These were done in response to expert commission recommendations, and not been properly documented. The changes included:
- Adding six NK-15 engines to the base
- Reducing the inclination of the L3 parking orbit from 65 deg to 52 deg and its altitude from 300 km to 220 km
- Extending the propellant tanks, and chilling the propellants - the fuel was now loaded at -15 deg C to -20 deg C, and the oxidiser at -191 deg C
- Increasing the thrust of the engines by 2%
- Lightening the panels of the booster's body
Mishin countered that test versions of all four stages except the first stage had been successfully tested on stands at Zagorsk. Furthermore, all electric, hydraulic, and structural tests had been completed on the 1M mock-up on the pad. The launch should go ahead with the 7K-L1S circumlunar payload and a launch date of 18 February 1969. Barmin declared his launch complex was ready for the firing.
Therefore the session concluded with the State Commission approving the roll-out of N1 booster 3L to the pad for electrical trials. In discussing the schedule delays, it was revealed that TsNIIMASH/NII-88 had conducted exhaustive tests on models of the N1. They had discovered problems with embrittlement of the new aluminium alloy used in the booster's tanks in place of the more ductile alloy used in the R-7, R-9, and N1 side panels. Existing tank parts that had been fabricated had to be scrapped and new articles built with a heavier alloy. And this had taken place simultaneously with efforts to reduce weight in the booster! Ten different alternative alloys were subjected to long, gruelling durability tests using partial structural articles built at Kuibyshev and Tyuratam before the correct substitute material was found. Furthermore, the high-altitude versions of the NK-15 planned for the second stage were not yet available. Therefore 3L would fly using the same low-altitude nozzle as the first stage engines. This change in turn meant that the planned new digital guidance system from NIIAP could not be used. A back-up analogue guidance system would have to be used in all three stages instead. Therefore, in truth, 3L would represent only a partial test of the rocket stages, not a test of the all-up booster.