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How Soyuz rides into orbit
For almost half a century, the manned Soyuz spacecraft has ridden into orbit on top of its namesake rocket. Over the decades, the spacecraft and its launch vehicle went through several upgrades, however the launch profile had not changed much. Spent stages of the rocket and other components fall into several designated areas in Kazakhstan and in Russia minutes after their separation. The spacecraft reaches orbit less than nine minutes after the liftoff, however in case of emergency, the capsule with the crew could land as far as 5,000 kilometers downrange or even splash down into the Pacific Ocean. As a result, an armada of search and rescue aircraft is deployed at airfields along the ascent trajectory all the way to Vladivostok in the Russian Far East and at least one ship is on stand by in the Sea of Japan. A total of nine fixed-wing aircraft, 16 helicopters are supporting the launch.
Critical milestones in the Soyuz launch (as of 2014):
Search and rescue support As of 2014, a nerve center responsible for search and rescue support of Soyuz launches was located in the city of Yekaterinburg, the home of Central Military District. On the eve of launches, aircraft of the 2nd command of the Air Force, VVS, and Anti-Aircraft Defense Forces, PVO, would be deployed from home bases in Uprun (Chelyabinsk Region), Koltsovo (Sverdlovsk District) and Tolmachevo (Novosibirsk Region) to airfields in Baikonur, Arkalyk, Dzhezkazgan, Karaganda, Gorno-Altaysk and Kyzyl, according to the TASS news agency. One hour before a scheduled launch, all search and rescue assets are brought to the so-called No. 1 readiness level. Operational search and rescue bases and their assets during manned Soyuz launches:
Pre-launch countdown In 2024, the Russian mission control listed the following countdown timeline for the Soyuz MS-25 mission:
A typical pre-launch countdown for a piloted Soyuz mission: L-6 hours: Crew departs its hotel in residential area of Baikonur Cosmodrome. L-5 hours 30 minutes: State Commission overseeing the launch to make GO/NO GO decision for fueling operations. L-5 hours: Fueling operations to begin on Soyuz rocket. L-4 hours 30 minutes: A Soyuz crew to put on their spacesuits in preparation for launch inside processing building at Site 254. L-4 hours 5 minutes: Rocket loaded with liquid oxygen. L-3 hours 30 minutes: Crew greets family and friends at Site 254. L-3 hours 5 minutes: Liquid oxygen fueling of the first and second stages of the Soyuz rocket completed. L-3 hours: Crew walks out from processing building at Site 254 to board a bus heading to the launch pad. L-2 hours 55 minutes: Crew departs for launch pad (most of the time at Site 1). L-2 hours 35 minutes: Crew arrives at launch pad. L-2 hours 25 minutes: Crew boards Soyuz. L-2 hours: Crew takes seats in the descent module of the Soyuz spacecraft, plugs suits into the vehicle's ventilation system, begins systems checks. L-1 hour 20 minutes: Hatch closed, leak checks are initiated inside the Soyuz. L-1 hour: Gyroscopes are activated on the launch vehicle, preparations of the rocket's flight control system begins. L-45 minutes: Service access structure begins retraction. L-34 minutes: Emergency Escape System, SAS, is armed. L-10 minutes: Gyros "uncaged" and recorders are activated. L-7 minutes: Pre-launch operations completed. L-6 minutes: Final launch countdown operations to auto, launch vehicle and launch systems are ready for liftoff. L-5 minutes: Commander’s controls active/helmets closed. Launch key inserted. L-4 minutes: Combustion chamber nitrogen purge. L-90 seconds: Ground propellant feed terminated. L-60 seconds: Vehicle switched to internal power. L-35 seconds: Auto sequence start. L-30 seconds: 3rd stage ground power umbilical separates. L-15 seconds: Second umbilical tower separates. L-12 seconds: Launch command issued. L-10 seconds: Engine turbopumps at flight speed. L-5 seconds: Engines at maximum thrust. L-0 seconds: Liftoff. Soyuz lifts off!
Like all other rockets in the Soyuz family, launch vehicles carrying piloted Soyuz spacecraft lift off with the four strap-on boosters of the first stage and the core booster of the second stage igniting simultaneously on the ground. Following a vertical liftoff from Site 1 or Site 31 in Baikonur, the Soyuz rocket heads east to enter an initial orbit with an inclination 51.6 degrees toward the Equator. According to one version of the flight profile, the emergency launch escape system would be jettisoned first (114-115 seconds into the flight) to maximize the payload carried during the mission. Alternatively, the escape rocket could be jettisoned after the separation of the first stage. From that point on and practically until the end of the powered flight, an emergency return to Earth can be accomplished with existing propulsion systems. The four boosters of the first stage separate slightly less than two minutes into the flight (T+118-119 seconds) at an altitude of 42-45 kilometers. They then crash 350 kilometers from the launch site. The payload fairing then splits into two halves and separates two minutes, 40 seconds into the flight at an altitude of 85 kilometers. Its fragments fall around 500 kilometers downrange, along with the launch escape rocket. The second stage separates slightly less than five minutes after liftoff at an altitude of 168-169 kilometers. Around 10 seconds later, a connecting ring, which serves as an interface between the second and third stages, splits into three sections and separates from the third stage. The third stage inserts Soyuz into orbit at an altitude of 205 or 208 kilometers and at a distance of 1,640 kilometers from the launch pad. As soon as Soyuz flies free, a valve onboard the third stage opens venting pressurized gas in the direction of the flight and pushing it away from the spacecraft. Upon reaching orbit, the Soyuz deploys a pair of solar panels, radio-communications and rendezvous antennas as well as sensors. Also, the docking probe in the nose of the spacecraft is extended into operational position. In the meantime, inside the ship, crew members can unbuckle their seatbelts and, after leak checks, open hatch from the descent module into the habitation module and use the toilet. By all accounts, it happens many hours after the last time cosmonauts had access to such conveniences on the ground. Yet, for many years, Russian cosmonauts would not adopt diapers -- an integral part of the US astronaut outfits onboard the Shuttle. Tests in orbit Normally, during the second orbit around the Earth, the crew and the control center in Korolev, near Moscow, test crucial systems onboard the spacecraft, including, two-way communication links with the ground, the flight control system, the radio-controlled rendezvous system and TV-transmitters. Rendezvous profile Since the beginning of the 1970s, the primary function of the Soyuz spacecraft has been the delivery of crews to orbiting space stations, for which developers adopted a two-day flight profile. The rendezvous maneuvers would be initiated on the first day of the flight and continued on the second day. An automated rendezvous system is designed to bring the Soyuz all the way to the station, including physical docking of the vehicles. During every stage of the rendezvous, the crew has the ability to monitor the progress of the flight and conduct docking under manual control, if necessary. At a distance of 150 meters from its destination (plus/minus 50 meters), as the the Soyuz normally orbits within the range of the Russian ground control network, the spacecraft enters station-keeping position. As two spacecraft fly in formation, mission control monitors telemetry data and TV pictures from both vehicles to give a "go" to final rendezvous and docking.
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