Russia’s Progress 53 cargo capsule carried out a successful but unexpected cosmonaut-assisted docking with the six-person International Space Station late Friday, following a four day journey that included a satisfactory test of the suddenly balky upgraded rendezvous system.
The linkup at the ISS Russian segment Zvezda module occurred at 5:30 p.m., EST.
The latest unpiloted Progress spacecraft, which delivered just under three tons of fuel, science equipment, spare parts, water, and compressed oxygen and air, will remain docked to serve as a source of propulsion for station altitude raising and debris avoidance maneuvers.
As Progress 53 moved within 60 meters of the station for Friday’s docking, the capsule's new KURS-NA automated rendezvous system faulted to the manually commanded TORU backup mode. Station commander Oleg Kotov was standing by, ready to transmit remote commands with a joystick, in case of difficulty.
Kotov’s steady hand issued commands from a Zvezda module command and video display panel that led to a linkup just two minutes later than scheduled.
Progress 53 lifted off from the Baikonur Cosmodrome in Kazakhstan atop a Soyuz booster on Monday at 3:53 p.m. EST.
On Wednesday, the Russian freighter carried out a scheduled pass within one mile of the station for a trial activation of the KURS-NA rendezvous system, which features three fewer antennas, upgraded electronics, lower power requirements and less mass than the automated rendezvous equipment it replaces. The changes also remove a potential docking obstruction.
The mid-week KURS-NA testing went well, with the freighter moving out in front of the ISS after rendezvous transmissions from Progress 53 were recognized by the station’s Russian segment. The freighter then moved behind and below the ISS to begin the final rendezvous and docking run.
The test mission was accommodated by changing the typical Progress mission timeline, six hours for the more recent “express” missions and two days for the typical cargo delivery.
The new KURS-NA system, which the Russians developed when components from a previous supplier became unavailable, are in line for use on future Soyuz crew as well as Progress re-supply craft.