NASA's Commercial Crew Program uses a loss-of-crew threshold of 0.5% for a 210-day ISS mission and 0.2% for ascent and entry.

Format Online paper / PDF

Location PART 3 - THE THIRD AXIS CHAPTER 13: SPECKLED INTELLIGENCE WALL-E and the Cosmic Rays

"NASA’s Commercial Crew Program uses a loss-of-crew threshold of 0.5% for a 210-day ISS mission and 0.2% for ascent and entry."

NASA's March 2026 Inspector General report documents Commercial Crew safety thresholds of 1 in 200 for a 210-day ISS mission and 1 in 500 for ascent and entry. These design requirements demonstrate how astronaut-safety objectives are expressed as measurable probabilistic targets.

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Source title NASA's Management of the Human Landing System Contracts

Source authors NASA Office of Inspector General

Source year 2026

Confidence high

Importance high