U.S. private spaceflight company SpaceX aborted the lift-off of its Falcon rocket and Dragon capsule to the International Space Station on Saturday morning due to technical problems.

"We are now reviewing the data, the vehicle is being safed by the crew. We won't be trying to launch again this morning," SpaceX announced through its twitter account.

Preparations for the company's trial cargo run to the space station had been proceeding smoothly until 4:55 a.m. EDT (0855 GMT). A NASA spokesman said the engine ignition sequence started, but there was an automatic shutdown by on-board computers. So instead of blasting off, the rocket remained on its launch pad amid a cloud of engine exhaust.

According to Elon Musk, CEO of the California-based company, the problems are likely related to "slightly high combustion chamber pressure on engine 5".

Saturday's flight was originally scheduled to occur on April 30, but has been delayed several times to complete final checks of the spacecraft's flight software. The next launch attempt will be Tuesday, if the problem can be resolved in time.

This was the first launch attempt by one of the private U.S. companies hoping to take over the job of delivering cargo and eventually astronauts to the space station for NASA.

Up to now, flights to the space station have always been a government-only affair.

Until their retirement last summer, U.S. space shuttles carried most of the gear and many of the astronauts to the orbiting outpost. Since then, American astronauts have had to rely on Russian capsules for rides. European, Japanese and Russian supply ships have been delivering cargo.

It will be at least four to five years before SpaceX or any other private operator is capable of flying astronauts.