Super Heavy-Starship climbs high but falls short on second test flight

Starship thunders away from its launch pad on its second test flight, trailing a one thousand foot exhaust plume. Image: Adam Bernstein/Spaceflight Now.

SpaceX’s gargantuan Super Heavy-Starship, the most powerful rocket ever built, blasted off on its second test flight Saturday and while the initial stages of the mission went smoothly, the first stage broke apart moments after separation from the Starship upper stage, which then blew itself up as it neared space.

Viewed as a successful learning experience by SpaceX, it was the second failure in a row to get the Starship upper stage into space, a frustrating disappointment for Elon Musk’s rocket company and a potentially major setback for NASA, which is counting on the Starship to carry Artemis astronauts to the surface of the moon in the next few years.

While SpaceX’s philosophy is to fly frequently, learn from mistakes and fly again, NASA will require a long string of successful missions before the agency will deem it safe to put astronauts aboard. SpaceX will no doubt resolve the issues that derailed Saturday’s flight, but every delay poses a threat to NASA’s moon landing timeline.

But SpaceX, at least, viewed the launching as more of a success than a failure.

“Congratulations to the entire SpaceX team on an exciting second integrated flight test of Starship!” the company posted on X. “Starship successfully lifted off under the power of all 33 Raptor engines on the Super Heavy booster and made it through stage separation”

Shattering the morning calm at SpaceX’s Boca Chica launch site on the Texas Gulf Coast, the Super Heavy’s 33 methane-burning Raptors ignited with a torrent of flame at 8:03 a.m. EST, instantly engulfing the rocket in billowing clouds of dust and steam.

Gulping more than 40,000 pounds of methane and liquid oxygen per second, the 397-foot-tall rocket slowly climbed skyward, thrilling thousands of area residents, tourists and journalists who looked on from nearby South Padre Island.

The launching came nearly seven months after an April 20 maiden test flight ended in a spectacular conflagration four minutes after liftoff, triggered by multiple first stage engine failures, problems separating the Starship from the Super Heavy and a catastrophic tumble. Maximum altitude: 24 miles.

The second time around, the rocket got farther and several of the systems that derailed the first test flight appeared to work normally. All 33 Raptor engines powering the first stage fired throughout the boost phase of the flight and a new “hot staging” system, in which the Starship’s engines ignited before separation, work as designed.

Moments after separation, the first stage flipped around and began lining up for a planned controlled splashdown in the Gulf of Mexico,, closer to the Texas coast. But moments later, it suddenly broke apart, possibly due to stresses imposed by the hot-staging technique.

Ship 25 and Booster 9 liftoff, causing little damage to the launch pad structure. Image: Adam Bernstein/Spaceflight Now.

The Starship, however, continued the climb toward space on the power of its six Raptor engines. All went well until about eight-and-a-half minutes into the flight when controllers lost contact with the rocket. The vehicle had disappeared from view in long-range tracking cameras by that point, but a sudden, shimmering disturbance in the atmosphere may have been a sign of the rocket’s destruction.

“We have lost the data from the second stage,” reported SpaceX engineer John Insprucker. SpaceX founder Elon Musk could be seen huddling with flight controllers, looking at computer monitors to get a sense of what might have happened.

Moments later, Insprucker said “the automated flight termination system on the second stage appears to have triggered very late in the burn as we were headed downrange out over the Gulf of Mexico.”

It’s not yet known why the Super Heavy booster broke apart or why the Starship upper stage apparently failed just before or after engine shutdown. But SpaceX commentators said the primary goal of the flight, testing the hot-staging systen for separating the upper and lower stages, appeared to work as planned.

Likewise, all 33 Raptor engines in the Super Heavy and the six powering the Starship appeared to fire normally for as long as the vehicles were visible. How other upgrades implemented in the wake of the April failure performed Saturday remains to be seen.

NASA is spending billions for a variant of the Starship to carry Artemis astronauts back to the surface of the moon. SpaceX is counting on the rocket to vastly expand its fleet of Starlink internet satellites and to power eventual low-cost government and commercial flights to the moon, Mars and beyond in keeping with founder Elon Musk’s drive to make humanity a “multi-planet species.”

Multiple test flights will be needed to demonstrate the reliability required for astronaut flights and it’s not yet clear how long that might take. While Saturday’s launch was far from a complete success, it did demonstrate solid engine performance and successful stage separation.

SpaceX’s Starship lifts off from its launch site at Boca Chica in South Texas. Image: Adam Bernstein/Spaceflight Now.

In the April flight, the pad was seriously damaged, the Super Heavy suffered multiple premature engine shutdowns, the stage separation system did not work and the rocket’s self-destruct system took longer than expected to activate.

The rocket reached a maximum altitude 24 miles, well below the 50-mile altitude NASA considers the “boundary” of space, before tumbling back toward Earth and exploding in a fireball of burning propellant.

The Federal Aviation Administration investigated the failure and cited “multiple root causes of the … mishap and 63 corrective actions SpaceX must take to prevent mishap reoccurrence.”

Musk said the company implemented “well over a thousand” changes” to improve safety and performance. The company finally received the required FAA launch license earlier this week after a final review of the rocket’s possible impact on area wildlife.

Along with hot staging, SpaceX added a powerful water deluge system to the launch pad to reduce the acoustic shock of engine ignition and the effects of their combined thrust. During the April launch, the base of the pad was heavily damaged, with steel and concrete debris blasted into the surrounding area.

Other major upgrades include the replacement of hydraulic actuators with an electrically-driven engine steering system and an improved, faster-acting self-destruct system.

The most powerful rocket in the world

Musk believes the Super Heavy-Starship will open a new era in space transportation.

It is by far the largest, most powerful rocket ever built, standing 40 stories tall and tipping the scales at more than 11 million pounds when fully loaded with propellants.

Burning methane with liquid oxygen, the rocket is capable of generating a staggering 16.7 million pounds of thrust, more than twice the power of NASA’s Space Launch System moon rocket and the legendary Apollo-era Saturn 5.

The Super Heavy first stage alone stands 230 feet tall while the Starship upper stage, designed to carry cargo, passengers or both, towers another 164 feet and is equipped with six Raptor engines of its own. It is capable of lifting up to 150 tons of cargo to low-Earth orbit.

Getting the Super Heavy-Starship flying on a regular basis is critical to NASA’s Artemis moon program. NASA gave SpaceX a $2.9 billion contract in 2021 to develop a variant of the Starship upper stage to carry astronauts down to the lunar surface in the next two to three years.

To send a Starship to the moon, SpaceX must first refuel it in low-Earth orbit, robotically transferring thousands of gallons of super-cold cryogenic propellants carried up by multiple Starship “tankers.” The number of tankers required is not yet known, but senior NASA managers have said more than a dozen will be needed for each Starship sent to the moon.

Starship bathed in light during final launch preparations. Image: Adam Bernstein/Spaceflight Now.

NASA’s contract requires one unpiloted lunar test flight before astronauts will make a landing attempt. Artemis managers continue to officially target late 2025 for the first lunar landing with astronauts on board, but that’s not remotely feasible given SpaceX’s pace developing the Starship system.

It’s also not known when SpaceX might be ready to launch paying customers aboard the new rocket. NASA’s moon program aside, at least three all-civilian missions have been booked to date.

Billionaire Jared Isaacman, who charted the first private Crew Dragon flight to low Earth orbit in 2019, plans to be aboard for the first piloted orbital flight of a Starship as part of his Polaris Dawn program.

Japanese billionaire Yusaku Maezawa, who paid the Russians for a visit to the International Space Station in 2021, also has chartered a Starship flight — “Dear Moon” — to carry him, an assistant and 10 artists and influencers on a privately funded around-the-moon voyage.

A third civilian Starship flight carrying 12 passengers, including space station veteran Dennis Tito and his wife, also has been booked. Tito paid the Russians an estimated $20 million for a visit to the International Space Station in 2001 and says he can’t wait to get back into space and share the experience with his wife.

It’s not known what SpaceX might be charging for a privately chartered Starship flight.