SpaceX's mega Starship rocket has a test flight planned tonight. Thursday's launch was delayed due to weather, according to SpaceX; on Friday, "visibility is forecast to be ideal."

Last week, the rocket triggered a last-second abort before liftoff for its 13th flight, which, at 407 feet (124 meters) tall with 33 main engines, is the world’s biggest and most powerful rocket. The company lost about $100 billion in market value afterward. Some of the engines failed to ignite, triggering a launch abort amid billowing clouds of smoke and vapor.

Elon Musk, the company’s founder and CEO, said two engines will be replaced “to be confident of a good flight” before sending Starship from Texas on a space-skimming journey halfway around the world.

SpaceX’s launch webcast showed the start of engine ignition three seconds before the planned liftoff, viewed from a drone high above the pad. Although the company did not elaborate, onscreen data showed four engines not firing, with the remaining 29 engines immediately shutting down and keeping the rocket anchored to the pad. It was the first time a full-scale Starship experienced a last-second abort like this.

The launch team immediately began draining the fuel from the rocket.

Everything was going SpaceX’s way, even the weather, until the partial engine ignition. In the end, the rocket’s automatic launch system worked as planned by halting everything. Too few operating engines could have doomed the launch. Some earlier Starship flights ended in explosive fireballs.

The replacements for the astronauts involved in NASA’s first medical evacuation are on their way to the International Space Station.

Elon Musk’s company had the newest, most advanced Starlinks aboard

Twenty of SpaceX’s newest and most advanced Starlinks were on board Starship for release during the planned hourlong flight from Starbase, the company’s hub near the Texas-Mexico border. The internet satellites were going to try communicating with Starlinks already in orbit while taking photos of Starship’s heat shield.

Neither the first-stage booster nor the spacecraft were meant to be recovered, with both ending up in the sea.

The rocket’s automatic launch system worked as planned by halting everything. Too few operating engines could have resulted in a failed launch. Some earlier Starship flights, for example, ended in explosive fireballs.

The inflight Wi-Fi war is heating up among the major airlines in the U.S.

World’s biggest rocket is key to putting astronauts back on the moon

NASA is counting on Starship to land its astronauts on the moon in the next few years. The space agency has hired SpaceX and Jeff Bezos’ Blue Origin to build and fly the lunar landers that will return humanity to the surface of the moon after an absence of more than half a century.

Both companies need to have their landers — Starship and Blue Moon — ready to fly by next year so that the newly named Artemis III crew can practice docking their capsule with them in orbit around Earth. The mission after that — Artemis IV planned for no earlier than 2028 — would use one of those landers to take two astronauts to the moon’s south polar region.

The Artemis II astronauts are home. The crew's Orion capsule safely splashed down at 8:07 p.m. ET, ending the record-breaking 10-day mission that took them around the moon.

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