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Raumfahrt - SpaceX’s Elon Musk: Starship Mission Update-53

16.03.2024

Starship lifts off on third test flight

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Starship lifts off on its third integrated test flight March 14. Credit: SpaceX webcast

WASHINGTON — SpaceX’s Starship vehicle lifted off on its third test flight March 14, making significant progress compared to its first two by achieving most of its planned test milestones.

The Starship/Super Heavy vehicle lifted off from the company’s Starbase site at 9:25 a.m. Eastern. The liftoff was delayed by nearly an hour and a half because of ships in restricted waters offshore. SpaceX reported no technical issues during the countdown.

The Super Heavy booster fired all 33 of its Raptor engines for nearly three minutes before executing “hot staging”, with the Starship upper stage’s engines igniting while still attached to Super Heavy before separating.

The booster then performed burns to attempt what SpaceX webcast hosts called a “soft splashdown” in the Gulf of Mexico, where it would not be recovered. However, the landing burn did not appear to go correctly, and the company later said that the booster broke apart 462 meters above the ocean after lighting several Raptor engines for a landing burn.

The Starship upper stage performed its burn, placing the vehicle onto its planned suborbital trajectory. It avoided the fate of the previous Starship launch in November, when the vehicle broke apart late in its burn after catching fire while venting propellant.

While in space on its suborbital trajectory, SpaceX opened a payload bay door that will be used on later Starship vehicles for deploying Starlink satellites. It also performed an in-space propellant transfer demonstration as part of a NASA contract where it would move propellant from one tank within the vehicle to another. SpaceX said it was evaluating the data from both tests.

SpaceX had planned to perform a brief relight of a Raptor engine on Starship about 40 minutes after liftoff, but the company said on the webcast that this test was skipped for reasons not immediately known. The company later said the engine test was called off because of the vehicle’s roll rates.

Several minutes later, the vehicle started reentry. A camera mounted on a flap on Starship provided dramatic images of the reentry, relayed through Starlink satellites. Telemetry was lost about 49 and a half minutes after liftoff when the vehicle was descending through an altitude of 65 kilometers. SpaceX later said on the webcast that it lost contact through both its own Starlink satellites as well as through NASA TDRSS data relay satellites at the same time, speculating that the vehicle may have broken up.

An onboard camera view of Starship’s reentry. Credit: SpaceX webcast

Reactions

While the mission did not achieve all its test objectives, the company considered the launch a success. “What we achieved on this flight will provide invaluable data to continue rapidly developing Starship,” it said in a statement.

NASA agreed with that assessment. “Congrats to SpaceX on a successful test flight! Starship has soared into the heavens,” NASA Administrator Bill Nelson posted on social media. The agency is closely following Starship’s development since it awarded contracts to SpaceX worth about $4 billion to develop versions of Starship for its Human Landing System program to be used starting with Artemis 3 as soon as late 2026.

“Congratulations to our colleagues at SpaceX on their third Starship flight test!” said Cathy Koerner, NASA associate administrator for exploration systems development. “Lessons learned from this milestone take us one step closer to returning astronauts to the lunar surface with Human Landing Systems provided by U.S. industry.”

There was praise across the Atlantic as well. “SpaceX continues to push the boundaries and the U.S. continues to set a model for how public and private can join forces to meet societal needs and boost commercialization within the space industry,” said ESA Director General Josef Aschbacher, noting that his agency was drawing from that experience for its own upcoming launcher competition.

Updated license

The launch came after a final regulatory milestone, an update Federal Aviation Administration launch license, issued late in the day March 13. The license required an additional environmental review after SpaceX changed the vehicle’s trajectory from the first two integrated test flights, targeting a splashdown in the Indian Ocean rather than near Hawaii.

That environmental assessment revealed that SpaceX expected Starship to explosively break apart upon splashdown. While Starship would vent some propellant while in space before reentry, the assessment stated that the company expected to have 70,000 kilograms of liquid oxygen and methane propellants in its main tanks and 30,650 kilograms in “header” tanks in the nose of the vehicle.

“Starship would impact the Indian Ocean intact, horizontally, and at terminal velocity,” the environmental assessment states. “The impact would disperse settled remaining propellants and drive structural failure of the vehicle. The structural failure would immediately lead to failure of the transfer tube, which would allow the remaining liquid oxygen (LOX) and methane to mix, resulting in an explosive event.”

The assessment noted that SpaceX did not plan to recover any Starship debris or have any boats or aircraft in the area to monitor the reentry and splashdown. It added that “any debris is expected to have sufficient mass to sink to the seafloor.”

The different trajectory allowed the company to perform tests such as the first in-space firing of the Raptor engine. Flying a steeper suborbital trajectory, with a planned maximum altitude of 235 kilometers, allows a test without substantially altering the splashdown location and threatening public safety, SpaceX hosts said on the company’s launch webcast.

Quelle: SN

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Update: 22.03.2024

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SpaceX's Starship could fly again as soon as early May

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