Trading quarantines, Americans from cruise land in US

A charter flight transporting passengers from the quarantined Diamond Princess cruise ship moves behind military airplanes after it arrived at Travis Air Force Base in Fairfield, Calif., Sunday, Feb. 16, 2020. (AP Photo/Hector Amezcua)

Buses carrying U.S. passengers who were aboard the quarantined cruise ship the Diamond Princess, seen in background, leaves Yokohama port, near Tokyo, early Monday, Feb. 17, 2020. The cruise ship was carrying nearly 3,500 passengers and crew members under quarantine. (Jun Hirata/Kyodo News via AP)

A charter flight transporting passengers from the quarantined Diamond Princess cruise ship arrives at Travis Air Force Base in Fairfield, Calif., Sunday, Feb. 16, 2020. (AP Photo/Hector Amezcua)

A bus carrying U.S. passengers who were aboard the quarantined cruise ship the Diamond Princess arrives at Haneda airport in Tokyo, before the passengers board a Kalitta airplane chartered by the U.S. government Monday, Feb. 17, 2020. The cruise ship was carrying nearly 3,500 passengers and crew members under quarantine. (Sadayuki Goto/Kyodo News via AP)

In this image from a video taken on Monday, Feb. 17, 2020, U.S. passengers who evacuated off the quarantined cruise ship the Diamond Princess and officials wait for the takeoff of a Kalitta Air airplane bound for the U.S., at Haneda airport in Tokyo.(Cheryl and Paul Molesky via AP)

TRAVIS AIR FORCE BASE, Calif. — Two charter flights carrying cruise ship passengers from Japan landed at military bases in California and Texas overnight, starting the clock on a quarantine period to ensure passengers don’t have the new virus that’s been spreading in Asia.