Posted on 02/07/2003 4:13:56 PM PST by RCW2001
Earlier Shuttle Adjusted Fiery Flight Amid Fears of Tile Damage
The Associated Press
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WASHINGTON Feb. 7 Two years before the Columbia disaster, NASA safety experts fearing similar damage to delicate heat tiles on the space shuttle Atlantis decided it was "prudent" to adjust its return path to lessen danger during the fiery descent, according to internal documents. NASA has indicated it did not instruct Columbia to perform this protective maneuver, called "thermal conditioning," though its experts feared damage to tiles in roughly the same critical areas. Atlantis suffered from ice chunks smashing into its wing during liftoff in May 2000. "If you favor one wing over the other, the wing that's not being favored is getting really hot," shuttle program manager Ron Dittemore said this week. "And so I'm sure that we didn't develop those scenarios." Dittemore added: "You would have had to make the decision that you knew so much information about the damage on the wing, that it was going to fail if you didn't protect it." The thermal-conditioning technique, described as far back as 1990 for NASA by researchers, involves pivoting the shuttle slightly left or right before it speeds through earth's atmosphere so that damaged tiles on one side might be exposed to lower temperatures. It's akin to a football player turning his body to favor an injury as he's tackled. Officials have maintained since last week's disaster there was no recourse after liftoff for the seven astronauts aboard Columbia even if NASA had known there might be serious damage to the shuttle's thermal tiles. "We couldn't do anything about it anyway," Dittemore said earlier this week. "We have no recourse if we lose tiles. Our only effective action is to prevent the loss of tiles through design and through test. And that has been perfectly adequate up to this point." A NASA spokesman in Washington, Michael Braukus, said Friday that the thermal maneuver never was considered for Columbia. Braukus said such a maneuver would have interfered with efforts to warm the shuttle's landing gear tires for a safe landing. He said the tires were unusually cold because Columbia orbited the planet for days with its landing gear aimed toward deep space. Atlantis adjusted its return flight because experts noticed a 6-inch ice chunk from its external fuel tank shattered about 8 feet from one of the hinged, flap-like devices, called "elevons," along the back of the wing that help the pilot steer. "It was prudent to take some precautions," according to NASA documents. The maneuver to pivot Atlantis to protect its right wing "increased the temperature margin and therefore reduced the potential for structural damage." Engineers similarly feared damage to tiles on Columbia's left wing, but they did not instruct Columbia to perform such a protective maneuver on Saturday. NASA officials believe the shuttle disintegrated over Texas shortly after it performed a routine turn to slow down. The first sign of problems was the loss of temperature readings from systems controlling Columbia's left-wing elevons. NASA confirmed Friday it received photos of Columbia from a powerful Air Force ground camera. Aviation Week & Space Technology, citing sources familiar with the shuttle investigation, reported that the images showed serious structural damage to Columbia's left wing near the fuselage. A top space official, Mike Kostelnik, said Friday those photos were taken when Columbia was experiencing "anomalies," but he denied that they showed significant damage to the shuttle's left side. The damage in May 2000 to Atlantis' right wing "was not considered a safety of flight issue," NASA's documents said, although inspectors later found a gouge in thermal tiles there about 5.25 inches by 1.5 inches and one-half inch deep. NASA officials have said they also concluded that possible damage to Columbia's insulating tiles didn't threaten the shuttle's safety. They based their conclusions on scientific models showing possible damage over an area about seven inches by 32 inches far larger than the damage to Atlantis years earlier. That Atlantis flight, which carried a Russian cosmonaut and equipment to the International Space Station, suggests there were at least options for an ailing shuttle. Outside experts said it was impossible to know yet whether flight adjustments by Columbia could have prevented its destruction. "You can yaw the vehicle to the side, you can roll the vehicle a little bit," said Steven P. Schneider, an associate professor at Purdue University's Aerospace Sciences Laboratory. He said some shuttle surfaces, such as near the fuselage or the back edges of the wings, could be better shielded during such maneuvers than others. "You can't change the trajectory too much." A 1990 study for NASA by outside researchers said threats to the shuttle from damaged thermal tiles which protect against temperatures that can reach 3,000 degrees could be lessened by rerouting important internal systems or changing the shuttle's re-entry profile. Using that technique, researchers wrote, "it may be possible to reduce the temperature of some weak, vulnerable areas." |
Seems like such an easy fix to prevent ice from falling...onto the wings.
I think the maneuver mentioned in this article is similar to one of the questions I posed to you on an earlier thread. Also, I haven't looked to see if it is posted yet, but apparently the Air Force in New Mexico got some high res pictures of Columbia about 1 minute prior to break up. The picture purportedly show significant damage to the left wing.
JMHO, but I'd think that would really upset the center of balance of the whole kit and kaboodle. Not saying it can't be done, but it gets a bit more complicated than that. Too much out of balance, and the rocket starts spinning like a pinwheel instead of launching in a straight line.
Yes, indeed. Even at the lower g's you get in a small plane, negative g's are quite uncomfortable, while positive g's just make your arms, head, etc. feel very heavy.
Now is the time for another technological triumph.
We must not abandon space. Instead we must build a better machine.
Get competent engineers with a can-do attitude. Set the price tag and let them know they can't exceed it. Tell them what we want done, but NOT how to do it.
Sit back and watch them produce a miracle.
The VentureStar suborbital flights from Edwards to Malmstrom in Montana would have proved the system but alas...earwax!
That ain't right. Why would they do that?
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