This afternoon, three astronauts launched on a two-day journey to chase down the International Space Station (ISS). When they catch up with the orbital outpost on Saturday, the trio — which includes NASA astronaut Peggy Whitson (who becomes the oldest woman to ever go into space), Russian cosmonaut Oleg Novitskiy, and French astronaut Thomas Pesquet — will bring the ISS crew back up to full staff.

Following a two-day journey, they will join NASA’s Shane Kimbrough, and Russia’s Sergey Ryzhikov and Andrey Borisenko for a six-month stay in space. This mission, dubbed Expedition 50, is a major milestone as it marks the 50th (or golden) expedition for the space station. And best of all, it’s part of a rocket launch double header.

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Pesquet is a space greenhorn, embarking on his first mission into space, and becoming only the 10th French astronaut to do so. He is joined by NASA veteran Peggy Whitson, who is 56 years old. Expedition 50 is Peggy’s third trip to the space station. (Fun fact: she will also celebrate her 57th birthday in space). John Glenn still holds the record for being the oldest human to fly in space at 77 years old.

NASA astronaut Peggy Whitson, Russian cosmonaut Oleg Novitsky, and French astronaut Thomas Pesquet launched to space today.
NASA astronaut Peggy Whitson, Russian cosmonaut Oleg Novitsky, and French astronaut Thomas Pesquet launched to space today. 

In 2007, Whitson made history by becoming the first woman to ever assume command of the space station, and as part of her third trip to space, she will go one step further and become the only woman to command the space station — twice. In April, she is expected to surpass Jeff Williams as NASA’s longest space flier. In total, Williams has logged 534 days in space.

Veteran cosmonaut, Oleg Novitsky, is commanding the Soyuz spacecraft during the trio’s planned two-day trek to rendezvous with the space station. During this time, the trip will test out systems on the upgraded Soyuz MS-03 spacecraft. If all goes according to plan, we could see future flights resume the standard four-orbit rendezvous profiles, which places crews on board the station within six hours as opposed to two days.

During their stay aboard the space station, Whitson and crew will conduct as smorgasbord of research experiments, including an experiment designed to study the properties of neutron stars. Researchers hope the experiment will allow engineers to determine if these cosmic beacons could be used as a form of interstellar GPS.

The crew will also welcome both a Russian Progress cargo ship and a Japanese HTV freighter in December. The HTV is carrying six special lithium-ion batteries that will replace the current nickel-hydrogen batteries in one of the stations solar arrays, which will call for two space walks in January.

Starting in March 2017, we will see some changes to the crew aboard the ISS, as Russia has indicated they will temporarily reduce the number of cosmonauts.

Currently, the Soyuz is the only vehicle capable of ferrying people to and from the ISS, but NASA is hoping that will change in 2018 when its Commercial Crew program gets off the ground. A typical Soyuz launch has two different crew setups. The first is like the configuration we see today — one cosmonaut accompanying a NASA astronaut and an international partner (such as the European Space Agency or the Japanese Aerospace Exploration Agency). The second features a NASA astronaut and two Russian cosmonauts. This type of rotation keeps the crew size at six. When NASA’s commercial partners begin launching people, we could see many more astronauts, albeit for shorter periods of time.

However, NASA released the crew manifests for the upcoming flights in 2017, and future launches that would have normally featured two cosmonauts, will only have one. So far, it’s unclear if that might change.

Photos via NASA (1, 2)