Soyuz 2.1a | Progress MS-34 (95P)

Soyuz 2.1a Launches Progress MS-34: Sustaining the International Space Station

On April 25, 2026, a Soyuz 2.1a rocket lifted off from the Baikonur Cosmodrome in Kazakhstan, carrying the Progress MS-34 spacecraft—designated as 95P—on a vital resupply mission to the International Space Station (ISS). This unmanned cargo flight underscores Russia's enduring role in maintaining the orbital outpost, delivering essential supplies amid evolving geopolitical dynamics in space exploration.

The primary objective of the Progress MS-34 mission is to transport approximately 2,500 kilograms of cargo to the ISS, including food, water, fuel, scientific equipment, and spare parts. As part of the Progress series, this spacecraft is engineered for automated docking with the station's Russian segment, typically within hours of launch via a fast-track rendezvous profile. Its payload capabilities extend beyond mere logistics; the vehicle can also perform orbital maneuvers for the ISS, such as reboosting its altitude to counteract atmospheric drag. Additionally, Progress missions often carry experiments in materials science, biology, and technology, contributing to ongoing research in microgravity. Once unloaded, the spacecraft serves as a waste disposal unit, burning up upon re-entry into Earth's atmosphere, which helps manage the station's limited storage space.

At the heart of this mission is the Soyuz 2.1a rocket, a modern iteration of the venerable Soyuz family. Standing about 46 meters tall with a launch mass of around 310 metric tons, the Soyuz 2.1a features a three-stage design powered by liquid-fueled engines. The first stage consists of four strap-on boosters, each equipped with an RD-107A engine burning kerosene and liquid oxygen, generating a combined thrust of over 800 metric tons at liftoff. The core second stage uses an RD-108A engine, while the third stage employs an RD-0110. Upgrades in the 2.1a variant include digital flight control systems and improved telemetry, enhancing reliability and precision compared to earlier models. These enhancements allow for a payload capacity of up to 7,000 kilograms to low Earth orbit, making it well-suited for ISS resupply.

The Soyuz launch vehicle's performance history is one of remarkable consistency. Since its debut in 2006, the Soyuz-2 series has achieved over 150 successful launches with a success rate exceeding 98%. This builds on the broader Soyuz lineage, which dates