After a month long stay, SpaceX's Dragon spacecraft returned from the International Space Station (ISS) this morning carrying about 3,800 pounds of cargo, including the results of scientific experiments Expedition 61 Astronauts conducted onboard the orbiting laboratory. Today marked the end of CRS-19, SpaceX's 19th mission under their Commercial Resupply Cargo Services contract with NASA.
A 5-hour journey back to Earth initiated when the SpaceX Dragon spacecraft was released from the space station's Harmony module at 5:05 a.m. EST. Flight controllers in Houston delivered remote commands to the station’s Canadarm2 robotic arm to release the craft.
Departure confirmed! @SpaceX’s #Dragon spacecraft was released from the @Space_Station at 5:05am ET. Next, Dragon will fire its thrusters to move a safe distance from the station, then execute a deorbit burn as it heads for a parachute-assisted splashdown: https://t.co/4UnTiSC051 pic.twitter.com/KlDGMLCy8R— NASA (@NASA) January 7, 2020
After drifting a safe distance away from the station, Dragon fired its engines to conduct a deorbit burn that took the craft right into Earth's atmosphere. Upon reentry, Dragon deployed its integrated parachutes to splash down into the Pacific Ocean about 271 miles southwest of Long Beach, California, at approximately 10:42 a.m.
Splashdown of Dragon confirmed, completing this spacecraft’s third mission to and from the @space_station!— SpaceX (@SpaceX) January 7, 2020
This was the third mission for this particular Dragon spacecraft, it is the second time SpaceX has reused the same Dragon craft three times for a NASA cargo mission, demonstrating the craft is still reliable to send and return cargo safely again after being reused. Reusing spacecraft is a huge accomplishment in the space flight industry because it reduces manufacturing and operation costs.
Some of the many scientific investigations that returned to Earth from the orbiting laboratory include:
40 Mighty Mice
This experiment is known as Rodent Research-19. SeJinLee, a professor at the Jackson Laboratory and University of Connecticut School of Medicine, and his team sent a group of 40 mice aboard SpaceX's Dragon spacecraft to the space station in December.
The mice were used for an experiment that will study how to combat muscle degradation in space. "When we engineered the mice to lack myostatin, they grew to twice their normal size," Lee said during a NASA conference. "We call them mighty mice." These engineered mighty mice do not have a key protein called myostatin, which inhibits muscle growth.
Myostatin can be used to treat a variety of muscle-wasting disorders. This research aims to figure out if blocking myostatin in mice can prevent muscle loss in space. The mice will live in four habitats on the station and will be compared with 40 other mice in similar habitats on Earth. All 40 mice are expected to be alive, now that they returned.
This investigation will help aid in the creation of a potential solution for muscle degradation. "Astronauts lose muscle and bone mass, so anything to prevent this can help maintain astronauts during space flight," Lee said, "It's also a huge problem for people here on Earth, in both children and adults. We hope to test a therapeutic strategy that will help (people with) lots of different conditions."
Tiny Aquatic Creatures
Another experiment called, Rotifer-B1, investigated Adineta vaga rotifers, which are tiny aquatic creatures found in freshwater ecosystems and soil. Rotifiers are highly resistant to radiation on Earth, so the experiment was launched to the orbiting laboratory to find out if the rotifer could adapt to space radiation in microgravity.
Perfect Crystals Experiment
The Growth of Large, Perfect Protein Crystals for Neutron Crystallography (Perfect Crystals) experiment, that aims to find the perfect solution to deal with radiation was also conducted at the ISS. On Earth, our bodies experience very low levels of radiation through a protein that naturally occurs in our bodies that helps us safely process radiation. This research will help scientists find a way to deal with the problem of radiation during spaceflight missions by using the same protein that is already inside our bodies.
"These are just a few of the hundreds of investigations providing opportunities for U.S. government agencies, private industry, and academic and research institutions to conduct microgravity research that leads to new technologies, medical treatments and products that improve life on Earth. Conducting science aboard the orbiting laboratory will help us learn how to keep astronauts healthy during long-duration space travel and demonstrate technologies for future human and robotic exploration beyond low-Earth orbit to the Moon and Mars."