The Space Shuttle Program’s Flight Readiness Review concluded Tuesday, setting the stage for the executive-level review at the Kennedy Space Center, which begins April 30. Following the final review, a firm launch date for the STS-125 mission to service the Hubble Space Telescope will be set. Launch is currently targeted for May 12 at 1:31 p.m. EDT.

Veteran astronaut Scott Altman will command the final space shuttle mission to service NASA's Hubble Space Telescope, and retired Navy Capt. Gregory C. Johnson will serve as pilot. Mission specialists rounding out the crew are: veteran spacewalkers John Grunsfeld and Mike Massimino, and first-time space fliers Andrew Feustel, Michael Good and Megan McArthur.

During the 11-day mission's five spacewalks, astronauts will install two new instruments, repair two inactive ones and perform the component replacements that will keep the telescope functioning into at least 2014.

In addition to the originally scheduled work, Atlantis also will carry a replacement Science Instrument Command and Data Handling Unit for Hubble. Astronauts will install the unit on the telescope, removing the one that stopped working on Sept. 27, 2008, delaying the servicing mission until the replacement was ready.

At NASA's Johnson Space Center in Houston, the STS-125 astronauts continue to train for the upcoming mission. Tuesday, Mission Specialists Mike Massimino and Michael Good rehearsed inside the tank at the Neutral Buoyancy Lab for the mission's fourth spacewalk.

At NASA's Kennedy Space Center in Florida, the rotating service structure at Launch Pad 39A surrounds space shuttle Atlantis, where payload operations continue throughout the week. With Atlantis' payload bay doors now open, technicians are loading the hardware necessary for the servicing mission.

FMI: www.nasa.gov, http://twitter.com/Astro_Mike