The 120-metric ton Starship rocket not only soared to the skies during its fourth test flight, but both stages also returned, with the booster landing in the Gulf of Mexico and the upper stage experiencing a chaotic reentry. This test brings the super-heavy lift vehicle closer to achieving reusability.
Starship’s Integrated Flight Test 4 was one for the books, if not just for the jaw-dropping views of the rocket getting pummeled by plasma on its way back down through Earth’s atmosphere.
SpaceX launched its Starship rocket off from the company’s Starbase facility in Boca Chica, Texas, on Friday at 10:50pm AEST. The rocket was loaded with more than 10 million pounds (4,500 metric tons) of propellant.
The rocket’s ascent went smoothly, although one of its 33 Raptor engines failed to ignite shortly after launch. The rocket’s previous two tests saw all 33 engines operate nominally throughout the flights. The engines had been a concern following Starship’s first test flight on April 20, 2023, when several engines failed during the launch and the rocket exploded just minutes after liftoff. This time around, the engine failure didn’t affect Starship’s test flight, but it is perhaps a point of concern regarding the engine’s reliability.
After liftoff, Starship pulled off a successful hot-stage separation, powering down all but three of the Super Heavy Booster’s Raptor engines and igniting the six second stage Raptor engines before separation. Starship then jettisoned the booster and the hot-stage adapter. According to SpaceX, future versions of the upper stage will carry an integrated hot-stage adapter, precluding the need to jettison the hardware after stage separation.
Following its separation, the Super Heavy booster performed its flip maneuver and landing burn that sent it towards the splashdown zone. This is what it’s all about: Starship’s sweet return.
“The payload for these flight tests is data,” SpaceX wrote on X. “Building upon what we achieved during Starship’s third flight test, our primary goal today is to get through the extreme heat of reentry.”
The last time the rocket took to the skies was on March 14. During this flight, Starship successfully performed a stage separation, completed a full-duration burn of the second-stage engines, demonstrated internal propellant transfer for NASA, and tested the Starlink dispenser door. The mission lasted for an hour and 49 minutes before the upper stage disintegrated to pieces during reentry.
This time around, the rocket survived its controlled reentry. Starship made it through peak heating and max aerodynamic pressure, using its flaps to control the vehicle while descending through the atmosphere at hypersonic speeds. Many of the vehicle’s 18,000 heat-shield tiles flew off during reentry, and one of the vehicle’s front flaps in particular was seen fighting for its life in dramatic footage captured by cameras placed on the rocket.
SpaceX placed one thin heat-shield tile and removed two others before the rocket’s launch to measure the heat in those areas without tiles and to test thermal protection options, according to the company. The reentry footage dramatically showed just how hot things got for the rocket on its way down, with plasma enveloping the vehicle during its descent.
Despite the heat, Starship continued its controlled descent and performed a landing burn before splashing down in the Indian Ocean about 65 minutes after liftoff. “Despite loss of many tiles and a damaged flap, Starship made it all the way to a soft landing in the ocean!” SpaceX CEO Elon Musk wrote on X. The rocket billionaire added that the issue with the flap should be resolved for Starship’s upcoming flight. He stated, “a newer version of Starship has the forward flaps shifted leeward. This will help improve reliability, ease of manufacturing, and payload to orbit.”
Previous Starship flights have prompted investigations by the Federal Aviation Administration, but SpaceX may be in the clear this time around. That could mean we get to see another Starship prototype liftoff sometime soon, ready to put on another show.