Preferences
There was an order of preference for abort modes. ATO was the preferred abort option whenever possible. TAL was the preferred abort option if the vehicle had not yet reached a speed permitting the ATO option. AOA would only be used in the brief window between TAL and ATO options. RTLS resulted in the quickest landing of all abort options, but was considered the riskiest abort. Therefore it was selected only in cases where the developing emergency was so time-critical the other aborts were not feasible, or in cases where the vehicle had insufficient energy to reach the other aborts.
Unlike all previous U.S. manned launch vehicles, the shuttle never flew unmanned test flights. To provide an incremental non-orbital manned test, NASA considered making the first mission an RTLS abort. However, STS-1 commander John Young declined, saying, "let's not practice Russian roulette."
Read more about this topic: Space Shuttle Abort Modes, Emergency Landing Sites
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“This is the great truth life has to teach us ... that gratification of our individual desires and expression of our personal preferences without consideration for their effect upon others brings in the end nothing but ruin and devastation.”
—Hortense Odlum (1892–?)