What was intended as a two-week test flight of SpaceX’s new astronaut-carrying capsule will now be a mission planned to last more than a month to help a short-handed crew aboard the International Space Station.
The launch of SpaceX’s Crew Dragon capsule, carrying two NASA astronauts, Douglas G. Hurley and Robert L. Behnken, is scheduled for May 27 from Kennedy Space Center in Florida. It would arrive at the space station the following day.
“This is a high priority mission for the United States of America,” Jim Bridenstine, the NASA administrator, said during a news conference on Friday.
That will end a drought of nearly nine years since the last time people headed to orbit from American soil. On July 8, 2011, the space shuttle Atlantis lifted off from Launchpad 39A; it returned to Earth 11 days later. Since then, NASA has relied on Russia and its Soyuz rockets for transportation to and from the space station.
Mr. Bridenstine noted that this would be only the fifth time NASA astronauts have flown on a new spacecraft for the first time. The previous ones were Mercury, Gemini and Apollo during the 1960s and the space shuttle in 1981.
“We should not lose sight of the fact that this is a test flight,” Mr. Bridenstine said. “We’re doing this to learn things. And it’s also true we’re taking it very, very seriously from a safety perspective.”
Like the last shuttle mission, the launch will occur at 39A, but almost everything else will be different. Instead of designing and operating its own spaceship as it did for the space shuttles and earlier programs like the Apollo moon landings, NASA has turned to two private companies, SpaceX and Boeing.
For SpaceX, the May flight is the last step to certify that its spacecraft meets NASA’s needs and requirements. As the Crew Dragon approaches the space station, for example, the astronauts will test flying the spacecraft by manual control before letting its automated system perform the docking.
The two astronauts will also get to use the bathroom facility in the capsule during the 19 hours from launch to docking at the space station. “The toilet?” Mr. Hurley said. “We’ll let you know how it works out. They have one. We’ll try it out, and we’ll let you know when we get back.”
Currently there are only three astronauts aboard the International Space Station — two Russians, Anatoly Ivanishin and Ivan Vagner, and one NASA astronaut, Christopher J. Cassidy. The smaller station crew is preoccupied with maintenance tasks, and that limits the amount of scientific research that can be performed.
NASA officials decided to extend the stay of Mr. Hurley and Mr. Behnken at the space station so that they can help Mr. Cassidy. The SpaceX capsule is currently certified to remain 119 days in orbit. Over time, oxygen atoms in the upper atmosphere react with materials on the capsule’s solar arrays, reducing the amount of power they generate.
The length of the stay also depends on the status of the next Crew Dragon, the first operational mission which is designated Crew-1, which is to take four astronauts to the space station later this year. SpaceX and NASA need the demonstration Crew Dragon to return to Earth to certify that the spacecraft meets NASA’s safety requirements and that it is ready to start routine missions.
“It is a trade off,” said Kirk A. Shireman, the program manager for the space station for NASA. “What we would like to do, from a space perspective, is keep them on orbit as long as we can until that Crew-1 vehicle is just about ready to go.”