Sensitive technology on board an Antares rocket that was headed for the International Space Station could slow investigation into its explosion shortly after lift-off on Tuesday evening.
The rocket was just a few seconds into its flight from NASA's Wallops Flight Facility in Virginia when flames from the rocket's exhaust flared and the lower stage of the rocket appeared to explode. The rocket fell vertically back onto the launch pad and a massive explosion followed.
NASA said no personnel were injured in the accident although the launch pad suffered major damage.
The rocket, which was built by Orbital Sciences Corp., was carrying an unmanned Cygnus spacecraft with about 5,000 pounds of cargo on board including classified equipment that uses sensitive cryptographic technology.
Shortly after the incident, an unidentified official on the range controller's audio channel noted that the cargo contained "class-5 crypto" and so the launch site must be kept secure.
The cargo included scientific equipment, earth observation micro satellites, student experiments and NASA cargo that was characterized as "very important and very high value to our customers."
"It was a rocket and it had hazardous materials on board that people should not be looking for or wanting to collect as souvenirs," said Frank Culbertson, Orbital's executive vice president, during a Tuesday evening news conference.
The Wallops Flight Facility lies on a thin island just off the Virginia coast and isn't easily accessible to the public, but the rocket explosion threw debris into the surrounding area and the sea which may complicate recovery of classified technology.
Since the earliest days of top-secret flight programs, the loss of classified technology after a crash has been a worry for government officials. Whether through theft or photography, the military is often keen to stop members of the public getting too close to the wreckage of crashed planes should any of its secrets get into the public domain.
When crashes happen overseas, that's unavoidable.
In 2011, the New York Times reported that Chinese military engineers were probably allowed to examine the wreckage of a crashed American stealth helicopter that crashed during the raid on Osama Bin Laden's compound in Pakistan. Later the same year, Iranian officials showed off a Lockheed Martin RQ-170 Sentinel drone that had came down in the country while flying above Iranian airspace.
The investigation into the explosion has already begun and will commence on-site at daylight on Wednesday. it will be conducted by the Federal Aviation Administration and Orbital with NASA and the National Transportation Safety Board (NTSB) participating as observers.
Investigators are asking members of the public to call 757-824-1295 should they find any debris.
Martyn Williams covers mobile telecoms, Silicon Valley and general technology breaking news for The IDG News Service. Follow Martyn on Twitter at @martyn_williams. Martyn's e-mail address is email@example.com