NASA will hold a series of news media briefings Sept. 8 - 9 to preview the space shuttle's fifth and final servicing mission to the Hubble Space Telescope. NASA Television and the agency's Web site will provide live coverage of the briefings from the Johnson Space Center and the Goddard Space Flight Center in Greenbelt, Md. Questions also will be taken from other participating NASA locations.

Shuttle Atlantis' 11-day flight, designated STS-125, is targeted for launch Oct. 8 and will include five spacewalks to refurbish and upgrade the telescope with state-of-the-art science instruments. Replacing failed hardware on Hubble will extend the telescope's life into the next decade.

NASA will discuss upcoming space shuttle mission STS-123 during a daylong series of media briefings from the Johnson Space Center beginning at 8 a.m. CST on Feb. 29. The briefings will be broadcast live on NASA Television and the agency's Web site. Questions also will be taken from participating NASA locations.

Space shuttle Endeavour's 16-day mission is targeted for launch to the International Space Station on March 11. The mission will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Five spacewalks will be conducted during the flight.

On Wednesday, U.S. Sen. Kay Bailey Hutchison (R-Tex.) hosted NASA Administrator Michael Griffin and Secretary of Agriculture Edward T. Schafer during the signing of a memorandum of understanding to enable the USDA's Agricultural Research Service to conduct plant related research on the International Space Station.

The research will improve our understanding of biological cellular mechanisms and may lead to creative new ways to improve American agriculture, protect the environment and contribute to better human health. The agreement reflects NASA's ongoing efforts to develop the space station as a national laboratory, with the ability to serve a broad range of users.