In a partial response to a report claiming evidence of several significant anomalies during a recent special astronaut launch that could affect the NASA astronaut crew launched last month, the space agency issued a statement denying the claims. However, the same statement simultaneously revealed that SpaceX recently discovered a different problem with a different component of the Crew Dragon spacecraft during ground testing.
On May 23, space exploration A report has published claiming the SpaceX Crew Dragon spacecraft ran into major problems during Axiom-1, the company’s first all-private astronaut launch to the International Space Station (ISS). According to sourced information and a possible internal SpaceX memo, some of the Dragon’s toxic fuel leaked during the 17-day flight, damaging or weakening parts of its heat shield, and “[caused] Dangerously excessive wear on entry.” Overall, the report appears to be well sourced, and even claimed that the NASA Engineering and Safety Center (NESC) has opened an investigation. Plus, when approaching for suspension, neither NASA nor SpaceX Initially willing to speak formally, which also meant that neither of them denied the accusations.
A day later, NASA submitted an official statement to Space Explorer explicitly denying that there had been any fuel leaks, heat shield contamination, or excessive heat shield corrosion on any of the “recent Dragon crew returns.”
NASA also dismissed concerns about reusing the previously launched Cargo Dragon 2 heat shield structure on Crew-4, which was launched just two days after Axiom-1 recovered and is scheduled to spend another four to five months in orbit. She also mentioned reusing the Heat Dragon’s armor tiles – Structures that take the brunt of most heating on entry and are submerged in salt water after each mission – very limited and only tried occasionally shipping Dragon missions.
At the same time, NASA revealed that “the new composite structure for flight heat shield on Crew-5 did not pass the acceptance test” at SpaceX’s Hawthorne California plant. The unrelated test failure was blamed on a manufacturing defect and NASA betrayed no sign of serious concern in its statement, suggesting the problem may be less serious than it appears. In response, NASA says SpaceX will simply use a different vehicle architecture for the Crew-5 heat shield, which is scheduled to launch no later than (NET) in September 2022.
Data related to the recent re-entry of the Dragon crew was normal – the system was implemented as designed without conflict. There was no excessive ghoul leakage during the return of the manned Dragon mission nor any heat shield contamination causing excessive wear. SpaceX and NASA perform a full engineering review of the heat shield’s thermal protection system after each return, including prior to launching the Crew-4 mission currently on the International Space Station. The heat-shield composite structure (the structure under the tiles) has been relocated in accordance with the normal planning and renovation processes. The thermal protection system on the Crew-4’s primary heat shield was new, as was the case for all human spaceflight missions. SpaceX has just demonstrated the reuse of PICA (Phenolic Carbon Absorbed Ablator) tiles, a lightweight material designed to withstand high temperatures, as part of a heat shield on cargo flights.
NASA and SpaceX are currently working on determining hardware allocations for the agency’s upcoming SpaceX Crew-5 mission, including the Heat Dragon’s shield. SpaceX has a rigorous testing process to put every component and system through its paces to ensure safety and reliability. In early May, the new composite hull heat shield for aviation on the Crew-5 did not pass the acceptance test. The tester did its job and found a manufacturing defect. NASA and SpaceX will use another heat shield for the flight, which will undergo the same rigorous testing before the flight.
Crew safety remains a top priority for both NASA and SpaceX and we continue to target September 2022 for the Crew-5 launch.
Still some anomalies. While NASA’s outspoken rebuttal should be considered the final word on the matter, it’s still very unusual for NASA and SpaceX to dismiss or not be able to quickly and publicly deny the claims within a few hours of being asked. This may simply be the result of poor internal and external communication for NASA and SpaceX or the love of both parties to withhold information from taxpayers about the systems and technologies that taxpayers themselves have paid for.
On the other hand, after the test run of Crew Dragon’s Demo-2 with larger-than-expected heat shield erosion in 2020, it’s almost impossible to imagine that NASA and SpaceX would have proceeded to launch Crew-4 two days after the Axiom-1 recovered without confidently verifying Ensure that heat shield erosion was within normal limits. The Phenolic Carbon (PICA-X) Thermal Protector Tile from SpaceX is It is said to be designed for corrosion [PDF] Less than a centimeter thick, about 7.5 centimeters (3 in) thick after each re-entry. Musk went even further, stating in 2012 that “[PICA-X] They can be used hundreds of times to re-enter Earth’s orbit with only a slight deterioration each time.” If this were true, it would be until far away Even a quick post-flight inspection of the Axiom-1’s Dragon capsule would be hard to miss what Space Explorer described as “dangerously excessive erosion.”
In theory, during a recovery, SpaceX’s recovery team would have immediately spotted even a minute propellant leak, since the first part of the operative process involves a small team with gas masks and detectors approaching the floating capsule to make sure it’s safe for others to approach. Liquid monomethyl hydrazine (MMH) and dinitrogen tetroxide (NTO) oxidizer are highly toxic in small quantities and MMH is a known carcinogen.
Finally, the news regarding potential fuel leaks and anomalous performance of the heat shield appears to have been a false alarm, although – coincidentally or not – a seemingly minor anomaly with the non-spatial Crew Dragon heat-shield chassis Act Speaking earlier this month. Despite this anomaly, Crew-4 and Crew-5 are nominally advancing and NASA appears satisfied with the Crew Dragon’s performance during several recent launches and recoveries.
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