Head to head

Long March 4B 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

Long March 4B: 4,200 kg

Soyuz U: 6,900 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	Long March 4B	Soyuz U
Flights flown	58	714
Success rate	98.3%	97.2%
Payload to LEO (kg)	4,200	6,900
Length (m)	44.1	51.1
Diameter (m)	3.35	2.95
Launch mass (t)	249	313
Stages	3	3

Long March 4B

Flight record

98.3% success rate57 of 58 flown · 1 failed

1999peak 2020 · 5 flights2026

Maiden flight 1999-05-10. Still flying.

Soyuz U

Flight record

97.2% success rate694 of 714 flown · 20 failed

1973peak 1979 · 47 flights2017

Maiden flight 1973-05-18. Retired.

Long March 4B is built by China Aerospace Science and Technology Corporation of China.Soyuz U is built by Russian Federal Space Agency (ROSCOSMOS) of Russia.

Full specifications and the complete launch history for each: Long March 4B · 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.