

SpaceX Starship: For the second time in five weeks, SpaceX has rolled Starship’s first orbital-class Super Heavy booster from its Starbase factory to the launchpad ahead of a challenging and multifaceted test campaign.
Deemed Super Heavy Booster 4 or B4, the 69m (~225 ft) tall rocket first rolled to the launch pad around August 3rd after SpaceX technicians fitted it with 29 Raptor engines in a single night. Followed by orbital-class Starship prototype S20 a few days later, the two stages of a Starship were stacked to their full height on August 6th, briefly creating the largest rocket ever assembled. Ship 20 was then quickly returned to the build site, where SpaceX workers completed an additional ~10 days of finishing touches – mainly focused on avionics wiring and secondary plumbing.
A week later, Booster 4 followed Ship 20 back to Starbase’s ‘high bay,’ where teams ultimately removed all 29 of its Raptor engines and spent the next four or so weeks performing similar final integration work. Now, after installing what looks like hundreds of feet of wiring, dozens of additional gas and fluid lines, compressed gas tanks, hydraulic ‘sleds’ SpaceX’s first flightworthy Super Heavy has once again returned to the launch site. Read more
Booster 4 rolling: pic.twitter.com/gw6uT58WeH
— Starship Gazer (@StarshipGazer) September 7, 2021
Booster 4 is about halfway to the launch site. Watch now on Starbase Live!https://t.co/2eKPnHZCih
— Stephen Marr (@spacecoast_stve) September 7, 2021
? for @NASASpaceflight pic.twitter.com/nvTwliYOXn
Water deluge nozzles have been spotted between the hold down clamps! pic.twitter.com/UbI7cvH3zZ
— RGV Aerial Photography (@RGVaerialphotos) August 20, 2021
29 Raptors rolling down Highway 4.
— Chris Bergin – NSF (@NASASpaceflight) September 7, 2021
Booster 4 making progress en route to the launch site.https://t.co/APLl78W8fn pic.twitter.com/aoOCNyLsb0