Why Elon Musk Called Orbital Sciences' Rocket Design a 'Joke' in 2012 In 2012, SpaceX founder mocked NASA-contractor design of rocket that exploded.

 -- Almost exactly two years before Orbital Sciences' rocket exploded Tuesday during a launch in Virginia, SpaceX founder Elon Musk mocked his competitor, calling its rocket design a "joke."

Orbital Sciences Corp., headquartered in Dulles, Virginia, produced the Antares rocket for NASA to supply the International Space Station. Investigators are now trying to determine what went wrong with the launch before a safety officer sent a self-destruct command Tuesday evening.

While discussing a possible SpaceX mission to Mars, Musk discussed the failings of large aerospace firms with Wired Magazine. These included an aversion to risk as well as the overuse of "legacy components."

"The results are pretty crazy," Musk said in the 2012 interview. "One of our competitors, Orbital Sciences, has a contract to resupply the International Space Station, and their rocket honestly sounds like the punch line to a joke. It uses Russian rocket engines that were made in the '60s. I don’t mean their design is from the '60s -- I mean they start with engines that were literally made in the '60s and, like, packed away in Siberia somewhere."

Musk tweeted about the explosion on Tuesday evening:

"We went through a careful assessment of what engine to use and what was available on the marketplace and you have to admit there’s not many U.S. engines available in that class to put into rockets like this," Frank Culbertson, executive vice president and general manager of Orbital's Advanced Programs Group, told ABC News.

Orbital obtained the engines from Aerojet, which purchased them from a Russian supplier "many years ago," Culbertson said. They were refurbished, modified and tested.

"So, we’re not sure why this one went bad and if it was the engine we don’t even know that yet, so we’ll have to continue the investigation," Culbertson said.

Musk and SpaceX did not respond to requests for comment from ABC News.

ABC News' James E. Hill and David Kerley contributed to this report.