NASA has announced a ‘Tanking Test’ for next week Wednesday to see if it has managed to repair a hydrogen leak that scuppered its two most recent attempts to launch the space shuttle Endeavour.

Crew at the Kennedy Space Center in Florida are still working on a plate attached to the shuttle’s external fuel tank, pinpointed as the source of the leak in a line that vents hydrogen from the tank. Seals on the ‘Ground Umbilical Carrier Plate’ were due to be inspected yesterday.

“They think they have a pretty good handle on what they think caused the leak,” says NASA spokesperson Candrea Thomas (SPACE.com). “The tanking test will tell, but they’re confident they’ve got this thing figured out.”

The next launch attempt is scheduled for 11 July.

Meanwhile, CNET News reports a different problem with another shuttle. A loose knob on shuttle Atlantis has become wedged against a window and engineers are struggling to remove it:

While the knurled knob is pressing against the pane in two locations, it’s not yet clear whether the glass has suffered any measurable damage. But access is tight and engineers considering removal options must make sure they don’t inadvertently damage the glass. Replacing a pressure pane, one official said, could take months because part of the cockpit instrumentation would have to be moved or disconnected to provide clearance.

Image: NASA staff work on the Ground Umbilical Carrier Plate / NASA, Jack Pfaller