Some of this equipment will help NASA examine the nature of eye problems that that several astronauts have suffered from during and after long-term missions. Scientists suspect these issues may be caused by an increased buildup of fluid in the head in microgravity conditions, but more study is needed to confirm the idea, said Marshall Porterfield, NASA's life and physical sciences director
Other payloads aboard Dragon will support genetic comparisons between the now world famous crew member and one-year ISS resident, Scott Kelly and his twin brother, Mark, who is being studied on Earth as a control.
"It's allowing us to make a leap from [missions of] six months to a year and project out what we need to do to protect humans over longer periods of time," Porterfield said during a prelaunch news conference Sunday (April 12).
Dragon's cargo also includes 20 mice and many other items.?The rodents are flying as part of an experiment that will look at how long periods of time spent in space can affect bone growth, density and strength. Space station crewmembers will X-ray the mice and dissect them, according to NASA officials.
The large amount of gear required for the science experiments has pushed other equipment off to later missions, underscoring NASA's priority for science and medical discoveries in a space environment. Dragon was originally supposed to fly parts to change a docking port to prepare the orbiting lab for commercial vehicles, but that payload was shifted to a later flight to give astronauts more time for science, said Kirt Costello, deputy chief scientist for the International Space Station.
"This [rodent] investigation requires a significant amount of crew time," Costello said during another news conference on Sunday (April 13) "We did have plans to fly a payload in the trunk; that payload would have taken a significant amount of time to install on orbit as our international docking adaptor system."
Dragon's cargo also includes experiments designed to improve medicine and robotics. One is a crystal-growth experimental study from Paul Reichert, a scientist at Merck Research Laboratories in New Jersey who previously flew protein-growth experiments on 11 space shuttle missions.
Reichert said he hopes this process will create larger and more uniform crystals for a class of drugs called biologics. Currently, many of these kinds of drugs can only be delivered by IV at a hospital, increasing costs and stay time for patients. Reichert's aim is to make biologics that could be more easily delivered to patients either by a one time injection at home, or in a doctor's office, eliminating the needs for hospital stays.
"That would have a significant impact on the ease of administration and the comfort of the patients," he said.
Dragon is also flying a synthetic muscle (an electroactive polymer) to the station, which will remain there for up to 80 days to test its resistance to radiation. This kind of synthetic muscle can hopefully be used in robots, making their movements and abilities more human-like, but first NASA wants to compare how it functions with what they already know about metal robotic movements.