The unmanned ISS Progress 35 supply ship undocked from the Pirs docking compartment Thursday. Filled with trash and station discarded items, the Progress will be used for scientific experiments until it is deorbited and burned up in the Earth's atmosphere next week.

ISS Progress 35 arrived at the station Oct. 17 after launching Oct. 14 from the Baikonur Cosmodrome in Kazakhstan.

Its departure clears the way for the ISS Progress 37 cargo ship that is scheduled to launch to the station April 28. ISS Progress 37 will bring to the station 1,918 pounds of propellant, 110 pounds of oxygen and air, 220 pounds of water and 3,031 pounds of spare parts and experiment hardware.

With Commander Alan G. Poindexter and Pilot James P. Dutton Jr. at the controls, space shuttle Discovery descended to a smooth landing at Kennedy Space Center in Florida. The STS-131 crew members concluded their successful mission to the International Space Station when the shuttle touched down at 9:08 a.m. EDT.

Discovery arrived at the station April 7, delivering more than seven tons of equipment and supplies. During the 10-day stay, Mission Specialists Rick Mastracchio and Clayton Anderson conducted three spacewalks to install a 1,700-pound ammonia tank assembly on the station's exterior to replace a depleted predecessor. They also replaced a rate gyro assembly, retrieved a Japanese experiment and two debris shields.