The European Space Agency is investigating potential damage to the International Space Station (ISS) docking port which was used by Progress 51P on April 26. The damage, caused by the undeployed Progress antenna, appears to have involved a navigational aid needed for ATV-4, scheduled for June.
The docking between the cargo spacecraft and the space laboratory may have damaged the Laser Radar Reflector (LRR) target. The LRR is needed for the automatic docking of the European ATV during the last part of the rendezvous operations. If the damage is confirmed, the device, recently replaced during an EVA by the Russian crew due to contamination of the optical section, will need to be replaced again. In this event, the European cargo ship could potentially be delayed for several months. ATV-4, named Albert Einstein, has been already delayed from April to June because of a glitch in an avionics box.
Progress 51P lifted off from Baikonour Cosmodrome, carrying three tons of propellant, food, water, scientific equipment, and spare parts, on April 24. Soon after Progress settled into orbit, one of the five KURS antennas required for the docking with the station failed to deploy. Russian engineers managed to circumvent the glitch with a software patch, aiding the KURS, which enabled the final approach and docking to be executed with negligible delay. Russian cosmonauts Vinogradov and Romanenko were on standby with TORU, the backup manual control system, located in the Zvezda module in the event that human intervention should be required. Although controllers at NASA’s Johnson Space Center had expressed concern about a potential collision between the off-nominal KURS antenna and the 4AO-BKA antenna, no suspicious noises were recorded during the operation.
Video courtesy of NASA
Historically, there have been only 2 cases of collision between service spacecraft and orbital stations. In January 1994, Soyuz TM-17 struck MIR space station with two glancing blows, 2 seconds apart, during proximity operations due to a switch error. A more serious accident occurred on June 25, 1997, during testing of the MIR station’s manual docking system. Progress M-34 cargo ship struck and punctured the MIR’s Spektr module, causing the station to depressurize and leading to Spektr being permanently sealed off. In addition, the solar arrays were also damaged which in turn led to a power crisis on board, causing the station to power down, which resulted in MIR beginning to spin and drift.
Progress 51 is scheduled to remain docked at ISS until June 11. ATV-4 is still planned to dock four days after Progress departs from the same port. However, if the damage is confirmed, the astronauts on board will need to perform an EVA to replace the recently changed target to allow the docking of the two remaining ATV vehicles.
This article was written by Matteo Emanuelli and originally appeared on Space Safety Magazine. It can be reviewed here: ATV-4
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