(Our old version of this page is still available, but not likely to be updated in the future.)

This is our Virtual AGC Document Library. New submissions are always welcome. Suggestions of where physical documents can be found for subsequent digitization appear on our Documentation Quest page. Our FAQ page points out various significant Apollo-centric websites that may contain documents we've not so-far collected.

In the list below, some documents are provided by multiple links. In general, when there's more than one link, the first one is to the one we feel most-inclined to recommend. The others may be lower resolution, larger downloads, mutilated by the OCR process, missing some pages, or have some other deficiencies that make them less preferable. But the less-preferable documents are sometimes useful.

To avoid clutter on your screens, some details we have — download size, archive from which the digitization was made, name of the person who scanned the document or financially subsidized it, the organizational affiliations of the authors, the organizations which assigned the document numbers — are omitted from the entries for the documents. You can get this kind of information anyway, should you desire it, by hovering the mouse cursor over the document title, author name, or document number. Notice the styling that's used to call your attention to the availability of the extra information; authors' names or document numbers without extra information available are not thusly highlighted.

Unless otherwise stated, documents are sorted by publication date, from earliest to latest, and those with unknown dating appear at the top of the list. Determination of the publication date is sometimes rather subjective.

Finally, this page is auto-generated from a database — actually a spreadsheet — and if you desire, you can download the spreadsheet. (In pulling it into your spreadsheet program, you mostly need to know that the columnar data is tab-delimited. There are additional rules that apply to fields containing comma-delimited lists or organizational affiliations, but I won't bother to explain those things further unless somebody actually asks me about them.)

Table of Contents


Recently Added Documents as of 2022-07-27

This section lists all documents updated in the last 2 months. Note that recently-added G&N engineering drawings are not included in the list.

The entries are arranged from most-recently added to least-recently added.

By the way, most documents listed in this section will also appear in one or more other sections of the library. In those other sections, you find the new entries distinguished by the badge , but we don't do that in this section, since obviously every document would have such a badge.

Added 07/27/2022
  1. SM6A-41-1-2, "Apollo Mission Simulator - Maintenance and Repair Procedures Manual - 012 Configuration - Basic Manual", volume II/II (=Section VIII) pp. 1 through 510, 12/22/1966, by General Precision.
  2. SM6A-41-1-2, "Apollo Mission Simulator - Maintenance and Repair Procedures Manual - 012 Configuration - Basic Manual", volume II/II (=Section VIII) pp. 511 through 1006, 12/22/1966, by General Precision.
  3. SM6A-41-1-1, "Apollo Mission Simulator - Maintenance and Repair Procedures Manual - 012 Configuration - Basic Manual", volume I/II (=Sections I-VII), 12/22/1966, by General Precision.
  4. SM6A-41-2-1, "Apollo Mission Simulator - Maintenance and Repair Procedures Manual - 012 Configuration - Visual System Manual", volume I/II (=Sections I-VII), 12/22/1966, by General Precision.
Added 07/25/2022
  1. 40M33622C, Rev C, "Interface Control Document - Definition of Saturn SA-502 Flight Sequence Program", 05/13/1966, by NASA.
  2. R-567, Rev 6, "Guidance System Operations Plan For Manned LM Earth Orbital and Lunar Missions Using Program Luminary 1B (Rev. 116) - Section 4 - PGNCS Operational Modes", section 4, 09/01/1969, by MIT Instrumentation Laboratory.
  3. R-693, Rev 02, "Guidance System Operations Plan - Apollo Soyuz Test Project Using Program Skylark 1", section 7, 10/01/1974, by MIT Instrumentation Laboratory.
Added 07/08/2022
  1. "Grumman Lunar Module Engineering Drawings LDW280-14317 to LDW280-16065" (not dated), by Grumman Aerospace Engineering Corporation.
  2. "Grumman Lunar Module Engineering Drawings LDW280-16066 to LDW280-17381" (not dated), by Grumman Aerospace Engineering Corporation.
  3. "Apollo Mission Control Center", 11/30/1961, by NASA.
  4. Rough draft, "Apollo Recovery Control Centers", 11/30/1961, by NASA.
  5. "Handwritten notes on IMCC bids", 1962, by Christopher C. Kraft Jr.
  6. "Handwritten notes on proposed IMCC and contractors", 1962, by Christopher C. Kraft Jr.
  7. "Slides Required for Apollo Talk", 1962, by Christopher C. Kraft Jr.
  8. "5-Year projections of IMCC contracter accrued cost, manpower, and obligations", 1962, by NASA.
  9. "Agenda for presentation by prospective contractors on the Integrated Mission Control Center procurement", 1962, by NASA.
  10. "Events Leading to Evaluation - IMCC Development", 1962, by NASA.
  11. "GOSS Obligations - Supporting Tabulation", 1962, by NASA.
  12. "IMCC Contractor Evaluation", 1962, by NASA.
  13. "IMCC Evaluation", 1962, by NASA.
  14. "MCC Plotboard Displays", 1962, by NASA.
  15. Rough draft, "MCC Remote Sites", 1962, by NASA.
  16. "Mercury Flight Control Facilities", 1962, by NASA.
  17. "Mercury Flight Control Facilities and Operation", 1962, by NASA.
  18. "Operations Control Plans for Manned Spaceflight", 1962, by NASA.
  19. "Philco Visualizations", 1962, by NASA.
  20. "Table of Organization - IMCC Development", 1962, by NASA.
  21. "Exhibit A - Apollo Operational Control and Information Flow Design and Development Contract", 01/17/1962, by NASA.
  22. "Memo - Technical Evaluation Plan - Apollo Operational Control and Information Flow Design and Development Contract", 02/05/1962, by Christopher C. Kraft Jr.
  23. "Final Report on the Technical Evaluation of the Industry Response to NASA RFP MSC-60-12", 03/20/1962, by NASA.
  24. "Memo - Technical Evaluation Report - Apollo Operational Control and Information Study Contract MSC-62-12", 03/21/1962, by Christopher C. Kraft Jr.
  25. "Letter Contract NAS9-366 - Apollo Information Flow", 03/28/1962, by C. D. Sword.
  26. "Memo - Plan to issue an RFP for implementation of IMCC", 08/16/1962, by Dave W. Lang.
  27. "Request for Proposal No. MSC-62-40 as Amended", 08/17/1962, by Dave W. Lang.
  28. "Design Criteria and Concepts for Integrated Mission Control Center", 09/01/1962, by Kaiser Engineers.
  29. WDL-TR-E120, Rev 1, "IMCC Systems and Performance Requirements Specification", 09/07/1962, by Philco Corporation.
  30. WDL-TR-E120, Rev 2, "IMCC Systems and Performance Requirements Specification", changes only, 09/07/1962, by Philco Corporation.
  31. "Eligibility of General Electric Company to participate in the IMCC Implementation Contract Proposal", 11/08/1962, by D. Brainerd Holmes.
  32. "Evaluation of Proposals", 11/16/1962, by Christopher C. Kraft Jr.
  33. "Guidelines for the Technical Panels in Conducting the Evalutation of the Bidder's Response to RFP No. MSC-63-297P", 12/03/1962, by Tecwyn Roberts.
  34. "IMCC Milestones", 12/19/1962, by NASA.
  35. "Status - Foundation-Steel-Deck contract", 1963, by NASA.
  36. "Visualizations of MCC-Houstion Floorplans", 1963, by NASA.
  37. "Telegram - Implementation of IMCC and Integration of GOSS", 1963, by James Stroup.
  38. "Eligibility of General Electric and Western Electric for IMCC Implementation Contract", 01/16/1963, by D. Brainerd Holmes.
  39. "Report of the Source Evaluation Board for the Integrated Mission Control Center", 01/16/1963, by NASA.
  40. Fact Sheet #170, "Fact Sheet - Mission Control for Manned Space Flight", 04/23/1963, by Christopher C. Kraft Jr., John D. Hodge, Eugene F. Kranz.
  41. "Statement of Facts Developed by General Accounting Office Relative to the Management of Automatic Data Processing Facilities and Related Contracts by NASA, Manned Spacecraft Center", 04/24/1963, by John J. Reese.
  42. "Agenda - Philco IMCC Contract Review", 07/26/1963, by NASA.
  43. "Memo - Interim Audit Progress and Status Report on IMCC Contract NAS 9-1261 with Philco Corporation", 09/20/1963, by NASA.
  44. "IMCC Program Cost Summary", 12/05/1963, by NASA.
  45. "IMCC - Mission Operation Wing Layout", 1964, by NASA.
  46. "IMCC Console Layout", 1964, by NASA.
  47. "Manned Spaceflight Control Center", 1964, by NASA.
  48. "Memo - Transfer of Electronic Computing Equipment from MSC-Langley to MSC-Houston", page 3 of 3 only, 1964, by NASA.
  49. "Real Time Computer Complex", 1964, by NASA.
  50. "Memo - RTCC Interim Facility Digital to Television (D/TV) Display Formats Test & Evaluation Report", 05/06/1964, by A. J. Pittock.
  51. "Manned Spaceflight Control Center Maintenance and Operations Activity Indoctrination Booklet", 07/01/1964, by Philco Corporation.
  52. "IBM Tour - Manned Spaceflight Center", 01/10/1965, by B. L. Sarahan.
  53. "List of Technical Reports and Memorandums Concerning Human Factor Engineering Design of NASA-MSC Equipment", 1968, by NASA.
  54. "Flight Director Log - Apollo 13", 04/17/1970, by NASA. Disclaimer: The contributer, Andy Anderson, has asked that the archives of the University of Houston, Clear Lake, be prominently credited. Thanks to both!
  55. TR155 I-02-213-01, "EECOM Engineer Console No. 213, Room No. 231", 04/25/1975, by NASA.
  56. "Attachment F - Contractual History of Major Implementation and Operations Milestones", 01/10/1985, by NASA.
  57. "MCC Development History", 08/22/1990, by M. Ray Loree.
Added 07/03/2022
  1. NASw-410-AM-04, Change 1, "Operator's Manual - Acceptance Checkout Equipment - Spacecraft", 06/01/1966, by General Electric Company.
  2. "Acceptance Checkout Equipment - Spacecraft, Operator Course Study Guides", 07/31/1966, by General Electric Company.
  3. "LPC 4-1 - Procedure for the Preparation and Processing of the Test Preparation Sheet", 04/05/1967, by A. J. Salvi.
  4. OCP-B-63005-LTA-8, "Checklist and Procedure - Vehicle Support Systems Installation Chamber B", 08/24/1967, by Manned Spacecraft Center, Grumman Aerospace Engineering Corporation.
Added 06/28/2022
  1. 1st Edition, "Apollo Lunar Orbit Chart (ALO) - Apollo Mission 14 - Lunar Revolutions 1, 18, 20, and 34", 11/16/1970, by U.S. Air Force Aeronautical Chart & Information Center.
  2. "Reference Cards - Fra Mauro Landing - Apollo 14 - AS-509 S/C 110 LM-8 G&N-214 G&N-611", 1971, by AC Electronics.
  3. "Apollo 14 Spacecraft Commentary - January 31 to February 9, 1971", 02/09/1971, by Manned Spacecraft Center.
  4. "Recreated LGC Duty Cycle, Apollo 14", 03/01/1971, by Grumman Aerospace Engineering Corporation.
  5. "Recorded LGC Duty Cycle, Apollo 14", 03/01/1971, by MIT Instrumentation Laboratory.
Added 06/01/2022
  1. Preliminary, "Preliminary Reliability Profile for Mission 204A", 06/22/1965, by General Electric.
  2. "Apollo Training - Sequential Systems (SECS, EDS, LES, ELS), Course No. A-324", 11/18/1966, by North American Aviation.
  3. EB-67-3314-U, MSC-A-R-66-5, "Supplemental Report on Communication System Performance During Mission AS-202", supplements Section 7.16, 07/21/1967, by M. R. Franklin.
  4. 05952-H341-R0-000, EB-R-67-7, "Apollo Communications Systems Performance and Coverage Analysis for Mission AS-204 / LM-1", 12/01/1967, by TRW.

Presentations

Presentations from the MAPLD '04 conference, by AGC developers and other knowledgeable folks.

Programmers' Manuals


Onboard Computer Users' Guides


Guidance System Operations Plans (GSOP)

The items below are arranged by MIT Instrumentation Laboratory document number.

Quick-Reference Cards, Data Cards, Cue Cards


AGC Pad Loads

Arranged by mission.

Erasable Memory Programs (EMP)


Software Listings

Here are listings of actual software for the various onboard guidance computers covered by the Virtual AGC Project. We don't have all of it, by any means, but we have what we have! While all of the software revisions listed below are equipped with comments — too many and too much, some may say — there tend to be much longer writeups on the pages specifically devoted to them. So if you want even more detail, I'd suggest looking in one of these places: the AGS page, the LVDC/PTC page, the LM AGC software page, or the CM AGC software page

The collection contains many software revisions which never flew in Apollo missions, and conversely there are missions for which we don't have some of the software. And, there are missions for which we may not have the exact software revision originally used, but do have a revision which is fine for successfully flying a simulated mission. Here's a mission-by-mission summary of what we presently have and don't have:

MissionCM AGCLM AGCAGSLVDC
AS-202non/an/ano
Apollo 1non/an/ano
Apollo 4yesn/an/ano
Apollo 5n/ayesnono
Apollo 6yesn/an/ano
Apollo 7non/an/ano
Apollo 8yesn/an/ano
Apollo 9yesfinenono
Apollo 10yesyesnono
Apollo 11yesyesyesno
Apollo 12noyesyesno
Apollo 13nofinenono
Apollo 14noyesnono
Apollo 15yesyesyesno
Apollo 16yesyesyesno
Apollo 17yesyesyesno
Skylab 2non/an/ano
Skylab 3non/an/ano
Skylab 4non/an/ano
ASTPnon/an/ano

If just seeing what went into each mission isn't enough for you, and you need to see the vast sweep of all the AGC and AGS software development from the beginning in 1963 until the end in 1971, I have a chart of that as well. Alas, there's no LVDC info in the chart, and I've had to leave out some AGC non-mission branches like LA MESH, DIANA, and so forth. But I included some non-mission branches, particularly SHEPATIN and ZERLINA, since we actually have representative copies of those. There's a small detail from the full chart to the right, and if you click that image, the full chart will appear. Admittedly, there's some guesswork involved because of lacking information, particularly in the very early years, but I think the chart captures pretty well what's going on. Each bubble in the chart represents some specific revision of some specific AGC program, or else a range of revisions when there's just too much information missing to distinguish between them. Gray bubbles are Block 1 code, brown bubbles are Block 2 CM code, yellow bubbles are LM code, and white bubble are AGS. The name of the AGC program is in red if core ropes were actually manufactured for that revision. The arrows connecting the bubbles tell you what revisions of what programs evolved into what other revisions. The arrows are also decorated with lists telling what PCRs, PCNs, software-anomaly reports, and ACB requests were involved in that particular stage of the evolution — though in many cases that's simply "TBD", as it actually is in the detail image at the right. The full chart, by the way, is about 40 times as high as it is wide, so be prepared to scroll downward a lot if you look at very much of it.

The table below is a list of all releases of AGC software (that we're aware of) for the purpose of manufacturing core-rope memory modules. This information was gleaned from many, many documents in the library, as opposed to a single authoritative source, so there are unfortunately many gaps and question marks in the table. A number of the software revisions for which we have the source code were never manufactured into memory modules, such as ZERLINA, SUPER JOB, and DAP AURORA, so they don't appear in the table at all. Conversely, there are many software revisions manufactured as ropes for which we have no contemporary source listing or modern reconstruction.

Assembly #
Software Name
Software Revision
Usage
Release Date
Reference(s)
1003203
ECLIPSE
A
System test TD R-140
2/64?
[1] Drawing 1003203
[2] R-700 Vol 3 Table 4-I
[3] FR-2-115 p. 80
1003203
ECLIPSE
B
System test TD R-132, TR R-140
2/64?
[1,2,3]
1021100-011
ARTEMIS
 Factory test
3/64
[2,3]
1021101
MOONGLOW
 Computer test
5/64?
[2,3]
1021102-011
SUNRISE
33?
System test
7/64
[4] FR-2-115 errata p. 12
[5] R-467 p. 5
[2,3]
1021102-021?
SUNRISE
38?
System test
 [6] R-700 Vol 1 p. 152
[7] E-1808 pp. 24-26
[3,4]
1021102-031
SUNRISE
45?
System test
11/28/64
[4,6,7]
1021103-011
SUNRISE
 System test
 [7]
1021103-021
SUNRISE
69?
System test
3/15/65
[8] JDC05278
[4,6,7]
1021103-031
SUNRISE
 System test
 [7]
1021103-041
SUNRISE
 System test
9/65?
[7,13]
1021104-011
ARES
 Factory test
1/65
[2]
1021105
CORONA (B*RLS 202)
 AS-202 Development
 [51] Apollo G&N Systems Index
1021106-011
CORONA (202*RELI)
0
AS-202 development
1/66?
[9] TR-66-310-5 p. 29
1021106-021
CORONA
261
AS-202 mission
1/66
[2]
[10] STG Memo #1415 p. 3
[11] Apollo Guidance and Control System Flight Experience p. 5
1021107-011
SUNSPOT
247?
Apollo 1 (canceled)?
  
1021107-021
SUNSPOT
 Apollo 2 (canceled)?
  
1021107-031
SUNSPOT
 AS-258 (canceled)
7/66
[2]
1021108-011
SOLARIUM
54?
Apollo 4 mission
11/66
[12] Drawing 1021108A
[13] R-700 Vol 1 p. 31-32
1021108-021
SOLARIUM
55
Apollo 4, 6 missions
11/66
[14] SOLARIUM 55 assembly listing
[2,12,13,14]
2021100
RETREAD
44
Computer test Block II prototype
7/65
[15] Drawing 2021100
[16] RETREAD 44 assembly listing
[2]
2021101-011
AURORA
85
LTA-8
3/3/66
[17] Drawing 2021101C
[57] Lunar Excursion Module PGNCS Manual Vol I, Table 3-IJ
[2,6]
2021101-021
AURORA
88
System test (LEM)
7/15/66
[18] RADC-TR-77-213 figure 3-1
[6,17,57]
2021101-031
AURORA
88
System test (LEM)
7/15/66
[57]
2021102-011
VENUS
 Factory test
1/66
[19] Drawing 2021102
[2]
2021103-011
RETREAD
50
System test
12/65
[20] Drawing 2021103A
[21] Dumped memory modules
[2]
2021104-011
SUNDIAL
B
System test, Block II C/M
6/16/66
[22] Drawing 2021104B
[49] System Course 3100 p. 266
[6]
2021104-021
SUNDIAL
C = D?
System test, Block II C/M
6/24/66
[6,22]
2021104-031
SUNDIAL
C = D?
System test, Block II C/M
3/1/67
[6]
2021104-041
SUNDIAL
E
System test, Block II C/M
5/66, 3/13/67
[2,6]
[23] Dumped memory modules
[24] ND-1021043 Table 3-IC-3
[50] KSC Rope Module Status 5/18/71
2021104-051
SUNDIAL
E
System test, Block II C/M
 [24]
2021104-061
SUNDIAL
Mixture
System test, Block II C/M
 [24]
2021105-011
NEWSPEAK
 Factory test
 [25] Drawing 2021105B
2021105-021
NEWSPEAK
 Factory test
5/66
[2,25]
2021105-031
NEWSPEAK
 Factory test
 [2]
2021105-041
TWOSPEAK
 Factory test
7/67
[2,25]
2021106-011
SUNBURST
 Apollo 5 development
2/67
[26] Drawing 2021106A
[27] R-700 Vol 3 Table 4-II
2021106-021
SUNBURST
116
Apollo 5 development
4/67
[26,27]
2021106-031
SUNBURST
120
Apollo 5
10/67, 3/67
[28] SUNBURST 120 assembly listing
[13,18,27,28]
2021107-011
LA MESH
 Factory test
6/67
[29] Drawing 2021107A
[2]
2021107-021
LA MESH
 Factory test
 [29]
2021108-011
SUNDISK
267
Apollo 7 development
11/15/67
[30] E-1142 rev 54 p. 50
2021108-021
SUNDISK
282
Apollo 7 mission
2/68, 9/68
[31] RADC-TR-77-213 table 4-6
[13,27]
2021110-011
SUNDANCE
292
Apollo 9 development, LM-3 ground test
4/68
[32] Drawing 2021110B
[27]
2021110-021
SUNDANCE
302
Apollo 9 development
7/68
[27,32]
2021110-031
SUNDANCE
306
Apollo 9 mission
10/68
[13,27,31]
2021111-011?
COLOSSUS (COLOSSUS 1)
234
Apollo 8 development
 [33] Drawing 2021151B
2021111-021
COLOSSUS (COLOSUSS 1)
236
Apollo 8 development
8/68
[34] Drawing 2021111B
[27,33]
2021111-031
COLOSSUS (COLOSSUS 1)
237
Apollo 8 mission
8/68, 9/68
[35] COLOSSUS 237 assembly listing
[13,27,31,33,34]
2021111-041
COLOSSUS (COLOSSUS 1A)
249
Apollo 9 mission
10/28/68
[36] COLOSSUS 249 assembly listing
[13,27,31,34]
2021112-011
LUMINARY (LUMINARY 1)
69
Apollo 10 development
11/21/69
[37] Drawing 2021112L
[38] LUMINARY 69 assembly listing
[39] Drawing 2021152N
[52] F Mission LM FSRR Minutes
[27]
2021112-021
LUMINARY (LUMINARY 1A)
96
Apollo 11 development
 [37,39]
2021112-031
LUMINARY (LUMINARY 1, LUM69)
69 rev 2
Apollo 10 mission
4/2/69, (ignore) 3/69
[13,27,31,37,39,52]
2021112-041
LUMINARY (LUMINARY 1A)
97
Apollo 11 development
4/69
[27,37,39]
2021112-051
LUMINARY (LUMINARY 1A)
99
Apollo 11 development
5/69
[27,37,39]
2021112-061
LUMINARY (LUMINARY 1A, LMY99)
99 rev 1
Apollo 11 mission
6/17/69, 4/69
[40] LUMINARY 99 rev 1 assembly listing
[13,27,31,37,39]
2021112-071
LUMINARY (LUMINARY 1B)
116
Apollo 12 mission
8/12/69
[41] LUMINARY 116 assembly listing
[56] MIT Presentation for the Mission H FSRR
[58] From LUMINARY 1A to LUMINARY 1C
[27,31,37,39]
2021112-081
LUMINARY (LUMINARY 1C)
130
Apollo 13 development
11/5/69
[53]
[27,37,39,58]
2021112-091
LUMINARY (LUMINARY 1C)
131
Apollo 13 development
12/3/69
[42] LUMINARY 131 assembly listing
[27,37,39,53,58]
2021112-111
LUMINARY (LUMINARY 1C, LUM131)
131 rev 9
Apollo 13 development
1/14/70
[27,37,39,53]
2021112-121
LUMINARY (LUMINARY 1C, LM131)
131 rev 1
Apollo 13 mission
2/4/70, (ignore) 2/5/70
[27,31,37,39,53]
2021112-131?
LUMINARY (LUMINARY 1D)
163
Apollo 14 development
5/70
[27,37,39]
2021112-141
LUMINARY (LUMINARY 1D)
173
Apollo 14 development
6/70
[27,37,39]
2021112-151
LUMINARY (LUMINARY 1D)
178
Apollo 14 mission
9/70, 4/18/70
[27,31,37,39]
2021112-161
LUMINARY (LUMINARY 1E)
210
Apollo 15-17 missions
3/22/71, (ignore) 3/20/71
[43] LUMINARY 210 assembly listing
[54] MIT LM Presentation for Mission J-1 FSRR
[18,31,55]
2021113-011
COMANCHE (COLOSSUS 2)
44
Apollo 10 development
2/69
[44] Drawing 2021153G
[45] Drawing 2021113G
[27]
2021113-021
COMANCHE (COLOSSUS 2)
45
Apollo 10 development
3/69
[27,44,45]
2021113-031
COMANCHE (COLOSSUS 2A)
51
Apollo 11 development
3/69
[27,44,45]
2021113-041
COMANCHE (COLOSSUS 2, MANCHE45)
45 rev 2
Apollo 10 mission
4/69, 3/69
[13,27,44,45]
2021113-051
COMANCHE (COLOSSUS 2A)
55
Apollo 11 mission
4/69
[46] COMANCHE 55 assembly listing
[13,27,44,45]
2021113-061
COMANCHE (COLOSSUS 2C)
67
Apollo 12 mission
7/17/69, (ignore) 7/18/69
[27,31,44,45,56]
2021113-071
COMANCHE (COLOSSUS 2D)
72
Apollo 13 development
10/20/69
[27,44,45,53]
2021113-081
COMANCHE (COLOSSUS 2D, MANCHE72)
72 rev 3
Apollo 13 mission
12/12/69
[27,31,44,45,53]
2021113-091?
COMANCHE (COLOSSUS 2E)
108
Apollo 14 mission
5/29/70
[27,31]
2021114-001?
ARTEMIS (COLOSSUS 3)
71
Apollo 15 development
 [47] Drawing 2021154
2021114-011
ARTEMIS (COLOSSUS 3)
72
Apollo 15-17 missions
3/1/71
[48] ARTEMIS 72 assembly listing
[55] MIT Presentation for Mission J-2 FSRR
[18,31]
2021115-011
SKYLARK
48
Skylab 2-4 and ASTP missions
11/11/71
[59] Programmed Guidance Equations for Skylark

Math Flow

The term "math flow" refers to the underlying, implementation-independent, mathematical algorithms that are — at some point in the development process — coded as guidance-computer instructions. Or another way of looking at it, I suppose, is that the math flow encompasses the algorithms needed to program the guidance computers, as opposed to the information need to use those computers after they're programmed.

There are several ways the Apollo and Gemini guidance computers' math flow are represented in our collected documentation. For example, there may simply be a set of mathematical equations that represent the physics of spacecraft motion. At the other end of the spectrum, there may be detailed sets of flowcharts that form an almost-complete pictorial representation of the eventual computer program's control flow and handling of variables. The entire continuum of possibilities is represented in this section, for all of the types of guidance computers covered by the Virtual AGC Project.

Space Guidance Analysis 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. 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.

Apollo Project Memos


Apollo Engineering Memos


Digital Development Memos

These memos primarily relate to the electrical design of the AGC.

Electronic Design Group Memos


Inertial Sub-System (I.S.S.) Memos


XDE Notes

These are notes from AC Spark Plug Division, commenting on topics peripheral to the AGC, such as ground-support equipment.

Digital Group Memos


Mission Techniques Memos


System Test Group Memos


AGC/AGS Software Requirements


LUMINARY Memos

The "LUMINARY Memos" are internal memos from the MIT Instrumentation Laboratory dealing with issues of LUMINARY software development, along with closely-related software branches such as ZERLINA.

Of particular interest, if you're concerned with the evolution of the AGC software, are the many memos 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 come pretty close to using them to document the complete evolution of LUMINARY, or at any rate from LUMINARY 4 (memo #22) through LUMINARY 209 (memo #205).

But back to the memos. Over 250 of them are known, of which we've gotten the majority from Don Eyles's personal collection. The items which are grayed-out relate to memos about which we have some information but not the actual memos themselves.

The items are arranged according to their memo numbers.

COLOSSUS Memos


SKYLARK (SKYLAB) Memos


Program Change Requests (PCR) and Notices (PCN)

Program Change Requests (PCRs) were the official mechanism by which proposed AGC software changes were submitted to the NASA's Software Control Board (SCB), for subsequent approval or rejection. The PCR was the normal tool for this, and PCRs could be created either by MIT/IL or by NASA, but did not take effect until action was taken by the SCB. The lesser-used PCN is almost the same as a PCR, except that MIT/IL unilaterally put them into effect as if NASA's SCB had approved them ... even though the SCB could end up disapproving the PCN and forcing MIT/IL to undo whatever work they had done in connection with it. Often the PCN was used for simple clerical changes in the GSOP, which were almost certain to eventually win SCB approval, but sometimes they were apparently used for issues that blocked further development and thus which would cause scheduling issues if it were necessary to stop work until the next SCB meeting. In any case, the signficance (for us) of either PCRs or PCNs is that since AGC software changes were governed by them, knowledge of the PCRs/PCNs is of tremendous importance in tracking changes between AGC software revisions ... or alternatively, of no importance whatever if you're not interested in understanding the evolution of the software.

When the full text of a PCR or PCN isn't currently available, information has instead come from other contemporary documentation, including: None of these sources are meticulous about using the exact titles of the PCRs.

All known PCRs and PCNs for which we have any information at all are listed, whether approved or disapproved by the SCB, and whether or not a copy is currently available in the library. Unless stated otherwise, PCRs/PCNs were approved for implementation. The entries below are arranged by PCR/PCN number. We've also added a rough categorization to each PCR/PCN entry as to which AGC program(s) it applies to: SUNDISK, SUNDANCE, LUMINARY, COLOSSUS (which includes COMANCHE and ARTEMIS), or SKYLARK.

Software Anomaly Reports and Assembly Control Board Requests

In this section, we cover Assembly Control Board Requests and Software Anomaly Reports. These acted similarly to PCRs and PCNs (see above), and have a similar importance for us in understanding the evolution of AGC software over time. The difference from PCRs/PCNs is that approvals or rejections were made by MIT/IL's Assembly Control Board (ACB) rather than by NASA's SCB. The scopes of the SCB's actions and the ACB's actions differed in that the SCB decided upon the contents of (or changes to) the software specification (which was regarded as the GSOP document), whereas the ACB examined discrepancies between the software and the specification, or else items left unspecified altogether by the GSOP (and therefore presumably of little or no importance to the SCB). Thus being entirely internal to MIT/IL, ACB Requests and Software Anomaly Reports could presumably be acted upon much more quickly and easily than was the case for PCRs and PCNs.

ACB Requests and Software Anomaly Reports have no titles as such, so the titles given below are actually extracts from the (often rather long) problem descriptions given in forms. The entries are sorted by document number.

Software Control Board (SCB)


Software Development Plans


Block I Specifics


Abort Guidance System (AGS)


Launch Vehicle Digital Computer (LVDC) and Friends

We have precious little LVDC documentation, and even less LVDC software. The Wikipedia article on the LVDC at the time I first wrote on this subject lamented that all of the LVDC software has probably vanished and does not exist any longer. Fortunately, that has turned out to be false, although there may be enough truth in it to make us very uncomfortable.