An unmanned Space Exploration Technologies rocket exploded about two minutes after liftoff from Florida, destroying a cargo ship bound for the International Space Station in the latest in a string of mishaps in supplying the orbiting outpost.
The 63m Falcon 9 rocket, built and flown by the company known as SpaceX that is owned by technology entrepreneur Elon Musk, had previously made 18 successful launches since its 2010 debut. Those included six cargo runs for NASA under a 15-flight contract worth more than $2 billion.
The accident soon after liftoff from Cape Canaveral Air Force Station was the second successive botched mission to resupply the space station. A Russian Progress cargo ship failed to reach the outpost in April following a problem with its Soyuz launcher. Russia plans to launch a replacement capsule on Friday.
The cause of the explosion was not yet clear, officials said.
"This was a blow to us. We lost a lot of research equipment on this flight," NASA Associate Administrator Bill Gerstenmaier told a news conference.
The explosion also marks a setback for SpaceX, which was poised to compete for the first time against United Launch Alliance, a joint venture of Lockheed Martin Corp and Boeing Co and the current sole launch provider for military and spy satellite launches, to launch a GPS III satellite.
An investigation into the explosion will ground the Falcon 9 rockets for "a number of months or so" but less than a year, SpaceX President Gwynne Shotwell told the news conference.
A preliminary analysis indicated a problem with the rocket's upper-stage engine, SpaceX founder Elon Musk said on Twitter.
The International Space Station crew - two Russian cosmonauts and an American astronaut - has about four months of food and supplies on board, so the accident does not pose an immediate problem for them.
However, NASA's second cargo transporter, run by Orbital ATK , remains grounded following a launch accident in October.
Equipment, food, experiments lost
SpaceX lost contact with the Falcon 9 about 2 minutes and 19 seconds after liftoff, NASA launch commentator George Diller said.
The accident occurred just before the rocket was to discard its first stage two minutes and 39 seconds after liftoff.
Despite the explosion, one SpaceX customer voiced support in the company and the Falcon 9.
"One inevitable failure for such a young system should not in any way shake anyone's faith in the rocket or the team. What's amazing is that it took this long to happen," said Mike Gold, business operations director with Nevada-based Bigelow Aerospace.
The spacecraft lost on Sunday carried 5,461 pounds (2,477 kg) of food, clothing, equipment and science experiments for the station, a $100 billion research laboratory that flies about 260 miles (420 km) above Earth.
The gear included the first of two docking systems for space taxis under development by SpaceX and Boeing to park at the station. NASA hopes to turn over crew transportation to the U.S. companies before the end of 2017, breaking Russia's monopoly.
Including its station cargo runs for NASA, SpaceX has a backlog of nearly 50 missions, worth more than $7 billion, including dozens of commercial communications satellites. The company last month won U.S. Air Force certification to fly military and national security missions on the Falcon 9.
SpaceX holds a second NASA contract, worth up to $2.6 billion, to upgrade its Dragon capsule to fly astronauts to the station. Boeing's contract is worth up $4.2 billion.
In addition to its launch pad at Cape Canaveral Air Force Station, SpaceX leases one of the mothballed space shuttle launch pads at the adjacent Kennedy Space Center and is building a new launch site in Texas.
The company has also flown once from a launch pad at Vandenberg Air Force Base in California.
