Many media outlets are reporting that the U.S. government's top-secret Zuma satellite may have run into some serious problems during or shortly after its Sunday launch. Zuma was launched atop a SpaceX Falcon 9 rocket from Florida's Cape Canaveral Air Force Station Sunday evening -- a launch that also featured a successful landing back on Earth by the booster's first stage. While everything seemed fine at the time, rumors began swirling within the spaceflight community that something had happened to Zuma. "According to one source, the payload fell back to Earth along with the spent upper stage of the Falcon 9 rocket," Ars Technica's Eric Berger wrote. Scientific American reports: To be clear: There is no official word of any bad news, just some rumblings to that effect. And the rocket apparently did its job properly, SpaceX representatives said. "We do not comment on missions of this nature, but as of right now, reviews of the data indicate Falcon 9 performed nominally," company spokesman James Gleeson told Space.com via email. Space.com also reached out to representatives of aerospace company Northrop Grumman, which built Zuma for the U.S. government. "This is a classified mission. We cannot comment on classified missions," Northrop Grumman spokesman Lon Rains said via email. All we know about the satellite itself is that it was destined for a low-Earth orbit and built for the U.S. government. We will update this story if we hear anything else about Zuma's status.