Count Until a Staff Member Posts! (394)

[Brisky]

20

Just before liftoff, the LOX turbopump in the #8 engine exploded (the pump was recovered from the debris and found to have signs of fire and melting), the shock wave severing surrounding propellant lines and starting a fire from leaking fuel. The fire damaged various components in the thrust section[41] leading to the engines gradually being shut down between T+10 and T+12 seconds. The KORD had shut off engines #7, #19, #20, and #21 after detecting abnormal pressure and pump speeds. Telemetry did not provide any explanation as to what shut off the other engines. Engine #18, which had caused the booster to lean over 45 degrees, continued operating until impact, something engineers were never able to satisfactorily explain. It could not be determined exactly why the #8 turbopump had exploded. Working theories were that either a piece of a pressure sensor had broken off and lodged in the pump, or that its impeller blades had rubbed against the metal casing, creating a friction spark that ignited the LOX. The #8 engine had operated erratically prior to shutdown and that a pressure sensor detected "incredible force" in the pump. Vasily Mishin believed that a pump rotor had disintegrated, but Alexander Kuznetsov argued that the NK-15 engines were entirely blameless and Mishin, who had defended the use of Kuznetsov's engines two years earlier, could not publicly come out and challenge him. Kuznetsov succeeded in getting the postflight investigative committee to rule the cause of the engine failure as "ingestion of foreign debris". Vladimir Barmin, chief director of launch facilities at Baikonur, also argued that the KORD should be locked for the first 15-20 seconds of flight to prevent a shutdown command from being issued until the booster had cleared the pad area.[42][43] The destroyed complex was photographed by American satellites, disclosing that the Soviet Union was building a Moon rocket.[36] After this flight, fuel filters were installed in later models.[36] It also took 18 months to rebuild the launch pad and delayed launches. This was one of the largest artificial non-nuclear explosions in human history and was visible that evening 22 miles (35 kilometres) away at Leninsk (See Tyuratam).[44]

[Bricket]

21
Oh, do you like being a developper?
Maybe you can help me: should I go for the job as Test engineer?

[Aveq]

22

hippopotamus

[Bricket]

23
Aveq, a small tip: try to post 2 words per post or else the system might get overloaded 

[Justin93Daniels]

24

Glad to be here!

[Brisky]

25

June 26, 1971: serial number 6L – dummy Soyuz 7K-LOK (Soyuz 7K-L1E No.1) and dummy LK module-spacecraft

Soon after lift-off, due to unexpected eddies and counter-currents at the base of Block A (the first stage), the N-1 experienced an uncontrolled roll beyond the capability of the control system to compensate. The KORD computer sensed an abnormal situation and sent a shutdown command to the first stage, but as noted above, the guidance program had since been modified to prevent this from happening until 50 seconds into launch. The roll, which had initially been 6° per second, began rapidly accelerating. At T+39 seconds, the booster was rolling at nearly 40° per second, causing the inertial guidance system to go into gimbal lock and at T+48 seconds, the vehicle disintegrated from structural loads. The interstage truss between the second and third stages twisted apart and the latter separated from the stack and at T+50 seconds, the cutoff command to the first stage was unblocked and the engines immediately shut down. The upper stages impacted about 4 miles (7 kilometers) from the launch complex. Despite the engine shutoff, the first and second stages still had enough momentum to travel for some distance before falling to earth about 9 miles (15 kilometers) from the launch complex and blasting a 15-meter-deep (50-foot) crater in the steppe.[45] This N1 had dummy upper stages without the rescue system. The next, last vehicle would have a much more powerful stabilization system with dedicated engines (in the previous versions stabilization was done by directing exhaust from the main engines). The engine control system would also be reworked, increasing the number of sensors from 700 to 13,000.[36][46]

[Aveq]

26


Break the servers 

[Emtile]

27

Butts

[Bricket]

28
No like seriously: just keep every post with 2 words minimum

[Aveq]

29


I don't think under two words would post anyway

[Brisky]

30

November 23, 1972: serial number 7L – regular Soyuz 7K-LOK (Soyuz 7K-LOK No.1) and dummy LK module-spacecraft for Moon flyby

The start and lift-off went well. At T+90 seconds, a programmed shutdown of the core propulsion system (the six center engines) was performed to reduce structural stress on the booster. Because of excessive dynamic loads caused by a hydraulic shock wave when the six engines were shut down abruptly, lines for feeding fuel and oxidizer to the core propulsion system burst and a fire started in the boattail of the booster; in addition, the #4 engine exploded. The first stage broke up starting at T+107 seconds and all telemetry data ceased at T+110 seconds. The launch escape system activated and pulled the Soyuz 7K-LOK to safety. The upper stages were ejected from the stack and crashed into the steppe. An investigation revealed that the abrupt shutdown of the engines led to fluctuations in the fluid columns of the feeder pipes which ruptured and spilled fuel and oxidizer onto the shut down, but still hot, engines. A failure of the #4 engine turbopump was also suspected. It was believed that the launch could have been salvaged had ground controllers sent a manual command to jettison the first stage and begin second stage burn early.[47]

[Emtile]

31

You can get around it by posting the numbers

[Bricket]

32
But yeah, let's keep going

[Aveq]

33


I want another hot chocolate

[Brisky]

34

Planned fifth launch
Vehicle serial number 8L was prepared for August 1974. It included a regular 7K-LOK Soyuz 7K-LOK and a regular LK module-spacecraft of the L3 lunar expedition complex. It was intended for a Moon flyby and uncrewed landing in preparation for a future crewed mission. As the N1-L3 program was canceled in May 1974, this launch never took place.