A brand new private cargo ship which is making its orbital debut experienced trouble with a computer data link on Sunday, delaying its arrival at the International Space Station by at least two days.

The rendezvous was aborted less than six hours before the scheduled arrival of Orbital Sciences Corp's Cygnus capsule, which is packed with 1,300lb of food and clothes for the space station crew. The Virginia-based company said it was working on a software repair, but it will be at least two more days until another approach is attempted.

Orbital Sciences said the two orbiting vessels established direct contact early on Sunday, four days after the Cygnus' launch from Virginia. But the Cygnus rejected some of the data, which interrupted the entire rendezvous. Until then, everything had been going well.

Because this is a test flight of the Cygnus, nothing valuable or urgent is on board. If necessary, it could keep orbiting the world for weeks, even months, before pulling up at the orbiting lab.

Orbital Sciences is the second private company to launch supplies to the space station. In 2012, the California-based SpaceX began accomplishing that job for Nasa. The space agency is paying the two companies to deliver goods to the space station, in the absence of the now-retired space shuttles. Orbital Sciences is planning to make its first cargo run under a $1.9bn contract with Nasa in December.

Three astronauts – an American, Italian and Russian – are currently aboard the orbiting outpost. On Wednesday, three more crew members will be launched from Kazakhstan. Orbital Sciences will have to work around that manned flight, delaying the Cygnus further if a Tuesday hookup is not feasible.