Decades-old Soviet engines powered US rocket that exploded

The Orbital Sciences rocket that exploded after launch was powered by a pair of rocket engines that were made during the Soviet era and refurbished, experts said.
The Ukrainian-designed AJ-26 engines date back to the 1960s and 1970s, and Aerojet Rocketdyne of Sacramento, California has a stockpile that it refurbishes for Orbital Sciences.
Orbital described the AJ-26 engine on its web site as "a commercial derivative of the engine that was first developed for the Russian moon rocket that would have taken cosmonauts to the moon."
In 2010, the company announced it would use the engines for its Taurus II rocket because "it achieves very high performance in a lightweight, compact package."
The Soviet Union poured $1.3 billion in investment over a 10-year period into developing the engines and building more than 200 of them in all, Orbital said.
Space analyst Marco Caceres of the Teal Group told AFP that the AJ-26 is "a powerful engine" that was designed to launch people to the moon, but never did.
"They did have problems with that engine back in the '60s and ultimately they stopped manufacturing it," he said.
In 1993, Aerojet began developing design modifications to make the engine suitable for commercial launches.
The staged-combustion, oxygen kerosene engines underwent testing at NASA's Stennis facility in Mississippi.
In May, an AJ-26 engine blew up during a ground test there, but in the immediate aftermath of Tuesday's accident, officials declined to link the two incidents.Orbital Sciences has begun investigating the cause of the rocket failure at Wallops Island, Virginia but has not released any conclusions yet.
Orbital engineers said there was no alarming signs leading up to the sunset launch.
The accident was the first catastrophic failure since private companies began supplying the International Space Station in 2010.
- Order to detonate -
The rocket exploded about six seconds after it lifted off from the seaside launch pad Tuesday at 6:22 pm (2222 GMT).
A ground controller at Wallops Island issued a command to destroy the vehicle, Orbital representatives said in a press conference late Tuesday, but gave no details on why.
"It is kind of standard procedure, that if you get something in your readings that indicate it is going to fail, you would detonate it sooner rather than later," explained Caceres.
"You don't want that vehicle to fly very high if you know it is going to fail."
John Logsdon, former director of the Space Policy Institute at George Washington University, agreed.
"There was something dramatic happening to lead the range safety officer to issue a destruct command," Logsdon told AFP.
"They know that something was really wrong and they have all the data from the rocket so it should not take long to find out what went wrong."
It was also the first attempt to launch the Antares 130, a more powerful kind of Antares than the 110 and 120 models that have flown in the past.
"I imagine they will be looking at a lot of issues," said Caceres, including whether there was too much weight on the rocket, or if there was a fuel leak or a corrosion problem.