SpaceX’s massive Starship rocket could take to the skies for the fourth time on June 5, with the primary goal of testing the second stage’s reusable heat shield as the vehicle attempts to safely re-enter the atmosphere for the first time.
Elon Musk, CEO he said on his social media platform that “there are many difficult issues to solve with this vehicle, but the biggest remaining problem is making a reusable orbital return heat shield, something that has never been done before.”
His post echoes comments he made earlier this month when he noted that the primary goal of Starship’s upcoming test was to “exceed maximum reentry heating.”
This means that the novel second stage heat shield, made up of around 18,000 hexagonal ceramic tiles, will be put to the test. Those tiles are designed to protect the second stage (which is also called Starship) from the extreme temperatures experienced upon re-entering Earth’s atmosphere. One of the biggest problems, Musk suggested, is the vulnerability of the overall system: “We are not resilient to the loss of a single tile in most places,” he said. That means a single damaged or defective tile could cause a catastrophe.
As Musk noted in his post, surviving re-entry is only part of the puzzle. The company will also need to establish a “whole new supply chain” for high-performance thermal protection boards and manufacture them at very high volume.
It’s a tough problem, but solving it would bring them closer to the holy grail of launch vehicles: total reusability. SpaceX made great strides in reusability with its Falcon 9 rocket, which has flown 56 times so far this year alone, but even though the company recovers the booster, the second stage is spent in its target orbit. By reusing both stages of the rocket, SpaceX hopes to reduce costs to a fraction of what they are today, while delivering many orders of magnitude more mass to orbit in a single launch. (SpaceX’s Transporter rideshare missions cost $6,000 per kilogram.)
If all goes as planned, the company will demonstrate the ability to return Starship to Earth through controlled reentry and a soft landing in the Indian Ocean. SpaceX also intends to return the booster, called Super Heavy, also by splashdown in the ocean. And it will be one step closer to bringing online the largest, most powerful launch system ever built, ready to transport cargo and eventually crew to Earth orbit and beyond.
This upcoming Starship launch will be the fourth in a series of orbital flight tests that It started last April. Before the launch can take place, SpaceX must receive 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 wrong for any reason, so it has been working closely with SpaceX throughout the Starship test campaign.
And previous Starship launches certainly went wrong: the first two ended in fiery mid-air explosions, and the third concluded with both Super Heavy and 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 they provided engineers with data about 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 fired at maximum duration as the vehicle ascended, and Starship It finally reached orbit for the first time.
Eventually, SpaceX aims to land both the Super Heavy booster and Starship’s second stage at its launch facility in southeast Texas, where they can be quickly overhauled and returned to the pad.