Head to head

Kosmos-2I 63S1 vs Kuaizhou 1A

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

Kosmos-2I 63S1: 300 kg

Kuaizhou 1A: 300 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	Kosmos-2I 63S1	Kuaizhou 1A
Flights flown	38	31
Success rate	68.4%	90.3%
Payload to LEO (kg)	300	300
Length (m)	31	19.4
Diameter (m)	1.6	1.4
Launch mass (t)	48	30
Stages	2	4

Kosmos-2I 63S1

Flight record

68.4% success rate26 of 38 flown · 12 failed

1961peak 1962 · 8 flights1967

Maiden flight 1961-10-27. Retired.

Kuaizhou 1A

Flight record

90.3% success rate28 of 31 flown · 3 failed

2017peak 2023 · 6 flights2025

Maiden flight 2017-01-09. Still flying.

Kosmos-2I 63S1 is built by Strategic Rocket Forces of Russia.Kuaizhou 1A is built by ExPace of China (company profile on Space Index).

Full specifications and the complete launch history for each: Kosmos-2I 63S1 · Kuaizhou 1A.

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