[4] This was much greater than what was expected to be encountered but significant uncertainties as to the surface temperatures and pressure of Venus resulted in the designers opting for a large margin of error.

[4] This degree of hardening limited the amount of mass available for scientific instruments both on the probe itself and the interplanetary bus.

[7] The lander was ejected once atmospheric buffeting broke the interplanetary bus's lock-on with Earth.

[9] A few weeks later, upon review of the tapes by radio astronomer Oleg Rzhiga, another 23 minutes of very weak signals were found on them.

[9][10] The spacecraft had landed on Venus, and probably bounced onto its side, leaving the medium gain antenna aimed incorrectly for proper signal transmission to Earth.

[12] From the spacecraft's rapid halt (from falling to stationary inside 0.2 second), it was possible to conclude that the craft had hit a solid surface with low levels of dust.