Staged-combustion rocket engine (S1.5400)
Motor cohete de ciclo de combustión escalonada (S1.5400)
- Date
- c. 1959 · confidence low
- Place
- Korolev, Moscow Oblast, Russia
- Credited to
- OKB-1 (Korolev; Mikhail Melnikov, building on ideas by Alexei Isaev)
- Field
- Movement
⚠️ Disputed: the sources disagree.
What it is
A cycle in which gas from a preburner drives the turbopump and is then burned entirely in the main chamber, with no propellant loss. The S1.5400 of the Soviet Blok L stage is the first engine of this kind to fly, and the basis of high-performance Russian engines.
The cycle theory is credited to Isaev (1949). The S1.5400 (11D33) is credited to Melnikov around 1959-1960 for the Molniya upper stage; the history of later Soviet engines (Kuznetsov, Glushko) is complex. Date and attribution are of medium confidence.
What it led to
- the RD-170 and RD-180 engines with high specific impulse
- spread to US (SSME) and European engines
- the full-flow cycle (Raptor)