SpaceX launched its 13th Super Heavy-Starship rocket Friday from Starbase, Texas; the booster splashed down off the Texas Gulf Coast, and the Starship upper stage splashed down in the Indian Ocean about an hour later.
Powered by 33 methane-fueled Raptor engines, the 397-foot-tall two-stage rocket produced some 16 million pounds of thrust and lifted off at 5:51 p.m. ET.
An attempted launch on July 16 ended with a last-second computer-commanded abort when four Raptors failed to start, after which telemetry was analyzed, six engines were replaced and a planned Thursday attempt was delayed 24 hours by low clouds.
All 33 first-stage engines fired normally for Friday's liftoff and the booster executed a flip to line up for a boostback burn, but the boostback burn "ended early," SpaceX later said; only 10 of 13 engines restarted to slow the rocket and only five appeared to be running when the booster hit the water at a higher speed than expected.
The Starship upper stage continued to space with all six of its Raptor engines operating smoothly and deployed 20 third-generation Starlink internet satellites using a Pez-like payload dispenser, releasing them one at a time from a slot near the nose of the vehicle.
Six of the Starlinks were equipped with cameras to inspect the Starship's heat shield tiles and general condition, and the Starship briefly reignited one Raptor engine in flight to demonstrate its ability to restart in space.
The spacecraft then endured a belly-first reentry, flipped upright and settled to a rocket-powered splashdown northwest of Australia 1 hour and 5 minutes after launch.
The Starlinks, on the same suborbital trajectory as the Starship, were expected to fall back into the atmosphere and burn up — or, as SpaceX puts it, "demise" — before reaching the sea.
The company, owned by Elon Musk, cited engine failure at liftoff during an aborted launch attempt last week; the flight was the second for the V3 version of Starship and the company's first flight as a publicly traded company.
Since achieving the largest IPO in history, SpaceX's stock has dropped drastically.
NASA has said it is counting on a variant of the upper stage to serve as a lunar lander for the Artemis program, and SpaceX will need to launch up to 15 or so Super Heavy-Starship tankers to refuel the lander before it can head for the moon and dock with an Orion capsule built by Lockheed Martin; the 165-foot-tall lander is intended to carry two crew members down to the surface and use an external elevator to transfer them to the surface and back, with the first such landing targeted for 2028.
The Government Accountability Office said, "SpaceX's progress in developing its cryogenic fuel management technologies is a top risk for the program," and added that "at present, SpaceX's plan for (moon missions) requires on-orbit propellant transfer between multiple Starship vehicles in low-Earth orbit before the HLS (Human Landing System) Starship can be sent to and dock with the Orion spacecraft in lunar orbit."
Blue Origin, owned by Jeff Bezos, is also developing moon landers to be launched by the New Glenn rocket; during preparations to test-fire the main engines of the third New Glenn, the launcher exploded and seriously damaged its pad, and NASA is pressing ahead with preparations for an interim Artemis flight next year in low-Earth orbit in which four astronauts in an Orion capsule will dock with a Blue Origin lander, open hatches and float inside as part of the test before rendezvousing and docking with a modified production-model Starship that will have no crew accommodations and that astronauts will not enter.