
NASA astronaut Ricky Arnold answers questions from the audience after speaking about his time onboard the International Space Station, Thursday, May 2, 2019 at NASA’s Goddard Space Flight Center in Greenbelt, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut Ricky Arnold speaks about his time onboard the International Space Station, Thursday, May 2, 2019 at NASA’s Goddard Space Flight Center in Greenbelt, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut Ricky Arnold speaks about his time onboard the International Space Station, Thursday, May 2, 2019 at NASA’s Goddard Space Flight Center in Greenbelt, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut Ricky Arnold speaks about his time onboard the International Space Station, Thursday, May 2, 2019 at NASA’s Goddard Space Flight Center in Greenbelt, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut Ricky Arnold speaks about his time onboard the International Space Station, Thursday, May 2, 2019 at NASA’s Goddard Space Flight Center in Greenbelt, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut Ricky Arnold speaks about his time onboard the International Space Station, Thursday, May 2, 2019 at NASA’s Goddard Space Flight Center in Greenbelt, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut Ricky Arnold answers questions from the audience after speaking about his time onboard the International Space Station, Thursday, May 2, 2019 at NASA’s Goddard Space Flight Center in Greenbelt, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut Ricky Arnold speaks about his time onboard the International Space Station, Thursday, May 2, 2019 at NASA’s Goddard Space Flight Center in Greenbelt, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut Ricky Arnold speaks about his time onboard the International Space Station, Thursday, May 2, 2019 at NASA’s Goddard Space Flight Center in Greenbelt, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut Ricky Arnold answers questions from the audience after speaking about his time onboard the International Space Station, Thursday, May 2, 2019 at NASA’s Goddard Space Flight Center in Greenbelt, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut Ricky Arnold speaks to students in the Science, Discovery and the Universe Scholars Program about his time onboard the International Space Station, Thursday, May 2, 2019 at the University of Maryland in College Park, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut Ricky Arnold speaks to students in the Science, Discovery and the Universe Scholars Program about his time onboard the International Space Station, Thursday, May 2, 2019 at the University of Maryland in College Park, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut Ricky Arnold speaks to students in the Science, Discovery and the Universe Scholars Program about his time onboard the International Space Station, Thursday, May 2, 2019 at the University of Maryland in College Park, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut Ricky Arnold speaks to students in the Science, Discovery and the Universe Scholars Program about his time onboard the International Space Station, Thursday, May 2, 2019 at the University of Maryland in College Park, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut Ricky Arnold speaks to students in the Science, Discovery and the Universe Scholars Program about his time onboard the International Space Station, Thursday, May 2, 2019 at the University of Maryland in College Park, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut Ricky Arnold speaks to students in the Science, Discovery and the Universe Scholars Program about his time onboard the International Space Station, Thursday, May 2, 2019 at the University of Maryland in College Park, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut Ricky Arnold presents a montage from his mission to Alan Peel, program director, and Erin Thompson, program associate, for the Science, Discovery and the Universe Scholars Program following his presentation to students, May 2, 2019 at the University of Maryland in College Park, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut and Maryland native Ricky Arnold takes a picture with a young fan before the Tampa Bay Rays take on the Baltimore Orioles, Saturday, May 4, 2019 at Camden Yards in Baltimore, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut and Maryland native Ricky Arnold is seen on field before the Tampa Bay Rays take on the Baltimore Orioles, Saturday, May 4, 2019 at Camden Yards in Baltimore, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut and Maryland native Ricky Arnold signs an autograph before the Tampa Bay Rays take on the Baltimore Orioles, Saturday, May 4, 2019 at Camden Yards in Baltimore, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut and Maryland native Ricky Arnold signs a baseball for a young fan before the Tampa Bay Rays take on the Baltimore Orioles, Saturday, May 4, 2019 at Camden Yards in Baltimore, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut Ricky Arnold presents Robert Gabrys, director of the Office fo STEM Engagement at NASA’s Goddard Space Flight Center, a montage from his mission onboard the International Space Station, Thursday, May 2, 2019 at NASA’s Goddard Space Flight Center in Greenbelt, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut Ricky Arnold presents Robert Gabrys, director of the Office fo STEM Engagement at NASA’s Goddard Space Flight Center, a montage from his mission onboard the International Space Station, Thursday, May 2, 2019 at NASA’s Goddard Space Flight Center in Greenbelt, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut Ricky Arnold speaks about his time onboard the International Space Station (ISS) during Expeditions 55 and 56, Friday, May 3, 2019 at the Challenger Center in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold speaks about his time onboard the International Space Station (ISS) during Expeditions 55 and 56, Friday, May 3, 2019 at the Challenger Center in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold watches a timer while students conduct an experiment on effervescence, Friday, May 3, 2019 at the Challenger Center in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the International Space Station (ISS), and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold speaks about his time onboard the International Space Station (ISS) during Expeditions 55 and 56, Friday, May 3, 2019 at the Challenger Center in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold is introduced to speak about his time onboard the International Space Station (ISS) during Expeditions 55 and 56, Friday, May 3, 2019 at the Challenger Center in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold speaks about his time onboard the International Space Station (ISS) during Expeditions 55 and 56, Friday, May 3, 2019 at the Challenger Center in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold speaks about his time onboard the International Space Station (ISS) during Expeditions 55 and 56, Friday, May 3, 2019 at the Challenger Center in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold speaks about his time onboard the International Space Station (ISS) during Expeditions 55 and 56, Friday, May 3, 2019 at the Challenger Center in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold speaks about his time onboard the International Space Station (ISS) during Expeditions 55 and 56, Friday, May 3, 2019 at the Challenger Center in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold poses for a photo after presenting the Challenger Center with a montage of images from his time onboard the International Space Station (ISS) during Expeditions 55 and 56, Friday, May 3, 2019 in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold poses for a photo with students after speaking with them about his time onboard the International Space Station (ISS) during Expeditions 55 and 56, Friday, May 3, 2019 in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold is seen during a talk about his time onboard the International Space Station (ISS) during Expeditions 55 and 56, Friday, May 3, 2019 at the Challenger Center in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold speaks about his time onboard the International Space Station (ISS) during Expeditions 55 and 56, Friday, May 3, 2019 at the Challenger Center in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold poses for a photo with students after speaking with them about his time onboard the International Space Station (ISS) during Expeditions 55 and 56, Friday, May 3, 2019 in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold speaks about his time onboard the International Space Station (ISS) during Expeditions 55 and 56, Friday, May 3, 2019 at the Challenger Center in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold speaks about his time onboard the International Space Station (ISS) during Expeditions 55 and 56, Friday, May 3, 2019 at the Challenger Center in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold presents the Challenger Center with a montage of images from his time onboard the International Space Station (ISS) during Expeditions 55 and 56, Friday, May 3, 2019 in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold speaks about his time onboard the International Space Station (ISS) during Expeditions 55 and 56, Friday, May 3, 2019 at the Challenger Center in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut and Maryland native Ricky Arnold is interviewed by Paul Mancano of MASN All Access before the Tampa Bay Rays take on the Baltimore Orioles, Saturday, May 4, 2019 at Camden Yards in Baltimore, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut and Maryland native Ricky Arnold is interviewed by Paul Mancano of MASN All Access before the Tampa Bay Rays take on the Baltimore Orioles, Saturday, May 4, 2019 at Camden Yards in Baltimore, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut and Maryland native Ricky Arnold is interviewed by Paul Mancano of MASN All Access before the Tampa Bay Rays take on the Baltimore Orioles, Saturday, May 4, 2019 at Camden Yards in Baltimore, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut and Maryland native Ricky Arnold talks with Baltimore Orioles shortstop Richie Martin before the Tampa Bay Rays take on the Baltimore Orioles, Saturday, May 4, 2019 at Camden Yards in Baltimore, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

CHUCK JACKSON, ASTRONAUT ARNOLD, JOHN NIX POSE WITH EXPEDITION 56 PLAQUE

NASA astronaut Ricky Arnold watches a timer while students conduct an experiment on effervescence, Friday, May 3, 2019 at the Challenger Center in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the International Space Station (ISS), and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold watches a timer while students conduct an experiment on effervescence, Friday, May 3, 2019 at the Challenger Center in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the International Space Station (ISS), and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

A student shakes a glass of water with an Alka-Seltzer tab in it while conducting an experiment on effervescence, Friday, May 3, 2019 at the Challenger Center in Lanham, MD. NASA astronaut Ricky Arnold helped them carry out the experiment which he also conducted during his 197 day mission onboard the International Space Station (ISS) during Expeditions 55/56. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut and Maryland native Ricky Arnold presents a montage of images from his mission and a Baltimore Orioles hat that was flown aboard the International Space Station to Baltimore Orioles manager Brandon Hyde before the Tampa Bay Rays take on the Baltimore Orioles, Saturday, May 4, 2019 at Camden Yards in Baltimore, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

NASA astronaut and Maryland native Ricky Arnold talks with Baltimore Orioles manager Brandon Hyde after presenting a montage of images from his mission and a Baltimore Orioles hat that was flown aboard the International Space Station before the Tampa Bay Rays take on the Baltimore Orioles, Saturday, May 4, 2019 at Camden Yards in Baltimore, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

A student holds up a glass of water with an Alka-Seltzer tab in it while conducting an experiment on effervescence, Friday, May 3, 2019 at the Challenger Center in Lanham, MD. NASA astronaut Ricky Arnold helped them carry out the experiment which he also conducted during his 197 day mission onboard the International Space Station (ISS) during Expeditions 55/56. Photo Credit: (NASA/Aubrey Gemignani)

A student observes a glass of water with an Alka-Seltzer tab in it while conducting an experiment on effervescence, Friday, May 3, 2019 at the Challenger Center in Lanham, MD. NASA astronaut Ricky Arnold helped them carry out the experiment which he also conducted during his 197 day mission onboard the International Space Station (ISS) during Expeditions 55/56. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold speaks with Beth Wilson of Smithsonian National Air and Space Museum's Stem in 30 production, Friday, May 3, 2019 at Six Flags America theme park in Upper Marlboro, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold is interviewed for a Smithsonian National Air and Space Museum production of Stem in 30, Friday, May 3, 2019 at Six Flags America theme park in Upper Marlboro, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold, center, and Smithsonian National Air and Space Museum's Beth Wilson, left, and Marty Kelsey, right, jump backwards as a model volcano erupts with fire during a Stem in 30 segment, Friday, May 3, 2019 at Six Flags America theme park in Upper Marlboro, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold answers questions from the audience about his time onboard the International Space Station (ISS) during a Smithsonian National Air and Space Museum production of Stem in 30, Friday, May 3, 2019 at Six Flags America theme park in Upper Marlboro, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold answers questions from the audience about his time onboard the International Space Station (ISS) during a Smithsonian National Air and Space Museum production of Stem in 30, Friday, May 3, 2019 at Six Flags America theme park in Upper Marlboro, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold answers questions from the audience about his time onboard the International Space Station (ISS) during a Smithsonian National Air and Space Museum production of Stem in 30, Friday, May 3, 2019 at Six Flags America theme park in Upper Marlboro, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold poses for a selfie with an audience member after speaking about his time onboard the International Space Station (ISS) during a Smithsonian National Air and Space Museum production of Stem in 30, Friday, May 3, 2019 at Six Flags America theme park in Upper Marlboro, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold answers questions from the audience about his time onboard the International Space Station (ISS) during a Smithsonian National Air and Space Museum production of Stem in 30, Friday, May 3, 2019 at Six Flags America theme park in Upper Marlboro, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold, center, and Smithsonian National Air and Space Museum's Beth Wilson, left, and Marty Kelsey, right, react after a model volcano erupted with fire during a Stem in 30 segment, Friday, May 3, 2019 at Six Flags America theme park in Upper Marlboro, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold answers questions from the audience about his time onboard the International Space Station (ISS) during a Smithsonian National Air and Space Museum production of Stem in 30, Friday, May 3, 2019 at Six Flags America theme park in Upper Marlboro, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold answers questions from the audience about his time onboard the International Space Station (ISS) during a Smithsonian National Air and Space Museum production of Stem in 30, Friday, May 3, 2019 at Six Flags America theme park in Upper Marlboro, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold answers questions from the audience about his time onboard the International Space Station (ISS) during a Smithsonian National Air and Space Museum production of Stem in 30, Friday, May 3, 2019 at Six Flags America theme park in Upper Marlboro, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold answers questions from the audience about his time onboard the International Space Station (ISS) during a Smithsonian National Air and Space Museum production of Stem in 30, Friday, May 3, 2019 at Six Flags America theme park in Upper Marlboro, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold answers questions from the audience about his time onboard the International Space Station (ISS) during a Smithsonian National Air and Space Museum production of Stem in 30, Friday, May 3, 2019 at Six Flags America theme park in Upper Marlboro, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold answers questions from the audience about his time onboard the International Space Station (ISS) during a Smithsonian National Air and Space Museum production of Stem in 30, Friday, May 3, 2019 at Six Flags America theme park in Upper Marlboro, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold answers questions from the audience about his time onboard the International Space Station (ISS) during a Smithsonian National Air and Space Museum production of Stem in 30, Friday, May 3, 2019 at Six Flags America theme park in Upper Marlboro, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold reacts as Marty Kelsey from Smithsonian National Air and Space Museum's production, Stem in 30, makes large bubbles behind him, while he speaks about his time onboard the International Space Station (ISS), Friday, May 3, 2019 at Six Flags America theme park in Upper Marlboro, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

Robert Gabrys, director of the Office fo STEM Engagement at NASA’s Goddard Space Flight Center, introduces NASA astronaut Ricky Arnold prior to a presentation to employees, Thursday, May 2, 2019 at NASA’s Goddard Space Flight Center in Greenbelt, Md. During Arnold’s 197 days onboard the International Space Station, as part of Expeditions 55 and 56, he ventured outside the space station on three spacewalks in addition to conducting numerous experiments and educational downlink events. Photo Credit: (NASA/Joel Kowsky)

JSC2008-E-053109 (21 April 2008) --- Astronaut Richard Arnold, mission specialist

JSC2008-E-053108 (21 April 2008) --- Astronaut Richard Arnold, mission specialist

JSC2008-E-053106 (21 April 2008) --- Astronaut Richard Arnold, mission specialist

JSC2008-E-053107 (21 April 2008) --- Astronaut Richard Arnold, mission specialist

Students are seen in the audience as NASA astronaut Ricky Arnold speaks about his time onboard the International Space Station (ISS) during Expeditions 55 and 56, Friday, May 3, 2019 at the Challenger Center in Lanham, MD. During Expedition 55/56, Arnold completed three spacewalks for a total of 19.5 hours outside the space station, and concluded his 197 day mission when he landed in a remote area near the town of Zhezkazgan, Kazakhstan in Oct. 2018. He also flew to the space station on shuttle mission STS-119 to deliver the final pair of power-generating solar array wings. Photo Credit: (NASA/Aubrey Gemignani)

JSC2004-E-47576 (17 Aug. 2004) --- Richard R. (Ricky) Arnold II, mission specialist-educator candidate in NASA's 2004 class of astronauts.

NASA astronaut Ricky Arnold, Portrait, Friday, June 28, 2019 at Michoud Assembly Facility, New Orleans, LA. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold, Portrait, Friday, June 28, 2019 at Michoud Assembly Facility, New Orleans, LA. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold, Portrait, Friday, June 28, 2019 at Michoud Assembly Facility, New Orleans, LA. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold, Portrait, Friday, June 28, 2019 at Michoud Assembly Facility, New Orleans, LA. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold, Portrait, Friday, June 28, 2019 at Michoud Assembly Facility, New Orleans, LA. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold, Portrait, Friday, June 28, 2019 at Michoud Assembly Facility, New Orleans, LA. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold, Portrait, Friday, June 28, 2019 at Michoud Assembly Facility, New Orleans, LA. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Ricky Arnold, Portrait, Friday, June 28, 2019 at Michoud Assembly Facility, New Orleans, LA. Photo Credit: (NASA/Aubrey Gemignani)

Marty Kelsey of Smithsonian National Air and Space Museum's Stem in 30 production heats a panel of a spacecraft to demonstrate it's ability to stay cool during a segment with NASA astronaut Ricky Arnold, Friday, May 3, 2019 at Six Flags America theme park in Upper Marlboro, MD. Photo Credit: (NASA/Aubrey Gemignani)
Astronaut Ricky Arnold assists with the installation of NASA's Cold Atom Laboratory (CAL) on the International Space Station. https://photojournal.jpl.nasa.gov/catalog/PIA22920

Picture 012

S119-E-006177 (16 March 2009) --- Astronaut Richard Arnold, STS-119 mission specialist, takes a moment for a photo while working on the middeck of Space Shuttle Discovery during flight day two activities. A procedures checklist manual floats freely near Arnold.

iss056e095029 (July 13, 2018) --- NASA astronaut Ricky Arnold works on gear inside the International Space Station.

HOUSTON, Texas -- JSC2008-E-053106: Astronaut Richard Arnold, mission specialist on mission STS-119.

S119-E-010760 (27 March 2009) --- Astronaut Richard Arnold, mission specialist, appears to be multi-tasking on the flight deck of the Earth-orbiting Space Shuttle Discovery on its final full day in space for STS-119. Arnold shares space with two other astronauts as he records activity with a camera while toting supplies with his other hand. Astronaut John Phillips, mission specialist, is at left.

S119-E-006758 (20 March 2009) --- Astronaut Richard Arnold, STS-119 mission specialist, (pictured on the mid deck), and other members of the Discovery crew, along with the two astronauts and a cosmonaut crew member of ISS-018, are looking forward to supporting the second spacewalk during this linkup. Arnold participated in the first extravehicular activity, March 19, as he joined astronaut Steve Swanson outside the confines of the orbiting complex to perform a variety of tasks.

iss055e063891 (May 7, 2018) --- NASA astronaut Ricky Arnold is pictured inside a U.S. spacesuit for a fit check verification ahead of a pair of spacewalks.

iss056e157121 (Aug. 25, 2018) --- The Expedition 56 crew members pose for a fun portrait in the International Space Station's Harmony module. Clockwise from top are Expedition 56 Flight Engineers Serena Auñón-Chancellor, Oleg Artemyev, Sergey Prokopyev and Ricky Arnold. Auñón-Chancellor and Arnold represent NASA while Artemyev and Prokopyev represent Roscosmos. In the center, from left, are ESA (European Space Agency) astronaut Alexander Gerst and Expedition 56 Commander Drew Feustel of NASA. Gerst will become commander of Expedition 57 when Feustel, Arnold and Artemyev depart the space station in October.

Officials, family, and friends gather to welcome home Expedition 56 Soyuz Commander Oleg Artemyev of Roscosmos, right, after he and NASA astronauts Drew Feustel and Flight Engineer Ricky Arnold landed their Soyuz MS-08 capsule near the town of Zhezkazgan, Kazakhstan on Friday, Oct. 5, 2018. Artemyev, Feustel, and Arnold 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)

S119-E-007491 (22 March 2009) --- Astronaut Richard Arnold, STS-119 mission specialist, floats on the middeck of Space Shuttle Discovery while docked with the International Space Station.

S119-E-006385 (17 March 2009) --- Astronaut Richard Arnold, STS-119 mission specialist, prepares to eat a snack near the galley on the middeck of Space Shuttle Discovery.

S119-E-008173 (25 March 2009) --- Astronauts Richard Arnold (left) and Joseph Acaba, both STS-119 mission specialists, are pictured on the middeck of Space Shuttle Discovery during flight day 11 activities.

iss056e136571 (Aug. 14, 2018) --- NASA astronaut Ricky Arnold replaces hardware and performs maintenance in the Combustion Integrated Rack facility located in the International Space Station's U.S. Destiny laboratory.