SpaceX pulls off unprecedented feat, grabs descending rocket with mechanical arms

In one of the most dramatic, high-risk space flights to date, SpaceX launched a gargantuan Super Heavy-Starship rocket on an unpiloted test flight Sunday and then used giant “mechazilla” mechanical arms on the pad gantry to grab the descending first stage out of the sky as the upper stage continued to space.

The spectacular capture, using pincer-like arms more familiarly known as chopsticks, represented a new milestone in SpaceX’s drive to develop fully reusable, quickly re-launchable rockets. It is a technological tour de force unmatched in the history of earlier space programs relying on expendable, throw-away rockets.

The Super Heavy-Starship rocket, the most powerful launcher in the world, blasts off from SpaceX’s Boca Chica, Texas, flight facility.

SpaceX

The 397-foot-tall rocket blasted off from SpaceX’s Boca Chica, Texas, flight facility on the Texas Gulf Coast at 8:25 a.m. EDT, putting on a spectacular sunrise show as the booster’s 33 methane-burning Raptor engines ignited with a ground-shaking roar and a torrent of flaming exhaust.

Three minutes and 40 seconds after liftoff, the Super Heavy booster fell away, flipped around and restarted 13 Raptors to reverse course and head back toward the Texas coast as the Starship upper stage continued the climb to space on the power of its six Raptor engines.

The booster’s flight computer was programmed to direct the stage to a splashdown in the Gulf of Mexico if any problems developed on the rocket or the launch pad capture mechanism.

The Super Heavy booster’s 33 Raptor engines, seen during fueling for launch.

SpaceX

But no such problems were detected and the Super Heavy continued toward its launch pad, descending and then slowing to a near hover between the two mechanical arms, which then moved in to grab the rocket as its engines shut down. SpaceX employees at the company’s headquarters in Hawthorne, Calif., burst into cheers and applause.

The remarkable capture, a key element in SpaceX founder Elon Musk’s drive to achieve “rapid reusability,” came as the Starship upper stage was still heading to space and splashdown in the Indian Ocean, simulating a touchdown on shore or, eventually, on the moon or Mars. Splashdown was expected an hour and five minutes after liftoff.

During the rocket’s fourth test flight in June, the extreme temperatures caused significant damage to the Starship’s protective tiles and steering fins. Multiple upgrades and improvements were put in place for Sunday’s flight to eliminate or minimize any such re-entry damage.

The two-stage Super Heavy-Starship, known collectively as the Starship, is the largest, most powerful rocket in the world with twice the liftoff thrust of NASA’s legendary Saturn 5 and nearly twice the power of the agency’s new Space Launch System moon rocket.

The Super Heavy booster descends to be captured by mechanical arms on the rocket’s launch gantry.

SpaceX

The 30-foot-wide Super Heavy first stage, loaded with 6.8 million pounds of liquid oxygen and methane propellants, stands 230 feet tall and is powered by 33 SpaceX-designed Raptor engines generating up to 16 million pounds of thrust. The Starship upper stage measures 160 feet long and carries 2.6 million pounds of propellant to power another six Raptors.

Both stages are designed to be fully reusable, with the Super Heavy flying itself back to its launch pad while the Starship travels to and from Earth orbit, the moon, or, eventually, Mars. The Starship is designed to touch down vertically on its own rocket power at landing sites on Earth and beyond.

But the primary goal of Sunday’s flight was to demonstrate the ability to capture returning Super Heavy boosters on the launch pad where they can be quickly refurbished, refueled and relaunched.

SpaceX perfected first-stage landings with its workhorse Falcon 9 rockets, successfully recovering 352 such boosters to date with powered touchdowns on landing pads or off-shore droneships. The smaller Falcon 9 first stages land on their own, deploying four landing legs a few seconds before touchdown.

Snatching the 230-foot-tall Super Heavy out of the sky with mechanical arms as the rocket descends and hovers right beside its launch gantry seemed an outlandish idea when it was first proposed during the booster’s initial development.

In an unprecedented feat, SpaceX successfully captured the descending Super Heavy using powerful mechanical arms on its launch gantry. 

SpaceX

But SpaceX engineers “spent years preparing and months testing for the booster catch attempt, with technicians pouring tens of thousands of hours into building the infrastructure to maximize our chances for success,” the company said on its website.

“With each flight building on the learnings from the last, testing improvements in hardware and operations across every facet of Starship, we’re on the verge of demonstrating techniques fundamental to Starship’s fully and rapidly reusable design,” the company continued.

SpaceX is under contract with NASA to supply a modified Starship to carry astronauts to landings near the moon’s south pole in the agency’s Artemis program.

To get a Starship lander to the moon, SpaceX must first get it into low-Earth orbit, then launch multiple Super Heavy-Starship “tankers” to refuel the moon-bound Starship for the trip to lunar orbit.

The astronauts will launch atop NASA’s Space Launch System rocket and fly to the moon aboard a Lockheed Martin-built Orion capsule. The crew will transfer to the waiting Starship for the descent to the lunar surface. NASA hopes to send the first woman and the next man to the moon in the 2027-28 timeframe, after an unpiloted Starship moon landing.

Rapid reusability is a key element of the program given the number of Super Heavy-Starships that will be required for a single moon landing. While Sunday’s test flight appeared to go smoothly, multiple flights will be needed to perfect the system and demonstrate the reliability required to carry astronauts.

How long that might take is an open question.

Over the past few weeks, Musk has launched a social media broadside against the Federal Aviation Administration, complaining that the agency’s bureaucracy takes too long to review and approve launch licenses and is, in effect, stifling innovation and slowing the development of the new rocket system.

The FAA did not grant a license to launch Sunday’s test flight until the day before. But this time around, the license covered multiple test flights using roughly the same flight plan.

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