Astronauts flying on a space shuttle mission to service the Hubble Space Telescope for a final time will speak to middle school students across America simultaneously at 1:15 p.m. EDT, April 30, from NASA's Goddard Space Flight Center in Greenbelt, Md.

Through NASA's Digital Learning Network (DLN), students at five middle schools and an invited student audience at Goddard will talk to the shuttle crew. Topics of discussion will include details about the upcoming STS-125 mission to service Hubble. Astronauts also will discuss career diversity among the crew. Each has a doctorate degree in a science, technology, engineering and mathematics discipline.

The Expedition 17 crew members are busy with science and preparations for the arrival of future spacecraft at the International Space Station.

Commander Sergei Volkov spent Thursday morning photographing the docking cone on the Zarya module in preparation for the Soyuz TMA-12 spacecraft relocation May 6.

Flight Engineer Garrett Reisman continued working with Coarsening in Solid Liquid Mixtures-2, an experiment which examines the kinetics of competitive particle growth within a liquid metal matrix.

Early Friday, the Jules Verne Automated Transfer Vehicle's main engines will fire for 12 minutes, 15 seconds to complete the two-part reboost of the station. Ignition is scheduled for 12:22 a.m. EDT.