So far, SpaceX has managed to land eight first stages of its Falcon 9 rockets after launching. This week, it will be relaunching one of those recovered boosters for the first time.

The event will be an important milestone for Elon Musk’s goal of reusability, flying rockets again and again to bring the cost of launching down. If all goes to plan, it’ll arguably be one of the most important moments in the history of private spaceflight.

Launch was scheduled to take place on Wednesday March 29, but has now been pushed back to Thursday March 30 at the earliest. A 2.5-hour window for the launch opens at 6pm EDT (11pm BST). The mission will launch the SES-10 satellite into a geostationary orbit for Luxembourg-based company SES, lifting off from Launch Complex 39A at Cape Canaveral in Florida.

This first stage flew originally back in April 2016, and it took four months to refurbish (that could be halved in future). It launched a Dragon capsule on the CRS-8 cargo mission to the International Space Station (ISS) for NASA, before landing back on a drone ship – the first drone ship landing, and the second landing for SpaceX following one on the ground in December 2015.

That booster is on permanent display at SpaceX’s headquarters in Hawthorne, California, making this the earliest landed booster that could be reflown. A landing will also be attempted on this launch on the drone ship Of Course I Still Love You, with a robot "Roomba" ready to secure it.

We should note that this will not be the first reusable rocket to go to space. That honor went to Blue Origin in Texas in 2015, who have flown their suborbital New Shepard reusable booster five times in total. Musk’s venture, however, will be the first orbital rocket to refly.

^{The moment the booster landed in April 2016. SpaceX}

On Monday, we’re expecting to see a static fire of the rocket, where it fires its engine while strapped down to the ground. This is the last major hurdle to prove the rocket is ready to be reflown.

SES, for its part, has been wholly supportive of SpaceX’s endeavors, and seemingly keen to be the first company to be involved in the mission. The company was SpaceX’s first ever customer, and now will become its first customer on a reflown rocket.

“Having been the first commercial satellite operator to launch with SpaceX back in 2013, we are excited to once again be the first customer to launch on SpaceX's first ever mission using a flight-proven rocket,” said Martin Halliwell, Chief Technology Officer at SES, in a statement back in August last year.

The flight had originally been scheduled for fall 2016, until that disastrous rocket explosion on September 1, which grounded the company for months. But it’s back up and running, with three launches – and two landings – already to its name in three months this year. Ultimately, SpaceX wants to launch rockets every two to three weeks.

Using reusable rockets is expected to lead to a 30 percent reduction in price for companies flying with SpaceX, although for now it’s estimated at 10 percent. Currently each launch costs about $60 million.

Alongside this – and upcoming missions to Mars – the company certainly has some grand goals. If the launch this week goes to plan, it’ll be another feather in the cap for Musk – and proof they can live up to their lofty ambitions.