Head to head

Electron 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

Electron: 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	Electron	Kosmos-2I 63S1
Flights flown	97	38
Success rate	95.9%	68.4%
Payload to LEO (kg)	300	300
Length (m)	18	31
Diameter (m)	1.2	1.6
Launch mass (t)	13	48
Stages	3	2

Electron

Flight record

95.9% success rate93 of 97 flown · 4 failed

2017peak 2026 · 30 flights2026

Maiden flight 2017-05-25. Still flying.

Kosmos-2I 63S1

Flight record

68.4% success rate26 of 38 flown · 12 failed

1961peak 1962 · 8 flights1967

Maiden flight 1961-10-27. Retired.

Electron is built by Rocket Lab of the United States (company profile on Space Index).Kosmos-2I 63S1 is built by Strategic Rocket Forces of Russia.

Full specifications and the complete launch history for each: Electron · 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.