Khrunichev Proton M

Proton-M is a three-stage heavy-lift launch vehicle using N2O4/UDMH propellant across all stages, with an optional Briz-M or Blok DM upper stage for geostationary missions.^[1] Payload capacity reaches 23,000 kg to LEO (200 km), 6,920 kg to GTO with Briz-M,^[2] and 3,250 kg to GSO.^[1] The vehicle uses a 4.35 m diameter fairing in short or long configurations.^[1] First launched on 2001-04-07, Proton-M has completed 116 flights with 105 successes and 11 failures as of 2026.^[1]

The vehicle is active but in wind-down: the last flight was 2026-02-12, with planned retirement before 2030.^[3] Proton-M has been the primary vehicle for the Elektro-L geostationary weather satellite series, including Elektro-L No.2 (2015), No.3 (2019), No.4 (2023), and No.5 (2026-02-12), the final mission using the Blok DM upper stage.^[3]