NASA has assigned five astronauts for upcoming missions aboard the International Space Station (ISS), the US space agency said Wednesday.
Astronauts Joe Acaba, Ricky Arnold, Nick Hague, Serena Aunon-Chancellor and Shannon Walker all have begun training for missions launching later this year and throughout 2018.
Acaba will be the first to launch, assigned to the Expedition 53 and 54 crews that already include Mark Vande Hei of NASA, and Alexander Misurkin of the Russian space agency Roscosmos.
They will launch aboard a Soyuz spacecraft in September.
Walker will train as a dedicated backup for Acaba.
Arnold will join NASA's Drew Feustel and a Russian cosmonaut for Expeditions 55 and 56 to launch in March 2018.
Arnold and Acaba's assignments were enabled by the recent agreement to add additional crew members in 2017 and 2018 to boost space station science and research.
First-time fliers Hague and Aunon-Chancellor will fall into the standard rotation for NASA astronauts. Hague will launch in September 2018 on Expeditions 57 and 58 with two Russian cosmonauts.
Aunon-Chancellor will join the Expedition 58 and 59 crews in November 2018, along with Canadian Space Agency astronaut David Saint-Jacques and a Russian cosmonaut.
"It's great to get to announce so many assignments at once," said Chris Cassidy, chief of the Astronaut Office at NASA's Johnson Space Centre in Houston.
"There's plenty of work to be done at the space station, and the research opportunities are almost limitless. These folks are all going to do great work and bring a lot of value to their crewmates," said Cassidy.
Between now and their launches, each of the astronauts will undergo a busy regimen of training on space station systems and the experiments they'll work with while in space.
This will be Acaba's third trip to the space station and his second long-duration mission.
He was selected as an astronaut in 2004, and flew on space shuttle Discovery's STS-119 station assembly mission in 2009, before returning for a longer stay in 2012, as part of the Expedition 31 and 32 crews.
Arnold will be visiting the space station for the second time, but this trip will be much longer than his last.
He also was selected in the 2004 class and flew with Acaba on STS-119. On that mission, he conducted two spacewalks, spending 12 hours and 34 minutes outside the space station.
Selected as a member of the 2013 astronaut class, Hague is a colonel in the US Air Force.
Prior to his selection, he worked as an adviser to the US Senate on matters of national defence and foreign policy.
Aunon-Chancellor joined the astronaut corps in 2009, and has been at NASA since 2006, when she became a flight surgeon.
She also served as the deputy lead for medical operations for NASA's Orion spacecraft before being selected as an astronaut.
Walker spent 163 days as a flight engineer for Expedition 24 and 25 in 2010.