Project Mercury was a complicated undertaking that involved a wide range of machine and facility. To address the myriad of components and procedures related to the Mercury Capsule, prime contractor McDonnell Aircraft Corporation (MAC) created a set of publications called Service (System) Engineering Department Reports, or SEDRs (pronounced cedars).1 SEDRs covered every conceivable system, component, operation and maintenance procedure related to the capsule in all phases of a mission including pre-flight, flight and recovery.
SEDRs were the astronaut's means of capsule test and preparation as well as conditioning for the variety of situations contemplated to be encountered.2 MAC grouped SEDRs according to function. NASAs Manual For Launch Operations for Project Mercury published by the Space Task Group in March 1960, listed 48 SEDRs.3 The SEDRs covered a range of topics like Capsule System Check on the communication system (SEDR 61), or environmental control system (SEDR 80). Special Tests like altitude chamber tests were also addressed (SEDR 83); along with overall System Tests including a simulated flight (SEDR 101). Prior to launch, Launch Operations and Servicing for the reaction control system (SEDR 74) and environmental control system (SEDR 82) were some of the subjects covered.
Among the topics addressed by MAC's SEDRs were so-called General Manuals. General Manuals covered the likes of capsule preparation and shipment (SEDR 102) and maintenance (SEDR 108). General Manuals were tailored to each capsule, or similar group of capsules, according to capsule number. MAC produced twenty (20) mercury capsules and each had a number depending on its place in the line of production. John Glenn road Capsule 13, Friendship 7, into orbit; while, Alan Shepard took his suborbital lob in Capsule 7. Gus Grissom's Liberty Bell 7 was Capsule number 11. A SEDR number followed by a dash and another number identified the particular capsule to which the SEDR applied; for example, SEDR 109-7 for Alan Shepard's Freedom 7 Capsule.
Early in Project Mercury the astronauts were provided a copy of the Project Mercury Indoctrination Manual distributed in May of 1959.4 The Indoctrination Manual later replaced by SEDR 104 was also the precursor to SEDR 109 which was introduced in the beginning of 1960.5 SEDR 104, a Familiarization Manual for the Mercury Capsule, and Astronaut's Handbook (SEDR 109), also known as the Capsule Flight Operations Manual were among the General Manuals published by MAC. SEDR 104, the Project Mercury Familiarization Manual, was an exhaustive presentation of spacecraft systems and components with subjects well detailed and illustrated. SEDR 104 complimented SEDR 109, the Astronaut's Handbook.
John Glenn and Alan Shepard discuss SEDR 109 while in
the Mercury Control Center.
Photograph Courtesy NASA
The Astronaut's Handbook, SEDR 109, was the astronaut's instruction manual on how to use the capsule.6 The Handbook's vinyl cover measured
6"x7.5" and was equipped with a metal three ring loose leaf binder that held the 5"x7" hole punched pages together. The Handbook was indexed in three
sections Normal Procedures, Emergency Procedures and Trouble Shooting. An Astronaut Check list, Emergency Procedures Checklist and fold out representations
of the control panel, gauges and other systems were included for reference. Sections were marked for quick access with checklists printed on heavier card
stock for easy recognition and heavier use. Emergency Procedures Checklist pages had a red and black hash-marked border in order to stand out. The checklists
told the astronaut what to do from the time he entered the capsule through the end of mission. The astronauts rehearsed various phases of flight using SEDR
109 in the Mercury Procedures Trainer, and in their respective capsules in Hangar S and at the launch pad prior to flight.
Project Mercury SEDR 109 was issued in two versions, one for Redstone flights and the second for Atlas flights. Examples of SEDR 109 used for Redstone flights included two editions one for Capsule 7, dated 15 August 1960, revised 15 October 1960, and another that covered Capsules 11, 15, 16 and 17, dated 30 January 1961. Atlas flights were represented by SEDR 109 for Capsule 13, dated 1 September 1961, revised 1 December 1961, Capsules 18 and 19, dated 1 December 1960, revised 1 February 1961, and Capsules 16, 18 and 19, dated December 1, 1961. These versions of the Handbook covered both suborbital and orbital configurations and procedures, and included capsules used by Shepard, Grissom, Glenn, Schirra and Carpenter.
SEDRs were important and occasionally controversial. Early in 1960, there was tension between quality control reflected in capsule system tests
performed using SEDRs, and pressure to commence with flight tests.7 This conflict manifest itself in criticism of SEDRs that were
not being updated sufficiently to address procedural and scheduling demands. Layered on the scheduling and quality control issues was the fact
that each capsule was a unique and evolving machine designed and equipped for a particular flight scenario. This required revision and updating
of relevant documents and SEDRs to reflect the most current condition and situation of the capsule. SEDR 109's looseleaf design with three ring
binder facilitated updating. Revisions were made by issuance of pink pages that listed individual changes, and instructed the user to replace and
discard outdated materials. The word REVISION was stamped on the title page of changed sections to alert users of their significance.
The astronauts commented on the rigors of capsule system tests involving SEDRs. Scott Carpenter noted the long hours necessary to work through various SEDR procedures in one case taking a full 24 hours.8 John Glenn recalled that working through the SEDRs made all the astronauts members of the "Wetback Club".9 Early Mercury Spacesuits lacked a urine collection device that combined with the difficultly of getting out of and back into the spacesuit to relieve themselves simply wasn't worth the effort. Guenter Wendt, Project Mercury Pad Leader, observed the astronauts were spending fifty to sixty hours per week in the simulator in Hangar S; Alan Shepard made 120 simulated flights prior to his actual flight.10 Often after long hours in tests that ran into the night, the astronauts would seek relief in pranks and other stress relieving activities.11
1 Swenson, Loyd S., Jr., James M. Grimwood, and Charles C. Alexander, This New Ocean: A History of Project Mercury, NASA SP 4201, p.245. (The Astronauts in We Seven, infra, refer to SEDRs as "Systems" Engineering Department Reports, see p.255).
2 By The Astronauts Themselves, We Seven, Simon and Schuster, New York, 1962, p.255
3 NASA, Manual for Launch Operations Project Mercury, Launch Operations Branch, Operations Division, Space Task Group, March 1960, Appendix B.
4 This New Ocean, p.245
6 We Seven p.256
7 This New Ocean, p.258
8 We Seven, p.255
9 John Glenn, Nick Taylor, John Glenn: A Memoir, Bantam Books, New York, 1999, p.229
10 Wendt, Guenter & Still, Russell, The Unbroken Chain, Apogee Books, Canada, 2001, p.32.
11 Id., p.28
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