After three failures in a row, SpaceX puts mega rocket upgrades to the test

After three catastrophic in-flight failures in a row, SpaceX readied a huge Super Heavy-Starship rocket for launch Sunday evening from the Texas Gulf Coast to put a variety of upgrades to the test and to deliberately stress the vehicle to learn more about its capabilities.

Test flight No. 10 is expected to get underway at 7:30 p.m. EDT, weather permitting, when the Super Heavy’s 33 methane-burning Raptor engines roar to life at the company’s Starbase manufacturing and flight facility near Brownsville, Texas, and the Mexican border.

The flight plan called for the 30-foot-wide 230-foot-tall Super Heavy booster, generating more than 16 million pounds of thrust, to propel the Starship out of the dense lower atmosphere before falling away, flipping around and heading back toward the coast.

During three of the nine previous test flights, the booster flew itself all the way back to its launch pad where giant mechanical arms on the service gantry plucked the descending rocket out of midair. This time around, because of the planned tests, the Super Heavy is expected to descend to splashdown in the Gulf.

“The primary test objectives for the booster will be focused on its landing burn and will use unique engine configurations,” SpaceX said on its web page. “One of the three center engines used for the final phase of landing will be intentionally disabled to gather data on the ability for a backup engine from the middle ring to complete a landing burn.”

The booster will then use two engines toward the end of the descent, hovering briefly before dropping to the Gulf.

The 160-foot-tall Starship, meanwhile, powered by six Raptor engines of its own, will head for a suborbital trajectory carrying it halfway around the world before a belly-first reentry, a flip back to vertical and a rocket-powered descent to splashdown in the Indian Ocean.

Along with deploying eight Starlink simulator satellites, the Starship’s flight computer will attempt a variety of other tests, including an in-space engine restart, to verify the performance of numerous upgrades implemented in the wake of the most recent test flight failures.

“The flight test includes several experiments focused on enabling Starship’s upper stage to return to the launch site,” SpaceX said. 

“A significant number of tiles have been removed from Starship to stress-test vulnerable areas across the vehicle during reentry,” the company added. “Starship’s reentry profile is designed to intentionally stress the structural limits of the upper stage’s rear flaps while at the point of maximum entry dynamic pressure.”

Working the bugs out of the giant launcher is critical to SpaceX and founder Elon Musk, who designed the ultra-heavy-lift rocket to launch thousands of next-generation Starlinks and other satellites in Earth’s orbit and to one day carry settlers and equipment to Mars.

The rocket also is critical to NASA, which is paying SpaceX more than $3 billion to develop a modified version of the Starship upper stage to carry Artemis astronauts to the surface of the moon in 2027.

But that flight will require 10 to 20 Super Heavy-Starship flights just to refuel the “Human Landing System,” or HLS, lander before it can head to the moon. Transferring thousands of gallons of super-cold liquid nitrogen and oxygen in space has never been attempted.

And it is still not known how SpaceX plans to control propellant temperatures to minimize the amount that will naturally warm up and turn into a gas, which must be vented overboard. SpaceX has provided no details.

Given the number of flights that must be successfully executed to demonstrate the reliability NASA will expect, the 2027 target date for the Artemis 3 moon landing is considered unrealistic, if not impossible to meet, by many aerospace observers.

China plans to launch its own astronauts on the moon in 2030, and, regardless of the outcome of Sunday’s test flight, it is unclear at this point whether NASA and SpaceX will get back to the moon using the Starship lander before the Chinese plant their own flag on the lunar surface.

Given the sheer size and power of the Super Heavy-Starship — it has more than twice the thrust of NASA’s current Space Launch System, or SLS, moon rocket — technical problems during development were not unexpected.

But given the short time between now and NASA’s first planned Artemis moon landing, the problems have clearly set the program back and cast doubt on the overall mission architecture, especially the requirement for 10 to 20 problem-free flights in short order just to fuel the lander for its flight to the moon.

The first three test flights of the Super Heavy booster and Starship upper stage in 2023 and 2024 ended in catastrophic failures with both stages destroyed, either while still attached to each other or after separation.

The fourth flight in June 2024 was generally successful with the Super Heavy flying itself back to a controlled splashdown in the Gulf while the Starship followed the planned sub-orbital trajectory to splashdown in the Indian Ocean. The ship’s fins were damaged by reentry heating, but otherwise worked as required.

The fifth flight in October 2024 was highlighted by a successful Super Heavy return to the launch pad gantry where giant mechanical arms snagged the rocket in mid air. The Starship, meanwhile, managed a second controlled splashdown in the Indian Ocean although it again suffered fin damage during reentry.

During the sixth integrated flight test in November 2024, the Super Heavy attempted another return to the launch site but it was diverted to a Gulf splashdown because of launch damage to critical sensors in the pad’s capture mechanism. The Starship again flew itself to a controlled Indian Ocean splashdown with minimal flap damage.

But the next three flights, in January, March and May of this year, ended with catastrophic failures. Two Super Heavy boosters successfully returned to the launch site, but the most recent broke up over the Gulf while testing a high angle-of-attack entry.

All three Starships were destroyed after catastrophic malfunctions, including two propellant leaks, an on-board fire and multiple engine failures.

In addition to the flight record, another Starship was destroyed on the ground when a high-pressure nitrogen tank exploded during an engine test firing at the Starbase launch site.