More than 150 military spouses, children and pets left Japan and flew into Seattle-Tacoma International Airport on Monday, and thousands more are expected to return to the U.S. over the next week, after the military set up a "voluntary authorized departure program."

More than 150 military spouses, children and pets left Japan and flew into Sea-Tac airport Monday, and thousands more are expected to return to the U.S. over the next week.

It was the second plane full of voluntary evacuees to travel across the Pacific Ocean from the earthquake- and tsunami-ravaged country. About 250 military dependents, including 190 children, touched down Saturday at Seattle-Tacoma International Airport, the nearest major U.S. airport to Japan.

At least 20 more flights out of Japan are planned for military families and families of U.S. Department of Defense civilian employees between Tuesday and Sunday, according to a schedule from the military.

Lt. Col. Randy Martin, a U.S. Army spokesman, was at Sea-Tac helping the passengers from Japan find nearby hotels or flights to other states. Martin said the military set up a “voluntary authorized departure program” for families of American forces in Japan just after U.S. Secretary of Defense Robert Gates authorized them to leave Thursday. An estimated 9,000 people showed interest in the program, but Martin wasn’t sure how many would participate.

For now, Martin said, all the passengers’ families whose final destinations are in the contiguous U.S. have to go through Sea-Tac, but that’s expected to change later this week. The Department of Defense could open up other major airports, including Denver International and Los Angeles International, to families flying in, and it also could allow the families to fly directly to military bases.

“Until then, we’re assisting the dependents in getting to their chosen location,” Martin said. “If a family has parents in Austin, Texas, a mom with her two or three children might choose to go there, and we’d send them there on a plane. If there wasn’t a flight available to get them there rapidly, we’d help them find suitable lodging in the meantime.”

It’s uncertain when, or whether, these families might return to Japan, given the possible danger of radiation from damaged nuclear plants and significant damage to the northeastern part of the country after a magnitude-9.0 earthquake and a devastating tsunami.

Martin said he isn’t sure whether the military will set up a program for families to cross the Pacific again when they are ready to return. All he knows is “the conditions that brought those family members home would need to change before they would be willing to return to Japan.”

Jill Kimball: 206-464-2108 or jkimball@seattletimes.com