This story has been updated.

At first, everything appeared to go smoothly. Elon Musk’s SpaceX cheered a successful liftoff of its Falcon 9 rocket Sunday evening. So did the Air Force’s 45th Space Wing, which operates the Cape Canaveral Air Force Station.

But on Monday, as reports surfaced that something went disastrously wrong with the classified satellite it had been hired to launch into orbit, SpaceX said that a review showed its Falcon 9 rocket “performed nominally,” or without incident.

Then in a statement issued Tuesday morning, SpaceX President Gwynne Shotwell said: "For clarity: after review of all data to date, Falcon 9 did everything correctly on Sunday night. If we or others find otherwise based on further review, we will report it immediately."

The mystery over what happened to the secretive satellite, known by its codename, “Zuma,” comes at a critical time for SpaceX, as it prepares to fly humans for the first time and keeps up a fierce rivalry for lucrative Pentagon launch contracts.

For years, Musk proclaimed that SpaceX could save taxpayers millions by offering the Pentagon launches for far less than its chief competitor, the United launch Alliance, the joint venture of Lockheed Martin and Boeing. ULA, meanwhile, maintained that responsibility for national security satellites that cost hundreds of millions of dollars and help guide precision bombs and conduct surveillance should not just go to the lowest bidder.

SpaceX launched Zuma on Sunday evening on its Falcon 9 rocket from Cape Canaveral in a mission so secretive that it is not known which government agency was responsible for the satellite, what the satellite cost or what it would do once in orbit.

Northrop Grumman, which manufactured the Zuma satellite, said in a statement that it could not comment on the mission because it was classified.

A website operated by the Pentagon did record a payload in space, but officials said that because the satellite is classified there were no details listed about its orbit.

"It seems to me that a plausible explanation is that it got put into orbit, and stayed up long enough to get cataloged," said Brian Weeden, the director of program planning for the Secure World Foundation, a think tank.

He added that if the satellite fell out of orbit it should have been noted on the website, known as But he added, "it would not be the first time that they've made errors with the catalog."

If something did go wrong with the mission, it’s not clear what happened or who is to blame.

But even if SpaceX’s Falcon 9 performed perfectly, it is not a good time for the company, founded by Musk in 2002, to have something go wrong on such an important mission.

For years, the company has been in a heated battle with ULA over big contracts to launch national security payloads, long seen by Musk as a key source of revenue. SpaceX is also under contract from NASA to fly astronauts to the International Space Station, and it maintains that the first test flights with humans on board could happen as soon as this year.

For nearly a decade, ULA had a monopoly on Pentagon launches. In 2014, SpaceX sued the Air Force arguing that it should be able to compete for the contracts. In 2015, the parties settled, and SpaceX was granted the certification that allowed it to bid. Since then, SpaceX has won two of three competitively bid launches.

As they battled with SpaceX, ULA’s executives launched a “results over rhetoric” campaign, highlighting the company’s long heritage in space.

At the time, ULA’s then-CEO accused SpaceX of trying to “cut corners” and “taking a dangerous approach.” Under mounting pressure from SpaceX, he was fired, and ULA’s new CEO, Tory Bruno, vowed to “literally transform” the company in order to compete with Musk — and he also continued to champion ULA’s track record of successful launches.

SpaceX, meanwhile, had two high-profile incidents. In 2015, a rocket blew up while carrying cargo to the space station. Then in 2016, another rocket exploded while being fueled ahead of an engine test. No one was hurt in either explosion.

In both cases, the company was grounded while it investigated the cause of those problems. As of now, it appears SpaceX is going to keep moving ahead with its launch manifest, and a test flight of its new, massive rocket, the Falcon Heavy, a sign that it is confident in its rocket’s performance.

“Since the data reviewed so far indicates that no design, operational or other changes are needed, we do not anticipate any impact on the upcoming launch schedule," Shotwell said. "Falcon Heavy has been rolled out to launchpad LC-39A for a static fire later this week, to be followed shortly thereafter by its maiden flight. We are also preparing for an F9 launch for SES and the Luxembourg Government from SLC-40 in three weeks.”

Meanwhile, with a launch for the National Reconnaissance Office scheduled for Wednesday, ULA is again poised to showcase its record of reliability with more than 100 consecutive launches without a failure.