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NASA mulls delaying space shuttle launch to July BY WILLIAM HARWOOD STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION Posted: April 28, 2005 NASA managers are debating whether to delay the shuttle Discovery's launch on the first post-Columbia mission to July because of time needed to complete ice debris analysis, implement proposed fixes and to resolve a handful of nagging problems, sources say. Launch currently is targeted for May 22 in a launch period that extends to June 3. But senior managers are considering a delay to the next available launch period, which opens July 13 around 3:45 p.m. EDT. Engineers at the Kennedy Space Center have delayed loading maneuvering thruster rocket fuel pending the outcome of the discussion. A teleconference was scheduled late today between shuttle program managers at the Johnson Space Center in Houston and at agency headquarters in Washington. A decision could be announced later today or tomorrow. The primary problem facing program managers is the potential threat of ice debris shaking off the external fuel tank during launch and causing impact damage to the shuttle's heat-shield tiles or wing leading edge panels. The shuttle Columbia was destroyed during re-entry Feb. 1, 2003, because of a hole in the left wing's leading edge that was caused by the impact of external tank foam insulation that broke off during launch 16 days earlier. The foam responsible for Columbia's demise was intended to prevent ice from building up around the fittings that attach struts holding the nose of the shuttle to the thank. The so-called bipod foam has been eliminated in favor of small heaters. Foam application techniques were changed to minimize the chances for foam shedding in general. Engineers believe the largest piece of foam that can come off the tank today is less than a half ounce. The piece that hit Columbia weighed some 1.67 pounds. But recent testing shows ice buildups in two areas of the tank still pose a threat. One of those areas is in the so-called intertank region between the upper oxygen tank and the lower hydrogen tank where an oxygen feedline bellows is located. The bellows allows the line to flex slightly during launch. The testing shows ice can build up on the bellows or on a bracket holding the line in place. Another ice problem area is near the tip of the tank around a bracket that holds a repressurization line. NASA managers held a second debris verification review, or DVR, at the Johnson Space Center in Houston earlier this week and still were unable to conclusively demonstrate ice was not a threat, according to sources who requested anonymity. NASA plans to install at least one heater on the next shuttle tank to eliminate the problem and they may opt to go ahead and do the same for Discovery's tank. Other options under discussion include the use of infrared spotlights near the pad to help prevent ice formation, but those plans are not yet mature. If a heater must be installed, Discovery would have to be hauled back to the Vehicle Assembly Building, which would rule out a launch during the May-June window. Other problems facing the launch team:
Much of the work could be completed at the launch pad, but getting it all done in time to make the May-June launch window - and completing the debris impact analysis - no longer appears likely. A launch delay to July would allow NASA to roll Discovery back to the Vehicle Assembly Building where engineers would have much better access and a controlled environment for any repairs or upgrades, including installation of a new external tank heater and replacement of the insulation blankets. NASA managers have said for months they are not being driven by the launch schedule and a delay to July would appear to be in keeping with that post-Columbia philosophy. But some senior managers, sources say, argue against giving up the May-June launch window unless it's absolutely necessary.
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VIDEO:
DISCOVERY'S FUELING TEST GETS UNDERWAY