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S5.98M

Russian rocket engine

Wikipedia contributorsAdapted for Fathomly · View authors
1 min read
Source updated June 9, 2026
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The S5.98M, also known as the 14D30, is a Russian rocket engine, currently powering the Briz upper stages. It was designed by KB KhIMMASH, the famous Isaev designed bureau. It burns a hypergolic mixture of unsymmetrical dimethylhydrazine (UDMH) fuel with dinitrogen tetroxide (N2O4) oxidizer in a gas-generator cycle.

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This article is adapted from the Wikipedia article “S5.98M”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.

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Briz (rocket stage)

The Briz-K, Briz-KM and Briz-M are Russian liquid-propellant rocket orbit insertion upper stages manufactured by Khrunichev State Research and Production Space Center and used on the Proton-M and Angara A5. The upper stages were also used on Rokot, one of Russia's smaller launchers, before its retirement in 2019.

Proton-M

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Rokot

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