How to watch SpaceX launch its Starship mega-rocket live

• Watch SpaceX try to skim Earth's orbit with its Starship rocket on Saturday.
• The last time the mega-rocket was tested, it blasted a crater in its launchpad and blew up midair.

SpaceX wants to test its fully-stacked Starship again on Saturday after its first flight ended in a fireball.

The launch was initially planned for Friday, but a grid fin actuator needed to be replaced postponing the launch, SpaceX announced Thursday on X.

If the rocket launch succeeds this weekend, the giant spaceship will reach space for the first time.

Starship is stacked atop its gigantic Super Heavy booster at SpaceX's facilities in Boca Chica, Texas.

Coverage should start about 35 minutes before the launch. SpaceX plans to broadcast the launch live on its website and on X, formerly Twitter.

Starship is the world's biggest and most powerful rocket, a behemoth that CEO Elon Musk says will one day ferry humans and city-building equipment to Mars.

SpaceX attempted the Starship's first stacked launch toward orbit in April, but it exploded in mid-air.

Getting this monster off the ground is quite an engineering feat. When stacked, Starship stands at almost 400 feet tall and 30 feet wide. It weighs almost 11 million pounds when fully fueled, per Spaceflight Now.

A successful flight would be a substantial milestone for SpaceX and for NASA. The rocket is crucial to the agency's plans to bring astronauts back to the moon for the first time in more than 50 years.

What to look out for during the second test launch

The Starship spaceship has been flying for years. But the fully integrated version of the mega-rocket — Starship stacked atop its Super Heavy booster — has only been launched once before, and that didn't end well.

SpaceX needs to be able to boost Starship out of orbit before it can fly toward the moon and Mars, so these tests are crucial.

The mega-rocket's first fully integrated flight in April was cut short nearly three minutes after liftoff after the spaceship failed to separate from its booster. The rocket tumbled out of control before bursting into a fireball.

It later came to light that its powerful Raptor engines had blasted a crater in the concrete launchpad. This reportedly caused debris to rain on a small city about five miles away.

Six out of the rocket's 33 Raptor engines also failed over the course of the launch.

Just under eight months later, SpaceX is ready to try again, Musk saying it has made more than a thousand changes to the rocket.

One crucial moment will happen about 2 minutes and 40 seconds after launch when the spaceship will try to separate from its booster.

SpaceX introduced hot staging to the rocket, which means the spaceship's engines will ignite while still attached to its booster to give it an extra kick before it flies off alone.

"It's the first time we're doing it. And I'd say that's the riskiest part of flight two," Musk said during a live-streamed interview at the International Astronautical Federation annual conference on October 5.

If the rocket "doesn't blow itself up during stage stuff, then I think we've got a decent chance to reach orbit," he added, though he noted that SpaceX will technically be shooting for "just a scootch below orbit," on this next test launch.

If all goes well, Starship should keep soaring into space, peaking at a near-orbital velocity of 17,500 mph around 150 miles from the ground, per Space.com. The rocket should then start falling back toward the ground at about 1 hour and 17 minutes into the flight.

The whole flight is planned to last about 1 hour 30 minutes, culminating in an "exciting landing!" SpaceX promised in a post published on its website, though it didn't specify why this may be.

After separation, if all goes according to plan, the Super Heavy booster will fire its rockets to slow down as it descends and lands in the Gulf of Mexico, per SpaceFlight Now.

Should Starship get safely into space this time, the expected 90-minute flight will see the spacecraft fly east over the Gulf of Mexico, make a partial circuit of Earth and splash down in the Pacific Ocean north Hawaii, per SpaceFlight Now.

Starship and Super Heavy are reusable systems, but this time SpaceX will aim for a simple splashdown in the ocean rather than landing vertically, as the first stages of SpaceX's Falcon 9 and Falcon Heavy rockets commonly do.

Speaking in an earlier interview in June, Musk had estimated this Starship launch had about a 60% chance of reaching its goal.

Abhi Tripathi, former mission director for SpaceX's Dragon spaceship, previously told Insider that Musk is "usually not as optimistic" as he seems now.

Tripathi added that he would consider this second test flight to be a success if two things happen.

"One, the damage to the launch mound and ground infrastructure is minimal, and two, at least 32 of the 33 engines stay lit."

"If I see those two things," he said, "I don't care what happens afterward. I will consider this a smashing success."

Like any space endeavor, things can go wrong during pre-flight checks. If the company needs to abort its flight on Saturday, it has a backup flight window on Sunday, Space.com reported.