NASA acknowledges it cannot quantify risk of Starliner propulsion issues

Decision Delay & Risk Modeling

• Many wonder why NASA keeps asking for “one more week” after a months‑long delay of an 8‑day mission.
• Explanations offered: more ground hot‑fire tests, detailed modeling of suspected failure modes, and validation of new software/configuration for autonomous operations.
• Some argue that if risk can’t be quantified at this point, crew return on Starliner should be off the table; others say extreme caution and slow decisions are appropriate when lives and the ISS are at stake.

Propulsion Failures & Root Cause Uncertainty

• Leading hypothesis discussed: Teflon valve seals swell at high temperature, restricting propellant, skewing mixture ratios, overheating thrusters, and triggering shutdowns.
• Key unresolved issue: several failed thrusters “recovered,” which doesn’t fit a simple permanent-deformation story, making risk hard to bound.
• Commenters stress that modeling is weak when the underlying mechanism isn’t fully understood.

Software, Autonomy & Undocking Risks

• Starliner’s current onboard software/configuration expects a crew for fault handling; fully autonomous fault‑response near ISS was removed or re‑parameterized since an earlier mission.
• Re‑enabling autonomous fault handling is said to require weeks of work and validation, effectively like a software update.
• Major concern: an uncrewed Starliner with misbehaving thrusters could collide with or damage ISS during undock/exit.

Return Options & ISS Constraints

• Two main paths debated:
  • Crew rides Starliner home despite uncertainties.
  • Starliner departs empty and is deorbited; astronauts return later on SpaceX Crew Dragon, likely via a reduced‑crew rotation mission bringing extra seats and suits.
• ISS docking ports and scheduling limit parallel vehicles; Starliner must vacate a port before the next Dragon can arrive.
• Supplies on ISS are considered adequate; main constraints are docking space and emergency return capacity for all crew.

NASA vs. Boeing, Politics & Public Trust

• Strong criticism of Boeing’s culture: cost‑cutting, management over engineering, outsourcing, and parallels to 737 MAX failures.
• Others focus frustration on NASA for earlier optimistic messaging and downplaying seriousness while conducting intensive tests, raising calls for an investigation into internal vs. public risk assessments.
• Some speculate election‑year and Musk/SpaceX optics influence decisions; others label that as unproven politicization.

Broader Engineering Lessons

• Recurrent themes: failures often occur at interfaces between contractors and subsystems, inadequate integrated testing, and weak documentation.
• Debate over “agile”/MVP mindsets in safety‑critical systems; several argue that stacking MVPs is incompatible with human‑rated spacecraft and that traditional, rigorous assurance is essential.