U.S. astronaut Neil Armstrong's Apollo 11 spacesuit is seen at the Smithsonian National Air and Space Museum in Washington D.C., the United States, July 16, 2019. The spacesuit is back on display after extensive conservation in celebration of the 50th anniversary of the Apollo 11 Moon landing. (Xinhua/Liu Jie)

Photo taken on July 16, 2019 shows the details of U.S. astronaut Neil Armstrong's Apollo 11 spacesuit displayed at the Smithsonian National Air and Space Museum in Washington D.C., the United States. The spacesuit is back on display after extensive conservation in celebration of the 50th anniversary of the Apollo 11 Moon landing. (Xinhua/Liu Jie)

U.S. Vice President Mike Pence speaks at the unveiling ceremony of U.S. astronaut Neil Armstrong's Apollo 11 spacesuit at the Smithsonian National Air and Space Museum in Washington D.C., the United States, July 16, 2019. The spacesuit is back on display after extensive conservation in celebration of the 50th anniversary of the Apollo 11 Moon landing. (Xinhua/Liu Jie)

Photo taken on July 16, 2019 shows the details of U.S. astronaut Neil Armstrong's Apollo 11 spacesuit displayed at the Smithsonian National Air and Space Museum in Washington D.C., the United States. The spacesuit is back on display after extensive conservation in celebration of the 50th anniversary of the Apollo 11 Moon landing. (Xinhua/Liu Jie)

U.S. astronaut Neil Armstrong's Apollo 11 spacesuit is seen at the Smithsonian National Air and Space Museum in Washington D.C., the United States, July 16, 2019. The spacesuit is back on display after extensive conservation in celebration of the 50th anniversary of the Apollo 11 Moon landing. (Xinhua/Liu Jie)

U.S. astronaut Neil Armstrong's Apollo 11 spacesuit is seen at the Smithsonian National Air and Space Museum in Washington D.C., the United States, July 16, 2019. The spacesuit is back on display after extensive conservation in celebration of the 50th anniversary of the Apollo 11 Moon landing. (Xinhua/Liu Jie)

Photo taken on July 16, 2019 shows the details of U.S. astronaut Neil Armstrong's Apollo 11 spacesuit displayed at the Smithsonian National Air and Space Museum in Washington D.C., the United States. The spacesuit is back on display after extensive conservation in celebration of the 50th anniversary of the Apollo 11 Moon landing. (Xinhua/Liu Jie)

U.S. astronaut Neil Armstrong's Apollo 11 spacesuit is seen at the Smithsonian National Air and Space Museum in Washington D.C., the United States, July 16, 2019. The spacesuit is back on display after extensive conservation in celebration of the 50th anniversary of the Apollo 11 Moon landing. (Xinhua/Liu Jie)

Photo taken on July 16, 2019 shows the details of U.S. astronaut Neil Armstrong's Apollo 11 spacesuit displayed at the Smithsonian National Air and Space Museum in Washington D.C., the United States. The spacesuit is back on display after extensive conservation in celebration of the 50th anniversary of the Apollo 11 Moon landing. (Xinhua/Liu Jie)