The MSC Systems Development Branch rejected a proposal that the Development Flight Instrumentation (DFI) on LEM-3 be deleted for the following reasons:

1. LEM-3 would be the first full-weight LEM launched on a Saturn V vehicle.

   This would be the only chance of obtaining necessary information about the responses of LEM during launch.
   - The AS-503 mission would offer the only opportunity of obtaining information on the characteristics of a fully loaded, mated LEM and CSM prior to attempting a lunar landing.
   - Three LEMs with DFI were considered the minimum number acceptable in the program to provide flexibility in flight planning and ability to accommodate the loss of LEMs 1 or 2 without a major impact on the program.

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   Bibliography:
   • Ertel , Ivan D; Morse , Mary Louise; et al, The Apollo Spacecraft Chronology Vol I - IV NASA SP-4009, NASA, 1966-1974. Web Address when accessed: http://www.hq.nasa.gov/office/pao/History/SP-4009/cover.htm.

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