From AMSAT Sarex reflector:
Commander Sergei Krikalev and Flight Engineer John Phillips left the International Space Station today for a short ride, relocating their Soyuz return craft from one docking port to another to free up a Russian airlock for a future spacewalk.

This will be a contact with teachers attending a class at Goddard Space Flight Center in Maryland and was set up to give NASA Explorer School Educators an opportunity to understand how to utilize satellite communications and satellite data in their classroom. One facet of this class is the use of ARISS in the classroom. Through this experience, they will be much better prepared when their schools perform an ARISS contact.

Contact is set for 1730 UTC on July 20 and should be audible on 145.80 to stations in and around the Maryland region of the USA.