Elon Musk demonstrates his power by firing three Falcon 9s in just over 24 hours

The undisputed number one player in the international space sector, the founder and CEO of SpaceX, the American billionaire Elon Musk, has once again stunned his strongest competitors in the United States, China and Europe.

The high-profile failure of his veteran Falcon 9 launcher on 12 July prompted Elon Musk to immediately set up a Commission of Inquiry which, placed under the supervision of the US Federal Aviation Administration (FAA), has ruled on the most likely cause of the accident. It has also given its approval to technical corrective measures to ensure the success of subsequent manned and unmanned missions.

In their official report, SpaceX engineers state that the problem detected and the solutions proposed ‘do not pose a risk to public safety’, which means that the official authorisation for the Falcon 9 to continue flying in space has not materialised in months as usual, but in a little more than two weeks.  

But there is more. To demonstrate its power and corroborate to all and sundry the reliability of its main ultra-terrestrial transport vector, the SpaceX company has made a great show of its mastery of space technology and its high launch capacity.

While it is the usual practice to test the reliability of the corrections introduced with a single launch, sometimes followed several months later by another, Elon Musk wanted to demonstrate his superiority with no less than three consecutive launches of as many rockets. And all three launches, something totally unusual... in little more than 24 hours!

A triple return to flight to make up for the days lost

Specifically, the three Falcon 9s took off into space on 27 and 28 July, one after the other, in a space of about 27 hours. They did so from locations about 3,600 kilometres apart. Two departed from SpaceX's assigned facilities at Kennedy Space Center and Cape Canaveral, both in Florida, on the Atlantic coast. The third was flown from the other end of the United States, Vandenberg Space Force Base in California, on the Pacific coast. 

In each of the three missions, some 20 Starlink satellites have been launched into orbit. In other words, the engineers who took the risk were Elon Musk's own. In doing so, the much-admired businessman wanted to certify his confidence in the improvements that have been made. In doing so, he is trying to secure take-off dates for his Falcon 9's long portfolio of customers, including Spain's FOSSA, Hisdesat, Sateliot and Satlantis, whose satellites are still scheduled to fly into space in 2024 and are not likely to suffer any delays, at least not major ones. 

In its official statement on 25 July, SpaceX said that its engineering teams had conducted a "comprehensive" review to facilitate the Falcon 9's return to service. The company confirmed that "the sensors that caused the failure of the Merlin second stage rocket engine have been removed, as alternatives are now available to perform the same functions". 

Elon Musk has already made 75 launches so far in 2024 and wants to regain his frenetic pace and reach the 144 flights he wants to achieve throughout the year, mostly thanks to the Falcon 9. His rocket is indispensable for US national security and for putting Pentagon spy satellites into orbit. 

It is also indispensable as a transport vehicle for manned flights, two of which are scheduled for the coming weeks: SpaceX Crew 9, for 18 August, with four astronauts bound for the International Space Station (ISS). Another is Polaris Dawn, a private mission also with four astronauts scheduled for the end of next month, which aims to spend five days in orbit without docking at the ISS.

The Falcon family, one of the most reliable in the world

But what are the changes and improvements made to Falcon 9? SpaceX stresses that the design change "has been tested at its rocket development facility at its McGregor, Texas headquarters, with the participation of SpaceX's research team and under FAA oversight".

Reviews and analysis of data taken during the flight have confirmed that in the first burn of the Falcon 9's second stage propulsion engine “a liquid oxygen leak occurred due to a crack in a sensing line of a pressure sensor connected to the vehicle's oxygen system”. 

The crack was caused by fatigue from high engine vibration and slack in the clamp that normally restricts the line. Despite the leak, the second-stage Merlin engine ran during its first ignition and completed its shutdown.

However, on the second ignition, the engine experienced "hard starting rather than controlled combustion," the report details. The result was that ‘the engine hardware was damaged and the upper stage lost attitude control. However, the second stage continued to operate and deployed the Starlink satellites.

Unfortunately, "all of the satellites were positioned in an environment of enormous aerodynamic drag at only 135 kilometres above the Earth", which caused them to re-enter the Earth's atmosphere, although "without posing a threat to public safety". 

SpaceX's official statement concludes that "our missions to safely deliver astronauts, customer payloads and thousands of Starlink satellites to orbit are critical and depend on the Falcon family of rockets - Falcon 9 and Falcon Heavy - to be among the most reliable in the world".