, Alarm, Flagword & Downlist Changes between LUMINARY 1A & LUMINARY 1B (Rev. 111)

101


8/4/69

Bruce McCoy, George Cherry

Level III/IV Tests Review

102


8/6/69

George Cherry (attached is 8/4 Eyles/Cherry PCR 854)

Some Results of the Apollo 12 Pinpoint Lunar Landing Data Priority Meeting

103


8/6/69

Craig Schulenberg

LUMINARY Revisions 108 - 113

104


8/8/69

David Moore, Don Eyles

LUMINARY 1B — Level 4 Lunar Landing Test Plan

105

COLOSSUS 209

8/14/69

Al Engel, Bruce McCoy

H Mission RTCC Compatibility Testing, Test Plan & Schedule (Preliminary)

106

COLOSSUS 210

8/14/69

Al Engel, Bruce McCoy

RTCC Compatibility Testing at MIT, Current Understanding of Scope, Responsibilities, etc.

107


8/20/69

Craig Schulenberg

LUMINARY Revisions 114 - 116

108


8/22/69

Bruce McCoy

LUMINARY 1B is Revision 116

109


9/9/69

Bruce McCoy

Work Around for P22 Bug

110

COLOSSUS 213

9/10/69

Bill Ostanek

Bad Other Vehicle State Vector

111


9/19/69

Bruce McCoy

Level 6

112


9/22/69

M. Albert

RTCC Compatable Uplink Edit

113

COLOSSUS 218

10/2/69

S. David

Configuration Control of RTCC Digital Environment

114


10/7/69

Russ Larson

Proposed Contents of LUMINARY 1C

115


10/9/69

Don Eyles

Notes on Implementation of Delta-Guidance

116


10/22/69

Larry Berman

ACB #L5/120 — Operation of Rotation Control

117


10/24/69

George Kalan

Special Crew Procedures Necessary for Controlling the CSM-Docked Configuration with the LEM DAP

118


10/27/69

Don Eyles

Landing Changes Put into LUMINARY 1C

119


10/30/69

Harry McOuat

New LOSSEM Numbers

120


11/5/69

Russ Larson

C13STALL

121


11/5/69

Bruce McCoy

What is LUMINARY 1C

122


11/6/69

Dana Densmore

LUMINARY Revisions 117 - 120

123


11/18/69

Don Eyles

More About Delta-Guidance

124


11/11/69

Dana Densmore

LUMINARY Revisions 121 - 130

125

COLOSSUS 232

11/21/69

D. Reinke

Work-around for P32 Bomb-Outs

126


12/2/69

Don Eyles

Delta-Guidance

127


12/3/69

Bruce McCoy

Re-release of LUMINARY 1C

128


12/3/69

Bruce McCoy

Level 6 Test Plan for LUMINARY 1C

129


12/5/69

Dana Densmore

LUMINARY Revisions 131

130


12/15/69

Russ Larson

LUMINARY 1C Program Notes

131


1/2/70

Dana Densmore

LUMINARY Revisions 132 - 135

132

COLOSSUS 240

1/8/70

Ken Greene

Definition and Usages of PCRs, PCNs, Anomalies & ACBs

133


1/9/70

Peter Volanta, G. Dunbar

Implementation of PCR 287

134


1/19/70

Dana Densmore

LUMINARY Revisions 136 - 139

135


1/23/70

Robert Covelli

Downrupt Losses During Periods of High Computer Activity Programs

136


1/29/70

Dana Densmore

LUMINARY Revisions 140 - 143

137


1/30/70

Russ Larson

LUM 131A REV 3 Testing

138


2/14/70

Don Eyles

Variable Guidance Period Servicer
or Revision 1

139


3/3/70

Don Eyles

Description of Variable Servicer

140


3/4/70

Allan Klumpp

A Collection of Known Manifestatons of Time Loss in Luminary Revision 131 and LM131 Revision 001 — Suggested Work-Around Procedures

141


3/10/70

Larry Berman

Replacement of LOGSUB in LUMINARY

142


3/18/70

Dana Densmore

LUMINARY Revisions 144 - 147

143


3/24/70

Allan Klumpp

Automatic P66

144


4/6/70

Don Eyles

Variable Servicer Tests

145


5/5/70

Dana Densmore

LUMINARY Revisions 148 - 151

146


5/?/70

Robert Covelli

The New R12

147


5/5/70

Allan Klumpp, Don Eyles, Bruce McCoy

Lunar Terrain Model

148


5/11/70

Bruce McCoy

Call It LUMINARY 1D

149


5/13/70

Don Eyles

Further Tests of ZERLINA

150


5/15/70

Dana Densmore

LUMINARY Revisions 152 - 154

151


5/19/70

Dana Densmore

LUMINARY Revisions 155 - 158

152


5/21/70

Don Eyles

Cyclical PIPA Reader

153


5/26/70

Sharon Albert

Variable Servicer Tests

154


6/1/70

Larry Berman

Luminary Dev. Memo #141 — Replacement of LOGSUB

155


6/1/70

Bruce McCoy

LUMINARY 1D Re-Release

156


6/9/70

Dana Densmore

LUMINARY Revisions 159 - 163

157


6/10/70

Dana Densmore

LUMINARY Revisions 164 - 167

158


6/18/70

Bruce McCoy, Dana Densmore

Revision 163 - 173

159


7/10/70

Russ Larson

Luminary 1D Program Notes

160


7/16/70

David Moore

Descent Trajectory Monitor Package

161


7/17/70

Don Eyles

ZERLINA 31

162


7/20/70

Don Eyles

A New Landing Analog Displays Routine

163


7/21/70

Don Eyles

Z Lives

164


7/22/70

Phyllis Rye, Peter Peck

Account Numbers

165


7/28/70

Don Eyles

The Return of R10FLAG

166


7/23/70

David Moore

DVTOTAL vs. VGDISP Discrepancy in Powered Flight

167


8/17/70

Bruce McCoy, Phyllis Rye

Luminary 1D: Which One, What Kind, How Many?

167 (rev 1)


9/17/70

Bruce McCoy, Phyllis Rye

Luminary 1D: Which One, What Kind, How Many?

168


8/18/70

Robert Covelli

"Erasable Memory Program" for a Guided RCS Burn

169


9/1/70

Harry McOuat

Effect of LSPOS "Burn Skinny" in Luminary-1D

170


9/15/70

Bruce McCoy

Level 6 Testing for Apollo 14

171


9/16/70

Don Eyles

Introduction to ZERLINA 50

172


10/11/70

Dana Densmore

LUMINARY Revisions 179 & 180

173


10/12/70

Dana Densmore

LUMINARY Revision 181

174

COLOSSUS 293

10/9/70

Bill Robertson

Summary of Program Change Requests Involving Astrodynamic Coordinate Systems, Ephemerides and Orientations, etc.

175


10/13/70

Dana Densmore

LUMINARY Revision 182

176


10/14/70

Dana Densmore

LUMINARY Revision 183

177


10/22/70

Don Eyles

ZERLINA 56

178


10/20/70

Peter Weissman

Inputs to LM DAP During Descent and Ascent

179


10/27/70

Dana Densmore

LUMINARY Revisions 184 & 185

180


12/15/70

David Moore

Apollo 14 LM De-Orbit Test

181


12/15/70

Don Millard

IMU Alignments and LUMINARY 202

182


12/8/70

Dana Densmore

LUMINARY Revision 186

183


12/9/70

Dana Densmore

LUMINARY Revision 187

184


12/15/70

Dana Densmore

LUMINARY Revisions 188 - 190

185


12/17/70

Dana Densmore

LUMINARY Revision 191

186


12/22/70

David Moore

APS Impulse Burn for APOLLO 14

187


12/18/70

Dana Densmore

LUMINARY Revision 192

188


12/20/70

Dana Densmore

LUMINARY Revision 193

189


12/28/70

Dana Densmore

LUMINARY Revision 194

190


12/29/70

Dana Densmore

LUMINARY Revision 195

191


1/4/71

Harry McOuat

Fixed memory hardware related constants in Luminary 1D

192


1/5/71

Dana Densmore

LUMINARY Revision 196

193


1/8/71

Dana Densmore

LUMINARY Revisions 197, 198, 199

194


1/22/71

Allan Klumpp

Analysis of the Yaw Divergence at P64 Terminus

195


1/11/71

Dana Densmore

LUMINARY Revision 200

196


1/13/71

Dana Densmore

LUMINARY Revision 201 & 202

197


1/15/71

Dana Densmore

Luminary Revision 203

198


1/29/71

Craig Work, Peter Weissman

DAP performance in Apollo 14 Level 6 tests

199


2/12/71

David Moore

P99 — Erasable Memory Program for a Guided RCS Burn — Luminary 1E

200


2/22/71

V. Dunbar, Peter Volante

Implementation and Testing of PCR 324, PGNCS/AGS RR Data Transfer

201

COLOSSUS 310

2/16/71

Dana Densmore

DOWNRUPT SEQUENCING, LOST DOWNRUPTS, AND IMPAIRED DOWNLINK INFORMATION

202


2/16/71

Dana Densmore

Luminary Revision 204

203


2/23/71

Craig Work, Peter Weissman

Guidance and Contol Stability Tests of LUMINARY 1E

204


2/24/71

Dana Densmore

Luminary Revision 205

205


2/26/71

Dana Densmore

Luminary Revisions 206, 207, 208 and 209

206


3/9/71

Peter Weissman

Attitude Error Analysis in Special FACI APS Tests

207


3/17/71

David Moore

Post-FACI Luminary 1E Tests for R40, Engine-Fail Routine

208


3/16/71

Allan Klumpp

Apollo 14 Descent Simulation Dispersions: Terrain Model Mismatch Aggravates Drooping Trajectories in P64 and Low Descent Rate in P66

209


3/23/71

Peter Weissman

Update to Luminary Memo 178, "Inputs to LM DAP During Descent and Ascent"

210

COLOSSUS 312

3/23/71

Peter Volante, Bill Ostanek

Testing on Non Sign Agreement in TEPHEM in Apollo 14

211 (rev 1)


4/28/71

David Moore

"Erasable Memory Program" for a guided RCS burn (for Luminary 1E)

212


3/29/71

Larry Berman

Effects of Delayed Tipover on Ascent Trajectories

213


3/31/71

Craig Work

Guidance and Control Stability Tests of LUMINARY 1E, Part 2

214 (rev 1)


4/6/71

Luminary Test Group

Level 6 Test Description for Luminary 1E

215

COLOSSUS 316

4/20/71

William Robertson

Limitations in the Astrodynamic Orientation and Ephemeris Routines

216


4/23/71

Craig Schulenberg, Peter Weissman

Impact of PCR 1107 (Abort Bit Backup) on Apollo 15 Abort Procedures

217


5/6/71

Russ Larson

Luminary 1E Program Notes

218


5/19/71

David Moore

Apollo 15 LM De-Orbit Performance Test

219


5/26/71

Craig Schulenberg

Descent Abort Procedures for Apollo 15

220


6/4/71

Craig Schulenberg

Erasable Memory Program for LUMINARY Rev. 210 to Provide Backup for DSKY Keys

221


7/12/71

Craig Work

DAP performance in the Apollo 15 Level 6 Tests

222


6/15/71

Luminary Test Group

Summary of Level 6 Test Results for LUMINARY 1E

223


6/17/71

Craig Schulenberg

Correction to Luminary Memo #220, "Erasable Memory Program for LUMINARY Rev. 210 to Provide Backup for DSKY Keys"

224


6/22/71

Craig Schulenberg, Phyllis Rye

Revision 1 of Erasable Memory Program for Backup for DSKY Keys

225


7/8/71

Peter Volante

Failure Protection of the PGNCS/AGS RR Data Transfer

226





227


7/13/71

Luminary Test Group

Level 6 Test of DSKY Keystroke Backup Erasable Progeram for LUMINARY 1E

228


7/21/71

David Moore, Peter Volante

Using P99 LM Deorbit Erasable Program in Earth Orbit (with full DPS/APS configuration)

229


7/15/71

David Moore, Craig Work, Peter Weissman

Post-FSRR (Luminary 1E) Docked DPS Burns

230


9/10/71

Larry Berman

EFFECT ON ASCENT OF INCORRECT TIME IN AGC

231


11/8/71

Don Millard

Level 6 Test Description for Mission 16 (PRELIMINARY)

232


11/16/71

Don Eyles

Low Thrust Landings

233

COLOSSUS

11/23/71

Margaret Hamilton

EMPs

234

COLOSSUS

11/30/71

Bruce McCoy, Don Millard

EMP Control Procedures — Final Iteration

235 (rev 1)


2/22/72

Don Eyles

Tentative EMP for Broken CDUX

236


12/23/71

Larry Berman

Crew Corrections for Cross Range Error due to Uncompensated Orbit Precession

237





238





239


2/22/72

Don Eyles

EMPs to Display H and H-dot on the DSKY

240


3/2/72

Luminary Test Group

Luminary Level 6 Test Results for Mission 16

24X
4/14/72
Don Eyles
Latest EMP 103B

241





242





243





244


4/18/72

Don Eyles

EMP for P47 Ascent

245





246





247


9/1/72

Don Millard

Level 6 Test Description for Mission 17 (PRELIMINARY)

248





249





250


10/20/72

Luminary Test Group

Luminary Level 6 Test Results for Mission 17

251





252


11/20/72

Don Eyles

EMP to Convert a Bad HMEAS

≥ 253





SKYLARK Memos, PCRs, and PCNs

SKYLARK, if you'll recall, is the AGC software that replaced COLOSSUS (and was adapted from it) in the command modules used for the Apollo-Skylab and Apollo-Soyuz missions.  We have the text of a few of the Program Change Requests (PCRs), though unfortunately as of yet, none of the Program Change Notices (PCNs), and just one of the Memos.  The table of PCRs and PCNs below mostly comes from Appendix A of Section 2 of the SKYLARK GSOP.  (Even so, the GSOP does not list all PCRs and PCNs, and is only current through March 1972.)

It's interesting to note that many of the changes listed in the PCRs are simply deletions of lunar code that would be unnecessary for a CM-to-Skylab mission.  I think that a "normal" software-developer perspective on this would be that deletion of the working code, even if the code itself is unnecessary, represents more of a risk in terms of creating undetected breakage than simply leaving the code in place and not using it would be.  However, in working with higher-reliability code — disclaimer: my only familiarity with such matters is in working with airborne code in the U.S., which is currently governed by a document called RTCA DO-178C, and thus I don't really know what they thought about it in 1970 in the space biz — there is a concept of "dead code", i.e., code that is never executed under the software requirements, and specifically never tested; the dead code must be completely removed from software beyond the absolute lowest level of criticality.  The theory behind this is that if somehow that dead code actually did manage to be executed for some reason, then the result would be bad.  I imagine that's the theory behind the removal in SKYLARK as well: i.e., the risk of executing bad code is worse than the risk of undetected breakage.  On the other hand, I suppose the removal could be just a matter of trying to reduce the cost, by physically removing a handful of ferrite memory cores and their associated wiring.  I wonder what the actual cost tradeoff would have been between lifting those cores into space vs all of the development and testing time associated with the removal?

Memo, PCR, or PCN #
Written
Approved
Author
Scope
Subject
PCR SL003
2/25/70
1/28/71
R. O. Nobles
Code and GSOP
Improved short-burn logic to desensitize with respect to variations in the SPS engine.
PCR SL004
3/3/70
1/28/71
S. A. Gorman
Code and GSOP
Deletion of unneeded verb 94 (cislunar tracking).
PCR SL005
3/3/70
1/28/71
S. A. Gorman
Code and GSOP
Deletion of unneeded verb 59 (optics calibration mark).
PCR SL006
3/3/70
1/28/71
S. A. Gorman
Code and GSOP
Deletion of unneeded verb 52 (offset landing site mark).
PCR SL007
3/3/70
1/28/71
S. A. Gorman
Code and GSOP
Deletion of unneeded verbs 44 and 45 (set and reset of surface flag).
PCR SL008
3/3/70
1/28/71
S. A. Gorman
Code and GSOP
Deletion of unneeded routine 57 (optics calibration routine).
PCR SL009
3/3/70
1/28/71
S. A. Gorman
GSOP only
Deletion of unneeded routine 33 (CMC-LGC clock synchronization).
PCR SL010
3/3/70
1/28/71
S. A. Gorman
Code and GSOP
Deletion of unneeded routine 05 (S-band antenna routine) and verb 64.
PCR SL011
3/3/70
1/28/71
S. A. Gorman
Code and GSOP
Deletion of unneeded programs 72-76.
PCR SL012
3/3/70
1/28/71
S. A. Gorman
Code and GSOP
Deletion of unneeded programs 65 (up control) and 66 (ballistic).
PCR SL013
3/3/70
1/28/71
S. A. Gorman
Code and GSOP
Deletion of unneeded option 4 (lunar surface alignment) from programs 52 and 54.
PCR SL014
?
?
?
Code and GSOP
Program 39 deletion.
PCR SL015
?
?
?
Code and GSOP
Program 38 deletion
PCR SL016
3/3/70
1/28/71
S. A. Gorman
Code and GSOP
Deletion of unneeded program 37 (return-to-earth).
PCR SL017
3/3/70
1/28/71
S. A. Gorman
Code and GSOP
Deletion of unneeded program 23 (cislunar midcourse navigation).
PCR SL018
3/3/70
1/28/71
S. A. Gorman
Code and GSOP
Deletion of unneeded program 22 (orbital navigation).
PCR SL019
?
?
?
Code and GSOP
Program 24 deletion.
PCR SL021
3/3/70
1/28/71
S. A. Gorman
Code and GSOP
Deletion of program 32 (CSI) due to development of new targeting procedures (probably PCR SL030 below).
PCR SL022
2/26/70
1/28/71
Bedford F. Cockrell
Code and GSOP
Change of a constant to desensitize with respect to gravitational perturbation by the moon.
PCR SL025
2/26/70
1/28/71
Bedford F. Cockrell
Code and GSOP
Extend VHF range beyond limit of 327.67 nautical miles.
PCR SL030
2/27/70
1/28/71
R. R. Regelbrugge
Code and GSOP
Addition of NCC maneuver computation capability.
PCR SL032
6/10/70
1/28/71
M. C. Contella
Code and GSOP
Incorporation of smoothing filter for VHF range rate computation and display.
PCR SL033
7/29/70
1/28/71
Bedford F. Cockrell
Code and GSOP
Use of fixed coordinate system to avoid mission-by-mission coordinate-system changes.
SKYLAB Memo 3-70
7/29/70
n/a
William M. Robertson
n/a
Detailed software-design data regarding PCR SL033.
PCR SL035
7/7/70
1/28/71
S. G. Bales
Code and GSOP
Addition of TEPHEM to telemetry downlist.
PCR SL036
7/9/70
1/28/71
C. B. Parker
Code and GSOP
New (backup) method of specifying attitude data in case of star tracker failure.
PCR SL040
?
?
?
?
Skylab digital autopilot
PCR SL042
?
?
?
?
Skylab four maneuver DKI sequence
PCR SL048
?
?
?
?
Conversion of RCS DAP phase plane fixed memory constants of erasable load.
PCR SL051 REV 1
?
?
?
Code and GSOP
Skylark downlist changes
PCR SL400
?
?
?
Code and GSOP
Program 15 deletion
PCR SL402
?
?
?
Code and GSOP
Eliminate 481 day TEPHEM limitation in Lunar-Solar ephemerides routine
PCR SL405
?
?
?
?
Transform optics angles to tracking angles.
PCN SL409
?
?
?
Code and GSOP
Modification to PCR SL022
PCN SL410
?
?
?
Code and GSOP
Delete Lunar capability
PCN SL411
?
?
?
Code and GSOP
Delete HAM targetting program
PCN SL412
?
?
?
Code and GSOP
Delete ECSTEER
PCR SL413
?
?
?
?
ATM orientation determination program (P50)
PCR SL414
?
?
?
?
Docked alignment capability in P51
PCR SL415
?
?
?
?
Docked alignment capability in P52
PCR SL416
?
?
?
Code and GSOP
Add gyro trim to R50
PCN SL417
?
?
?
Code and GSOP
Deletion of 9 dimensional capability
PCN SL422
?
?
?
Code and GSOP
Initialize rendezvous navigation to update the CSM state vector
PCR SL423
?
?
?
Code and GSOP
Change conic to precision integration in all rendezvous targetting programs.
PCR SL424
?
?
?
Code and GSOP
Improve minkey gyro torquing logic
PCR SL428
?
?
?
?
Modification of Skylark Memo #14: Preliminary Skylab Rendezvous Targeting Plan for the Skylab GSOP
PCR SL431
?
?
?
?
R04 roll preference specification
PCR SL434
?
?
?
Code and GSOP
Correct αATM in P50.
PCN SL435
?
?
?
Code and GSOP
Do not automatically take VHF in P20
PCN SL436
?
?
?
Code and GSOP
Nominal use of ATM sources in P52 and P54.
PCN SL438
?
?
?
Code and GSOP
Incorrect star tracker angle in P55.
PCR SL439 REV 1
?
?
?
Code and GSOP
VHF range rate filter enable/disable by extended verb.
PCN SL442
?
?
?
Code and GSOP
Modification to R22
PCR SL448
?
?
?
?
Modification no. 4 to Skylark memo no. 14
PCR SL449
?
?
?
?
Forced firings for docked DAP auto maneuvers
PCR SL452
?
?
?
?
Precision integration for V90
PCR SL454
?
?
?
?
Docked DAP alarm codes
PCN SL455
?
?
?
Code and GSOP
Change to P35, P36 and R00 to fix anomaly ART 07
PCN SL456
?
?
?
Code and GSOP
Zeroing HOLDFLAG
PCR SL459
?
?
?
?
VHFR changes
PCR SL464
?
?
?
Code and GSOP
Set NN = 0 in P35
PCN SL467
?
?
?
Code and GSOP
Change VHFTIME to MARKTIME on the powered downlist.

SCB Meeting Notes

The Software Control Board (or perhaps Software Change Board, or perhaps Software Configuration Board, I'm not really sure, but does it really make a difference?) meetings were meetings held between the MIT Instrumentation Lab and the Manned Spacecraft Center, and I presume other parties as needed, to approve or disapprove PCRs (Program Change Requests) and PCNs (Program Change Notices), as well as to report the closure of such items.  As such, they can serve (for our purposes) to fill in gaps in LUMINARY Memo or COLOSSUS Memo series in order to track AGC revision-to-revision changes.  We don't have many of these, but Don Eyles has given us a few in order to help understand some of the changes in Luminary 131 for Apollo 13 that weren't tracked by the LUMINARY Memos.

Apollo Experience Reports

Miscellaneous Guidance & Navigation

These items are alphabetical by author, though the "author" is sometimes an organization when no individual authors are listed.  A lot of the documents in this group originally came from the now-defunct AGC website of MIT's Dibner Institute for the History of Recent Science and Technology; but whenever the opportunity has arisen, those versions of the documents have been replaced by better scans, so even when the document titles are the same, these may not be the same scans found in other online sources.

The document was prepared while I was working for Al Hopkins and Ray Alonso at the Instrumentation Laboratory and describes the analysis of the crux of a proposed backup system if the AGC became overloaded during the LEM trajectory.  Although the backup method described was never used, the document shows the type of analysis that went on "behind the scenes" in support of the entire mission.

Abort Guidance System (AGS) and its computer (AEA)

Please see the documentation section of the AGS page.

Launch Vehicle Digital Computer (LVDC)

We have precious little LVDC documentation of any kind, and no LVDC software at all.  The Wikipedia article on the LVDC laments that all of the LVDC software has probably vanished and does not exist any longer.  Well, I don't believe that.  (They're smart enough to send a man to the moon, but too stupid to put the documents in a file cabinet afterward?  I hope not!)  There must be some former LVDC developer somewhere who was proud enough of his work to retain some souvenirs.  If you know any LVDC developers, please help us to get in contact with them.

Systems Handbooks

Operations Handbooks

Operational Data Books

Technical Crew Debriefings

Mission Reports

Flight Plans

Checklists

Familiarization Manuals

Launch Vehicle Flight Evaluation Reports

These documents relate primarily to the Saturn rockets, but one notable feature is that chapter 2 of each document provides a detailed mission timeline for events insofar as they relate to the various stages of the rockets.

Miscellaneous Mission Documents

Note that this section doesn't include things like GSOP documents, which have their own section above, but is simply a catch-all for everything I haven't already listed that's mission specific or specific to a mission class.

Max Faget was a fanatical advocate of the optical tracker as the primary rendezvous navigation sensor. If he had had his way there would have been no rendezvous radar. This was an undocumented chapter in the Apollo program known to those of us who participated as the Rendezvous Wars. Under our tutelage, supported by extensive in-house Monte-Carlo analyses, the Astronaut Office took an uncompromising position on behalf of the radar as the primary rendezvous navigation system.

The wars continued into the Shuttle program, and were lost by our side because the FOD was able to make the case that they could support all rendezvous operations with ground-based tracking, and there was therefore no argument for autonomous on-board capability. Max got his way on the Shuttle, there was no rendezvous radar. By that time I was back in Houston working for a small company under contract to MPAD for orbital operations analysis. I got fired for refusing to lie to Draper about the availability of reference mission data to support some independent analysis they were doing for my former colleagues in SED. Thus ended my involvement in the wars, and I've always treasured those memories.

This document contains nomographs for computing the TPI and M/C maneuvers using LM boresight elevation angle measurements, and raw rendezvous radar data from the tape-meter readout. During the months prior to Apollo 11, I was able to use the GN&C analysis program in Monte-Carlo mode to construct computation tables for the CDH and CSI burns. This was done by perturbing the trajectory about the nominal, and developing power-series expansion functions for the maneuvers in terms of the resulting radar range and range-rate perturbations, obtained from measurements at fixed intervals before each burn.  We wanted to be able to verify the on-board maneuver solutions independently of the ground, or in extremis do without them altogether, and still carry out the rendezvous as long as we had an operating radar.  Hence our fanatical determination to have the radar as the primary rendezvous sensor.

I'm not sure these nomographic and tabular backups were known to the Instrumentation Lab. They were brute force, but they worked. Never needed, though; the IL software and systems were iron-bottomed and gold-plated... [ellipsis Clark's]

Status Reports to NASA

From MIT Instrumentation Laboratory

From AC Electronics

From Bellcomm

From Bendix

From Raytheon

From TRW

General Apollo documents unrelated to computing systems

Press Kits and Releases

Miscellaneous

Gemini spacecraft computer

Something Completely Different

In this section, we provide some stuff that doesn't directly pertain to any of the computers in Apollo or Gemini.  But if the original developers give me interesting and sometimes unique material, or if I find interesting material related to them, I'd like to present it anyway.




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