“IF”: A Study of Contingency Planning for the Project Mercury Mission

Undated public-information booklet from the Space Task Group at Langley Field, written as “a primer for the layman” explaining the redundant and manual-backup systems built into the Mercury-Redstone spacecraft, using the MR-4 mission as its running example. Structured as a long series of “IF…then…” contingencies — escape-tower and automatic abort-sensing (ASIS) backups, environmental control, power, and communications redundancy, and the full parachute and recovery-aid sequence — it closes with a step-by-step narrative of the escape-tower firing sequence under the heading “Mercury-Redstone Abort.”

Despite the MR-4 example, this booklet was reproduced as section 8 of the MR-3 press kit catalogued just above, issued ahead of Alan Shepard’s May 5 1961 flight.