The International Space Station soon returns to a stable rotation of four U.S. Operating Segment (USOS) crew members thanks to the first launch of NASA's Commercial Crew Program (CCP).
"Returning to stable rotation effectively doubles the amount of time we have available for research," says NASA ISS Deputy Chief Scientist Jennifer Buchli.
Since 2010, the CCP has worked with Boeing and SpaceX to design, build, test and operate systems to transport humans to low-Earth orbit. These partners have conducted multiple test missions as part of the process to begin regularly flying crew missions to the space station.
Demo-1, SpaceX's inaugural uncrewed flight, tested the end-to-end capabilities of the company's new system. The next step is Demo-2, scheduled for launch from Florida no earlier than May 27, with NASA astronauts Robert Behnken and Douglas Hurley aboard the Crew Dragon spacecraft.
This and future commercial flights are key to ongoing scientific work on the space station, the only platform for long-duration research in microgravity. During its nearly 20 years of continuous occupation, the orbiting lab's residents have conducted almost 3,000 experiments in many scientific fields, as well as technology demonstrations. CCP is part of ongoing efforts to increase the time dedicated to advancing important science and technology demonstrations to enable future missions to the Moon and Mars.
Typically, the space station crew consists of six people, three of them USOS crew members, but it functions with as few as three total crew. NASA's commercial crew contracts call for the flights to transport four crew members to space at a time. The more crew members, the more time they can dedicate to scientific research, and the more research, the more results.
Those results include thousands of scientific papers, many in top scientific journals. They also fuel a growing space economy and private sector interest in space as well as support for NASA's Artemis program to return humans to the Moon and on to Mars. Space station investigations generate many and varied benefits to humanity as well, ranging from improvements in development of pharmaceuticals to better disaster response, improved materials manufacturing, advances in robotics, bioprinting human tissue and much more.
While many station experiments now require less crew involvement thanks to increasingly automated research facilities, hands-on astronaut participation remains key for numerous microgravity studies. Safe, reliable and cost-effective transportation to and from the space station is what enables these experiments to continue, and that's where commercial flights come in.
Commercial crew flights also enable NASA to adjust the duration of astronaut visits in order to close gaps in data about how long-duration space missions affect human health, Buchli says. "We have quite a bit of data about the physiological changes astronauts experience during six-month expeditions and short duration flights through the Space Shuttle program. But to increase our understanding of astronaut health and develop countermeasures, we need missions of roughly one year as well as durations of 30 to 60 days. Varying mission lengths will enable us to reduce risks to astronaut health for longer exploration missions to the moon and Mars."
The commercial flights increase the amount of cargo that can be sent to the station as well, and they have the capability to return scientific samples to Earth and put them in the hands of researchers more quickly. That opens up the microgravity lab to even more types of research.
NASA also continues to validate performance of Boeing's Starliner in anticipation of a flight carrying NASA astronauts Nicole Mann and Mike Fincke and Boeing's Christopher Ferguson to the space station.
"We are looking forward to launching astronauts to the station from the U.S. again and returning to an increased four crew presence through the Commercial Crew Program," Buchli says.
Because CCP capability ultimately means more science, and science is what the space station is all about.