Proton's dual launch complex at Site 81
The historic launch complex for the Proton family of rockets in Baikonur Cosmodrome, Kazakhstan, approaches its retirement.
Site 81 in Baikonur with Pad No. 23 (left) and Pad No. 24 (right).
Two original launch pads for the Proton rocket -- No. 23 and No. 24 -- are located at Site 81, which is also known as Facility No. 333 ("Ob'jekt 333" in Russian). The two pads are separated by a distance of about 600 meters, calculated to be safe enough for one of the pads to survive an explosion at the other. At the same time, both pads share much of the support infrastructure located between them. The dual launch complex is situated around 2.5 kilometers from the Proton's assembly and processing facilities at Site 92.
Pad No. 24, also known as the "right" pad is the oldest active launch facility for the Proton, and it hosted the first launch of the rocket in 1965. The pad was under renovation for almost two decades starting in 1979, and no launches took place there until 1999. Yet, in the first decade of the 21st century it became the most extensively used launch pad for the Proton rocket. Along with Pad No. 39, Pad No. 24 was converted for the launches of the Proton-M rocket, however, payloads developed at ISS Reshetnev, such as GLONASS-M navigation satellites and Globus-1M military communications satellites, could only be launched from Pad No. 24 until at least 2014. During the refurbishment of Pad No. 39 in 2012, industry sources reported a backlog of Proton-M missions competing for the use of Pad 24.
At the beginning of 2018, Roskosmos announced plans to retire Pad No. 24 by 2023, while simultaneously considering whether to refurbish the facility for the launches of the Proton-Light variant. However, because the development of the Proton-Light and Proton-Medium rockets had never been funded, by July 2018, Roskosmos State Corporation made a quiet decision not to replace equipment at Pad 24, which had its warranties expiring in 2020 and, instead, mothball the pad during the same year. It essentially meant that from 2020 and until 2025, when the Proton family was expected to retire, the launch vehicle would only have the single operational launch No. 39 at Site 200. In the meantime, the entire Site 81 would go out of commission after 55 years in operation.
An aerial view of a Proton launch pad at Site 81 circa the 1970s.
Pad No. 23, also known as the "Left" pad, was completed in 1966 and it was used for the first time in 1967 for the launch of the L1 (Zond) spacecraft. The pad was taken out of service for renovations at the end of the 1970s and it remained officially under repair for almost a decade. Proton-K rockets were launched from Pad No. 23 until December 2004, however the funding needed to convert the facility for the Proton-M rocket was not provided. Instead, Pad No. 23 was slowly stripped of its equipment to provide spare parts for renovations of Pad No. 24. By 2019, the facility was also reported to be flooded which essentially rended it unusable, even though formally it had been listed as mothballed.
When most space launch complexes in Baikonur were transferred to civilian control at the end of the 1990s, Site 81 remained under the jurisdiction of the Strategic Missile Forces, RVSN, for several more years. It was finally transferred to the control of the KBOM design bureau at the beginning of 2006. The organization initiated a number of upgrades at the site, including the installation of new test and monitoring equipment.
"Left" launch pad (No. 23) for the Proton rocket at Site 81. Click to enlarge. Copyright © 2000 Anatoly Zak
A Proton rocket on the launch pad at Site 81. Copyright © 2000 Anatoly Zak