The Leonov was equipped with a "Sakharov Drive", a propulsion system that employed a pulsed thermonuclear reaction to heat while expelling propellant material. A variety of propellants could be used; the most efficient was hydrogen, but methane, ammonia, and water could also be used.
In order to slow into Jovian orbit, the Leonov preformed aerobraking, by barely skirting the outer edges of the atmosphere, using the resultant drag force to slow them down into the proper orbit. This was the second time a manned spacecraft had been able to perform this maneuver, the first being the ill-fated Chinese spacecraft Tsein.
To prevent the spacecraft from burning up in Jupiter's thick atmosphere, Leonov deployed an inflatable low-density heat shield, made of an extremely durable, heat resistant material. The shield was discarded shortly after aerobraking.