SpaceX is studying a daring system to “catch” the Super Heavy!

Unlike the main floor of the Falcon 9 returning to the ground using landing legs, the Super Heavy could be caught in mid-flight, a few feet above the ground! Two days ago, Elon musk shared on twitter a video showing the Starbase launch tower being construction at its Boca Chica, Texas site. 122 meters high, this tower already has a nickname: “Mechazilla”. It has the particularity of having mechanical arms which can be closed or opened at different altitudes. They will be used as “clamps” to catch theSuper Heavy floor before it hits dry land and hold it a few feet off the ground. These arms will also be able to pivot, which will allow them to reposition the stage on the launch pad. But that’s not all. Their great freedom of movement will also allow them to recover a Starship positioned nearby so that it can be installed on the Super heavy.

The mass and precision of the return, main difficulties

This is the theory. In practice, this will be anything but easy. If the idea seems simple, its implementation is very risky. In the scenario of SpaceX, the floor returning from its mission must approach the tower as slowly as possible, without crashing to the ground, in order to be retrieved by the two arms which will grab it (by closing around it) until it is that the floor support supports rest on top of the arms. These supports are not to be confused with the ailerons used for the attitude control of the stage when it returns to dry land. With a mass weighing more or less 100 tonnes, the launch tower must be sufficiently anchored in the ground and robust to hold the stage at arm’s length and in the air. Another difficulty, and not the least, the accuracy of the return must be centimeter, otherwise the floor could collide with the tower!

That said, there are obviously several advantages in using such a mechanism. First, it saves the Super Heavy from having to use a landing leg system, which saves mass and the cost of the system. Then, this also avoids having an additional crane for all maneuvers and lifting and positioning operations of the SuperHeavy and the Starship. Finally, this mechanism allows to considerably reduce the delays of return in flight of Super heavy. Elon Musk estimates that his launcher could be ready to fly in just under an hour!

Note that ArianeWorks, the ADF / Latesys group and the University of Reindeer work on the Smartcatcher concept which consists in catching the launcher a few meters before touching the ground using a system of cables which would enclose it in a sort of polygon.