In a new NASA briefing, Hans Koenigsmann, SpaceX’s vice president of construction and flight reliability, was able to explain in more detail why the recent second Falcon 9 launch abortion occurred and how it delayed the The company’s first operational astronaut launch.
Now, scheduled to take off at 7:49 pm Eastern Standard Time (NET) (NET) on November 14 (Saturday), SpaceX’s Crew Dragon Crew-1 mission was originally scheduled for late September, October 23 and 10 Launched on the 31st. However, on October 2, the new Falcon 9 booster (the same level as Crew-1’s own new booster) automatically aborted the GPS III SV04 satellite launch attempt two seconds before launch. CEO Elon Musk quickly blamed the rare last-second stoppage on “unexpected pressure rise in turbomachinery gas generators.”
Probably it was manufactured side-by-side with the problematic GPS III SV04 Falcon 9 booster B1062 at SpaceX’s Hawthorne, California plant. Once a better understanding of the cause of the suspension was gained, the Crew-1 Falcon was checked almost immediately 9 booster B1061 to find any commonality.
Just a week before the latest briefing, Kathy Lueders, NASA’s human space program administrator and former commercial crew program manager, revealed in a statement on Twitter that SpaceX is still analyzing the reasons for the suspension. But it has been determined that at least one Crew 1 booster engine will need to be replaced, as well as one engine on the Falcon 9 booster B1063.
Now, at NASA’s Crew-1 briefing on October 28, SpaceX’s Koenigsmann revealed that the company has finally decided to replace the nine Merlin 1D engines of the Crew-1 booster B1061 instead of two of them. Thanks to Falcon 9’s eponymous 9-engine booster design and SpaceX’s prolific rocket factory, the process was completed very quickly, requiring only the redirection of the already qualified Merlin 1D engine from a considerable storage pool. According to Koenigsmann’s wording, SpaceX has installed two replacement engines on the Crew-1 booster.
But what caused the suspension of the GPS III SV04 launch and how did it affect Crew-1?
Rocket engine and “nail polish”
According to Koenigsman, during the fast and complicated electromechanical ballet process before the firing of the first stage of the Falcon 9 stage, the rocket’s automatic flight computer observed two of the GPS III SV04 boosters (nine Merlins). 1D engine) seems to be ahead of schedule, so speak. The computer immediately stops the ignition process to avoid the “hard” (that is, high pressure or damage) startup that might otherwise be possible. SpaceX quickly began to inspect the rocket within 24 hours, but could not find any physical or electrical errors in the Merlin 1D engine and engine part of Falcon 9.
Out of caution, SpaceX removed the two misbehaving engines and shipped them to the development and test facility in McGregor, Texas, and to some extent, miraculously, copied them on the test bench. The same premature start behavior. After a lot of more and more detailed inspections, SpaceX finally narrowed the possible cause to a very small pipeline, supplying air to one of the engine’s gas generator safety valves. In a seemingly random subset of the relatively new Merlin 1D engines, SpaceX eventually discovered that the overflow valve lines provided by the supplier are sometimes blocked by Koenigsmann, a protective paint like “red nail polish”.
Used to selectively exclude parts of the engine oil pipe in a surface treatment process called anodizing, because the paint was not successfully removed when the engine parts were selected at random, or the paint accidentally flowed into the blockage due to excessive enthusiasm cleaning . In the end, for whatever reason, a small blockage is enough to cause the affected Merlin 1D engine to always try to ignite a small portion within a second.
Crucially, when SpaceX discovered the possible cause and cleared the blocked pipeline, every previously affected Merlin 1D engine performed well, almost directly confirming the cause and solving the Falcon 9’s suspension on October 2 problem.
Astronaut goes into isolation
In anticipation of a simple solution that SpaceX can solve the gas generator problem, NASA commercial crew planning manager Steve Stich revealed that SpaceX’s Crew-1 mission astronauts-Shannon Walker, Victor Glover and Mike Hopkins, and JAXA (Japan) astronaut Noguchi Noguchi A routine pre-launch quarantine procedure is expected to be released on November 14.
Stich also provided a more specific Crew-1 schedule, starting with the integrated Falcon 9 and Crew Dragon static fire-resistant test network on November 9th, and a comprehensive launch on November 10th before the first launch attempt on November 14th. Dry clothes rehearsal. It is worth noting that due to coincidental orbital dynamics, the successful launch on November 14 will allow the Crew Dragon to ascend its orbit and rendezvous with the International Space Station within eight and a half hours after liftoff, which is a relatively common transit speed of 27.5 hours. Three times faster.
Please pay close attention to the launch date of the mission for the latest news.