A secret SpaceX spy satellite code-named Zuma didn’t reach orbit in this past Sunday’s failed launch. SpaceX estimates the cost of the missing U.S. government asset (which doesn’t officially exist and it’s officially not lost) is estimated to be in the billions of dollars. It’s “presumed to be a total loss.”
From the Wall Street Journal: Lawmakers and congressional staffers from the Senate and the House have been briefed about the botched mission, some of the officials said. The secret payload—code-named Zuma and launched from Florida on board a Falcon 9 rocket—is believed to have plummeted back into the atmosphere, they said, because it didn’t separate as planned from the upper part of the rocket.
Once the engine powering the rocket’s expendable second stage stops firing, whatever it is carrying is supposed to separate and proceed on its own trajectory. If a satellite isn’t set free at the right time or is damaged upon release, it can be dragged back toward earth.
The lack of details about what occurred means that some possible alternate sequence of events other than a failed separation may have been the culprit.