Unmanned Antares rocket from Orbital Sciences explodes on launch

An unmanned commercial rocket headed to the International Space Station exploded six seconds after liftoff Tuesday at a complex off Wallops Island, Virginia. NASA reported no injuries from the explosion and that all ground crew had been accounted for.

This was [company]Orbital Sciences Corporation[/company]’s third commercial launch to resupply the space station. The launch was delayed from last night after a boat was in the launch vicinity.

“What we know so far is pretty much what everyone saw in the video,” Orbital Science executive vice president Frank Culbertson said during a NASA press conference Tuesday night. “We don’t really have any early indications of what might have failed.”

The company will investigate the debris that fell from the rocket, the data that streamed from it during the launch and the many videos captured during the launch, Culbertson said. He would not estimate for how long Orbital Sciences will be grounded.

Onboard the rocket was 4,883 pounds of cargo, which included 1,300 pounds of food and 1,600 pounds of scientific research projects on everything from pea shoot growth in space to devices to study the blood flow of crew member’s brains in space. Planet Labs reported that it had 26 mini-satellites on board the rocket, although it said the loss of the satellites would not have a huge impact on the company.

Previous Antares rockets have carried Planet Labs’ mini-satellites along with other crowdfunded CubeSats to space before. This mission was not carrying any critical hardware to the space station, so the astronauts and its technology are not in any danger, ISS program manager Mike Suffredini said during the press conference.

“We lost quite a bit of research hardware. We lost some spares that we’ll have to of course replace,” Suffredini said. “But the station is in great shape. The crew is in great shape.”

A SpaceX launch scheduled for December will likely carry the cargo needed to replace what was lost on the Antares rocket.

Orbital Sciences has yet to say what caused the explosion, which appeared to originate from the bottom part of the rocket, where the engines are located. The Antares contains two AJ26 engines originally developed for the Russian space program. A different AJ26 engine exploded in May during tests by GenCorp, the company that provides the engines to Orbital Sciences. Orbital Sciences then delayed its launch scheduled for around that time to ensure there were not widespread issues with AJ26 engines, SpaceNews reported in July.

The Antares rocket during a successful launch. Photo by NASA/Bill Ingalls.

The Antares rocket during a successful launch. Photo by NASA/Bill Ingalls.

Orbital Sciences said during the press conference that it cannot yet determine if the AJ26 engine was involved in the failure.  The company did command the rocket to self-destruct after noticing that the launch had started to go haywire.

“The history of this engine has been well documented,” Culbertson said. “Basically this was an engine that was designed to carry cosmonauts to the moon. It’s an extensively tested engine and is very robust and rugged. These engines were taken through the normal acceptance testing and pressure testing, etc. We didn’t see any anomalies to indicate there were problems with the engine.”

Orbital Sciences is one of two companies (the other is SpaceX) that has a deal with NASA to send rockets to resupply the ISS. In August, a SpaceX rocket exploded over Texas during a test run.

Elon Musk later tweeted his support for Orbital:

Here’s video of the explosion:

Orbital Sciences acknowledged there was a vehicle “anomaly” on Twitter:

This post has been updated to reflect NASA’s statement, include information revealed during a press conference Tuesday night and with more details about the cargo.