More than 2,000kg of supplies and scientific experiments including a demonstration satellite for surveying asteroids have been destroyed in an Antares launch explosion.
Antares, developed by US private company Orbital Sciences, was scheduled to lift off from Nasa’s Wallops Flight Facility in Virginia at 06:22 EDT on Tuesday 28 October. The rocket was to send Orbital Sciences’ Cygnus resupply vehicle packed with cargo on its fourth journey – third commercial – to the International Space Station (ISS).
However, instead of a triumphant take-off terrified onlookers witnessed the rocket turn into a fireball just a couple of seconds after lifting from the launch pad and come crashing down with a huge explosion.
"We were standing outside waiting for it to launch and we saw bright red, and then we saw a big black cloud, and it shook the whole building where we work," said Ronda Miller, manager of the Ocean Deli in Wallops Island, Virginia, who witnessed the incident from about 8km afar.
The incident, marking the first catastrophic failure of a rocket developed by a private contractor under Nasa’s Commercial Orbital Transportation Programme, is currently under investigation with some suggesting the Antares AJ-26 engines could have contributed to the disaster.
The engine, based on a Russian NK-33 Moon rocket engine design, exploded in May this year during a ground test at Nasa’s Stennis Space Center in Mississippi.
Neither Orbital Sciences nor the engine manufacturer – California-based Aerojet Rocketdyne – has released any information about the May failure.
"We need to go through this investigation and be very thorough before we determine whether that's a factor in this or not," said Frank Culbertson, Orbital Sciences' executive vice-president.
"What we know so far is pretty much what everybody saw on the video. The ascent stopped, there was some disassembly of the first stage, it looked like, and then it fell to Earth. We don't really have any early indications of exactly what might have failed."
Nasa said none of the cargo aboard the destroyed Cygnus capsule was critical for the survival of the astronauts aboard the ISS, reassuring the public the crew has enough food aboard to survive for months. Apart from regular supplies including food and clothing, the capsule carried scientific equipment and experiments.
A prototype satellite of US start-up Planetary Resources, which has an ambitious plan to mine precious materials on asteroids, was among the lost cargo. The Arkyd 3 cubesat was supposed to be launched into space by a small private launcher from aboard the space station.
An experiment for space-based observation of meteorites as they burn upon entering the Earth’s atmosphere – the first of its kind – and a series of student-made experiments were also lost in the explosion.
“While Nasa is disappointed that Orbital Sciences' third contracted resupply mission to the International Space Station was not successful today, we will continue to move forward toward the next attempt once we fully understand today's mishap,” said William Gerstenmaier, associate administrator of Nasa’s Human Exploration and Operations Directorate.
“Orbital has demonstrated extraordinary capabilities in its first two missions to the station earlier this year, and we know they can replicate that success. Launching rockets is an incredibly difficult undertaking, and we learn from each success and each setback. Today's launch attempt will not deter us from our work to expand our already successful capability to launch cargo from American shores to the International Space Station.”
The area where the debris scattered has been sealed off pending further investigation and to prevent unauthorised manipulation with the burnt fragments as the Cygnus cargo contained some classified cryptographic equipment.
Nasa officials said damage to the launch pad and surrounding area appeared limited. The rocket itself and the cargo ship it carried were valued at $200m. Orbital Sciences had the mission partially insured.
"This is the only pad that's certified for launching the Antares rocket, so repairing it will be one of our high priorities," Culbertson said. "We will not fly until we understand the root cause and the corrective action to make sure this doesn't happen again."
The Tuesday Antares launch was previously delayed due to a boat entering the restricted safety zone below the rocket’s planned flight path. Orbital Sciences already carried out four successful re-supply missions towards the ISS, the first of which was a technology demonstration.
The destroyed rocket was equipped with a more powerful upper-stage engine than its predecessors and carried 15 per cent more cargo than the previous missions.
Orbital Sciences is currently in the process of merging with Alliant Techsystem.
The company was only the second private space transportation provider to deliver cargo to the ISS as part of a $1.6bn deal with Nasa covering a total of eight resupply missions.
Orbital Sciences' stock fell 15.5 per cent to a two-month low of $25.65 in after-hours trade.
The ill-fated Cygnus was the first of two cargo ships scheduled to dock at the space station this week. Russia launched its Progress ship aboard a Soyuz rocket early on Wednesday from the Baikonur Cosmodrome in Kazakhstan.
Video: As it happened – the Antares explosion