Earlier this year, Roscosmos announced it would be reducing its crew on each International Space Station expedition from three to two. This means only five people will participate in each expedition as opposed to the normal six. As such, NASA has updated the 2017 crew assignments for the outpost.
In a bid to save money to launch the long-delayed Nauka science module, Roscosmos announced they would be cutting back on its yearly Progress cargo launches from four per year to three, which is not enough to support the usual six cosmonauts per year. However, according to the Russian state corporation, only two cosmonauts – four per year – are needed to maintain the Russian orbital segment of the outpost.
This reduction has been described by Roscosmos as a temporary measure. Three-cosmonaut crews would return as soon as the science module is launched, which is currently scheduled for late 2017 or early 2018.
NASA and other international partner crews will continue with minimal impact to each expedition mission. U.S. orbital segment crews will continue to rely on commercial cargo ships from SpaceX and Orbital ATK as well as from the Japanese H-II Transfer Vehicle for food, supplies, and equipment.
Updated crew assignments
In March 2017, two members of Expedition 51/52 will launch in Soyuz MS-04. They will be NASA astronaut Jack Fischer and Russian cosmonaut Fyodor Yurchikhin.
Two months later, in May 2017, Soyuz MS-05 will launch with NASA astronaut Randy Bresnik, European Space Agency astronaut Paolo Nespoli, and Russian cosmonaut Sergey Ryazanskiy to form part of Expedition 52 and 53.
Then, in September 2017, Expedition 53/54 will launch in Soyuz MS-06, which will include NASA astronaut Mark Vande Hei and Russian cosmonaut Alexander Misurkin.
Finally, in October 2017, Expedition 54/55 will launch in Soyuz MS-07 with NASA astronaut Scott Tingle, Japanese astronaut Norishige Kanai, and Russian cosmonaut Alexander Skvortsov.
Currently residing on the outpost are members of Expedition 50. This includes NASA astronaut Shane Kimbrough, and Russian cosmonauts Andrei Borisenko. They have been in space since October 2016. Joining them on Nov. 19, upon docking in their Soyuz MS-03, will be NASA astronaut Peggy Whitson, Russian cosmonaut Oleg Novitskiy, and ESA astronaut Thomas Pesquet.
The Expedition 50 crew will be the last, for at least a year, to have six members. Additionally, with some Soyuz spacecraft launching to the space station with only two crew members, this means that, for brief periods of time, the crew size will reduce to only two. The first is expected in May 2017 between when Soyuz MS-03 leaves the station and when MS-05 launches. That will be the smallest number aboard the ISS since Expedition 13 in 2006.
History of ISS crew size
Starting with Expedition 1, crew sizes were set at three with the expectation of increasing as the outpost grew. However, between 2003 and 2006, ISS expeditions only included two people. This was because of the grounding of the Space Shuttle fleet after the loss of Columbia on Feb. 1, 2003.
The reduction was necessary for a number of reasons. One of the biggest had to do with supplies. Back then, only the Space Shuttle and Progress were capable of bringing cargo to the outpost. It would be a number of years before Europe’s Automated Transfer Vehicle or Japan’s HTV would fly. Additionally, there wouldn’t even be a commercial cargo program until 2006 and those vehicles didn’t fly until 2012.
As such, to save money and maintain a crew caretaker presence on the outpost, it was opted to reduce crews from three to two. Once the Space Shuttle started flying again in 2006, expeditions once again grew in size. In 2009, with the station nearly completed and ATV and HTV flying, crew sizes increased to six to allow for a large amount a science to be conducted while maintaining the station.
Once Nauka is launched, Russia will reinstate a third cosmonaut into its crews. Additionally, in late 2018, when commercial crew spacecraft start supporting the ISS crew rotation, NASA is also expected to add a third crew member. This means the ISS crew size could increase to seven as early as 2019.
NOTE: While this article was written by Derek Richardson, it was originally published at SpaceFlight Insider. Feel free to head over there to read all the stuff they write about!