First manned Boeing Starliner launch scrubbed over valve problem The HillBoeing Starliner crewed mission postponed shortly before launch Phys.orgLaunch Roundup: Starliner's crewed debut, new rocket variant, and more Starlink missions - NASASpaceFlight.com NASASpaceflight.comBoeing Starliner's first astronaut-crewed flight launch called off due to stuck valve ABC News