Space vehicle, due to lift off from Texas, is crucial to Elon Musk's plans to reach the moon and take humans to Mars

The latest iteration of Elon Musk's gargantuan Starship space rocket is poised to launch into the skies above Texas on Sunday for the first time in three months, with the billionaire entrepreneur's ambitious timetable for reaching the moon and conquering Mars hinging on the success of the pivotal mission.

Skywatchers are eager to see which version of the world's most powerful rocket will be produced for its 10th launch attempt. Of its nine previous uncrewed outings, dating to April 2023, failures have outnumbered the successes. All three test flights this year ended in huge explosions and debris raining down on Caribbean islands from the Bahamas to the Turks and Caicos in January and March, and the Indian Ocean in May.

Sunday night's test flight, from SpaceX's sprawling complex in Starbase, Texas, formerly known as Boca Chica, has a launch window opening at 6.30pm CT, and has various mission objectives, including the first successful deployment of Starlink communications satellite simulators.

Starship was moved to its launchpad on Thursday in anticipation of good launch weather for Sunday night's attempt.

Musk has remained uncharacteristically quiet ahead of the mission. "Getting ready to launch Starship," he posted on Thursday to the X platform he also owns, alongside images of the rocket assembly moving into position. SpaceX has not achieved a safe return landing of the upper stage of Starship, which Musk is hoping to have certified for human spaceflight as early as next year.

SpaceX engineers have made a number of changes following reviews of the rocket's previous failures, which include "a catastrophic explosion" that destroyed a Starship rocket during a ground test in June. The company is testing a variety of new heat-resistant tiles designed to stand the stresses of re-entry, and aims to return the upper stage to its landing site for the first time.

The entire Starship stack, at 403ft (123 meters), is considerably larger and more powerful than Nasa's Apollo-era Saturn V rocket that last took humans to the moon in 1972.

Musk's vision is a fully reusable space vehicle capable of repeated return trips to Mars beginning in late 2026 without astronauts, then with crews making the six-month space voyage as early as 2029. Ultimately, the SpaceX and Tesla founder aims to build a thriving city for humans on the red planet in the coming two to three decades.

Experts say it is a hugely ambitious undertaking. First, Musk needs to prove SpaceX can launch and recover Starship's components safely from short hops into the atmosphere, to say nothing of a journey to the moon.

Only four Starship launches have been considered successful, although the company has made progress in recovering the first-stage Super Heavy rocket booster by capturing it in a giant pair of robotic arms nicknamed the chopsticks.

SpaceX said it would not attempt to catch the booster from Sunday's flight because the component would instead be used for in-flight experiments "to gather real-world performance data on future flight profiles and off-nominal scenarios".

In the eyes of investors, the mission is also a test of Musk's commitment to focusing on his core businesses - space and electric vehicles - since leaving his controversial government job as head of the so-called department of government efficiency (Doge) in May. When he left the government, Musk said he would return to his businesses. He has since backtracked on the pledge and said he will start a new political party, though he may already be backing off the initiative.

Ethics watchdogs have questioned Musk's former role for the White House, in which he slashed tens of thousands of government jobs in the name of efficiency while preserving and benefiting from billions of dollars in federal contracts.

Donald Trump said this month he planned to relax regulations that will allow Musk, and fellow billionaires with space ambitions such as the Amazon founder, Jeff Bezos, to avoid reviews previously required by the National Environmental Policy Act (Nepa) before launch permits can be granted.

Authorities and environmentalists have expressed concerns over the environmental impacts of SpaceX operations in Mexico, after the explosion near its border in June, and in Hawaii, where authorities and environmentalists fear the impact on its sensitive marine ecosystem from new rules that will allow Musk to launch 25 Starship flights from Texas instead of just five.

SpaceX tests launch of massive Starship rocket after three explosive failures