What capability gap did the Space Shuttle retirement immediately create for the US?
Answer
Reliance on Russia's Soyuz spacecraft for astronaut transport to the ISS
The retirement of the Space Shuttle fleet in 2011 created an unprecedented vulnerability for the United States space program, as it resulted in a nearly decade-long gap in domestic human spaceflight capability. This meant that for that period, the US became entirely reliant on Russia's Soyuz spacecraft to transport its astronauts to and from the International Space Station (ISS). While this reliance was challenging, the long-term effect of this gap was the vital catalyst that spurred the growth and maturation of the Commercial Crew Program, leading to domestic crew transport providers like SpaceX and Boeing.

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