From ABC News.

A not-so-secret, secret reusable spaceplane operated by the United States Space Force is scheduled to lift off for its eighth mission on Thursday, Aug. 21, from the Kennedy Space Center in Florida.

Space Force is not disclosing the length of this upcoming mission or the exact time of the launch, but a Federal Aviation Administration advisory indicates that the launch window is between 11:40 p.m. ET on Thursday and 5:11 a.m. ET on Friday.