SpaceX is preparing to launch its Moon and Mars rocket Starship on its fourth test flight on Thursday, pending a launch licence from US authorities.

Elon Musk's company is contracted by Nasa to carry humans to the Moon in 2026 using Starship technology under the agency’s Artemis programme, which is behind schedule and making budget overruns.

Meanwhile, China is steadily advancing towards its goal of landing astronauts there by 2030, having landed several uncrewed Moon missions since 2013, helping to demonstrate its growing prowess in space exploration.

It also partnered with Italy, Sweden and France in its latest mission that put the Chang'e-6 vehicle on the far side of the Moon on June 1 to collect samples.

This will be Starship's fourth test flight in more than a year, with each attempt taking the company closer to making the rocket commercially operational.

“Starship is ready to fly,” Mr Musk posted on X on Monday, along with photos of the rocket assembled on a launch pad in Boca Chica, Texas.

Starship, a two-stage reusable rocket, consists of the Super Heavy Booster and the Starship spacecraft.

Apart from a partnership with Nasa, seats on the rocket were also sold to Japanese billionaire Yusaku Maezawa as part of his dearMoon project, in which he would have taken eight artists around the Moon with him.

But, on Saturday, he announced that he was cancelling the project, saying he thought Starship would be launch-ready by 2023.

“I signed the contract in 2018 based on the assumption that dearMoon would launch by the end of 2023,” he said.

“It’s a developmental project so it is what it is, but it is still uncertain as to when Starship can launch.”

US billionaire Jared Isaacman is also working with SpaceX through his Polaris programme, a series of privately led space missions aboard Falcon 9 and Starship.

SpaceX Starship lifts off on third test flight: in pictures

Slow but steady progress

During its third test flight in March, the Starship vehicle reached orbit for the first time.

This meant significant progress for SpaceX, despite the mission ending in failure when neither the booster nor the spacecraft splashed down successfully.

Engineers were able to show that the spacecraft can perform a hypersonic re-entry and its ability to open and close its payload door in orbit.

These milestones were crucial in validating that the rocket has a reliable design and functionality.

Mr Musk has been vocal about the upcoming test flight, stating that the objective is to get past maximum heating, the phase when the spacecraft experiences its highest thermal loads during re-entry.

Achieving this would prove the reliability of Starship's thermal protection systems, which include more than 18,000 hexagonal tiles.

The Super Heavy Booster’s performance is also under scrutiny, as it is yet to successfully complete a splash down, although in the previous test it performed significantly better than the earlier ones.

All 33 Raptor engines remained lit last time as the Starship spacecraft separated and accelerated to orbit.

The booster’s ability to complete its flip manoeuvre for a controlled descent also marked a critical step towards its reusability.

Starship also achieved a key technique called hot-staging, where the spacecraft’s engines ignite before separating from the booster.

This method reduces the time and altitude lost between stage separations, improving the vehicle's efficiency in reaching orbit.

Moon race speeds up

The Artemis programme’s reliance on private companies like SpaceX and Blue Origin, which is also contracted to land humans on the lunar surface, is part of a broader strategy to exploit commercial innovation for Nasa’s exploration goals.

SpaceX’s $2.89 billion contract with Nasa involves using Starship for the Artemis 3 mission, aimed at taking astronauts to the Moon in 2026.

If successful, it will be the first crewed lunar landing since Apollo 17 in 1972.

Meanwhile, China's space agency continues to make headlines with its lunar missions.

The Chang'e-6 mission’s success on the far side of the Moon, carried out with international co-operation, shows China's strategic and diplomatic approach to space exploration.

“China just landed a probe on the far side of the Moon – this time nearer the south pole, to gather volcanic samples using a scoop and drill and blast them back to Earth,” Canadian astronaut Chris Hadfield posted on X on Sunday.

“They've partnered with Sweden, France and Italy. Proving the tech needed to land Chinese astronauts by 2030.”