A SpaceX Falcon 9 rocket launches the classified Zuma payload, January 7, 2018.
Space Exploration Technologies Corp, led by entrepreneur Elon Musk, launched its first satellite for the US military with its Falcon 9 rocket in May of a year ago.
A United States official and two congressional aides, all familiar with the launch, said on condition of anonymity that the second-stage of SpaceX's Falcon 9 booster rocket failed.
"We can not comment on classified missions", Tim Paynter, Vice President for the company, said earlier. On Monday, Ars began to hear discussion from sources that the mysterious Zuma spacecraft-the goal of which was never specified, nor which USA military or spy agency had backed it-may not have survived.
Officials who spoke with NBC said the missing satellite most likely broke up or landed in the sea.
This was SpaceX's third classified mission for the USA government, a lucrative customer.
The loss, if it was determined to be a failure of SpaceX hardware, could be a "real threat" to the company's future defense business, said Loren Thompson, defense analyst at the Lexington Institute. The satellite could have stopped working on orbit - or, if it failed to separate from the second stage because of a problem, it could have tumbled back toward Earth, she said. This may be because the satellite failed to separate or disconnect from the rocket once it reached orbit around Earth. The sources would not confirm what exactly the payload was, saying it was classified. However, the company has completed more than ten successful supply missions to ISS.
SpaceX launched two other national security missions a year ago: a satellite for the National Reconnaissance Office in May and the Pentagon's autonomous space plane, known as the X-37B, in September.
Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics, said on Twitter that SpaceX did not supply the payload adaptor, which shoots the satellite off the rocket, for this mission. The company later said it had cleared the issue.
"I think the rocket itself is considered an extremely reliable vehicle", he said. The thrust its 27 engines can produce is equivalent to 18 Boeing ( BA ) 747s and makes it two times more powerful than any other rocket operating today, according to SpaceX.
"The data reviewed so far indicates that no design, operational, or other changes are needed", SpaceX president Gwynne Shotwell said in a statement as quoted in the report.
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.
This article was originally published at 10:20 a.m.