SpaceX plans to launch an updated version of its Starship megarocket — a new prototype of the system that NASA hopes will carry its astronauts to the moon in two years — on a critical test flight Tuesday. The stakes for Starship, and by extension for Elon Musk’s rocket company, have perhaps never been higher. SpaceX is developing Starship as part of NASA’s Artemis program and racing against its rival, Jeff Bezos’ Blue Origin, to build a lunar lander for NASA to use in 2028, when it aims to put