Space shuttle Discovery has some leaky valves that could delay its launch next month.
NASA discovered the helium leaks over the weekend. The valves are part of a control system used to maneuver the shuttle in orbit and for re-entry.
NASA spokesman Allard Beutel said Monday that engineers will conduct additional tests later this week, to see if they can live with the problem.
If any valves need to be replaced, Discovery would have to be moved from the pad back into the Vehicle Assembly Building. That would result in a lengthy delay.
For now, Discovery is scheduled to blast off April 5 on a two-week supply mission to the International Space Station. Only four shuttle missions remain.