SpaceX’s massive Starship rocket could take to the skies for the fourth time on June 5, with the primary goal of evaluating a reusable second-stage heat shield as the vehicle makes its first attempt to safely enter the atmosphere.
CEO Elon Musk said on his social media platform X that “there are many difficult problems to solve with this vehicle, but the biggest remaining problem is creating a reusable heat shield with re-orbit, which has never been done before.
His post echoes comments he made earlier this month when he noted that the primary goal of the starship’s next test was to “go through maximum reentry heating.”
This means that the new heat shield of the second stage, composed of approximately 18,000 ceramic hexagonal tiles, will be put to the test. These plates are designed to protect the second stage (which is also called the Starship) from the extreme temperatures encountered when re-entering the Earth’s atmosphere. One of the biggest problems, Musk suggested, is the overall vulnerability of the system: “In most places, we’re not immune to losing a single tile,” he said. This means that one damaged or defective tile can lead to disaster.
As Musk noted in his post, surviving the return is only one piece of the puzzle. The company will also have to create an “entirely new supply chain” for the high-performance heat shield plates and produce them in very high volume.
It’s a tough problem, but solving it would move them closer to the holy grail of launch vehicles: full reusability. SpaceX has made great strides in reusability with its Falcon 9 thruster — which has flown 56 times so far this year alone — but while the company is rebuilding the booster, the second stage is spent on its target orbit. By reusing both rocket stages, SpaceX hopes to bring costs down to a fraction of what they are today, all while delivering many orders of magnitude more mass into orbit in a single launch. (SpaceX’s Transporter mission costs $6,000 per kilogram.)
If all goes according to plan, the company will demonstrate the ability to return a starship to Earth via a controlled reentry and a soft splashdown in the Indian Ocean. SpaceX is also looking to return the booster, called the Super Heavy, via the ocean as well. And it will get one step closer to bringing the largest and most powerful launch system ever built online, ready to carry cargo and possibly crew into and beyond Earth orbit.
This next starship launch will be the fourth in a series of orbital flight tests that began last April. Before the launch can proceed, SpaceX must obtain a commercial launch license from the US Federal Aviation Administration, the agency responsible for regulating commercial launches. The FAA also oversees the investigation of rocket launches that fail for whatever reason, so it worked closely with SpaceX during the Starship test campaign.
And previous starship launches have certainly gone awry: The first two ended in fiery explosions in mid-air, and the third ended with both the Super Heavy and the Starship presumably disintegrating before impacting the ocean. But for SpaceX, which uses an iterative approach to hardware development, each test was ultimately successful because it provided engineers with data about the rocket in a real-world flight environment. And it’s true that each mission went further than the last: During the third flight, the vehicle’s ascent engines burned for the duration, and the Starship finally reached orbit for the first time.
Ultimately, SpaceX will aim to land both the Super Heavy booster and the Starship second stage at its launch facility in Southeast Texas, where they can be quickly refurbished and returned to the pad.