Roscosmos launched its Progress MS-23 spacecraft to the International Space Station on Wednesday. Liftoff, atop a Soyuz-2.1a rocket, occurred 12:56 UTC (6:56 p.m. local time), from the Baikonur Cosmodrome in Kazakhstan. It docked without issue a few hours later.
Progress MS-23 is the latest in a long series of uncrewed Progress cargo spacecraft which Russia uses to deliver supplies to the International Space Station (ISS). It is the 23rd flight of the Progress MS vehicle and is also designated Progress 84P by NASA – which signifies that it is the 84th Progress cargo delivery mission to the ISS. This number includes missions flown by earlier versions of the Progress vehicle.
Now Progress MS-23 has docked with the Poisk module Wednesday, it joins Progress MS-22 at the station. Launched on Feb. 9, this vehicle is currently docked at the aft port of the Zvezda module.
Onboard Progress MS-23 is more than 2,500 kg of cargo. This includes 600 kg of propellant for refueling the ISS; 630 kg of drinking water, and 40 kg of pressurized gases. The remaining 1,290 kg consists of research equipment and tools, consumables and kits for scientific experiments, clothing, food, and hygiene products to support the work and life of the crew of Expedition 69.
An item of note aboard Progress MS-23 is URM-D, a universal workstation that is to be installed on the outside of the Zvezda module as part of a future spacewalk. Progress is also carrying BMSTU-Sail, a free-flying solar sail experiment, which will be manually launched by cosmonauts — also during an upcoming spacewalk.
Ahead of its launch, the Progress spacecraft was shipped to the Baikonur Cosmodrome by rail. Arriving on July 5, 2022, it was transferred to the processing building at Site 254. Here, crews performed inspections and testing of the spacecraft, including some to ensure that all mechanisms needed to deploy the spacecraft’s solar panels performed as expected. The vehicle was then transferred into storage until the start of its launch campaign.
On April 10, it was announced that Progress MS-23 had passed tests in an anechoic chamber, and on April 20, vacuum tests were completed. Next, engineers from RSC Energia refueled the thermal control system and tanks of the Rodnik water supply system. On April 27, the solar panels were once again deployed and illuminated to ensure that they would properly generate electricity in flight.
On May 10, fueling of the Progress spacecraft was approved. Before being transported to the fueling station at Site 31, the spacecraft underwent control weighing and balancing. Once fueled, Progress was transported back to Site 254 for final launch preparations to continue.
Progress MS-23 was joined to the transfer compartment of the Soyuz launch vehicle on May 16. The transfer compartment provides mechanical connections between the spacecraft and the fairing and allows for integration of control systems between the spacecraft and the onboard control systems on the rocket.
One day later, the four-meter payload fairing that will protect Progress on its way to space was rolled into position and attached to the transfer compartment. The assembled unit was then prepared for transportation to Site 31 to be mated with the Soyuz rocket, which was already undergoing its own assembly process.
The Soyuz-2.1a rocket that will carry Progress MS-23 was sent to Baikonur in February. On March 31, engineers from RSC Energia checked the functionality of its motion control and navigation systems, tested the thermal control systems, and tested the automation of the onboard power supply and combined propulsion system.
On May 11, the four first-stage boosters were attached to the central core, which serves as the rocket’s second stage. Once the transfer compartment had been fully integrated with Progress and shipped to Site 31, final assembly could take place. On May 19, the integrated transfer compartment third stage were added to the vehicle to produce the fully-assembled Soyuz rocket.
With this complete, the Soyuz 2.1a launch vehicle was rolled out of the integration building and installed on its launch pad at Site 31/6 on May 21.
The Soyuz-2.1a is one of three active variants in the Soyuz family of rockets, and of these, it is the one that most closely resembles the type’s original design. The rocket’s first stage consists of four liquid-fueled boosters which are mounted radially around a central core — which makes up the second stage of the rocket.
Each of the four boosters is powered by an RD-107A engine, burning RG-1 propellant – a highly-refined form of kerosene similar to the US RP-1 – and liquid oxygen (LOX). Each RD-107A is equipped with two smaller vernier engines to help control the rocket’s trajectory.
The center core, designated Blok-A, is the second stage of the rocket. It uses a single RD-108A engine, derived from the RD-107A but featuring four vernier engines instead of two. The third stage is powered by a single RD-0110 engine, which ignites shortly before the second stage separates, in a process known as “hot staging”.
Before launch, the Soyuz-2.1a rocket is loaded with fuel and oxidizer and the two large gantry towers surrounding the rocket are lowered to their launch positions. The first and second stage engines ignite together about 16 seconds before liftoff. Once the engines have spooled up to full thrust, the Soyuz 2.1a rocket lifts off from Site 31/6.
After clearing the launch pad, the vehicle establishes itself on a launch azimuth aligned with the ISS’s orbital inclination of 51.6 degrees.
The four side-mounted boosters of the first stage are the first part of the rocket to separate, doing so just under two minutes into the flight. Booster separation makes a formation in the sky known as the “Korolev Cross”, after Sergei Korolev, a pioneer of early Soviet rocketry who designed the Soyuz and R-7 family of rockets.
After first stage separation, the second stage continues to burn until it is depleted of fuel. Shortly before burnout, the third stage ignites its engine and separates to continue the ascent into orbit. The third stage completes orbital insertion, with Progress separating to begin its chase of the International Space Station.
It took Progress MS-23 about four hours and 24 minutes from launch to rendezvous with the ISS, much shorter than other spacecraft due to the mission profile that is being used. It is expected to remain at the space station until November. Upon completion of its mission, the vehicle will be loaded with trash and other unwanted items from the station to burn up in the atmosphere as it re-enters.
(Lead image: The Soyuz 2.1a rocket erected at Site 31/6 ahead of the launch of Progress MS-23. Credit: RSC Energia)