Musk hopes "Mechazilla" will catch and assemble the Starship and Super Heavy boosters for rapid reuse
In January of 2021, Elon Musk announced SpaceX's latest plan to increase the number of flights they can mount by drastically reducing turnaround time. The key to this was a new launch tower that would "catch" first stage boosters after they return to Earth. This would forego the need to install landing legs on future Super Heavy boosters and potentially future Starship returning to Earth.
Musk shared this idea in response to a tweet made by an animator who goes by the Twitter handle Erc X, who asked if his latest render (of a Starship landing next to its launch tower) was accurate. As usual, Musk responded via Twitter, saying:
"We're going to try to catch the Super Heavy Booster with the launch tower arm, using the grid fins to take the load… Saves mass & cost of legs & enables immediate repositioning of booster on to launch mount—ready to refly in under an hour."
The ground crews at SpaceX's South Texas Launch Facility near Boca Chica recently finished stacking the nine sections of bolted steel that make up the tower, which now stands about 145 m (440 ft) tall. With this phase complete, the teams can now undergo the process of outfitting the tower with large actuator arms, hydraulic systems, fuel lines, and other components that will convert it into what Musk has affectionately nicknamed "Mechazilla."
This was likely a reference to the character "Mechagodzilla" from the Godzilla movie franchise, a robotic version of Godzilla that squares off with the original in the 1974 film "Godzilla vs. Mechagodzilla." The moment Musk announced this new tower, people in the space community have been speculating what it might look like. The first to oblige him was a 3D designer (Youtube handle Mini3D) who created an animation based on Musk's description the very next day.
The latest comes again from Erc X, who used the completed tower as the starting point for his latest animation. The animation is captioned: "Mechazilla <1 Hour Turnaround," and shows a fully-operational tower "catching" a spent Super Heavy booster (which just returned from deploying a Starship to orbit) and transferring it to launch stand. The actuator arms then turn to grab onto another Starship and stack it onto the top of the Super Heavy.
We also see a secondary arm move into place once the Starship and Super Heavy are stacked (likely a support arm). Musk let Erc X know how close he was to capturing the tower. "Pretty close. Booster & arms will move faster. QD arm will steady booster for ship mate," he tweeted, followed by, "And ship will be caught by Mechazilla too. As with booster, no landing legs. Those are only needed for moon & Mars until there is local infrastructure."
So Musk is promising a turnaround time of less than one hour now and has confirmed that future Starships will be retrievable using this same apparatus and others like it. This latter scenario is likely to occur if and when Starships begin making taking passengers on point-to-point flights between major cities—a service that Musk has promised will be available once the Starship is cleared for commercial flights.
In the same thread, Musk was asked if such a structure would ever be built on Mars and if Super Heavy boosters might be built there for missions to the outer solar system. "Yes on both counts. That would be a great outcome for civilization," replied Musk. Erc X posted several other animations of what a Mechazilla retrieval would look like as well, which you can see by checking out his Twitter feed.