First, the space shuttle. ZUI this NASA press release dated 25 Feb:
NASA's Space Shuttle Program has established a plan that could support shuttle Discovery's launch to the International Space Station, tentatively targeted for March 12. An exact target launch date will be determined as work progresses with the shuttle's three gaseous hydrogen flow control valves.
At NASA's Kennedy Space Center in Florida, technicians have started removing Discovery's three valves, two of which will undergo detailed inspection. Approximately 4,000 images of each valve will be reviewed for evidence of cracks. Valves that have flown fewer times will be installed in Discovery. Engineering teams also will complete analysis and testing to understand the consequences if a valve piece were to break off and strike pressurization lines between the shuttle and external fuel tank. Hardware modifications may be made to the pressurization lines to add extra protection in the unlikely event debris is released.
NASA and contractor teams have been working to identify what caused damage to a flow control valve on shuttle Endeavour during its November 2008 flight. Part of the main propulsion system, the valves channel gaseous hydrogen from the main engines to the external tank. After a thorough review of shuttle Discovery's readiness for flight on Feb. 20, NASA managers decided more understanding of the valve work was required before launching Discovery.
If Discovery's tentative launch date holds, there will be no effect on the next two shuttle launches: STS-125 to NASA's Hubble Space Telescope and STS-127 to the International Space Station.
And second, Kepler. ZUI this press release dated 26 Feb:
Launch of NASA's Kepler telescope is targeted for no earlier than Friday, March 6, from Pad 17-B at Cape Canaveral Air Force Station in Florida. There are two launch windows, from 10:49 - 10:52 p.m. and 11:13 - 11:16 p.m. EST.
Kepler is a spaceborne telescope designed to search the nearby region of our galaxy for Earth-size planets orbiting in the habitable zone of stars like our sun. The habitable zone is the region around a star where temperatures permit water to be liquid on a planet's surface.
Liquid water is considered essential for the existence of life as we know it. The vast majority of the approximately 300 planets known to orbit other stars are much larger than Earth, and none is believed to be habitable. The challenge for Kepler is to look at a large number of stars in order to statistically estimate the total number of Earth-size planets orbiting sun-like stars in the habitable zone. Kepler will survey more than 100,000 stars in our galaxy.
Engineers are reviewing all common hardware between the Delta II rocket carrying the Kepler telescope and the Taurus XL launch vehicle. On Tuesday, a Taurus carrying NASA's Orbiting Carbon Observatory failed to reach orbit. Managers want to confirm there will not be similar issues with Kepler's Delta II.
Kepler's original March 5 target launch date was moved one day later to accommodate the additional time for analysis. The March 6 target date still must be confirmed by the U.S Air Force, which manages the eastern launch range. Kepler's Flight Readiness Review is on Monday, March 2.