NASA plans shuttle tanking test

4 p.m. Update:NASA officials now say that engineers are drawing up plans for a tanking test, but managers still have not made a final decision to proceed with the fuel-loading operation. If the agency decides to press ahead with a test, it would take place around June 1. Our earlier item (below) indicated the test was a done deal.

NASA will fuel shuttle Discovery's external tank at its Kennedy Space Center launch pad in early June as part of an exercise aimed at testing changes made to the 15-story reservoir.

More than a half-million gallons of supercold liquid hydrogen and liquid oxygen will be pumped into the bullet-shaped tank during a three-hour fuel-loading operation that is tentatively scheduled to take place around June 1.

Among other things, the test will enable engineers to determine whether four new liquid hydrogen fuel depletion sensors in the tank are working properly.

One of the four sensors originally installed in the tank generated unexpected readings during an electrical test in late February. NASA managers decided to replace all four as a result.

The replacement work forced NASA to delay launch of Discovery on the agency's second post-Columbia test flight from May to July. The mission remains scheduled for launch on July 1.