![]() Shuttle technicians have repaired similar cracks on external tanks by removing the fractured aluminum and replacing it with a twice-as-thick stringer section, before replacing the foam. It's a known failure method."Įngineers are now evaluating images of the cracks to determine the best repair options that can be performed with Discovery remaining at her seaside launch pad at Kennedy Space Center. "They understand the stresses that go on at cryogenic temperature levels while loading the tank. "Even though the foam didn't come off, the crack underneath propagated up, so the cracks in stringer led to the crack in the foam above it," Beutel explained. The cracks in the stringer likely pushed the metal outward to sufficiently dislocate the foam, NASA officials said. The fractures were found underneath the area of cracked foam, and early analysis suggests they were the root cause of the foam damage. The two 9-inch (23-cm) cracks were located at a site called the "stringer," which is an aluminum strip that provides structural integrity to a part of the fuel tank known as the intertank - the partition between the liquid oxygen and liquid hydrogen tanks. 10) on a section of the tank's aluminum skin. While removing the cracked foam layer that covers the tank, two new fractures were found yesterday (Nov. 12), Beutel said.Įngineers also removed damaged foam insulation on Discovery's external tank that cracked during initial loading operations for the shuttle's most recent launch attempt on Nov. This is very different."īased on early evaluations, the team should be ready to install a new flight seal and umbilical carrier plate tomorrow (Nov. "Last year the issue was a slight misalignment of the whole carrier plate. "They found that the flight seal was not properly aligned when they opened up the GUCP," Beutel told. This could account for why the leak cropped up earlier in the tanking process, and leaked significantly greater amounts of hydrogen, than the two previous events, NASA spokesman Allard Beutel said. Both of these were caused by slight misalignments of the carrier plate itself, but this new leak was caused by a different issue - a misalignment of the flight seal inside the ground umbilical carrier plate. Similar leaks have occurred during launch preparations for two previous shuttle missions, both in 2009. ![]() ![]() Data collected from the initial inspections will be evaluated today. NASA technicians worked overnight to remove the component, and initial inspections were performed on the faulty seal and its corresponding connector before they were sent to labs for more thorough examinations. No portion of thismaterial may be reproduced in any way without the written consent of FLORIDA TODAY. Published underlicense from FLORIDA TODAY. Video - Astronaut Escape Ship Blasts Off.New Video - Building the International Space Station.Special high-tech x-rays uncoveredno cracks or voids during extra testing prior to Discovery's move to the pad,he said. Herring said the suspectramp on Discovery's tank has no known flaws. Foam insulationapplied to them smoothes airflow over the brackets and prevents ice build-ups. NASA engineers still aretrying to determine the root cause of the foam loss from the ice frost ramps.Each tank is equipped with 34 of the metal support brackets. ![]() That problem is not expected to delay Discovery's launch. More than 150 tests wereperformed on that area of Discovery's tank prior to its move last week tolaunch pad 39A. NASA engineers say an adhesive failed to bond properly with a substrateprimer on the aluminum lithium skin of the tank. Hot gases blowtorchedthrough the hole during atmospheric reentry, leading to the disintegration ofthe spaceship 16 minutes before a planned landing here at KSC.Įndeavour's tank also shedan unusual amount of thin foam from a ribbed center section during its July 15launch. The concern is thatbreakaway foam could do critical damage to shuttle wing panels or thermaltiles, which protect orbiters and astronauts from extreme heat duringatmospheric reentry.Ĭolumbia and its seven-membercrew were lost in 2003 when a 1.67-pound chunk of foam broke free 81seconds into flight, blasting a 6- to 10-inch hole in its left wing. On the Endeavour flight,foam chunks that weighed about 0.044 pounds - or about doublethe allowable amount - broke free from a bracket high up on the shuttle'sbullet-shaped tank. Larger-than-allowable chunksof foam insulation broke free from a so-called ice frost ramp during thelaunches of Atlantis in May and Endeavour in July. A recommendation to flyDiscovery as is or roll the shuttle back to the Vehicle Assembly Building forrepairs will be made on Aug. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |