Sergey Boitsov to attempt a world record with a stratospheric jump Multiple world record holder Sergey Boitsov will attempt a jump from a hot-air balloon at an altitude of around 11–12 km, aiming to beat the current record of 10 060 m set by Polish athletes. The jump will take place in celebration of Russia’s National Flag Day and in support of the IFY–2026 The preparation is no ordinary training: altitude chamber tests at the Cosmonaut Training