Head to head

Kosmos 11K63 vs Kosmos-2I 63S1

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 11K63: 300 kg

Kosmos-2I 63S1: 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 11K63	Kosmos-2I 63S1
Flights flown	126	38
Success rate	93.7%	68.4%
Payload to LEO (kg)	300	300
Length (m)	31	31
Diameter (m)	1.6	1.6
Launch mass (t)	48	48
Stages	2	2

Kosmos 11K63

Flight record

93.7% success rate118 of 126 flown · 8 failed

1965peak 1970 · 20 flights1977

Maiden flight 1966-05-24. Retired.

Kosmos-2I 63S1

Flight record

68.4% success rate26 of 38 flown · 12 failed

1961peak 1962 · 8 flights1967

Maiden flight 1961-10-27. Retired.

Kosmos 11K63 is built by Strategic Rocket Forces of Russia.Kosmos-2I 63S1 is built by Strategic Rocket Forces of Russia.

Full specifications and the complete launch history for each: Kosmos 11K63 · Kosmos-2I 63S1.

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