The launch of the Space-X Falcon Nine and Dragon was set for April 30 or May 3 but has now been postponed by a week, AFP reports.
"After reviewing our recent progress, it was clear that we needed more time to finish hardware-in-the-loop testing and properly review and follow up on all data," a spokeswoman for SpaceX Kirstin Brost Grantham is quoted as saying, adding that they would have to coordinate with NASA on a new launch time.
The Dragon capsule was due to be launched atop the Falcon Nine rocket from Cape Canaveral Air Force Station in Florida, Space.com says.
It explains that the launch was part of a demonstration mission to test the unmanned spacecraft for future cargo deliveries to the International Space Station as part of an agreement with NASA.
The capsule is reusable and can carry cargo as well as up to seven crewmembers, according to USA Today.
The newspaper says that the Dragon's maiden flight took place in August 2010, during which it orbited Earth twice and splashed down in the Pacific Ocean. The Falcon 9 reached orbit in June 2010 after three failed launches.
NASA and SpaceX are expected to announce a new target launch date later this week, CNET says, but it is widely speculated to take place on May 7.