This is the actual NASA graphic illustrating the "Space Poop Challenge." NASA hide caption

NASA astronaut Shane Kimbrough shows a pouch of turkey he will be preparing for his crew in celebration of the Thanksgiving holiday, aboard the International Space Station. AP hide caption

Astronaut Kate Rubins and Expedition 48 Cmdr. Jeff Williams speak during an interview aboard the International Space Station last month. NASA via AP hide caption

Tina Buechner da Costa (left) hopes to become Germany's female astronaut. Claudia Kessler (right), CEO of HE Space, is organizing a campaign to send the first German woman into space. Soraya Sarhaddi Nelson/NPR hide caption

U.S. astronaut Scott Kelly shows a victory sign after landing safely on Earth after nearly a year in space. Kirill Kudryavtsev/AFP/Getty Images hide caption

Extravehicular crewmember 2 (EV2) Terry Virts is reflected in the helmet visor of EV1 Barry Wilmore during Extravehicular Activity 29 (EVA 29). Earth is in the background. Courtesy of NASA hide caption

It may be a long trip. Don't forget to pack the tampons. NASA hide caption

On Friday, a Russian Soyuz rocket will send an unmanned cargo ship with more than 3 tons of food, water and fuel for astronauts aboard the International Space Station. Russian Federal Space Agency hide caption

Expedition 45 poses for a Star Wars themed portrait NASA hide caption

India's test crew module floating in the Andaman Sea after splash down. N. Balbantray/Indian Space Research Organization (ISRO) hide caption

Air Force Col. Steven Nagel joined NASA in 1978 and flew four space shuttle missions, logging more than 700 hours in space. He retired from the space agency in 2011. Nagel died of cancer on Thursday. NASA hide caption

During the Apollo 12 mission, astronaut Alan Bean holds a container of lunar soil. The astronaut Charles "Pete" Conrad, who took the photograph, is reflected in Bean's faceshield. Bean says he used to think that in his lifetime, we'd build a base on the moon and start preparing to travel to Mars. Hulton Archive/Getty Images hide caption

Screen grab from astronaut Chris Hadfield's rendition of David Bowie's "Space Oddity" — performed on the International Space Station. Chris Hadfield/YouTube hide caption