WASHINGTON -- Chinese space officials skipped out early on an invitation-only exploration workshop sponsored by NASA.

Roughly 180 people from industry, academia and government participated in the four-day workshop held April 25-28 at the Ronald Reagan Building and International Trade Center here.

Among them were 60 international participants representing 12 countries. But none of the half-dozen China National Space Administration officials that NASA invited stayed past the workshop's opening day, according to participants. "Apparently they were not at the individual breakout sessions," NASA Administrator Shana Dale said. "I don't know the reasons why. It was nothing on our part."

Workshop participants were divided into seven breakout groups to spend the rest of the week brainstorming ideas for what to do on the surface of the Moon. Dale called the workshop "an incredibly productive week with exactly what we wanted--free-flowing dialogue with the opportunity for creative and out-of-the-box thinking."

Dale said the dialogue begun in Washington would continue at a space exploration workshop the European and Italian space agencies are holding in May, as well as additional venues throughout the year.

"As you know 2005 was the year in which we defined our exploration architecture," Dale said, "and 2006 is the year we plan to develop a global exploration strategy for what we do on the surface of the moon and also the preliminary planning for Mars and other destinations."