SpaceX Launch Delayed
SpaceX says the launch of its Falcon 9 rocket on May 7th now "appears unlikely".
A spokesperson for the commercial space exploration company, Kirstin Brost Grantham, said in a statement that SpaceX is "continuing to work through the software assurances process with NASA."
Earlier this week the company tested fired the engines on the rocket in preparation for the launch.
A new launch date has not been set.
SpaceX is planning to launch its Dragon capsule into low earth orbit on top a Falcon 9 rocket.
The aim of the mission is to berth the capsule with the International Space Station. If it's successful it will be the first time a commercial spacecraft has been sent to the ISS.
The capsule is loaded with cargo for this mission, but the rocket and the spacecraft are designed to eventually carry astronauts into orbit.