Almost every day for the past few weeks, workers with welding guns and torches have climbed onto the launch pad of SpaceX's Starship in South Texas to make final improvements before the next test flight of the world's largest rocket.
Livestreams of the launch site from LabPadre and NASASpaceflight.com have shown sparks raining down from two mechanical arms extending from the side of the Starship launch tower at SpaceX's Starbase launch site on the Gulf Coast east of Brownsville, Texas. With permission from LabPadre, which runs a YouTube page with several live views of Starbase, we're posting several views of the welding here.
If SpaceX has its way, on Starship's next flight, these arms will close to catch the booster's first stage, called Super Heavy, as it descends back to Earth and slowly hovers over the launch pad.
This method of rocket recovery is quite different from the way SpaceX lands its smaller Falcon 9 booster, which has landing legs to touch down on offshore platforms or on concrete foundations on land. Catching the rocket with large metal arms — also called “Mechazilla arms” or “chopsticks” — would shorten the time until the booster can be reused and simplify its design, SpaceX said.
SpaceX has launched the almost 121-meter-high Starship rocket four times. Most recently in June, when the Super Heavy Booster, itself around 71 meters high, made a precise splashdown in the Gulf of Mexico directly off the coast of Starbase.
On the same flight in June, Starship's upper stage flew halfway around the world and re-entered the atmosphere over the Indian Ocean. The craft survived re-entry and splashed down in the open ocean northwest of Australia. That flight marked the first time either part of the Starship rocket returned to Earth intact, but SpaceX was unable to recover either the booster or ship stages.
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Lessons learned from the June test flight prompted SpaceX to replace thousands of heat shield tiles on the Starship vehicle for the next mission. Although the craft survived reentry in June, onboard camera footage showed that numerous tiles had been torn off the vehicle. Last month, SpaceX tested the engines on the booster and the Starship scheduled for the next launch.
On August 8, SpaceX said Starship and Super Heavy were “ready to fly, subject to regulatory approval” from the Federal Aviation Administration. An FAA spokesperson said the agency is reviewing SpaceX's proposed flight profile for the next Starship test flight, during which SpaceX plans to attempt to land the booster on the launch pad. This will be the first time SpaceX attempts to return the stainless steel Super Heavy booster, which is as long and wider as a Boeing 747 jumbo jet, to a land landing.
Although the rocket appears ready to fly, SpaceX officials clearly believe there is more work to be done at the launch pad. Upon closer inspection, it was clear that welders were adding structural supports or doublers to certain parts of the tentacle arms. Elsewhere on the arms, workers were seen removing and installing other unknown pieces of hardware. SpaceX has not specified exactly what type of work teams are doing at the Starship launch pad in Texas, but the focus is on strengthening the hardware needed to catch the Super Heavy booster.
All of this work is taking place during the hottest time of year in South Texas. Most days this month, afternoon temperatures have risen to 95 to 100 degrees Fahrenheit, with oppressive humidity. Much of the work on the catchment arms has taken place at night, when temperatures drop below 80 degrees Fahrenheit.
It's unclear how long it will take for the FAA to grant SpaceX a license to launch and recover the rocket on its next test flight, or when SpaceX will complete upgrades to the launch pad. SpaceX founder and CEO Elon Musk suggested earlier this month that the flight could launch in late August, but the condition of the launch pad and remaining testing suggest a launch is likely at least a few weeks away.
Once workers complete their tasks of rigging the launch pad and clearing the area of scaffolding and cranes, SpaceX will likely load the Super Heavy booster and Starship upper stage and fill them with fuel during a full countdown rehearsal, as it has done before every previous Starship launch.
Musk has indicated several times that the company will attempt to capture the Super Heavy booster on the next flight, which will also accelerate Starship's upper stage to near-orbital speeds for another reentry demonstration over the Indian Ocean. Last month, SpaceX released a video teasing a booster capture on the next Starship flight, showing the rocket returning to Starbase with its Raptor engines firing.
Meanwhile, SpaceX has built a second Starship launch tower next to the existing launch pad in Texas. The company still has a lot of work to do to outfit the second launch pad before it's ready for a Starship flight, but SpaceX could have it ready for use sometime next year. SpaceX also plans two Starship launch pads in Cape Canaveral, Florida. All of these locations will allow SpaceX to launch Starships more frequently. The company is also completing a sprawling factory near the Starship factory in South Texas, just a few miles inland from the launch pads there.