Did US government's secret Zuma mission fail or not?

The mission, code-named Zuma, was shrouded in secrecy from the start. A SpaceX rocket was to blast off from Florida before delivering a military satellite into orbit.

Even its existence was a carefully guarded secret. Details only emerged in paperwork submitted days before its original launch date in November.

So what to make of anonymous briefings by American officials after Sunday’s launch claiming the satellite was lost after it either failed to separate from the rocket or something went wrong with the launcher.

SpaceX has pushed back against the explanations, saying it did everything right, leaving amateur satellite watchers with a burning question: either Elon Musk’s space exploration company has just lost billions of dollars of top-secret military hardware or someone really does not want you to know about America’s newest satellite.

An American official, speaking anonymously to Bloomberg, insisted the rocket had failed. Yet later, two officials said the satellite failed to separate from the second stage of the Falcon 9 rocket and is assumed to have broken up or plunged into the sea.

The satellite is assumed to be "a write-off", one of the officials told Reuters.

Marco Langbroek, a Dutch academic and part-time space watcher who tracked public information on Zuma, said the information remained “hearsay” and that shifting claims had left him sceptical of the explanations so far.

“The reports initially said that the Falcon 9 failed, and that certainly is incorrect. It didn't, as the observations from Sudan show,” he said, “and as SpaceX has stated.”

Remarkably, a pilot flying just north of Khartoum snapped a photograph of the Falcon 9 rocket that was delivering the payload.

“It started with a greenish light in the top of my front window. At first I thought it was a reflection from some light source behind me, but it turned out not to be,” said Peter Horstink, the pilot of a 747-400 freighter, in an e-mail published on Dr Langbroek’s SatTrackCam blog.

His photograph shows a mesmerising blue spiral, an image which Dr Langbroek said was consistent with the upper section of the rocket as it depressurised and vented fuel before re-entering the earth’s atmosphere.

That suggests the upper stage of the rocket achieved orbit, he added.

Read more: All eyes on mystery payload being launched into space

Furthermore, the Joint Space Operations Centre of the US Department of Space, which detects man-made objects orbiting Earth, logged a new “payload” entry after the Zuma launch.

“So something reached orbit for at least one full revolution, otherwise this catalogue entry would not have happened,” said Dr Langbroek.

SpaceX has also disputed briefings that its rocket failed. James Gleeson, its spokesman, said initially: “We do not comment on missions of this nature; but as of right now reviews of the data indicate Falcon 9 performed nominally.”

That is aerospace engineering speak for things going according to plan.

On Tuesday, the company pushed back harder.

Gwynne Shotwell, SpaceX president, released a statement saying the Falcon 9 rocket “did everything correctly” on Sunday night and any other suggestion was “categorically false”.

It leaves as many questions as answers.

No one knows what the satellite’s role, intended mission or even which US agency was responsible for it.

A video of the mission was narrated by a SpaceX employee without offering details of the payload. The feed was cut before the satellite was due to be deployed, much like during other classified launches.

Northrop Grumman, the military contractor which built the satellite for an as yet undisclosed US agency, said it could not comment on classified missions.

For now, SpaceX says its busy programme of launches remains on schedule. Last year it recorded 18 launches and is planning even more for 2018.

Its new, more powerful rocket, the Falcon Heavy, is already on its launch pad at Nasa’s Kennedy Space Centre awaiting an engine test firing this week.

It is slated to launch by month’s end, although that date may well be pushed back once testing is complete. It has already been loaded with Mr Musk’s personal Tesla Roadster, a cheeky replacement for the usual “boilerplate satellite” — essentially a hunk of metal of the size and weight of a normal payload — used for test flights.