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 Drew Feustel poses for a photo with the NASA Human Exploration and Operations team just after speaking about his experience on two space shuttle missions, STS-125 and STS-134, and a long duration mission onboard the International Space Station at NASA Headquarters, Thursday, May 9, 2019 in Washington, DC. Feustel most recently spent 197 days living and working onboard the International Space Station as part of Expedition 55 and as commander of Expedition 56. Feustel ventured outside the space station on three spacewalks, moving him up to second among U.S. spacewalkers with a cumulative time of 61 hours 48 minutes over nine spacewalks. 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)

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 Drew Feustel speaks about his experience on two space shuttle missions, STS-125 and STS-134, and a long duration mission onboard the International Space Station at NASA Headquarters, Thursday, May 9, 2019 in Washington, DC. Feustel most recently spent 197 days living and working onboard the International Space Station as part of Expedition 55 and as commander of Expedition 56. Feustel ventured outside the space station on three spacewalks, moving him up to second among U.S. spacewalkers with a cumulative time of 61 hours 48 minutes over nine spacewalks. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Drew Feustel speaks about his experience on two space shuttle missions, STS-125 and STS-134, and a long duration mission onboard the International Space Station at NASA Headquarters, Thursday, May 9, 2019 in Washington, DC. Feustel most recently spent 197 days living and working onboard the International Space Station as part of Expedition 55 and as commander of Expedition 56. Feustel ventured outside the space station on three spacewalks, moving him up to second among U.S. spacewalkers with a cumulative time of 61 hours 48 minutes over nine spacewalks. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Drew Feustel speaks about his experience on two space shuttle missions, STS-125 and STS-134, and a long duration mission onboard the International Space Station at NASA Headquarters, Thursday, May 9, 2019 in Washington, DC. Feustel most recently spent 197 days living and working onboard the International Space Station as part of Expedition 55 and as commander of Expedition 56. Feustel ventured outside the space station on three spacewalks, moving him up to second among U.S. spacewalkers with a cumulative time of 61 hours 48 minutes over nine spacewalks. 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 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 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 Drew Feustel speaks about his experience on two space shuttle missions, STS-125 and STS-134, and a long duration mission onboard the International Space Station at NASA Headquarters, Thursday, May 9, 2019 in Washington, DC. Feustel most recently spent 197 days living and working onboard the International Space Station as part of Expedition 55 and as commander of Expedition 56. Feustel ventured outside the space station on three spacewalks, moving him up to second among U.S. spacewalkers with a cumulative time of 61 hours 48 minutes over nine spacewalks. 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 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 Drew Feustel speaks about his experience on two space shuttle missions, STS-125 and STS-134, and a long duration mission onboard the International Space Station at NASA Headquarters, Thursday, May 9, 2019 in Washington, DC. Feustel most recently spent 197 days living and working onboard the International Space Station as part of Expedition 55 and as commander of Expedition 56. Feustel ventured outside the space station on three spacewalks, moving him up to second among U.S. spacewalkers with a cumulative time of 61 hours 48 minutes over nine spacewalks. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Drew Feustel speaks about his experience on two space shuttle missions, STS-125 and STS-134, and a long duration mission onboard the International Space Station at NASA Headquarters, Thursday, May 9, 2019 in Washington, DC. Feustel most recently spent 197 days living and working onboard the International Space Station as part of Expedition 55 and as commander of Expedition 56. Feustel ventured outside the space station on three spacewalks, moving him up to second among U.S. spacewalkers with a cumulative time of 61 hours 48 minutes over nine spacewalks. 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 Drew Feustel speaks about his experience on two space shuttle missions, STS-125 and STS-134, and a long duration mission onboard the International Space Station at NASA Headquarters, Thursday, May 9, 2019 in Washington, DC. Feustel most recently spent 197 days living and working onboard the International Space Station as part of Expedition 55 and as commander of Expedition 56. Feustel ventured outside the space station on three spacewalks, moving him up to second among U.S. spacewalkers with a cumulative time of 61 hours 48 minutes over nine spacewalks. 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 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)

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)

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)

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 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 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)

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)

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)

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 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, 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 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, 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 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 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)