5 horror movies to watch this Halloween season 5:48 Starship, the world's biggest rocket built by Elon Musk's SpaceX, is finally set to launch today. Following a scrubbed test on Monday, the colossal Space Launch System is ready for its first test flight, taking place from the company's Starbase near Boca Chica Village in South Texas. Musk kept expectations low for the first attempt on Monday, and it was indeed warranted. Following a pressurization issue, the launch was officially called off, rendered a test, and postponed. Musk tweeted the update, adding "Learned a lot today, now offloading propellant, retrying in a few days." Now, the rescheduled launch is due between 9:30 and 10:30 a.m. ET on Thursday, though launch times could change. The broadcast will begin 45 minutes before liftoff in the YouTube stream above.