On Sunday night SpaceX launched the Zuma satellite into space. What we know for sure is that the first stage of the rocket behaved nominally enough such that it was able to safely return to Earth and make a land-based landing along the Florida coast.

SpaceX, however, never officially confirmed mission success. On Monday, Ars began to hear discussion from sources that the mysterious Zuma spacecraft—the purpose of which was never specified, nor which US military or spy agency had backed it—may not have survived. According to one source, the payload fell back to Earth along with the spent upper stage of the Falcon 9 rocket.

Later on Monday afternoon another space reporter, Peter B. de Selding, reported on Twitter that he too had been hearing about problems with the satellite. "Zuma satellite from @northropgrumman may be dead in orbit after separation from @SpaceX Falcon 9, sources say," de Selding tweeted. "Info blackout renders any conclusion - launcher issue? Satellite-only issue? — impossible to draw."

This was just SpaceX's third national security mission and was seen as critically important in winning further lucrative business from the US Department of Defense. In response to a query on Monday afternoon, a SpaceX spokesperson told Ars, “We do not comment on missions of this nature, but as of right now reviews of the data indicate Falcon 9 performed nominally.”

A media query to Northrop Grumman, which manufactured the satellite, was not immediately returned Monday. (Update: Tim Paynter, Vice President of Strategic Communications for Northrop Grumman, said, "This is a classified mission. We cannot comment on classified missions.”)

Actions taken by SpaceX on Monday indicate its confidence in the rocket's performance during the Zuma launch. Earlier in the day, SpaceX founder Elon Musk shared photos of the nighttime launch on Twitter. Also, the company continued with preparations for future launches, including rolling the Falcon Heavy rocket back out to a different launch pad in Florida for additional tests.

Ars will update this story as more information arrives.