NASA Administrator Bill Nelson, center, speaks with Bulgarian Minister of Finance Assen Vassilev during a meeting, Wednesday, Feb. 7, 2024, at the Mary W. Jackson NASA Headquarters building in Washington. Photo Credit: (NASA/Joel Kowsky)

Bulgarian Minister of Finance Assen Vassilev, center, and Bulgarian Ambassador to the United States Georgi Panayotov, right, are seen as they meet with NASA Administrator Bill Nelson, Wednesday, Feb. 7, 2024, at the Mary W. Jackson NASA Headquarters building in Washington. Photo Credit: (NASA/Joel Kowsky)

Bulgarian Ambassador to the United States Georgi Panayotov, left, NASA Administrator Bill Nelson, center, and Bulgarian Minister of Finance Assen Vassilev, right, pose for a picture prior to a meeting at the Mary W. Jackson NASA Headquarters building, Wednesday, Feb. 7, 2024, in Washington. Photo Credit: (NASA/Joel Kowsky)

NASA Administrator Bill Nelson, right, is seen as he meets with Bulgarian Minister of Finance Assen Vassilev, Wednesday, Feb. 7, 2024, at the Mary W. Jackson NASA Headquarters building in Washington. Photo Credit: (NASA/Joel Kowsky)

NASA Administrator Bill Nelson, right, speaks with Bulgarian Minister of Finance Assen Vassilev during a meeting, Wednesday, Feb. 7, 2024, at the Mary W. Jackson NASA Headquarters building in Washington. Photo Credit: (NASA/Joel Kowsky)

NASA Administrator Bill Nelson, left, speaks with Bulgarian Minister of Finance Assen Vassilev during a meeting, Wednesday, Feb. 7, 2024, at the Mary W. Jackson NASA Headquarters building in Washington. Photo Credit: (NASA/Joel Kowsky)

NASA Administrator Bill Nelson, left, shakes hands with Bulgarian Minister of Finance Assen Vassilev, as they meet at the Mary W. Jackson NASA Headquarters building, Wednesday, Feb. 7, 2024, in Washington. Photo Credit: (NASA/Joel Kowsky)

Bulgarian Minister of Finance Assen Vassilev, center, and Bulgarian Ambassador to the United States Georgi Panayotov, second from right, are seen as they meet with NASA Administrator Bill Nelson, Wednesday, Feb. 7, 2024, at the Mary W. Jackson NASA Headquarters building in Washington. Photo Credit: (NASA/Joel Kowsky)

NASA Administrator Bill Nelson, left, speaks with Bulgarian Minister of Finance Assen Vassilev, center, and Bulgarian Ambassador to the United States Georgi Panayotov, right, during a meeting at the Mary W. Jackson NASA Headquarters building, Wednesday, Feb. 7, 2024, in Washington. Photo Credit: (NASA/Joel Kowsky)