NASA astronaut and Astronaut Office Representative Shannon Walker plants a tree with the help of Russian Orthodox Priest, Father Alexander, during a traditional ceremony at the Cosmonaut Hotel in Karaganda, Kazakhstan, Tuesday, Oct. 2, 2018. Walker is in Karaganda to help support the Expedition 56 crew Soyuz landing from the International Space Station. Photo Credit: (NASA/Bill Ingalls)

Russian Orthodox Priest, Father Alexander, watches over the landing zone after the Soyuz MS-08 spacecraft landed with Expedition 56 Commander Drew Feustel and Flight Engineer Ricky Arnold of NASA, along with Flight Engineer and Soyuz Commander Oleg Artemyev of Roscosmos near the town of Zhezkazgan, Kazakhstan on Thursday, Oct. 4, 2018. Feustel, Arnold, and Artemyev are returning after 197 days in space where they served as members of the Expedition 55 and 56 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Charles Bolden, right, joins in a group portrait with the niece of Martin Luther King, Jr., Alveda King, far left, Father Frank Pavone, wife of Martin Luther King, Jr's brother, Mrs. Naomi Barber King, Dr. Cameron Alexander, Dr. Frederick D. Haynes III, daughter of Martin Luther King, Jr., Dr. Bernice A. King, Kasim Reed, Mayor of Atlanta, Dr. Christine King Farris, Martin Luther King, Jr's sister, and Ms. Raj Razdan shortly after the 44th annual Martin Luther King, Jr. Commemorative Service on Monday, Jan. 16, 2012 at Ebenezer Baptist Church in Atlanta. Photo Credit: (NASA/Bill Ingalls)

Expedition 39 Soyuz Commander Alexander Skvortsov of the Russian Federal Space Agency, Roscosmos, center, receives the traditional blessing from a Russian Orthodox priest at the Cosmonaut Hotel prior to his launch on the Soyuz rocket to the International Space Station, Tuesday, March 25, 2014, in Baikonur, Kazakhstan. Skvortsov, Flight Engineer Steve Swanson of NASA, and Flight Engineer Oleg Artemyev of Roscosmos will spend six months living and working aboard the ISS. Photo Credit: (NASA/Bill Ingalls)

Flight Engineer Oleg Artemyev of the Russian Federal Space Agency, Roscosmos, right, receives the traditional blessing from a Russian Orthodox priest at the Cosmonaut Hotel prior to his launch on the Soyuz rocket to the International Space Station, Tuesday, March 25, 2014, in Baikonur, Kazakhstan. Artemyev, Soyuz Commander Alexander Skvortsov of the Russian Federal Space Agency, Roscosmos, and Flight Engineer Steve Swanson of NASA will spend six months living and working aboard the ISS. Photo Credit: (NASA/Bill Ingalls)