Head to head

Atlas IIAS vs Soyuz 2.1a

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

Atlas IIAS: 6,580 kg

Soyuz 2.1a: 7,020 kg

Side by side

9 comparable figures

The highlighted value wins the row. Rows where neither direction is better, like length or stage count, highlight nothing.

Metric	Atlas IIAS	Soyuz 2.1a
Flights flown	30	58
Success rate	100%	98.3%
Payload to LEO (kg)	6,580	7,020
Payload to GTO (kg)	2,810	2,810
Liftoff thrust (kN)	4,391	4,149
Length (m)	47.54	46.3
Diameter (m)	3.04	2.95
Launch mass (t)	204	312
Stages	3	3

Atlas IIAS

Flight record

100% success rate30 of 30 flown

1993peak 1997 · 5 flights2004

Maiden flight 1993-12-16. Retired.

Soyuz 2.1a

Flight record

98.3% success rate57 of 58 flown · 1 failed

2004peak 2023 · 7 flights2026

Maiden flight 2004-11-04. Still flying.

Atlas IIAS is built by Lockheed Martin of the United States (company profile on Space Index).Soyuz 2.1a is built by Progress Rocket Space Center of Russia.

Full specifications and the complete launch history for each: Atlas IIAS · Soyuz 2.1a.

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