SpaceX is making good progress on Starship’s first two Super Heavy boosters, both of which could potentially be ready for their first major test campaigns before the end of the year.

On November 19th, some ten weeks after the process began, SpaceX craned Super Heavy B5’s methane (LCH4) tank on top of its oxygen (LOx) tank, marking the end of major structural assembly for the 69m (~225′) tall booster. A team of welders has since been working around the clock to weld the two tanks together and complete a transfer tube that routes methane propellant down through B5’s oxygen tank.

Two days prior, CEO Elon Musk shared a photo of SpaceX’s other Super Heavy booster (B4) which has been slowly progressing towards test readiness for more than three months. It’s unclear why SpaceX has been so sluggish to prepare Super Heavy B4 for testing but with B5 finally approaching the finish line, the company will soon find itself in a position where it will need to decide which booster to proceed with towards the program’s near-term end goal: the first orbital Starship test flight.