The lander falls from 65 km through three modelled cloud decks — a hazy sulfuric-acid haze near the top, a dense cloud band in the middle, and a thick lower haze — before the aeroshell and parachute are jettisoned and retro-braking carries it to touchdown. Altitude, hull pressure and hull temperature are interpolated along real Venus atmosphere profiles, so the hull heats and pressurises gradually rather than jumping straight to the surface extreme.
altitude(t) = lerp(65 km, 0, descentProgress)
pressure(alt) = 92 · exp(−alt / 15.9 km)
temp(alt) = 462 − 8·alt (°C, alt in km)
- Playback speed — scales both the descent and the post-landing survival clock; the clock still always tops out at the real 127 minutes.
- Survival clock — counts simulated on-surface minutes. At 127:00 the hull's pre-launch cooling and insulation are spent and the electronics overheat, exactly as happened to Venera 13 on 1 March 1982.
- Comparison table — Venus's pressure and heat dwarf Mars's near-vacuum cold and even Earth's own conditions, which is why every successful Venus surface mission has been Soviet and none has lasted more than about two hours.