Posted on 12/28/2004 12:03:32 PM PST by BenLurkin
WASHINGTON (AP) - NASA takes a major step toward returning astronauts to space when engineers this week ship an improved rocket fuel tank that has been refitted to avoid the falling debris that caused the destruction of Columbia and the death of seven astronauts. National Aeronautics and Space Administration officials said that the redesigned fuel tank, a massive vessel that supplies propellant for the launch of the space shuttle, will start a barge trip on Friday from a Mississippi assembly plant to the launch site on Florida's east coast.
Sandy Coleman, NASA's external tank project manager, said improvements made on the fuel tank "gives us confidence that problems like what happened on Columbia will not happen again.
"This is the safest, most reliable tank NASA has ever produced," Coleman said Tuesday in a telephone news conference from the Marshall Space Flight Center in Huntsville, Ala.
The changes in the external tank add less than 150 pounds in weight. The total cost of the new tank, including tests and redesign, is still being calculated, but it will be more expensive than the $40 million cost of the old-style tank, said Coleman.
Coleman said the tank was expected to start on Friday a barge trip from the Michoud Assembly Facility near New Orleans to the Kennedy Space Center. The barge journey, which crosses the Gulf of Mexico, rounds the tip of Florida and then up the east coast, takes five to six days.
NASA plans a May or June launch of space shuttle Discovery. The space shuttle fleet has been grounded since the Columbia accident as NASA scrambled to make changes in hardware, procedures and personnel to comply with recommendations from the Columbia Accident Investigation Board.
Fixing the external tank was a key part of the NASA's recovery, officials said.
The tank holds the liquid hydrogen and oxygen which are the propellants for the shuttle's main rocket engines during launch. The supercooled chemicals cause the formation of ice on the outside of the tank as the shuttle is prepared for launch.
Insulation, applied as a foam, reduces the amount of ice. But investigators believe it was chunks of foam insulation that peeled off the external tank during launch which led to the destruction of Columbia. The debris, moving at a high relative speed, ripped a hole in the left wing of the space shuttle. On Feb. 1, 2003, as the spacecraft re-entered the Earth's atmosphere, superheated gas penetrated the wing through the hole and melted metal struts. The craft shattered, showering east Texas with flaming debris. Seven astronauts were killed.
The Columbia Accident Investigation panel conducted tests to prove that chunks of the light weight foam insulation could cause the damage that was fatal to Columbia. The tests included using an air canon to fire foam insulation chunks at test wing panels.
To correct the problem, engineers from NASA and Lockheed Martin Space Systems, manufacturer of the fuel tanks, conducted extensive tests to find out why the foam insulation broke loose during launch.
This led to several changes including new ways of applying the foam insulation, the addition of heaters at key points to prevent the formation of ice before launch, and adding cameras that can monitor the outside of the tank during launch.
"We can never completely eliminate foam coming off the tank," Coleman said Tuesday. But she said tests suggest that any debris that does fly free will not cause damage like that which destroyed Columbia.
Redesign of the external tank was considered to be a key and critical part of NASA's effort to return the shuttle to space, but is only one of a long list of recommendations from the Columbia Accident Investigation Board. NASA also is designing ways to check for launch damage to the space shuttle after the vehicle is in orbit. The agency is also developing ways for spacewalking astronauts to fix damage to wing panels like that which destroyed Columbia.
The Huygens probe, built and managed by ESA, will remain dormant until the onboard timer wakes it up just before the probe reaches Titan's upper atmosphere on Jan. 14, 2005. Then it will begin a dramatic plunge through Titan's murky atmosphere, tasting its chemical makeup and composition as it descends to touch down on its surface. The data gathered during this 2-1/2 hour descent will be transmitted from the probe to the Cassini orbiter. Afterward, Cassini will point its antenna to Earth and relay the data through NASA's Deep Space Network to JPL and on to the European Space Agency's Space Operations Center in Darmstadt, Germany, which serves as the operations center for the Huygens probe mission. From this control center, ESA engineers will be tracking the probe and scientists will be standing by to process the data from the probe's six instruments.
Maglev would do very well for launches from the surface of the moon. Could even be useful for launches from the earth's surface. A long track running up a tall mountain, and there you are with 90% of your orbital requirements met.
And nothing can go wron........................
Why redesign? It was the envirowackos complaints about the previous material (which to my knowledge was 100% reliable) taht caused NASA to adopt the man-killer foam that brought down the Columbia.
I'm not sure that I understand why not.
If we can accelerate through our thick atmosphere with rockets, seems to me that we oughta be able to do it with Maglev.
Of course, you might not want to start out at sea level in Florida. Maybe launch 'em off a mountaintop in Colorado or somewhere 10K ft above sea level -- that way you don't have to fool around with the thickest part.
True, but a maglev boost to high altitude would save a bunch of fuel/weight
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