Just so we're clear about this, SpaceX built a Mars rocket out of rolls of steel.
In South Texas.
And on Tuesday evening, a little more than an hour before the Sun sank into the rolling Texas horizon, this Starship prototype rumbled to life and left the ground for the first time. It rose from a stand, with its single Raptor rocket engine burning clean. Video shows the 30-meter-tall vehicle ascending to about 150 meters, moving laterally, and then beginning to descend.
As Raptor threw out prodigious amounts of fire and kicked up a heap of dust, it was not immediately clear whether the prototype rocket survived its ordeal. But as the dust settled and the smoke cleared, the shiny, beer-can shaped rocket could be seen still standing, leaning a little, sunshine glinting off its steel sides.
Just the guts
This was not the entirety of Starship, the large spacecraft that will be launched into orbit atop a Super Heavy rocket, which does not yet exist. This prototype lacked key structural elements, including a large nose cone, flaps, an interstage, and more. But critically, this vehicle contained Starship's propulsion system.
The most challenging parts of any rocket are the engine and the plumbing to reliably and rapidly feed it oxidizer and fuel. Then there are the large tanks needed to hold these liquid propellants at high pressures and ultra-cold temperatures. The trick is to build these structures as light as possible, while also capable of containing the propellants. Among the key aspects of Tuesday's test was demonstrating that Starship's stainless-steel structure could withstand the harsh environment of a launch and landing.
Moreover, Tuesday's test also proved that SpaceX has a handle on the thrust vector control system for its Raptor engine, as it was installed slightly off center, and had to compensate throughout the short flight. Given the results, SpaceX clearly has made progress on flight software for this vehicle.