Watch live: SpaceX is launching a new Starship rocket prototype. The last 2 attempts ended in explosions.

• SpaceX plans to launch a new Starship rocket prototype tens of thousands of feet into the air on Wednesday.
• Elon Musk estimated a 60% chance of a successful landing. The last two prototypes blew up.
• Watch live feeds of the flight attempt below.
• Visit the Business section of Insider for more stories.

SpaceX plans to rocket its latest Starship prototype tens of thousands of feet into the air on Wednesday afternoon.

The challenge is landing it back on the ground - that maneuver has ended in explosion both times the company previously attempted it. This time, SpaceX founder Elon Musk estimated that the prototype has a 60% chance of a successful landing.

The prototype represents the upper stage of a two-part system: Eventually, a roughly 23-story booster called Super Heavy would heave the Starship spaceship toward orbit. Musk's long-term vision is for the system to one day fly astronauts to the moon and power hypersonic travel on Earth. He has said he plans to build 1,000 Starships in order to carry people and cargo to Mars.

But first, SpaceX has to figure out how to land the rocket, since that is critical to making the system reusable. Full reusability could help Starship slash the cost of reaching space 1,000-fold.

The newest prototype is called Starship serial No. 10, or SN10. SpaceX is preparing to launch it at about 4:30 p.m. CT on Wednesday, after a flight computer automatically aborted an attempt to lift off at 2:14 p.m.

The abort was due to a "slightly conservative high thrust limit," Musk said on Twitter. "Increasing thrust limit & recycling propellant for another flight attempt today."

When it lifts off, SN10 should roar nearly 33,000 feet above SpaceX's facilities in Boca Chica, Texas. Then one by one, it should shut off its engines as it nears the peak of its flight, flip sideways, and plummet back to Earth in a controlled belly flop. As it nears the ground, the rocket should fire its engines once again to flip itself upright in time to slow its descent and touch down gently on the landing pad.

The last two times SpaceX conducted such a flight, the prototypes slammed into their landing pads and exploded.

SPadre.com captured the second incident from a camera on top of a building about 6 miles away:

Watch SN10's launch attempt live 

SpaceX will start a new live feed a few minutes before launch. We will embed that video below once it's available. In the meantime, fans of the company are also on the ground and streaming their own live video of the launch site.

We recommend starting with NASASpaceflight's video stream, given the broadcasters' knowledge and multiple quality camera views.

The commentators on the feed keep track of preparations at the SpaceX facilities that indicate progress toward liftoff - things like clearing the launchpad, activity in the tank farm next to SN10, and the loading of liquid propellant into the rocket. 

LabPadre offers six unique views of the Starship launch site. Below is the channel's main 4K-resolution feed.

For a more distant view of the launch site - broadcast from the top of a hotel resort in South Padre Island about 6 miles away - check out SPadre's 24-hour live feed.

The Federal Aviation Administration has also issued airspace-closure notices for the area from 8 a.m. to 6:30 p.m. CT on Thursday and Friday - backup dates in case weather or technical issues cause SpaceX to scrub the Wednesday attempt. Likewise, Cameron County has given notice that a nearby road will be closed on those days, which is another prerequisite for launch.

SpaceX faces regulatory hurdles to get Starship to orbit

SpaceX's two previous test flights - those of prototypes SN8 and SN9 - were considered successes despite their explosive endings. That's because they demonstrated that Starship is capable of rocketing to suborbital heights and then controlling its fall.

However, those flights both resulted in FAA investigations, since the agency wanted to determine the cause of the explosions. It turned out that SN8 had fallen victim to low pressure in a propellant tank, which led the spaceship to fall too fast and slam into its landing pad. An additional issue with that attempt was that SpaceX hadn't gotten the proper FAA approval, violating its launch license.

This triggered its own investigation, which then held up the SN9 flight. Once that prototype did fly, one of its three Raptor engines failed to relight as the rocket neared the ground.

All those investigations have been closed, an FAA spokesperson told CNN reporter Jackie Wattles. And the launch-license updates for the SN10 flight are approved, according to Washington Post reporter Christian Davenport.

Eventually, SpaceX will want to rocket a Starship into orbit to test its ability to reenter Earth's atmosphere. That will require a different type of FAA license, but obtaining it means clearing many regulatory hurdles, including a thorough environmental assessment. (The environmental impact statement SpaceX previously completed for Boca Chica launches focused on the company's smaller rockets, rather than its larger Starship-Super Heavy system.)

The company is waiting to start that environmental assessment, but depending on the findings, it's possible SpaceX may need to conduct a new impact statement, which could take up to three years. Complicating matters is a leaked FAA draft document, obtained by Insider, which revealed that SpaceX plans to dig natural gas wells in Boca Chica to fuel Starships and on-site power plants. Such plans could affect SpaceX's environmental review process.

This story has been updated. It was originally published on February 23, 2021.