SpaceX supply ship unloaded by robots and astronauts
BY STEPHEN CLARK
Posted: May 5, 2014
The International Space Station's Dextre robot plucked a high-tech laser communications terminal from the trunk of a Dragon commercial cargo craft Monday, completing two weeks of unpacking the SpaceX supply ship's 4,600 pounds of experiments and provisions.
The Dragon spacecraft arrived at the space station April 20, two days after launching on top of a SpaceX Falcon 9 rocket from Cape Canaveral Air Force Station, Fla. The unmanned cargo ship is the third operational vehicle SpaceX has sent to the space station under a $1.6 billion contract with NASA.
The space station's astronauts were charged with removing the gear packed inside the Dragon's internal cargo hold. The job of unloading the capsule's trunk fell to the outpost's Canadian-built robotics system.
The crew last week finished transferring cargo from the Dragon spacecraft's pressurized section, totaling 1,576 pounds of science and research equipment supporting more than 150 experiments, 1,049 pounds of crew supplies, 449 pounds of vehicle hardware, and 271 pounds of spacewalk tools, including a fresh spacesuit.
Among the items were legs for the space station's Robonaut 2 humanoid robot, a research investigation aimed at demonstrating vegetable growth in a habitat aboard the complex, and an experiment funded by the National Institutes of Health seeking to identify the cause of a suppressed immune system during long-duration space missions. Scientists say the research could help treat auto-immune diseases like arthritis and diabetes.
The Dragon's cargo delivery also replenished dwindling food stockpiles on the space station.
For the first time, SpaceX hauled technological experiments inside the Dragon spacecraft's external trunk: the High-Definition Earth Viewing payload and the Optical Payload for Lasercomm Science, or HDEV and OPALS.
The space station's Dextre robot -- a 12-foot-tall, two-armed device with a toolkit for myriad repair and maintenance tasks -- moved the HDEV camera suite to a mounting plate on the European Columbus lab module May 1.
The camera system was activated and started transmitting high-quality views outside the space station May 2. You can watch live video from the HDEV camera system here.
Developed by engineers at the Johnson Space Center in Houston, the HDEV system includes four commercially available high-definition video cameras to stream live video of Earth for online viewing, according to a NASA fact sheet.
The experiment will help NASA determine what cameras work best in the harsh environment of space.
On Monday, Dextre was again at work, this time pulling OPALS from Dragon's cargo bay.
The schedule calls for ground controllers to relocate the robot arm Tuesday while OPALS remains in the clutch of Dextre. Final mounting of the laser communications box on an external logistics carrier is set for Wednesday.
The robotics operations are commanded by U.S. and Canadian engineers at NASA's Johnson Space Center in Houston.
The optical communications payload will demonstrate high-speed data links between the space station and a ground station in Wrightwood, Calif., near Los Angeles.
When the space station flies overhead, OPALS will send a pre-formatted video to the ground station via laser beam. Lasers offer a much faster way of transmitting large data files than conventional radio systems, potentially by a factor of 10 to 100, according to NASA.
OPALS was designed and built at NASA's Jet Propulsion Laboratory.
Matt Abrahamson, OPALS mission manager at JPL, said Monday the downlink experiments should begin by early June, after several commissioning tests over the next few weeks. The planned mission duration is 90 days.
"OPALS was constructed from commercial off-the-shelf parts that degrade with time in the radiation environment we expect at the space station," Abrahamson said. "Our plan is to achieve our mission goal to downlink enhanced-definition videos to the optical ground station during that 90-day timeframe."
Astronauts inside the space station have begun refilling the Dragon capsule with equipment assigned for return to Earth. Approximately 1.8 tons of hardware and experiment samples will be inside the Dragon spacecraft when it splashes down in the Pacific Ocean on May 18.
Release of the Dragon spacecraft by the space station's robot arm is set for May 18 at about 9:30 a.m. EDT (1330 GMT). Splashdown is scheduled for 3:05 p.m. EDT (1905 GMT) about 300 nautical miles west of Baja California, where recovery boats will await the capsule.
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