The CRS-22 Dragon cargo ship undocked from the station's Harmony module at 10:40 a.m. EDT (1440 GMT), departing for a return to Earth and an eventual arrival in the the Gulf of Mexico off the coast of Tallahassee, Florida.
It will take 37 hours for Dragon to return to Earth, with splashdown set for Friday, July 9, at 11:30 p.m. EDT (0330 July 10 GMT), NASA officials said in a live webcast, likely due to a 48-hour delay in departure caused by Tropical Storm Elsa surging along the eastern coast of the United States. Splashdown will not be broadcast live.
Usually a Dragon ship returns to Earth within a day or two of undocking or unberthing, as some of the experiments are typically refrigerated. The experiments will be sent back to NASA's Space Station Processing Facility at the agency's Kennedy Space Center in Florida to minimize the effects of gravity on the samples, the press release stated.
But the agency said it would not rush the splashdown process. "Certain parameters like wind speeds and wave heights must be within certain limits to ensure the safety of the recovery teams, the science, and the spacecraft," NASA said in a Wednesday press release.
The ship, carrying 5,000 lbs. (roughly 2,265 kilograms) of equipment, experiments and other things, was supposed to depart the station on Tuesday (July 6) and then Wednesday (July 7), but continued high winds and dangerous conditions from Elsa forced delays.
The cargo ship departed the Kennedy Space Center in Florida on June 3 for a docking on June 5, carrying 7,300 lbs. (3,311 kg) of supplies for the space station crew. Among its cargo were new Boeing-built ISS Roll-Out Solar Arrays that spacewalking astronauts have been deploying this month to boost power levels on the ISS. (The older arrays are still working, but are beyond their design lifetime and showing expected power declines.)
In NASA's words, some of the key experiments Dragon will return from space include:
- Lyophilization-2, which "examines how gravity affects freeze-dried materials and could result in improved freeze-drying processes for pharmaceutical and other industries."
- Molecular Muscle Experiment-2, which "tests a series of drugs to see whether they can improve health in space, possibly leading to new therapeutic targets for examination on Earth."
- Oral Biofilms in Space, which "studies how gravity affects the structure, composition, and activity of oral bacteria in the presence of common oral care agents."
SpaceX's next cargo ship, Dragon CRS-23, is expected to launch from Launch Complex 39A at the Kennedy Space Center on Aug. 18, according to Spaceflight Now's worldwide launch schedule. The flight will be the 23rd mission by SpaceX conducted under a Commercial Resupply Services contract with NASA.
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