The holidays might be a time of slowed activity for most companies in the tech sector, but for SpaceX, it was a time to ramp production efforts on the latest Starship prototype — “Starship SN1” as it’s called, according to SpaceX CEO Elon Musk . This flight design prototype of Starship is under construction at SpaceX’s Boca Chica, Texas development facility, and Musk was in attendance over the weekend overseeing its build and assembly.

Musk shared video of the SpaceX team working on producing the curved dome that will sit atop the completed Starship SN1 (likely stands for “serial number 1,” a move to a more iterative naming system and away from the “Mark” nomenclature used for the original prototype), a part he called “the most difficult” in terms of the main components of the new spacecraft. He added that each new SN version of the rocket SpaceX builds will have minor improvements “at least” through the first 20 or so versions, so it’s clear they expect to iterate and test these quickly.

As for when it might actually fly, Musk said that he hopes this Starship will take off sometime around “2 to 3 months” from now, which is still within range of the projections for a first Starship high-altitude test flight given by the CEO earlier this year at the unveiling of the Starship Mk1 prototype. That prototype was originally positioned as the one that would fly for the high-altitude test, but it blew its top during testing in November and Musk said they’d be moving on to a new design rather than repair or rebuild the Mk1.

Musk also shared new details about the construction process for Starship, including that SpaceX will move its build process for future spacecraft to an enclosed building starting with Starship “SN2” in January — though mostly to block out the winds experienced in Boca Chica, as Musk says that welding for stainless steel (the primary material for the Starship fuselage) is much less sensitive to dust and debris than aluminum.

In another tweet, Musk detailed another change from SpaceX’s previous operating model in developing Starship: The future spacecraft’s development is being focused at Boca Chica currently, he said, while SpaceX’s Cape Canaveral teams are “focused on Falcon/Dragon.” Up until now, SpaceX has been operating two separate teams working in parallel on Starship prototypes at both sites. Musk didn’t detail what will become of Starship Mk2, the other earlier prototype that was currently in development at Cape Canaveral in Florida.

Musk also shared updates about his tunneling company, The Boring Co. (they hope to open their Vegas tunnel to drivers in 2020), Starlink (could be available to customers in the Caribbean either in 2020 or 2021) and chocolate chip muffins.