Supply mission lets astronauts breathe easier

 作者:拓跋稞     |      日期:2019-02-27 06:09:01
By Kelly Young A Russian supply ship docked with the International Space Station early on Sunday (0042 GMT), but not without a hitch. The Progress cargo ship normally flies on autopilot as it approaches the station, but this time, a communication problem prevented Progress from docking on its own. Russian cosmonaut and ISS commander Sergei Krikalev took over the controls and guided the ship over the final 100 metres to the station. Ground control in Moscow was unable to use the automated docking system because of a power failure at the ground station that sends the command to the Progress ship to start the approach. Rather than wait for power to be restored, Russian ground control opted for Krikalev to control the Progress, says NASA spokesman Rob Navias. Krikalev had never controlled a Progress from space, “but he’s the most experienced cosmonaut in history”, Navias says. Krikalev will set the world record for cumulative time in space during this six-month stint on the ISS. The Progress ferried over two tonnes of supplies to Krikalev and US crewmate John Phillips. The space station’s main oxygen generator, the Elektron, broke down several weeks ago so the station was relying on Earth to deliver all of its oxygen. The two crewmembers have been inserting two solid-fuel cartridges a day into Russian-made oxygen-generating candles. Prior to the Progress’ arrival, the crew had less than 90 of these cartridges remaining onboard, plus about 160 kilograms of pressurised oxygen. The Progress brought up 40 more cartridges and an extra 110 kilograms of pressurised oxygen. This equates to an additional 85 days of oxygen for the crew. Krikalev will also install a newly-delivered set of filters for the Elektron oxygen generator on Thursday to try to revive the ailing machine. “We’ll keep our fingers crossed,” Kirk Shireman, ISS operations and integrations manager for NASA, told reporters prior to the launch. “We plan for the worst and hope for the best.” The Progress cargo ship also carried 180 kilograms of fuel to raise the station’s orbit, and over 1360 kilograms of spare parts. Among the supplies was a new digital camera to take pictures of space shuttle Discovery as it approaches the space station on its next launch. The pictures will be analysed to determine whether Discovery’s heat shield sustained any damage during launch. Another digital camera onboard has a memory problem and does not always record images to its internal disk, so NASA wanted to ensure that there were spares onboard. Krikalev and Phillips began hauling supplies out of the ship on Sunday. The spacecraft also ferried water,