Russian Progress supply ship poised for launch from Baikonur

A Soyuz-2.1a rocket stands on its launch pad at the Baikonur Cosmodrome in Kazakhstan. The Soyuz will launch with the Progress MS-18 supply ship for the International Space Station. Credit: Roscosmos

A Soyuz rocket is ready to boost Russia’s Progress MS-18 supply ship into orbit Wednesday from the Baikonur Cosmodrome in Kazakhstan, setting course for a two-day chase of the International Space Station.

The liquid-fueled launcher is scheduled to lift off from the Site 31 launch complex at Baikonur at 8:00:32 p.m. EDT Wednesday (0000:32 GMT Thursday) to begin a nearly nine-minute climb into orbit. Launch is set for 5 a.m. local time at Baikonur, located in a remote section of Kazakhstan east of the Aral Sea.

Ground teams at Baikonur transferred the Soyuz-2.1a rocket to its launch pad at sunrise Monday aboard a rail car, then raised the vehicle vertical with a hydraulic lift. Gantry arms swung into position at the pad, giving workers access to the rocket for final inspections and closeouts.

Russian officials plan to meet a few hours before liftoff to give approval for technicians to load kerosene and liquid oxygen propellants into the Soyuz rocket.

An automated countdown sequencer will send commands for pressurization of the launcher in the final minutes before liftoff.

The Soyuz rocket will take off with nearly a million pounds of thrust. The launch is timed for the moment Earth’s rotation brings the Baikonur Cosmodrome under the International Space Station’s orbital track.

After releasing four first stage boosters, an aerodynamic fairing, and core stage, the Soyuz third stage engine will deliver the Progress MS-18 cargo freighter into orbit at T+plus 8 minutes, 45 seconds.

A few seconds later, the Progress supply ship will detach from the Soyuz rocket, then immediately unfurl its power-generating solar arrays and navigation antennas to help guide the unpiloted craft toward the space station.

Burns using the 23.6-foot-long (7.2-meter) spacecraft’s small rocket thrusters will allow the Progress to match the orbit of the space station, setting up for a radar-guided rendezvous and docking with the Russian segment’s Zvezda service module at 9:34 p.m. EDT Friday (0134 GMT Saturday).

Russia’s Progress MS-18 supply ship inside a processing facility at the Baikonur Cosmodrome. Credit: Roscosmos

The Progress MS-18 spacecraft will link up with the rear docking port on Zvezda. With the help of cosmonauts on the station, Russian engineers have traced a small air leak on the station to the transfer compartment leading to Zvezda’s rear port.

The compartment has been sealed from the rest of the space station since the departure of a previous Progress spacecraft from the rear docking port in April. But cosmonauts will re-open the compartment to unload cargo delivered by the Progress MS-18 spacecraft.

The mission is the 79th Russian Progress supply craft to launch toward the International Space Station since 2000.

Roscosmos, Russia’s space agency, said the Progress MS-18 spacecraft will deliver around 5,377 pounds (2,439 kilograms) of supplies to the station.

Russian ground teams loaded 3,327 pounds (1,509 kilograms) of dry cargo into the Progress freighter’s pressurized compartment, according to Roscosmos. The space agency said the mission carries 1,036 pounds (470 kilograms) of propellant to refuel Zvezda module’s propulsion system, 926 pounds (420 kilograms) of fresh drinking water, and 88 pounds of compressed gas to replenish the space station’s breathing air.

The launch of the Progress MS-18 supply ship this week follows the relocation of the Progress MS-17 cargo craft last week from one space station docking port to another. Progress MS-17 moved to a docking port on Russia’s Nauka lab module, the newest element of the space station, to help perform leak checks of the module’s propulsion system.

Progress MS-17 will undock from the space station next month to clear the way for arrival of another new Russian module, named Prichal, set for launch from Baikonur on Nov. 24.

Meanwhile, NASA is gearing up to launch four astronauts to the space station Sunday from Kennedy Space Center in Florida. The crew will ride a SpaceX Dragon capsule to the station to begin a six-month expedition in orbit, replacing an outgoing team of astronauts scheduled to return to Earth in early November.

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