Head to head

Soyuz U vs Soyuz-U

Two vehicles in the same payload class. Every figure below comes from the same two sources for both rockets, and a row appears only when both publish the input.

Payload to low Earth orbit

Relative

Soyuz U: 6,900 kg

Soyuz-U: 7,050 kg

Side by side

7 comparable figures

The highlighted value wins the row. Rows where neither direction is better, like length or stage count, highlight nothing.

Metric	Soyuz U	Soyuz-U
Flights flown	714	71
Success rate	97.2%	100%
Payload to LEO (kg)	6,900	7,050
Length (m)	51.1	34.54
Diameter (m)	2.95	2.95
Launch mass (t)	313	298
Stages	3	2

Soyuz U

Flight record

97.2% success rate694 of 714 flown · 20 failed

1973peak 1979 · 47 flights2017

Maiden flight 1973-05-18. Retired.

Soyuz-U

Flight record

100% success rate71 of 71 flown

1982peak 1987 · 10 flights1995

Maiden flight 1982-12-23. Retired.

Soyuz U is built by Russian Federal Space Agency (ROSCOSMOS) of Russia.Soyuz-U is built by Soviet Space Program of Russia.

Full specifications and the complete launch history for each: Soyuz U · Soyuz-U.

Specifications from Launch Library 2 by The Space Devs, launch records from Space Index. Derived figures are computed here; see sources and method.