SpaceX’s massive Starship rocket may take off for a fourth time on June 5, with the primary objective of evaluating the second stage’s reusable heat shield as the vehicle attempts to safely re-enter the atmosphere for the first time.
CEO Elon Musk said on his social media platform X that “There are a lot of hard issues to solve with this vehicle, but the biggest remaining problem is creating a reusable orbital reentry heat shield, which is not it’s never been done before.”
His post echoes comments he made earlier this month, when he noted that the main goal of the upcoming Starship test was to “pass maximum re-entry heating.”
This means that the new heat shield of the second stage, made up of around 18,000 hexagonal ceramic plates, will be put to the test. Those plates are designed to protect the second stage (also called the Starship) from the extreme temperatures experienced when re-entering Earth’s atmosphere. One of the biggest issues, Musk suggested, is the vulnerability of the system in general: “we’re not resilient to the loss of a single plate in most places,” he said. This means that a single damaged or faulty tile can lead to disaster.
As Musk noted in his post, surviving recovery is only one piece of the puzzle. The company will also have to create an “entirely new supply chain” for high-performance heat shield plates and produce them at a very high volume.
It’s a tough problem, but solving it would bring them closer to the holy grail of release tools: full reusability. SpaceX made great progress in reusability with its Falcon 9 rocket, which has flown 56 times so far this year alone, but although the company recovers the booster, the second stage is spent in its intended orbit. By reusing both rocket stages, SpaceX hopes to reduce costs to a fraction of what they are today, all while delivering many orders of magnitude more mass into orbit in a single launch. (Ride-sharing missions on SpaceX’s Transporter cost $6,000 per kilogram.)
If all goes according to plan, the company will demonstrate the ability to return the Starship to Earth via a controlled reentry and a gentle splashdown in the Indian Ocean. SpaceX is also aiming to return the booster, called the Super Heavy, via ocean splash as well. And it will be one step closer to bringing the largest and most powerful launch system ever built online, ready to carry cargo and eventually crew into Earth orbit and beyond.
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 launch operations. The FAA also oversees investigations into rocket launches that go awry for whatever reason, and so it has worked closely with SpaceX throughout the Starship test campaign.
And previous Starship launches have certainly gone awry: the first two ended in fiery mid-air explosions, and the third ended with both the Super Heavy and the Starship likely disintegrating before hitting the ocean. But for SpaceX, which takes an iterative approach to hardware development, each test was ultimately a success because it provided engineers with data on the rocket in a real-world flight environment. And it’s true that each mission has gone further than the last: During the third flight, the engines received full burnouts as the vehicle climbed, and the Starship eventually reached orbit for the first time.
Eventually, SpaceX aims to land both the Super Heavy booster and the Starship second stage at the launch facility in southeast Texas, where they can be quickly refurbished and returned to the pad.