SpaceX discovered the substance after one of the company’s launches in October was halted just prior to takeoff. Then the launch of one of SpaceX’s Falcon 9 rockets, which was supposed to deliver a new GPS satellite for the US Army, was delayed just two seconds before takeoff. “It was a good failure, ” Hans Koenigsmann, vice president of assembly and flight reliability at SpaceX, said at a press conference. ” The system worked exactly the way we programmed it. “

SpaceX today revealed the details: the rocket automatically halted its launch after two of Merlin’s nine main engines tried to start up too early. An early start could cause a so-called hard start where different fuels and engine fluids combine in the wrong order. The Falcon 9 shut down before that happened, but such a launch could damage the equipment. “It’s not so bad, but, you know, in most cases, this causes a chatter when the engine is running, ” said Mr. Königsmann. – And it can cause minor damage to the engine. In extreme cases, this can lead to greater damage to the engine “.

After the mission was canceled, SpaceX tested the engines and found a reddish varnish blocking the pressure relief valve in both engines. It is similar to nail polish and is used for surface treatment – it is likely to be from the days of engines. The engines came from one of SpaceX’s suppliers, but the exact company was not named. “Perhaps this person is now more generous with cleaning fluid or something else, ” said Mr. Königsmann. ” Now it’s hard to understand the reasons.”

SpaceX said it is working with a supplier to resolve the issue and will be reviewing all equipment more thoroughly soon. After the mission was canceled, SpaceX also tested all engines in its fleet. They looked for anything that could lead to an early launch and identified five potentially problematic engines on three different missiles. Two of them were on the Falcon 9 rocket, which will send four astronauts on the Crew-1 mission in November.

SpaceX noted that the varnish was found mostly on new engines that were built recently, and not on engines that have already flown into space. The company is now in the process of replacing engines ahead of the Crew-1 mission, which is tentatively scheduled for November 14. It takes 2-3 days to remove the engines and the same time to replace them with new ones.

Prior to the Crew-1 mission, the company must launch a joint European-American satellite called Sentinel-6, which is designed to map the oceans. SpaceX found a dubious engine in the Falcon 9 rocket for this mission – it too had to be replaced. Now NASA wants to see how this launch progresses before making a final decision on permission to deliver people to the ISS. The launch of Sentinel-6 is currently scheduled for November 10 from Cape Canaveral.

Meanwhile, the four astronauts for the Crew-1 mission have already begun the quarantine process, staying at home with their families, before going into more stringent quarantine two weeks before the flight.