An initial eight-day Boeing Starliner test mission to the International Space Station will be extended indefinitely to test the spacecraft's thrusters. Test pilots Butch Wilmore and Suni Williams are safely aboard the ISS and are not stranded in space, NASA commercial crew program manager Steve Stich said ... But there is no targeted return date "until we get the testing completed," Stich said. ... The Starliner's service module contains thrusters, helium lines and other systems that NASA officials need to study before discarding the module upon re-entry and allowing it to burn up. Those components require further study to determine...