NASA’s unmanned Antares rocket explodes on launch

An unmanned Antares supply rocket exploded just after liftoff from a commercial launch pad in Virginia on Tuesday, marking the first accident since NASA turned to private operators to deliver cargo to the International Space Station. 

The 14-story rocket, built and launched by Orbital Sciences Corp, bolted off its seaside launch pad at the Wallops Flight Facility in eastern Virginia at 6:22 p.m. The cause of the accident was not immediately available. NASA officials said no one was injured in the blast.

"We will understand what happened — hopefully soon — and we'll get things back on track," Orbital Sciences' executive vice president Frank Culbertson told his team an hour after the failure. "We've all seen this happen in our business before, and we've all seen the teams recover from this, and we will do the same."

The roomful of engineers and technicians were ordered to maintain all computer data for the ensuing investigation. Culbertson advised his staff not to talk to news reporters and to refrain from speculating among themselves.

"Definitely do not talk outside of our family," said Culbertson, a former astronaut who once served on the space station.

It was the fourth Cygnus bound for the orbiting lab; the first flew just over a year ago. SpaceX is scheduled to launch another Dragon supply ship from Cape Canaveral in December.

The Cygnus cargo ship Tuesday had held 5,000 pounds of experiments and equipment. By coincidence, the Russian Space Agency was proceeding with its own supply run on Wednesday, planned well before the U.S. mishap.

It was also hauling "some classified cryptographic equipment, so we do need to maintain the area around the debris in a secure manner," said Mike Pinkston, Orbital Science’s program manager for the Antares rocket.

Virginia-based Orbital Sciences is one of two companies hired by NASA to fly cargo to the International Space Station (ISS), a science lab in the lower Earth orbit, comprised of multinational teams of astronauts and cosmonauts. Fifteen nations own and operate the station, which orbits about 260 miles above Earth.

Cygnus was expected to remain in orbit for several days before reaching ISS on Nov. 2, when astronauts would start unpacking the load and reload it with trash that would eventually burn in the atmosphere upon the rocket's return.

Besides the classified payload, the rocket was carrying experiments devised by eighteen teams of American high school science students participating in the Student Spaceflight Experiments Program (SSEP). Their proposals were selected from a pool of 1,487 applicants.

Henry Gertsen, 17, a senior at L&N STEM (Science Technology Engineering and Math) Academy in Knoxville, Tennesse, had travelled with his classmates to watch the launch Tuesday. They had devised an experiment to test how human waste decomposes in the microgravity of earth orbit. They used corn starch to simulate the waste matter.

Gertsen and his group traveled along with one his teachers, club sponsor David Hawkins, and six other members of the SSEP club, who range from grades 6 to 12. They had been planning the project since February.

“I’m disappointed,” Gertsen said of the sudden change of plans.

A YouTube video Gertsen shot shows awed gasps from the crowd as the rocket ignited turning into frantic shrieks as the hundred viewers nearby realized something had gone very wrong with the launch.

“It was really scary at the time,” he said, speaking by phone from a car headed back to Tennessee — a 10-hour trip back to Tennessee.

Tuesday's planned flight was to be the third of eight under Orbital Science’s $1.9 billion contract with NASA. The second U.S. supply line to the station is run by privately owned Space Exploration Technologies, or SpaceX, which is preparing for its fourth flight under a separate $1.6 billion NASA contract.

SpaceX and Boeing won contracts in September to build a vessel to ferry humans to the ISS, ending the American space program’s dependence on Russia’s disposable Soyuz shuttle amid a renewal of political tensions between Moscow and Washington. 

There's no word yet whether Gertsen and his classmates' experiment will be able to hitch a ride on the next launch. 

"It would be great to have our experiments go up still," said Gertsen. "With how much time we put into designing them, it would be disappointing to not be able to follow through."

Al Jazeera and wire services. Wilson Dizard contributed reporting.