UPDATE Feb. 15: A SpaceX Falcon 9 rocket on Feb. 14 successfully launched four Space Development Agency (SDA) Tranche 0 Tracking Layer satellites and two Missile Defense Agency (MDA) hypersonic- and ballistic-missile tracking satellites into low Earth orbit, U.S. Defense Department said in a Feb. 15 statement. All six were built by L3 Harris Technologies.
The statement said the six satellites were "safely delivered into orbit and are conducting initial testing and checkout," and that two years of in-orbit testing would follow.
