This article is the second in a series on NASA publications. In the first article, I presented an overview of NASA Special Publications, emphasizing the General Publications (SP number <1000). Those who have not read the first article will benefit greatly by reading it prior to this one. This article focuses on the Special Publications written under the auspices of the NASA History Office (SP-4000 series) and particularly on the category of Reference Works (SP-40XX). The titles and assigned SP numbers for this category appear below. These are most typically seen in softbound editions, but most were also released in hardbound, but in very low press runs. In more recent years, the NASA History Office has published more in hardback.

Note the change in numbering for the most recent publications. Beginning in the year 2000, the NASA History Office has begun adding the year of publication to the SP number.

The SP-40XX series is designed to provide researchers with basic reference material on the activities of NASA.� Most of the volumes in this series are not narratives, but are chronologies (short descriptions of events by date) and data books (tables and charts providing basic facts without interpretation). "Space Medicine in Project Mercury" (SP-4003) is a notable exception. Written by Mae Mills Link of the Office of Manned Space Flight, this 198-page volume is a basic historical narrative of medical concerns surrounding the Project Mercury flights. The scarce publication includes a short review of aerospace medicine, Mercury chimpanzee flights and the manned Mercury flights. Its very presence as one of the earlier NASA Special Publications seems to reflect the high priority given in the early 1960s to space medicine.

Only the manned space flights were apparently worthy of chronologies. The first such chronology and indeed the first SP-4000 volume was on Project Mercury (SP-4001). James M. Grimwood of the Historical Branch of the Manned Space Craft Center in Houston compiled this 238 page book also numbered as MSC Publication HR-1. Grimwood went back to 1944 in identifying major events leading to Project Mercury and by 1958 moves into almost a day by day accounting of the program. The last entry, June 12, 1963 recounts James Webb's testimony before the Senate Space Committee, stating, "there will be no further Mercury shots." Ten appendices include data, launch site, and budget summaries, contractors, and launch vehicle deliveries to the Cape. A very convenient index allows researchers to locate specific information. The book includes, as do the other manned space flight chronologies, many black and white illustrations and diagrams. The Mercury chronology is an excellent resource for information about Project Mercury. Where else could one read about "Gentle Bess", the pig McDonnell used to test the Mercury spacecraft landing impact. By the way, McDonnell discovered that pigs tend not to survive for long periods of time on their backs even when not dropped in a spacecraft!

Project Gemini had its turn when in 1969 NASA published its chronology (SP-4002) compiled by Grimwood, Barton C. Hacker and Peter J. Vorzimmer. It is a similar, but slightly longer (308pp) publication. It's possible by reading this volume to trace the development and later rejection of the paraglider allowing for a ground landing. Also of interest are early proposals and designs for a lunar lander to be used with the Gemini spacecraft.

It took NASA four volumes to complete a chronology of the Apollo Spacecraft (SP-4209). This set is quite comprehensive and difficult to obtain. Volume 1 (269pp), compiled by Ivan D. Ertel and Mary Louise Morse is the most common, covering to November 7, 1962. Volume 2 (277pp) by Morse and Jean Kernahan Bays, takes us to September 30, 1964. Volume 3 (286pp) compiled by Courtney G. Brooks and Ertel continues to January 20, 1966, while Volume 4 (463pp) by Ertel, Roland W. Newkirk and Brooks completes the set, ending in anticipation of the fifth anniversary of Apollo 11 on July 13, 1974.

Of these four books, Volume 4 is typically the most sought after because it includes the Apollo 204 fire and all of the manned flights. All volumes contain excellent illustrations and interesting details of the flights. For example, these are a particularly good resource for those trying to track the use of Apollo boilerplate spacecraft used in tests.

The Skylab chronology (SP-4011) is the last of the manned volumes. Newkirk, Ertel and Brooks compiled this 458-page book that treats the four Skylab flights as well as development. To this date, no chronology per se has been published for the Apollo-Soyuz Test Project or for the Space Shuttle in this series. "A Chronology of Space Shuttle Flights, 1981-2000" as been published by NASA as HHR-70, October, 2000.

The Astronautics and Aeronautics series are a basic reference to major events of this type for the year. They contain a great deal of information, are indexed, but typically include no illustrations. These are useful in examining the chronological context in which events occurred or decisions were made. They are not for the casual reader! In the 1960s, a book was published for each calendar year. More recently, a single volume has covered five years in the same number of pages.

Future resource guides on NASA Special Publications may include the other NASA History books, New Series in NASA History, NASA Educational Publications, Reference Publications and Conference Publications.