Head to head

Electron vs Kosmos 11K63

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 11K63: 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 11K63
Flights flown	97	126
Success rate	95.9%	93.7%
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 11K63

Flight record

93.7% success rate118 of 126 flown · 8 failed

1965peak 1970 · 20 flights1977

Maiden flight 1966-05-24. Retired.

Electron is built by Rocket Lab of the United States (company profile on Space Index).Kosmos 11K63 is built by Strategic Rocket Forces of Russia.

Full specifications and the complete launch history for each: Electron · Kosmos 11K63.

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