Q&A with Elon Musk, SpaceX’s founder and CEO

A 154-foot-long solid rocket booster will be ignited for two minutes Tuesday at a remote test site in Utah, wrapping up a series of five ground firings to prove the motor’s readiness for flight on NASA’s Space Launch System.

SpaceX will test out new stabilizing fins that could help land the first stage of its Falcon 9 rocket on a floating barge in the Atlantic Ocean after liftoff on a space station resupply mission in mid-December, according to Elon Musk, the company’s billionaire leader.

The Transporter-16 mission is the 21st mission in the company’s smallsat rideshare program. Liftoff of the Falcon 9 rocket from Vandenberg Space Force Base occurred at 4:02 a.m. PDT (7:02 a.m. EDT / 1102 UTC).