SEI meaning in Military and Defence ?

The Space Exploration Initiative was a 1989–1993 space public policy initiative of the George H. W. Bush administration.

On July 20, 1989, the 20th anniversary of the Apollo 11 Moon landing, US President George H. W. Bush announced plans for what came to be known as the Space Exploration Initiative (SEI). In a speech on the steps of the National Air and Space Museum he described plans calling for constructing Space Station Freedom, sending humans back to the Moon "to stay" and ultimately sending astronauts to explore Mars. He proposed not a 10-year Apollo-style plan, but a long-range continuing commitment based on the three above elements, ending with "a journey into tomorrow – a journey to another planet – a manned mission to Mars." The President noted it was humanity's destiny to explore, and America's destiny to lead. He asked Vice President Dan Quayle to lead the National Space Council in determining what was needed to carry out these missions in terms of money, manpower and technology.

In the event, execution of the initiative was assigned to NASA, but the initiative did not survive long into the administration of the next president, Bill Clinton.