The Soyuz 2.1A converted the flight control system from analog to digital, which allowed launch from fixed platforms. It also allowed big fairings and payloads. It is currently used for crewed Soyuz and Progress flights to the ISS.
Progress Rocket Space Centre, formerly known as TsSKB-Progress, is a space science and aerospace research company which is known for manufacturing launch vehicles and satellites. Most notably, Progress Rocket Space Centre is the manufacturer of Soyuz launch vehicles.
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