What, if anything, happened to the top-secret Zuma payload launched on a SpaceX rocket Sunday?

It was a public launch that lit up the Sunday night sky from the Space Coast, followed by a sonic boom and rocket booster landing that many saw and heard from Cape Canaveral Air Force Station.

But what we don't know has been the headline of this mission: A classified payload called Zuma, built by Northrop Grumman for the U.S. government, was being delivered to orbit. Very few know what it was.

Now, its fate is also a mystery. Did something happen to Zuma after separating from the rocket's second stage?

Dale Ketcham of Space Florida, the state's aerospace and spaceport development authority, tried to shed some light on the fate of Zuma.

"I don't think we can know," Ketcham said. "It may be doing exactly what it was supposed to, and this is all part of an exercise."

But Ketcham said it's common for launch providers such as SpaceX to supply adapters to custom-fit payloads like satellites.

"In this case, it appears, at least from what we can see on social media, that Northrop Grumman, the builder of the payload itself, may have built the adapter," he said. "And that would put them as responsible on whether it separated from the second stage."

SpaceX released a statement via their president, Gwynne Shotwell, who was adamant the company was not to blame:

"After review of all data to date, Falcon 9 did everything correctly Sunday night. If we or others find otherwise based on further review, we will report it immediately. Information published that is contrary to this statement is categorically false. Due to the classified nature of the payload, no further comment is possible."

A Northrop Grummam representative said by phone: "This is a classified mission. We cannot comment on classified missions."

The launch broadcast was cut off shortly after the rocket's nose cone separated, which is standard under secret national security missions.

Shotwell said the Zuma mission should have no impact on its upcoming Falcon 9 launch in three weeks or the test launch of the Falcon Heavy.