Musk has previously hinted that the event might show off the completed prototype ahead of its first suborbital flight. There’s also a possibility that SpaceX will narrow down the time frame for that flight, which might happen as soon as October. Other updates may include design tweaks and revisions of the long-term schedule. Many details aren’t set in stone, and there’s a chance you may see significant changes.

As it stands now, the Starship prototype will have three Raptor engines (six in the finished version) and should reach an altitude of up to 12.5 miles before returning to Earth. The final craft is meant to enter commercial service by 2021, complete a tourist trip around the Moon by 2023 and eventually conduct missions around the Solar System. It’s not certain that SpaceX will reach these goals, however. The firm is known for its optimistic timelines (it first expected a Falcon Heavy test flight in 2013), and hasn’t even constructed the Super Heavy Booster needed for more ambitious missions. A lot needs to fall into place for SpaceX to meet its goals, and you may have a better sense of its progress after the presentation.

Update 9/28 6PM ET: SpaceX has bumped the update to “no earlier than” 9PM Eastern from the original 8PM due to weather. We’ve updated the story accordingly.

After a poster on NASASpaceflight.com uploaded pictures of another Starship vehicle (f.k.a. BFR) under construction in Florida — to go along with prototypes being built in Texas — Elon Musk explained what’s going on. The CEO tweeted that “SpaceX is doing simultaneous competing builds of Starship in Boca Chica Texas & Cape Canaveral Florida.” He said the plan is to find out which location is the most effective even if the answer “might be both.”

Still, if the plan is to get these on the moon ASAP — with other billionaires making plans for lunar travel as we speak — doubling up on production seems like a good idea. For now, SpaceX’s next launch is scheduled for tomorrow to launch 60 of its Starlink internet satellites on a Falcon 9 rocket.